@SuperHawk996

Those are NICE!

Look at how thick the walls are!

You're going to have far less trouble sealing to the head with those.

Nice FAT sealing surface!

What stroke are you pairing those with?

That is some very good news for you. Those heads represent many many hours of development by Len Hoffman and Jake Raby.

When setup right with proper valvetrain geometry and then the right tuning (ignition timing too), you should be in for some serious HP, but with cool running and longevity too. They come with really good parts too, like springs, valves, guides, retainers, and calling them "ported" doesn't do them justice to the development and time invested to get them to flow just right. And they are expensive.

You might have Nickies too. Maybe the rest of the motor is by RAT, but since it wasn't started, it's more likely a kit. But, that's still good news because RAT used very good parts. Parts that were matched to the motor and the intended purpose. So, since a 914 owner had it, it's unlikely a "camper" (bus) motor. All good news. Definitely want to make sure she's put together 100% right before you start her up.

Good luck! And, go out and buy a lottery ticket, OK.

Man, I would hate to tear that down if it was professionally assembled.

I’d hate to start it if it were not.

It's worth the small $ to invest and find out exactly what lies within

Pict of cylinder. Any idea what it is? I'm hoping to take one head off in a day or two and measure cylinder. Click to view attachment

First of all, looks like 2.0 heads to me. Cylinders look like iron but I could be wrong. The spacers under them are legion. I think you need to pull a head at this point just to know the valve size and deck height, but if I were you, I wouldn't crack the case. I know all the old fuddy duddies are going to tie their underwear in knots over that but if everything looks good up top, you can verify plenty of valve clearance (which you can do by pulling the head) and you can get a measure of the compression, I would have to ask myself if I could do better job than the last guy on the bottom end. Would I take it right out onto the track? No, I would carefully get it going and build up confidence in the previous person's build.

If you see everything looking like quality, I would go for it. But that is me.

Magnet sticks to cylinders so definitely not aluminum.

What is a legion spacer?

I guess I’ll wear the old fuddy duddie title with honor.

There is no rocket science to putting a bottom end together but there are a lot of details that matter.

Without some decent lube on the cam, it’s not impossible to wipe out a cam in the first 20 minutes of initial break-in run time. The more aggressive the cam, the more I want assembly lube not just coincidental oil splash.

Don’t know about you but I’d like to be sure there is some assembly lube on all the bearings rather than depending on cranking the engine with ignition disabled to build oil pressure. Did the oil pump get coated with some light grease so that it builds oil pressure quickly or will it take extended cranking to build oil pressure?

What are the bearing clearances? What do you do if it starts up and has low oil pressure - then what? Yeah, disassemble and look at & measure bearing clearances.

Did the cam get a single thrust bearing or was it done Raby style with a double thrust bearing? For that matter what cam is in there?

Were the rods torqued properly? What rods are in it, stock or maybe H-beam or I-beam. So many details that matter. Especially if this is truly a hot-rod build looking to be spun up (otherwise why bother with double valve springs).

I’ll grant you that whoever paid for RAT / HAM heads probably wasn’t his 1st rodeo but there is no guarantee this wasn’t quickly assembled by someone else just to get it sold and moved along down the road.

looks like multiple spacers stacked. Sign of amateur build.

A pro build would only use one spacer.

Multiple spacers are multiple leak paths.

Likewise multiple spacers can be less rigid than a single spacer unless flatness of each is perfect. This affects head bolt torque.

Positives:
Heads- look like Raby heads with welding around the spark plug wells (Raby did this).
Proper retainers/springs.
Look like oversize rocker arm studs.

Negatives:
Raised numbers on piston crowns. I believe those would have been machined off if built by someone knowledgeable. I'd have removed them.
And then I'd have ceramic coated the tops...

I've NEVER seen raised numbers in forged stuff. The forging process would destroy them.
Someone else said "cast" and I'm prone to agree due to those numbers and the rough valve depressions.

Cast iron jugs.
Stock head studs and re-used head nuts.
Grey RTV on case studs.
If they used grey RTV, a master would use a x-acto knife during curing to trim the excess.
Possibility of internal clips in the lifters.

The value of the heads FAR exceeds the posibility of destroying said heads without a full tear down.

I'd take lots of pictures and check a bunch of stuff during the tear down but that would get reduced to individual componets before I'd put fire to it.

