So, the head was mailed today to the Corvair Ranch for valve seat exam/repair and final assembly. I was tired of messing with it. I will finish the CC of it when it gets home and assemble

butcher

Hey doc, Two words. Family Practice. Your skills as a surgeon worry me.

Blah blah.

When I did the other head I left the old valves in to protect the seats....I thought I was more skilled and didnt need to do that with this head ah well, its only $$

Let us pontificate on the future of a CIS system on this mill. In my research I have found at least one other individual that had attempted, futilely, to put both a Corvair engine and CIS into his bus. This resulted in no improvement, crappy running and decreased, abysmal fuel mileage.

Why do you think this set up didnt work?

Hard to say from those photos but where is the fuel distributor? Biggest issue with CIS as I see it is fuel pressure and learning how to set it at the WUR. It took me years (really) to figure out why mine was all over the map. Vaccum is also an issue.

REfresh me on what parts you are using for your CIS. 911 stuff?

I never worked on CIS before my Alien build. There are three guys in town that have CIS experience. Two of them are the exclusive Volvo guys. The other guy is a Volvo, Ferrari and VW guy. I couldn't even pay these guys with an open check book to help me or take the car in to tune it. If I can help you I will. CIS is easy once you get the fuel pressure set.

PS: don't bother messing with the adjustment at the fuel distributor. It is for fine tuning only not for fuel pressure. Every CIS guy here in town came out to the car with a long allen wrench and dicked with the dizzy adjustment only to foul it up more than it was when I brought it to them.

All of the parts except the housing as I will make my own. Making my own down tubes, too. I will be using the Volvo distributor housing.

Are you using 4 intake runners or 6? How are you using a Volvo Dizzy if it's 6 runners? Bertone V6 engine stuff?

My system consists of:
Stock 3.0 CIS from 911
Distributor mount/air box from Volvo - remote mount
Heads are as in the pic, individual ports
Aftermarket fuel pump with appropriate pressure and flow rating

Thanks for the call, Rick. I have considered that the guy whose engine is pictured above did not know exactly what he was doing.

My intentions are to make a plenum that is closer to the fan, and shorter down tubes. I am not sure where the injectors are going, yet, but this guy may have them too far away from the valve which would cause a rich running condition.

Things that I considered with this guys report, if all pressures and plumbing were correct:
- Injector location
- Plenum and down tube volume (his look large). Too large and response is slow, too small and response is erratic.
- System used. I am not sure what he got his CIS out of.

Some more ramblings about the engine:

Stock CR for a corvair 140 is 9.25:1

I was running 7.25:1 and it was kicking ass, but running rough. Now I am manning up and raising the CR to stock or there about.

Bore 94mm
Stroke 74.6125mm
Head gasket .04in
Deck height .038in (I need to verify. I cant find my notes, and my calc has .08 in the collumn )
Chamber 50cc
Pistons are flat top

In my research I have found that the magic # for higher CR and no detonation is a clearance of about .04" between quench and the piston top.

Problem #1 :

he used a 924/audi t.b. that was designed for a 2.0 liter 4 cylinder

Problem # 2 :

The runners a REALLY long for a 3.0+ engine thus creating more top end h.p. than low end that a bus really needs

Problem # 3 :

The T.B. is effectivey at a 180* bend to the runners thus creating an extremely awkward flow into an already lenghty runner

Problem # 4:

In my experiecne most people DO NOT know hw CIS works and DO NOT know how to set it up and " tune it "

Sheeze! That's what me and Doc were talking about today. That plemium is too small and the throttle body is in a very weird place. The 928 is directly under a very large plenium aith a direct connection to the fuel dizzy.

Hey Doc --

One other thing to consider with CIS is the fuel lines. I shoehorned a Golf Mk2 1.8 engine into a factory diesel Vanagon Westfalia many years ago. I was warned that the fuel lines MUST be made using very high quality SS-jacketed material to stabilize the CIS "pulses." Apparently, cheapo lines that bulge can wreak havoc on the system. I can't remember what company I paid (dearly!) to make those longer-than-stock lines, but I never had any problems with the setup. YMMV.

Geoff

Good eye, Scott. I would not have know that about the TB. Mine will likely be better. With you and Rick, we all agree that most dont know how to tune the CIS. That book you lent me helped me understand a lot so that this should be a no brainer.

Every time you let a project linger, you loose things I did some work today on the engine, sort of. I made a fixture to hold the barrels in place today so I can work on the other side while I await the return of my other head.

Click to view attachment

I got the other 3 pistons cleaned up and then I could not find the damn clips for the rod pins Looks like I will have to source some more

Happy day!

I found my clips for the pistons so I installed the P/C. I checked the new deck height and it is 0.063". I rechecked a chamber on the head and it was 50cc. I installed the head and began working the rocker geometry out

After very little trial and error, the pattern was perfect and the rod length locked in Now I need to wait for the other head to come back, and to send these rods off to be measured and matched. They are longer than stock by a bit.

So, for those of you keeping score at home, here are the stats:

Bore = 94mm
Stroke = 74.6125mm
Deck = 0.063"
Chamber volume = 50cc

I am leaving the head gaskets off as they drop the CR lower than I want (<9). With no head gasket the Cr = 9.47:1

The CIS will like the compression. BTW: do you have an accumulator? You need to use an accumulator. That's what reduces the pulse in the fuel system. I used one from a Volvo turbo CIS car.

