'Twas a pleasant summer's eve so I took the case halves outside for a refreshing douche. This is a makeshift parts cleaner assembled from an oil pan, aquarium pump, and an Oxford comma. Purple Simple Green is used to remove the last of the machining swarf and bits. I wish they would name it "Complicated Purple."

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I received the case halves from Tom Stark a while back for some modification and he did a stellar job. A common problem with the cases is that the depth of the oil passages for the main bearings are too shallow. Indeed, some are so shallow that they're not a passage at all. Add to that that the passages are sometimes misaligned with the bearing holes, creating a blockage.

Enter Tom Stark, who has a setup where he uses a mill to widen and deepen the passages. It's a huge improvement for more oil volume. Frankly I don't know how the unmodified passages allowed any oil through them in the first place. Often when I work on this project I repeat the mantra with an inward voice, "GM just did not care."

Here you can see the detail of the enlarged oil passage. I'm sorry that I don't have a "before" photo handy. But trust me, the depth was all over the place and it blocked the original bearing oil holes by over half.

Another modification is enlarge the oil hole itself that leads to the main oil gallery.

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Before I installed the bearings I took some measurements on the inside crank registers. Tom did also but I wouldn't be doing my job if I didn't double check. Besides, this is really all about having fun with arithmetic anyway.

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More importantly, I also started the blueprinting process so I took careful measurements of the mains along the crankshaft.

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Time to check the bearing clearance and oil passage holes.

The bearings themselves are Clevite 77. For mains #2 and #3 the bearings are the same. But somewhere along the way GM changed the size for #4. Bob Helt says this has to do with a lumpy idle problem encountered before the change. Observe:

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Here you can see how well the diameter of the oil hole in the bearing meets the enlarged oil passage. Helloooo oil volume:

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Here are the bearings installed in the case halves:

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I torqued the case halves back together to measure the inner diameter of the bearings. And, unhappily, they all measured about 0.010" too large. Bummer. This troubled me for a while because way way back I had a machinist check out the case, bearings, and crankshaft to make sure they were all in spec. So where did this 0.010" difference come from?

Then I finally remembered. I have two crankshafts and completely forgot that I had two cranks because (a) I'm chemo-brained and (b) it's been a long, long time.

I forgot that initially I had the original crank measured, magnafluxed, ground, and polished to 0.010" undersize. Then I sent it off to be cryogenically treated. But over the years enough doubt was cast on the cryo process that I replaced it with a factory nitrided crank. It's important to understand that the better Corvair cranks were nitrided from the factory, but my original crank was not as discussed in a previous post. So eventually I bought a NOS nitrided crank thinking it was the better surface hardening method over cryo.

But the fact is that I really do not know. It's been debated so much that I honestly don't know which would better fit my needs, which mainly have to do with longevity. But now I have two great cranks with absolutely no way of truly knowing which is better.

It's apples and oranges most likely. Nitriding is a suface hardening process and cryo is a process to remove any internal stress and improve it's overall toughness. Oy. Anyway, here they are:

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So my choice is to either use the cryo'd crankshaft and use the bearings I already have, or use the nitrided crank and order two new sets of bearings. One pisser is that you cannot buy individual bearings. You have to buy a complete set. And it turns out the big shell bearing for main #1 is not out 0.010" but 0.0065". So if I buy new bearings I have to buy two whole sets to get the sizes that I need. Super!

Either way I have one great crankshaft for sale. I'm open to which way I should go if anyone knowledgeable about metallurgy cares to opine.

Cheers.

Today I spent some time getting the rest of the measurements for the bottom end.

The camshaft got the plastigauge treatment and it's dead nuts 0.002" clearance across the board. The service manual says it needs to be between 0.0015" to 0.0035", so that makes me happy.

I measured the ID of the big ends of the piston rods and that's where this gets interesting. And by interesting I mean super boring. With the bearings I have in hand they're a perfect fit for the rod journals which measures 0.010" undersize from standard. No problem there since one of my two cranks measures 0.010" undersize...

.... the crogenically treated one. So that's the answer to above soliloquy. If I stay with the cryo'd crankshaft, then I can keep my main bearings, rods, and rod bearings. The rods have already been machined to fit the VW piston pins. That's a pile of money and time I don't want to spend in replacing stuff. Plus, the measurements for the crank and rods have been beautiful so far. I sort of hate to throw all that out since it all fits together so sweetly.

Plus, science. It occurred to me today maybe instead of looking for an answer to cryo vs nitriding I should instead pop in the cryo'd crankshaft and see what happens. At worst it will simply wear down faster. It's not like it's just going to split apart. So one day when one of you owns this car and takes the engine apart, do us all a favor and measure the wear along the journals and note the mileage. That way we can all know. Of course it isn't great science since I'm not building an identical engine using the nitrided crank, but there's enough data out there to get a comparison.

Empiricism or bias confirmation? You decide.

If you in the future are the owner of this car and have disassembled the engine then you'll want to know that the main journals measure basically 2.0985" and the rod journals more or less at 1.9327". Good luck, time traveler!

So I damn near ruined my case halves.

There are eight (8x) case studs that clamp the case halves together, but they are a slop fit and allow the halves to slide around a little at higher temps and revs. So for a long time ARP case studs have been available that have a larger diameter in order to create an interference fit. Great.