It's looking more like a kit build with RAT heads.

Still a KILLER deal IMO!

I think the raised numbers are just an optical illusion but I could be mistaken. The multiple spacers is concerning.

95.95mm in a 96mm bore equals .05mm PTW clearance or .002".

This is a clearance for cast pistons...

It's a TIGHT clearance for cast pistons in an air-cooled application!

Not really. 0.03 mm was initial clearance when 914 engines were built. Per the Tech bulletin for the Bus engines the clearance was later opened to 0.05mm

Here are OEM 914 shallow dish pistons for a 2.0L 94mm - marked 93.97
Click to view attachment

Here’s is the excerpt from the bus bulletin that has later been applied genetically by the aftermarket to Type 4 pistons and cylinders
Click to view attachment

Bus would have had more susceptibility to seizing due to the brick in the wind aerodynamic loads plus the cargo loads that are way, way higher than the load imposed on a 914. So 0.05mm of clearance is more than adequate for a 914.

I believe Raby has run Nickies with as low as .00075” (0.019mm) piston to cylinder clearance somewhere along the line. I can’t find the source for that so take it as unverified. That of course would be possible because the piston is running in an aluminum cylinder that is expanding as fast as the piston as it heats up.

Side topic @technicalninja
Comparison of HAM head to OEM (2.0L)
Click to view attachment

Yes. Forgot about the double cam thrust bearing (actually just an extra thrust bearing taken from another regular cam bearing set). When we mocked up the motor, we had some binding with a double thrust bearing set from the type 4 store. Required some clearancing. Pretty sure the RAT motor kits had them. Would want to check that before start-up.

As you wish, we can grant you the title of "Old Fuddy Duddy".

RAT/HAM heads welded around the spark plug holes to relocate them to the more favorable 2 liter position.

Thanks for the pics SH!
Answered some questions I had.
That has minimal chamber re-shaping.

I'm betting your Nickies will not fit in your HAM heads as is...

You're going to have to have those fly cut to the larger diameter and then re-ceramic coated due to the loss of coatings on the flat sections.

Got the heads BEFORE the Nickies did you?

That would piss me off!

Sorry to be such a newbie….what is “PTW” clearance? How would I measure that?

Piston to wall

Bore clearance. You measure the bore with an inside micrometer and the piston skirt with an outside micrometer and the difference is the PTW clearance.

The point you measure the piston is CRITICAL. Most manufactures have a specific spot, normally about halfway down the skirt below the pin bore as the measuring spot.

Pistons ARE NOT perfectly cylindrical. They are shaped like a barrel (a little tint bit) and measuring diameter of the crown or skirt will give you different readings...

I have used a feeler gauge, will get you close. maybe not close enough for a race application, but for the street I think it's fine. Generally at 90 degrees to the pin

Cylinders are 96mm bore. Intake valves are 44.06 or so. Exhaust valves are 35.95 mm or so. Will measure pistons and deck height next.

Click to view attachment

Click to view attachment Click to view attachmentClick to view attachment

Those have had the chambers worked far more than SuperHawks!

I LIKE your heads!

Please take pictures of the intake and exhaust ports.

I'd REALLY, REALLY like pictures of the ports directly below the valves.

You would have to take the valves out which, if you've not done that before, you shouldn't "learn how" on those heads.

I can't have everything I want...

Now, if it was me, I'd rip those apart to change the valve stem seals (or O-rings) and hand lap ALL of the valves.

If those have been sitting for years hand lapping should be done.

Yes, go ahead and take them apart!

I will walk you through a hand lapping if you desire it.


A quick test to test valve sealing is to fill up the intake and exhaust port with a liquid and watch if the liquid seeps by the valve into the chamber.

I normally use mineral spirits as I'm planning tear down anyway.

A safer fluid (for using the heads without tear down if sealing is good) would be liquid WD40. You can buy this stuff in gallons.
https://www.homedepot.com/p/WD-40-1-Gal-Mul...mp;gclsrc=aw.ds

Wouldn't bother me at all to test heads with WD, drain, blow them out, and then run without pulling them down.

Stand the heads so the port face is horizontal at the top and fill the port up. Wait 5-10 minutes and see if the level has dropped.
A TINY amount of leakage may occur through the valve stem.
You will see that around the springs.
Active dripping will require attention.

Water or Mineral spirits I'd want to tear down to fully remove.