Yup, I am using a NOS Volvo one. Way cheaper than the Porsche part, same characteristics.

that engine in the bus was a wild assed guess on the intake runners and plenum!

the runners too big in dia. and long would make it fall on it's face across the board, the small plenum will make the runners "fight" each other in pulses in harmonic phases thru the rpm range.

it would be best to use a similar sized engine to model the runners and plenum on.

The 3.0 CIS system that I am using will pretty much be mimicked. Right size, right parameters. I will be making a bigger, rectangular plenum with shorter down tubes. I am wondering if it is worth it to put trumpets inside the airbox leading into each down tube. This is supposed to help air flow immensely.

if the point of entry for the runner tubes are not radiused you should do something to smooth the air entry to the runner.

The adapters to the head are pretty ugly in their transition. I will post a pic when I get home to show you.

Eric Shea and Jeff Hailpern will be done with their cars before this thing is finished.

this? how does it mate to the plenum?

Here are some close ups of the intake adapter. Basically, there is a plate welded onto the top with round holes that transition immediately into square.

I also took a close up of the mating surface to the head. It shows that you can used square O-rings, but I dont know where to get such things. I will likely just cut out gaskets from gasket paper.

Note, this adapter is not the one used in the other guys failed attempt. His were welded in pipes so had a smoother transition.

No need to be mean. I dont know how close you guys are, but I am really close

What do you mean finished? I just want it on the road.

How about some awesome news?!

After doing the calculations on the adjusted rods, and converting over to the hydraulic stock lifters, the correction is that the rods I need to use needed was .1115" shorter.....the stockers fit! Now I just need my head back so I can finish assembly

Today finds me with half of an engine done I am mixed about this

I love these roller rockers I got them because they are cool, and they should cut down on heat and valve-train wear. .

I also made my own gaskets for the intake manifolds out of a roll of gasket paper I had. Came out pretty nice

Suck it, E-Hole!

I am fighting the urge to use my mega-jolt on this engine. If I had it programmed with advance curves already I would do it, but I dont so I would have to do a lot of extra research. Maybe I can install it later when it is running

Damn feature creep.

Not surprising after 57 pages and 1133 posts that you'd make that comment. If you think feature creep is a problem now, just wait til when you start outfitting it for actual travel.

Nice progress Doc, heads and intake look great!

Dirk Wrights Disease

Dude, your whole automotive life could be described as "feature creep." It is not surprising that it has bled over to this facet of your project too...

Zach

You know what would be cool . . . if you had Scotty paint it red and black like your logo.

You could program your mega-jolt while he's doing that.

What? And paint over the airbrushed mural of the buxom broad in the steel bustier and teh flaming sword? Scotty spend an entire weekend on those areoles! No way they just get painted over!

so . . you're channeling RealRed now?

..

A friend of mine has something that I thought he said they only made like 11 of them. I think he called it a DK10??

Click to view attachment

One side of the engine is done today. The aluminum is ugly, but I had to do a lot of building up to do, and subsequent grinding. Eventually, I had to leave some globs on as the material was too thin. New injectors and hardware are installed

Here is a link to the agonizing design of the CIS system
http://www.914world.com/bbs2/index.php?showtopic=167036

So, one of the design things needing to be addressed to meet the and of the month deadline for completion is how to hook the CIS box to the intake. I have been looking at Volvo air boots, but the best think I am seeing is the 924 boot here:
http://www.ebay.com/itm/Brand-New-Porsche-...de7&vxp=mtr

Any other suggestions? I am wishing to go from vertical to horizontal and with the 924 boot I can do this with a simple elbow

I hope you bring this to Hershey Mike, cant wait to check it out











p.s. I will try not to cut you off this year

That looks very similar to the 3.0L intake!

You can do something like I did for the Volvo intake and the welded up elbow. I cut the original intake boot and made the elbow to fit my needs! Then I clamped the cut intake to the elbow to match everything together!

The problem I see in cutting the OE boot is that it is oval. The 924 boot is circular so plumbing the rest would be easier with standard plumbing supplies

At present, I am waiting to get the pipes for the down tubes, they ship on the 19th and this has held everything up. Once the plenum is built, i can install the engine, decide location of the airbox, measure FI hose lengths and order them, and make new engine tin while I wait. I can still make the end of the month deadline, but having to order out all of these damn parts is killing my timeline.

Back to posting in this thread. I have the heads done up and installed, the adapters welded up and installed withe new injectors and hardware, welded on the mounts for the AAR and the WUR. I diagrammed out the vacuum, fuel and electrical schematics that I will use to guide assembly and found that I am in need of 3 electrical plugs for the AAR, WUR, and CSI. I also found that I need a thermotime switch for the CSI....I think a 914 one should work so any used ones out there? You can also appreciate the billet pulleys I got to keep the belt form getting scruffed on rusty steel pulleys. Still need to keep the man crank pulley rust free and the alternator one, too.

Some more victory last night with the making of the base plates for the intake system I first made my own gaskets, then I transferred the pattern onto the 1/4" 6061 Al plate and drilled out the holes. It all lines up! The down tubes are reported to ship tomorrow and I cant wait for them to get here so I can get this all buttoned up and installed for testing.
Click to view attachment

I also took a different route with the air box for the flapper and dist. I had been generously given a nice aluminum setup out of a Volvo, but the filter that would have to be used would be of the cone-style KN that would be pretty small. So, I came across a setup for a VW rabbit (I think) that uses readily available disposable filters. I also found a refresh kit with new copper washers and a gasket for the flapper assembly. Good price and looks appropriate for what I need.

Wonder what the wagon would look like with a 914 painted on the side.