The trouble is that outfits like Clark's or others-that-shall-not-be-named will sell or rent a reamer that provides the exact diameter necessary to make the correct fit. But Clark's doesn't have them any more and other vendors failed to even mail me back and didn't answer the phone.

Since I couldn't obtain the "special" reamer, I had to try something else.

My first plan was to get an adjustable reamer, which I hate. I've never had good luck with them. I ended up buying a few of them before I found one that was even marginal quality. Even with my measuring stand it's hard to set the tool to exactly the right size. Every time the tool is set and tightened, it threw out my measurement. I drilled the first hole to a depth of about 5mm and then measured the new bore.. and it was way WAY out of size. Not a big deal since there was so much meat left, but I wasn't happy. So I spent a few hours with a piece of scrap aluminum sneaking up on the bore size, but it left a positively brutal finish.

I didn't think the adjustable reamer would last for all sixteen holes and the finish was unacceptable, so I went to Plan B.

The dimension in question is the outer diameter of the case studs at the center bulge, measuring 15/32" (0.4688"). I ended up using a 29/64" drill bit (0.4531") and then using the reamer. It's the best match I could find but hand reaming .016" sucks, especially when it's sixteen holes.

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On the right side of the engine the bore is increased all the way through. On the left side of the engine the bore is only increased about an inch to give the studs someplace to seat.

I'm not super happy about the outcome, but it will work and the fit is quite good. But I worry about what might happen if any of the mating bores are a little off. It makes for white knuckles.

Anyway, all of the prep is now done. Now I need to thoroughly clean out the engine halves again and it's time for assembly. FINALLY.

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Alright...

It's 102 degrees (39c) outside so I hosed myself down with the garden hose and pulled out my bucket-based parts washer. I very thoroughly and very carefully washed out both case halves, blasted them with clean water, and then with compressed air and set them out to dry. No problem on a horrible day like this.

So let's start the assembly.

Before cleaning it, I pulled and numbered each of the main bearings. After cleaning the cases I cleaned the bearings with mineral spirits, popped them into place, and smeared on some good synthetic assembly lube.

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I cleaned the crank with the nastiest residue-free cleaner I had (Berkebile 2+2) and made very sure it was as clean as I could get it and that no remnants of plastigauge were left behind. The crank popped into place and rotates as smooth as can be.

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Here is the timing mark on the crank. It's remarkably small and barely looks like it was deliberately placed. I drew some reference lines with a marker to verify it's position in relation to the mark on the camshaft.

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I couldn't photograph and install the cam at the same time, but it's the same procedure as an air cooled VW. Line up the marks and walk the cam into it's home. In this photo you can look into the bolt hole of the crank gear and see that my sharpie-based cam and crank marks line up correctly.

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Here they are together in the case.

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And then I clean, install, and lube the opposite main bearings and camshaft and mate the other case half. I bolted the case halves together with the OLD case bolts because I want to make sure it continues to freely spin as I torque down the nuts. I'll have to separate them once last time to smear on some Yamabond or or something. But first I want to degree the cam and then verify end play.

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The factory service manual says to measure crankshaft end play and make sure it's between .002-.006". You can see here that mine is at .004". That's a relief.

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The next step is to degree the cam. It's next to impossible for this particular cam to be that far out of whack, and if it is I'll need to use an offset Woodruff key, which means pulling it all apart again. I hope that doesn't happen. Mostly I just want to verify the cam/crank timing. In the meantime I think I need to buy an adapter so I can connect a degree wheel.

More soon.

Sooooooo let's degree this thing and make sure I didn't install the camshaft off by a tooth or something stupid. I like sanity checks. Here's the situation as of a few hours ago. I installed rings onto one of the pistons (more on this later) and then the piston into cylinder #1. Then I made a high quality genuine Red Planet Industries piston stop.

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I've been following a Corvair aircraft engine build by a cat named Mark Langford, and he has a good write up on degree-ing the cam. He even provides a nice template to use with the existing crank pulley. Here's the link:

http://www.n56ml.com/corvair/degree_cam.html

The idea is to use the piston stop to find actual TDC for this engine. Install the high quality piston stop, rotate the engine one way and until it stops and use the centerline of the case to mark the pulley. Then rotate the other way until it stops and make another mark. In between both marks is actual TDC. (Full disclosure, I also removed the high quality piston stop and rigged up a dial micrometer).

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It turns out that it's very nearly dead nuts accurate. I was more than surprised.

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Here's Mark Langford's template taped to the pulley. I failed to get any clear photos of the dial indicator gauge on the intake and exhaust lifters. Oh well. This is already super boring for everyone but me.

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So finally I ended up with the following numbers. Basically there's no place where my cam deviates by more than one degree, so I'm very very happy indeed.

Intake at .005"
Card Me
Open 25 24
Close 65 64

Intake at .050"
Card Me
Open 1 2
Close 35 34

Exhaust at .005"
Card Me
Open 72 72
Close 32 33

Exhaust at .050"
Card Me
Open 42 42
Close 8 7

Huzzah!

That was a '65 I saw in a pic back there, prefer the '66 myself.

'Tain't boring a'tall, not that I know exactly what you're doing...

Impressive nonetheless. As well as your constitution.