Tearing down is easy with the proper tools. You need a valve spring depressor.
You slightly compress each valve spring, remove the keepers, release the compressor and remove the springs and retainer.
Keep everything in order and mark the parts to allow replacement in the same port.

I could easily pull the valves in less than 5 minutes per head.

So lighter than OEM con rods. Looking good.

Pistons and cylinders from AA Performance Products. Budget oriented parts vs the big names but nothing wrong with their stuff at all - lots of folks using them. Mahle style slipper coating on the skirts is a nice touch.

Decent amateur build based on what we’ve seen.

Did you measure stroke?

Did you check the stroke during disassembly?

You measure the depth of the piston at BDC versus the deck height at TDC.


Did you check deck height during tear down?

You measure how far down the bore the piston is at TDC. This is done with feeler gauges or dial indicator


Have you checked crankshaft endplay yet?
This is done with a dial indicator.

If you don't know
BDC = bottom dead center
TDC = top dead center

Those are ends of the stroke.

The cast pistons, which I agree are FINE, need cleaning bigtime!

You can probably re-use the rings, but you need to clean the piss out of them and their respective groves in the pistons.

Those appear to have never been run...

My heads are the AA 2.0L china casting but valves, seats, springs reworked by HAM.

IIRC the RAT / HAM are the AMC 1.8L casting (better quality history) but then welded and reworked to mimic the 2.0L generally.

I’m going to go with Emery here - if valves are sealing properly (they will be) - I wouldn’t tear down the heads. RAT & HAM are top notch and I don’t see that their work needs to be double checked or re-done.

I guess maybe I’m not so fuddy duddie after all.

I'm actually in agreement with you. I did say "don't learn how on these heads" and provided a method of verification that did not require tear down.

I STILL want to see the ports however!

Badly!

My bad. For some reason I read it the opposite; ie now is the time to learn.

SuperHawk, how would you test to see if the valves were seating properly?

The statement of "not needing to be double checked" IS the ROOT of ALL mechanical failures in my book.

You insult Mr. Murphy by stating that.
Mr. Murphy likes kicking you in the nuts...

I double and triple check everything ALWAYS!
I caught WAY TOO much shit to ever stop.

The only other way to test valve sealing is with a dedicated valve seat vacuum tester and that is something even I don't have...

I’m going to reiterate what Ninja said earlier

Be sure you are indexing the flywheel to the crank and keeping all parts indexed and identified so they can go back to the EXACT same location.

Not sure if this Flywheel, crank, rods, fan assembly was dynamically balanced as an assembly. Probably not with amateur build but if it was you want things in the same spot.

A tell on dynamic balancing is if you find what seem to be drilled or ground spots where minor amounts of weight are removed to balance the assembly.

The book / DVD will have details.

If I couldn’t find evidence of dynamic balance work having done, I’d seriously consider doing it if you intend to really spin this motor up beyond factory redline. Should be able to outsource to a local performance shop - maybe Seattle or Tacoma area if necessary.

What you’ve proposed is perfectly fine. Low viscosity, low surface tension fluid.

We should change the name of this forum from 914 world to supper ninja technical hawk

100%!

If they put those nice rods in and DIDN'T balance, I'd FIRE THEM!!!

Point taken

OK!

Should we NOT have discussions regarding builds?

Would the other members prefer to not have SuperHawks and my input?

@technicalninja

Picture of RAT case with Serial number

Just so all can see what one of these RAT cases done my Jake looks like

Best Bob B

Click to view attachment

+1 on the suggestions to dynamically balance the motor if you don't see evidence of balancing or drill marks on the pressure plate/flywheel, etc. Dynamic balancing, not static "balancing."

Take all the reciprocating parts to the balancer. Crank, Rods, pistons, flywheel, clutch/pressure plate, etc. One of the signs of a RAT built motor (not a kit) is the fasteners were indexed to the location on the clutch/flywheel.

Here are measurements so far. I still need cam lift.

Stroke 78mm

Cylinder Diameter 96mm

Deck Height .052 in 1.32 mm

Intake Valve 44.06 mm

Exhaust Valve 35.95 mm

Good looking numbers!

I'd pick a single shim to reduce deck height to .040.

I've always balanced my pistons and rods myself.
The machine shop won't invest the time that I am willing to, and they are never as accurate.