Oh right, yes my Barracuda is a '65. It's virtually all new underneath. New 360ci engine, gearbox, disc brakes, larger clutch / bell housing, driveline, 8-3/4" rear end, new interior, re-upholstered everything, hydroboost p/s and p/b, hydraulic clutch, headers, a million other things. I found a painter in town that I really like so I'm thinking about finally getting it painted. Or maybe I'll sell it. The Barracuda is a gentleman's cruiser, not a hot rod. A true GT car. I'll decide what to do with it and the end of the year. All I do is work on it. I almost never drive it. But that's starting to change finally. But I might sell it because I have yet another project - a Beetle. Long story. More on that later.

The '66 and '65 are nearly the same car. The '66 had some cosmetic differences and a slightly different gauge cluster. And some little differences in the 273ci engine. Both are very cool though. I hardly ever see them around any more.

Seriously - after I sell off all this stuff I'm dedicating my life to cheap hobbies.

[quote name='r3dplanet' date='Jul 2 2017, 05:14 AM' post='2502276']
Sooooooo let's degree this thing and make sure I didn't install the camshaft off by a tooth or something stupid. I like sanity checks. Here's the situation as of a few hours ago. I installed rings onto one of the pistons (more on this later) and then the piston into cylinder #1. Then I made a high quality genuine Red Planet Industries piston stop.

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I did essentially the same thing using a spark plug modified by knocking out the ceramic & ground electrode and welding in a longer stub that would contact the piston somewhat before TDC. rotating to this stop one way, then the other nailed TDC exactly

That would work great. There's always another way. But in this case I wasn't prepared to install a cylinder head yet, but I'll use your idea when I get to that point for quality control. Thanks!

This seems like a good moment for an update. Lots of work happening lately.

First, I finally got the case halves to bolt up to spec with the ARP case studs. Some deep thoughts from me to you on this subject:

1. Have a machine shop do the reaming to enlarge the stud holes. I ended up with a mess after my adventure with the adjustable reamer. Don't use one! Eventually I used a 15/32" spiral reamer to clean up the job but I still had to make some adjustments and white-knuckled my way through it. If the alignment is slightly off you'll never get the case halves to mate and the crankshaft will freeze.

2. I had to ditch my Craftsman torque wrench. It was off by 10lbs and it took me forever to realize it. Plus, it's hard to situate the torque wrench in such a way that the head of the wrench doesn't apply pressure to one of the inside head studs. That throws off the torque value quite a lot.

3. Or just don't do it and keep the stock case studs.

4. Tom Knoblauch wisely states that if you do this, just do the inner four studs, not all eight. The outer areas of the case have alignment pins and don't need the studs. Save yourself the headache of doing all eight.

Next, it was time to attach the oil pickup and pan. Both are from Otto Parts, a cool aftermarket go-fast Corvair parts supplier that is part of Clark's Corvair Parts. This engine will get a few Otto parts: oil pan, valve covers, oil pickup, case studs, all sorts of things.

After bolting the engine halves together, I spent some time with a surfacing stone to make sure the oil pan mating surface was flat as possible. This lets me use one of my favorite tools: a huge 1/2" thick tapered glass plate. It's great for surface measurements, flatness gauging, motorcycle fork plane comparison, with sandpaper as a surfacer, a million and one uses. After a little stone work the mating surface is flat, flat, flat. Mostly just little burrs or imperfections - nothing serious.

Here's the oil pan:

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And here's the oil pickup installed:

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The Best Glass Tool of All Time:

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Here's checking the mating surface for flatness. Not pictured are the feeler gauges.

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And here's a problem. I laid the oil pan onto the engine and it rocks something awful, like an 1/8" at the corner. At first I was freaked out thinking it might be the engine case. But it's not. Despite the beautiful machined finish of the oil pan mating surface, the trouble is indeed a manufacturing fault. I wrote a message to the vendor and hope to hear back from them tomorrow. Check it out:

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Yikes! That's not an easy bit of work to bolt onto a mill and re-surface. And even if I did I worry about the distance from the bottom of the oil pickup to the bottom of the oil pan. Hopefully it's not a big deal to get a better one.

While the oil pan issue is getting resolved, I'm turning my attention to the [choose a noun] cover. The service manual calls it the "engine rear cover." But some people refer to it as just the rear cover, or the front cover, or the pulley cover (even though it doesn't cover the pulley), the distributor cover, the oil pump cover, etc. I'm going to call it The Cover of Many Uses.

Here's a front and rear view with some helpful labels:

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Here's something very important if you need to use a remote oil filter which is basically all 914 conversion adventurers. The stock oil filter needs to be cut off because it will try to occupy the same space as the firewall. So the oil filter neck is cut and threads tapped for hoses running to a remote oil filter.

Don't do the following! Read on to Page 9 instead!

The Cover of Many Uses provides a perch for an oil bypass valve. If the oil filter should become clogged, or if the oil is very cold and thick, it builds up oil pressure. Should this happen then the bypass filter opens and routes oil back to the pan to keep oil flowing. One bit of trouble is that so does adding a remote filter. But oils and filters have come a long way since 1960 so it's not really a problem any more, especially if you like to change your quality oil and filter on schedule.

What could be a problem is that unless the bypass valve isn't modified (plugged) in some way, then the valve will always be opened and the oil will never get filtered. That's bad. So I'm using an old racer's trick to plug the valve opening with a nickel. This will force all of the oil through the filter. This is not an original Red Planet Industries epiphany. It's been done a thousand times by builders and tinkerers before me.

I didn't like the idea of using a nickel but I sorted through my huge glass jar of change and found a remarkably beaten nickel from 2014. If put back into circulation it would get pulled right away, so it became the candidate. The valve opening hole measured .802" on my cover, and that's not a measurement of a common object. So a nickel it was. I measured other coins I had also. A Mexican 50 cent coin works well, as does a 5 cent Euro coin, but the British £1 coin works best due to it's thickness. I just didn't want to spend a whole pound for this operation, and managed to save $1.26 in the process.

The nickel needed to be filed down a bit before I popped it in, peened the edge, and filled the gap with good old JB-Weld.

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Still needed is the oil pressure valve bits (mine are worn) and the installation of the oil seal. I have the seal but the pressure valve bits are in the post. That's coming up... [i]in the future!

It's Saturday night and I'm full of steroids so I decided to do some more work on the engine. Tonight's project was to get the piston rings measured and installed. I'm using the piston rings that came with the AA pistons for the first and third rings, but the second rings are "gapless" Total Seal rings. If I had to do this job again I'm not sure I'd bother using the Total Seal rings.

Here's the setting on my coffee table:

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The first thing to do is to measure the gap in the empty space where the rings almost, but not quite, meet. I'm doing this for what amounts to five rings per cylinder x6 cylinders. In the past on other engines and parts, the gap is very often too small. I got lucky here and only had to file a couple of rings very gently. I'm using the rule of thumb that for every inch of bore, figure .0035 - .004. For 92mm (3.622 inches) I should aim for .013 - .015 thousandths. And I got exactly that.


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Starting with the rod side of the ring (or "bottom") the first ring to go is the accordion spacer ring. The ends butt against each other but do not overlap. This ring must go first before the other two that wedge on the upper and lower side.

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The Total Seal rings are a bit fiddly, and induce a vague sense of uneasiness. The instructions didn't seem to show my rings, but I snooped about online and found the orientation. First spiral on the larger ring, with the gap on the bottom. Then spiral on the very thin bottom ring into that gap. Gently squeezing around it seems to manage to work as one piece. I was careful to make sure the gaps of each ring were 180 degrees from each other.

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I'm just showing how the ring looks here. It actually installs upside down from what you see here.

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On the top ring you really have to look carefully for the "top" mark. Even a smear of oil hides the stamp. This one just spirals on like all the others.

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Now it's time to install the connecting rods. This can be done in two ways: first, assemble the piston, cylinder, connecting rods, and wristpins and then install the assembly into the block. Second, you could install the rods to the crankshaft and then install the pistons and cylinders and finally bork the wristpins in. I bumbled about both ways and decided on the first method.

I really wish the Mahle wristpin clips were as easy as these circlips to install on my BMW R75/5. What a farking pain the Mahle clips are. Ugh.

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Here are three views of the left, center, and right side of the completed piston rings. Just for reference. I looked around online and never found the clarity I was looking for, so here it is. Not that I haven't spaced the ring gaps around the piston into their "final" position. This is just to highlight how the rings should fit. After this, I spaced them all 120 degrees or so from each other, making sure the 2nd Total Seal rings were 180 degrees apart. None of the gaps align with the wristpins. I honestly doubt this makes any difference as these rings will all spin about when the engine is running.

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Last, here is the assembled piston and rod. Note the "#4" stamps on the big end at the bottom of the photo. This indicates that it's piston and rod #4 on the crankshaft. This stamp should point upwards, so it's legible looking down in from the top of the case.

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I assembled #3 and #4 first because I was worried about the clearance of the big end rotating inside the case. The head studs stick inside the case longer on these two registers and so I temporarily installed these two first and spun the crank to make sure. I have about 1/4" of clearance on each side. Not a lot of room, but it's enough.

Oh right. Oops. Here's photo of the whole assembly:

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Good to see you working on it Marcus. I know its been a long haul. Hope to see you at WCR this next weekend

I had to remove and install the cylinder assemblies a couple of times after my last entry. There was quite a bit of confusion as to which direction the pistons should point, and I ended up re-ringing every piston ring.

The conventional wisdom says that in a standard Corvair engine the pistons would normally point to the flywheel. Reverse rotation engines with stock Corvair cylinders have pistons that point toward the oil pump cover. But I couldn't find any info at all on which direction to point them if the engine is both reverse rotation AND has VW pistons and cylinders. I really do not want piston slap, but it may not be the end of the world if it happens. After consulting two engine builders who knew much about my project they said to point them toward the flywheel. So I did. Don't take this as gospel because it hasn't been tested yet.

I failed to get a photo, but each piston skirt is clearanced right next to the wrist pin housing. This is because the big ends of the pistons rotate so closely to each other inside the case that the piston skirt will butt into the the opposing rod cap. In order allow the engine to spin, each piston is installed with the clearanced section facing the inside of the opposing piston. Then in order to make all of the pistons point the same way, each pair of opposing pistons was installed one pair at a time (#1 + #2, #3 + #4, and #5 + #6) allowing a full rotation of the crankshaft to ensure a nice spin. Also, the pistons and rod caps are numbered only on one side where the cap meets the small end. They MUST meet. One more time: THEY MUST MEET. But they don't have to point upward. That is, the numbers can face to either to top or bottom of the case so long as the numbers face each other. Here's #1:

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It happens that I had to flip two pistons and swap #5 and #3 to make it all fit correctly. No big deal. Just be aware.