If you have a V configuration engine the machine shop needs the pistons/rods/rings/pins/clips to calculate "bob" weight.

I still don't let them do the balancing of the above.

If you're an inline or a boxer they machine shop does not need the above to balance the crank and I'm a HUGE believer in sending the absolute minimum parts to the machine shop.

It's hard for them to lose stuff that you keep in your shop...

Now, they DO NEED EVERYTHING that attaches to the crank.

If they are doing a proper job, they will balance the crank first by itself and then add an item and rebalance (doing the metal reduction to the new addition only), add another part, and so on. This is time consuming.

The quick and dirty way is to assemble it all and just balance it once...

Both ways will give you the same result but the long way will allow you to replace a single part and effect the total out of balance the least amount.
You also have the option to balance just that item and be near perfect.

SO two ways to balance...

One is the old school proper way
One is the new "Get-er-done" varity that is far more common now

I need an engine stand yoke for my build. My welding table would be a fine bench mount. What engine stand combination due you use? Hate to spend $400 for a one time use.

I am glad to have top notch guys here to share their experiences, generally invaluable information.

Thanks all contributors

I use a Harbor Freight rolling base and a nice 3 arm yoke that I got off Thesamba.com.

Unfortunately I tried to get a link for you and it looks like the guy that used to build them (very affordable ~$120) has passed away and is no longer found in classifieds over at Samba.

You might post a WTB here and and see if someone has one they might sell but isn’t using. They were well made and capable of holding a six cylinder engine fully dressed.

The two arm yoke would work in a pinch for a /4 but the 3, 4, or 5 arm yokes are way stronger but get more expensive too. The 3 arm was a good compromise that works for me.

I bought a cheap ass one as I was NOT planning on building a six.

Mine has two arms and came with a bracket that could be mounted on a bench.

Mine fits in a normal cheap ass engine stand of which I have 10-15.
Way too many!
It's like they BREED when I'm not looking...

I make 3/4" plywood bases on the engine stands and I'll add wheel/tire until I'm close
to have a second safety.

The 2-arm stand has worked fine with 2 complete 2.0l on it now.

I had to "fab" mounting hardware as its not perfect.

If you can get 3 or 4 arm used inexpensively that's probably money well spent.

You should always be able to get what you paid for it from another member down the road.

You MIGHT get an offer to borrow one from another member in the next few posts.

This happens far more often than you would think on this forum!

Should this happen, you should buy the beer!

https://aapistons.com/products/bench-mount-...AiABEgIgNPD_BwE

That's the one I bought!

$50!

Your engine is too nice to use a cheapy.

But, that will actually work...

EDIT: The thread title needs to be changed!
It should read "Killer find 2256 Raby headed engine thrash" or something similar.

On balancing...

Pistons/rods I will balance to +/- 0.5 grams

But the entire assembly I will accept +/- 2 grams.

Doesn't have to be super close!

When an engine runs it ends up with oil entrained on all of the parts and this oil "ropes" differently on different parts.

Due to the amount of oil hanging on the parts the engine will NEVER be in "perfect balance".
It CANNOT happen unless you get rid of the oil!

Dry sump has less of this happening but it's still significant.

When someone tells me the entire assembly is +/- some tiny amount it just means that they don't understand what is happening inside an engine while it's running...

When a good machine shop calculates "bob weights" for a V engine they should ALWAYS include 5 grams for this entrained oil in each bob weight.

Head porting photos. Just ordered AA 2 arm bench mount yoke. Looks pretty solid but will weld additional material if it looks questionable.

Click to view attachment Click to view attachment

Thanks for the pics!

Those ridges in the port say "CNC" ported.

It ALMOST looks like the port is undercut just beyond the valve seat.

That "flies in the face" of normal porting techniques...

Most ports work best with throats at 85% of the seat diameter.

Those throats look bigger than the seat!

Maybe it's a "Type4" type of thing...

I'd love different angles and better shots of the exhaust port which I believe is the "Achilles Heel" of Type 4 head flow.

The 2.0l heads I've messed with had pretty decent intakes and the VERY WORST exhaust ports I've seen.

It didn't look like there was a decent way to "fix" the exhaust port IMO.

Looks like you might have a rockin /4 engine. Take you time with the assembly and keep us posted with your results

It looks like a ton of work for a little old 4, tell you what, why don't I just take that off your hands? I have a old bus engine fully assembled that I could give you instead.