I found a problem with the prior piston ring clearances. At previous clearances, the engine just really struggled to spin. To correct that problem I removed all the rings and re-gapped them to .016" for the top ring and .019" for the second ring. I also ditched the Total Seal 2nd rings. One reason why is because I broke two of them, and I think they were the main contributors to the binding.

Anyway, now all six are installed and it all spins nicely. Tight, but not too tight.

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Now we can finally move on to the heads. Admittedly I had more trouble than I wanted, but I figured out all the trouble and rectified. The problem solving is enjoyable but thankfully it's moving faster and getting more fun.

Let's have some fun with the heads.

Here's a photo of the valves along with the .040" copper head gaskets. Yes, the heads are filthy. Yes, they are clean now.

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There are two things I want to do. First, I need to get a sense of the gap between the valves and the piston top. Second, I'd like to get the compression ratio together.

Using the tried and true Play-Doh method, I shoved a bunch of Doh into the combustion chamber and trial fitted one of the cylinder heads and torqued it down. The idea is to get a physical mold of the valve impression and then carefully measure the thickness of the squished Doh.

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Note that I'm using .010" base gaskets (actually .0118") with a thin smear of copper RTV on the base gaskets. That plus the .040" copper head gaskets (well, .0386") I should have the correct .050" overall head gasket thickness. I fitted two solid lifters into the corresponding bores along with the stock pushrods and gave the engine two turns. I took it apart and realized I made the mistake of not using enough Doh, so I did it again. Ideal clearance is between .35"-.40", and mine measure .371". Crazy impressive and totally not my doing. That's the work of Tom Knoblauch who did the machine work on the cylinders, pistons, and elsewhere. Now that I know how to appreciate such things, I'm super appreciative!

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Then I realized that it was way too early to be doing this measurement because I'm not using stock pushrods or rockers. Oops. More on that later.

While I'm waiting for some parts to arrive, let's measure the volume of the combustion chamber. This is a well known method that I see all the time. It's not triple accurate, but it's good enough. I bought an acrylic plastic circle of 3-15/16" diameter and drilled two holes. One to fill with liquid, the other to capture and release air bubbles. I'm using Water Wetter because it has good contrast and low surface tension. I'm sure you have all seen this a million times before. I had to do this process a number of times either because I had bubble trouble or just sloppy technique. But the result is an average of 51cc from all three chambers. They were actually dead nuts accurate as far as my testing ability goes.

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Running the info through various online calculators shows that I have a 9.35:1 compression ratio. Nifty. That's very close to the factory 9.25:1 ratio, and not enough to bother with using thicker gaskets to compensate. If anyone cares, here's the data:

Bore: 92mm
Stroke: 2.94"
Deck height: 0
Piston dome/dish: 0
Chamber volume: 51cc
Number of cylinders: 6
Compressed gasket thickness: .050"
= 9.35:1

I hope that whoever ends up with the engine will be good enough to use high octane non-ethanol fuel, as a gentleman always should.

Cool stuff, and hopefully a little diversion from the not cool stuff.

Hi Marcus - great to read about your progress.

Are you still going to use the spring loaded idler? I was strongly advised not to on my reverse rotation engine - the pulley being on the 'pull' side of the crank and that tension overpowering the spring etc. on my engine all is working well with the standard set up.

And you say above "whoever gets this engine" - are you not going to put it into your 914 after all?

Feel free to email me any time - I think you'll still have my email address.

Cheers

DaveO

You know, that's a really great question. I had intended to use it right up until you mentioned this. I thought that whole point behind the spring loaded idler was to prevent belt failure on reverse rotation engines. Hmm..

Your progress is looking great Marcus. I was contemplating this swap a few months ago but sticking with the flat4. I even had a talk with California Corsairs which is right down the street from me. They had blocks stacked up to the ceiling there!

Here's some inspiration for ya from some shop images I took from there...

Ha! Look at all that! Very cool! Maybe I should drop the compression and add a turbo.

Hi Marcus,

Have a close look at the generator cooling blades on the photo that Adam posted. Vairy interesting indeed methinks. What to infer from that?

DaveO

Yeah, right? That's a reverse rotation alternator fan on a stock generator that doesn't spin backwards. Interesting. Maybe someone rebuilt the generator into an alternator?

More progress today and it's all about vanity. I pulled out the powder coating gear and coated some things. Also made an unpleasant discovery along the way. The long block is getting about finished but on pause due to some more head gaskets on order. Plus it was a nice day and I didn't have to spend it connected to a medical probe-u-lator.

Most of the parts are cast aluminum and so really don't need to be prettied. Nobody will see them. Eh. Because they're cast they cannot be anodized so powder it is. First up, the engine cover / fan housing got some treatment with a little file to remove a million little casting boogers. I wish I would have taken the extra time to polish the whole cover because it didn't turn out super in the end. But it's nice enough. Actually, I wish GM had done a better job and polished it but.. eh.

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This is the largest piece I've ever put into my little bench top oven and it barely squeaked in. I put together some alumin(i)um mounts to move it about without bothering the powder. More machine gray.

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Then it was off to do the dipstick tube and oil filler cover. Here's the unpleasant discovery. It's full of what I think are glass beads from the blasting process from the guy on eBay from whom I purchased it. This would have a been a super quick way to kill the engine if assembled this way. This sort of thing drives me nuts, bananas, crackers, or any other snack food euphemism one cares to invent. I pulled out the rotary tool and polished it's innards and then cleaned it with mineral spirits and a brush. Took five minutes. I can't understand the mind of the seller who couldn't be bothered. Just a little quality control could save an engine. I'll be he has worms in his brain. It wasn't obvious as the oil pump pressure plunger was already installed. Unless I took steps to remove it for inspection it would have made for a really bad outcome.

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I didn't get any photos of the Cover of So Many Uses but it was coated also. So are the pushrod tubes but I did those with high-temp silver and then polished the business ends. It's traditional to paint them white, and I may yet for No Good Reason.

The day's tally:

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I'll be installing the pushrod tubes very shortly. There are twelve of them of course. Thinking about the concept of "twelve" today brought this to mind:

https://www.youtube.com/watch?v=VOaZbaPzdsk

Sure looks great! Your posts show a lot of detail. In reference to the blingish images above, which way does that belt turn in a stock motor? Sorry to be so simple about these. Rode in a new one once upon a time but know so little.

Good question. I've hardly thought about it until now. If you scroll up and look at the engine photo posted by 1adam12, have a look at the big fan in the middle. On a stock engine it will rotate clockwise. Naturally in a reverse rotation engine the fan spins counterclockwise. That has historically caused trouble with throwing belts. I'm going to have to investigate this when the time comes. DaveO90s4 knows more than I do.

A little follow-up from the previous modification where a nickel was stuffed into the oil bypass hole. After third thoughts and some social confirmation, there's really no reason to do this. So it's time to free Thomas Jefferson.

Torches and digging:

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Tom looks pissed. He has every right to be. I feel bad because I always liked the guy. Except the slavery part. You can just see the disappointment on his face, "Marcus! Get me out of this damn hole!"

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Now I have a perfectly good nickel.

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And finally a little cleanup. Good as new.

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I think Marcus meant to say:-

Good question. I've hardly thought about it until now. If you scroll up and look at the engine photo posted by 1adam12, have a look at the big fan in the middle. On a stock engine it will rotate counterclockwise. Naturally in a reverse rotation engine the fan spins clockwise.

(In a normal Corvair engine the crank will pull the fan belt from the horizontal fan via the alternator pulley. Thus the alternator is on the tensioned side of the belt. With a reverse rotation engine the alternator is of course on the less tensioned part of the belt travel)

Traditionally, the white paint is VHT high temp, and is only used on the tube end closest to the exhaust stub. This helps prevent the exhaust heat from transferring to the o-ring on that end and to the oil draining through the tube. The tube also helps dissipate heat from the oil, so the opposite end of the tube stays unpainted (or only lightly painted).

Thanks! That's good to know. I'll make the modification to mine today.

Today just had enough room in it to put together the cooling fan bearing assembly.

I bought a bearing and polished aluminum housing and then squished them into place. On the subject, does anyone want my old Snap-On hydraulic press? It disassembles, which is nice, because it stands seven feet tall. It needs plenty of love but if anyone wants to come and get it they can have it for nothing.

Here's the pressed bearing and housing.

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Then the tricky bit. It may not seem like it but pressing the bearing shaft into the engine top cover needs to be a precise exercise. The distance from the deck to the top outer diameter of the bearing needs to be between 4.46"-4.49". The idea is that when assembled there is a critical gap distance between the fan blades and the engine cover. Too close and it will make contact and be sad, too far and the forced air won't make enough pressure to cool the engine. I spent quite a lot of time trying to get this just right. If you ever do this, I think the easier measurement is the gap between the bottom of the bearing housing and the top of the fan cover, which is .040". Yes, I know the powder coating looks crappy.

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I still need to find the fan-to-cover measurement, the one that really matters. I'll find it and report back. With gaskets in place it looks to be 1/4". Here's what it looks like mocked up with the bearing, fan, pulley, and cover.

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You might be thinking, "Marcus, the orange looks terrible. Your color sense is lacking and your sensibilities are crude." And you be right. I coated the fan to match the car, but now it looks loud and out of place. Oh well. Orange it is. I happen to like orange a lot but I get your point.

On the subject of fans, here's the vertical fan setup I drool over. I think it would look much more at home in the 914. I want one more than I want my next breath. Feast your pupils:

http://americanflat6.com/products/verticalfans.html

Dear Marcus, re vertical fans. I very very respectfully disagree:-). Vertical fans are just oh so passé. Every 914-6 has them. The horizontal fan is - in a 914 - pretty unusual.

And the horizontal fan works.

And there is damn allclearance in that area too in a 914-C6. What with the crank pulley very close to the firewall, the firewall sloping back into the engine bay as it rises, the air restriction into the fan and the difficult tight turn the air has to take to get into the fan aperture.

Plus how to top er up with oil? And how to readily accesss the Cover of Infinite Uses?

I'm inclined to think for normal road use it is a solution to a problem that does not exist.

(Note: all above comments with respect to Corvair engine in 914. I make no comment re clearance etc for Porsche engine in 914 engine bay)

And I like the orange fan too:-)

Cheers

DaveO

Geez, is pragmatism all you have to offer?

There's a bit to know about rocker arms if you ever take this path and build your own engine. The stock rockers are just fine for a stock engine. They are made of stamped, hardened steel. The business end of it slides along a fixed radius, keeping in contact with the valve stem at all times. But there two undesirable characteristics. First, they can be inconsistent with one another and may not be suitable for big bore engines. Second, all that friction creates a lot of unnecessary heat.

To rectify this you can go with a full roller setup, but that is expensive for the set that Clark's sells, or you can spend even more and get a bespoke roller cam and lifter combo. The rollers do away with the stock girdles (pushrod keepers) and use a larger, rigid bar instead. Also required are longer, stronger ARP studs and bigger valve covers. Some vendors use lovely but lousy Chinese-made rollers that blow apart rapidly. These are the ones that Dr. Evil put into his bus engine. I was very tempted to buy them as well but quickly walked away after Dr. Evil's unwelcome experience. If you look through Corvair forums you'll see that this particular product has lots of similar failures.

A whole roller set wasn't in my budget so I'm going with the next best thing - small block Ford roller tip rockers manufactured by Comp Cams. These are also used in some Olds models. So yes, Ford parts in my GM/VW engine because why not? The part number is 1442-16. These are ball mounted, not stud mounted. The steel is thick and hardened and very strong. Racer approved. I'm just using them to keep the heat down.

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Why these roller tip rockers? Lots of reasons: way stronger than stock, less heat / friction, a fraction of the cost of a full roller assembly, and the lift ratio is very close the stock Corvair ratio, which itself is a matter of some debate. They do need to be modified. On the large central stud hole one side needs to be clearanced so that when mounted it will pivot far enough over to allow the roller tip to ride evenly over the valve stem. Also, the oil hole points directly down thereby filling up the chamber with oil. So the hole needs to be welded up and another oil hole drilled on the other side so oil shoots into the right place.

Here is are the original oil holes welded up.

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And new drilled oil holes on the other side.

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And all of them together. On the top row are the for the intake valves, the bottom row for exhaust. Be sure to order the matching pivot ball mounts if they don't come in the box. The balls mounts have four serrations to allow for more oil flow.

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With the rocker arms sorted out it's finally time to doodle with the rocker geometry.

With non-stock cam, cylinders, base gaskets, and head gaskets it's reasonable to think that the stock pushrod length will be incorrect. So I ordered from Clark's an adjustable pushrod toolkit that comes with two adjustable pushrods and a pair of solid lifters.

The idea is simple: when the valve opens and closes the valve stem tip needs to travel smoothly along the roller tip. Or the roller tip needs to travel smoothly across the valve stem tip. Not too high, not too low. So if the head and base gaskets are correct (I double checked mine and they are) then all that needs to be done is to lengthen or shorten the adjustable pushrod to make it kosher.

First I do this visually. At rest the roller tip should be towards the bottom of the valve stem, and at full lift the roller tip should be towards the top of the valve stem. Here are exaggerated pics to show the difference.

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And here is a top view of the roller tip touching the valve stem. It really needs to roll along very flat on the valve stem. If the rocker wasn't clearanced to one side, it couldn't be made to ride flat.

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The instructions say to use a little piece of oiled paper and squish it onto the valve stem. This leaves a circular impression with the roller path clearly visible. It needs to be as close as centered as possible. I used blue Sharpie on the roller tip instead because it was easier to read.

The tolerance is about 1/2 turn on the adjustable pushrod, or .025" by my measurement. A little note here about tolerance: pushrods are available in different sizes, so the choice is made to the nearest .025". Not the end of the world if off by a little bit.

The pisser is that the solid lifter in the kit has a lower contact point with the pushrod than the hydraulic lifters. I'm using Melling JB-817 lifters. The difference in height of the contact point is 0.109" lower for the solid lifter. That means that in addition to getting the adjustable pushrod just right, this distance needs to be subtracted. Depending on the hydraulic lifter you use, this distance can be different.

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Then it's time for the arithmetic. This is where I get confused on what should be a simple task. The desired pushrod length is supposed to be the adjustable rod length + the lifter difference - the valve preload. Depending on the source, the pre-load is anywhere from 1/4 turn to 3/4 turn. So I'm using 1/2 turn, or .025".

.... and doing so leaves me with a pushrod 0.20" SHORTER than stock. This blows my mind because every other write-up I've studied with VW big bore stuff shows a longer pushrod. Not shorter. I averaged my two best lengths and averaged them to get 10.040". I measure the stock rods at 10.240".

The trouble here is that (a) I'm not sure this is correct and (b) I can't find shorter pushrods in this size. I might sacrifice one of my new hydraulic lifters by welding it solid and measuring again. Bummer.

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I'll sleep on it.

Not sure I've ever seen a spec for the distance between the fan and the sheet metal. The critical measurement is the fan bearing flange to the top cover gasket surface. If that's right, the fan should be fine.

It's a hydraulic tappet isn't it? I never knew how those were measured, but thought that they pumped up when run. How does that figure in the calculations? I like the numbers and notes!

Odd off topic question. Can a set of Del 36's be used on a Corvair 140 engine? I looked around to see if anyone had done this and wasn't finding anything

As far as all the write-ups I've seen indicate, there shouldn't be any special consideration for the hydraulic lifters. But having said that, I've decided to go ahead and weld up a hydraulic lifter and re-do the measurements just to see if I can get a more accurate reading. Great question. Food for thought.

Do you mean the dual throat DRLA carbs? If so, then yes you can. You need a pair of custom manifolds that adapt the carb to the head. There are custom units out there for triple bore carbs, but I'm using Weber 40 carbs. Tom Knoblauch makes them at americanflat6.com. I have a photo back at the top of Page 8, post 141.

Basically you can make any manifold you want if you can TiG weld and have a mill. I don't have those but I know who does. For me it was an easy choice because I'm very familiar with Weber / Dellorto carbs.

The stock lifters are set to 0 and then tightened a specific amount....then you run the engine and adjust until quiet. No shit. Videos out there and special valve covers are sold or made. Its a mess to do, Ive done it.

As for roller rockers, go with a known source. I "saved money" from a guy that ended up not only selling cheap chinese crap, he sold the ones for a chevy V8 which have a different angle of attack. He promised they were correctly angled for corvair, I asked specifically. Well, check out my bus thread towards the end to see the destruction. The first one ate through the rocker stud and the others were not far behind.

An expensive cautionary tale. It still makes me angry. More so because that guy is still selling them.

The valve adjust videos are very cool. You slice a crappy valve cover down the long axis so it captures the oil (sort of) and then you tighten the rocker nut to quiet the valve. According to the book Performance Corvairs the best way to do this is as follows:

1. Set rocker distance to just touching (zero lash as Dr. Evil said).
2. Run the engine, and then on each rocker nut tighten until it quiets, or about 1/2 turn - which I found out yesterday with valve geometry is about .020".
3. Turn off the engine after all are completed and let it cool.
4. Give each valve another 1/8 turn.

I have some tooling being made up will get back to the geometry soon...

... but first let's make a sandwich.

The process is easy for once. Clean the top of the engine case with acetone. Coat the first of two identical engine cover gaskets.

<shameless product placement>
I use Permatex High Tack in the spray bottle. It's my favorite gasket sealer because it's clean to use and has a long working time so I can relax and have fun. I wish Gasgacinch had a spray version also. But these two are very similar, even the same color and smell.

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</shameless product placement>

Then add the baffle plate, the other coated gasket, and then the top cover. Like so:

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Finally just torque down all sixteen to 150 inch pounds after kissing each new bolt with a bit of JetLube. I went in three stages of 50 in/lbs until 150. I'm using stainless 5/16-18 x 1" bolts with lockwashers and washers. I don't want to besmirch the aluminum case.

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Here's the Dagwood all assembled. It feels a bit sad to not see the pistons any more. Not that I want to have a major problem and have to get back into it that far. Perish the thought.

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Awesome. Love the orange fan and pretty much everything else

I uses Great Stuff, which is more gooey. Ill have to try your stuff.

I like Permatex "Right Stuff" if I'm going metal to metal for sure. I've never tried is as a gasket sealant. Maybe I should..

Okay. I'm doing little bits of this and this and that while I sort out two remaining issues - the oil pan and modified lifters for rocker geometry. Those will take a few days at least so it's time to work on pesky bits.

My attention has mostly been the Cover of Many Uses. It took quite a while to sand down the mating surfaces and lap them completely flat. I'm using my ever-handy flat glass plate and sandpaper. While in there, the 90 degree oil cooler connector is getting the same treatment.

Just to review, the Cover of Many Uses is a two-part assembly which houses the distributor, oil pressure sender, oil filler, mechanical fuel pump, and two oil bypass valves, one oil pressure regulator, and the oil pump spur gears. But it's getting a bit of a reprieve because I'm using an electric fuel pump instead of the mechanical one. Better all around.

The oil pump threw me for a bit of a loop. Here's the order of installation:

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The clearance between the spur gears to the bottom plate is suppose to be .002-.003". Fair enough. The new oil pump comes with different size gaskets but none of them measured to nominal thickness. So a .010" gasket is really .0075". Great. I don't like Plasti-Gauge but this seems like an okay place for it. But no variant of gasket would get the correct clearance. Except for one, but when I twisted the drive gear with a screw driver to simulate the distributor gear, it rubbed against the bottom plate.

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Further irritation came from the fact that use of feeler thickness gauges didn't match the Plasti-Gauge readings. Finally I realized that my NAPA-branded feelers were the wrong size! According to my micrometer, the .002 feeler is .007, and the .003 is .009. Lovely. I have a nice Mitutoyo set on order.

The last bit of despair came when I measured the original oil pump gears with the new ones. As you can see, the new ones are .798-ish, but the old one is dead nuts on .800". The service manual says GM will happily provide oil gears in increasing thicknesses of .001" to get the correct fit, but those are long gone. I called the parts vendor and the guy measured some on the shelf and said, "yeah, they're all like that."

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Right. So I have another oil pump coming from Melling, and maybe it will be the right size. Normally I wouldn't squawk but oil pump clearances are critical.