Engine rebuild, experienced/professional advice needed

Tipi_dwl · Post by **Tipi_dwl** » Tue Sep 02, 2008 9:10 pm

Ok, I'm gonna rebuild the engine on my '69, as it leaked oil and #3 cylinder compression was only 6bar (87 Psi). It was 8-10bar (115-145Psi) in others, which I consider as OK. Oh and it had a clacking noise under engine braking...

I will need your help as this is the first 356/912 engine I'm dealing with. I've rebuilt a couple of VW flat fours and I've got Brooklands Manual, but any advice you've got is appreciated.

Disassembly started without big issues. #4 exhaust rocker had the other nut loose, so that was the first suspected reason for clacking noise. Oil leak on the left side was caused by broken o-rings on the head nuts. Sorry about the bad camera phone pic.

I have pretty decent 'low hour' '69 (616) industrial engine heads I think I'll use, even though current heads seems to OK too. Are these the same heads, or do industrial heads need machining for automotive use?

More pics on my first disassembly session. At the same time I was trying out my new oil sump.

As I took the block apart on last weekend the cruel truth revealed. It was also leaking a lot from the clutch housing so I presumed the crank seal was bad. What I was afraid of, was that the noise was coming from a loose flywheel, and unfortunately my fear was justified. The fly wheel and crank are badly damaged. My luck is to have skillfull friends, and one of them will weld up the holes and machine new ones.

But the cam is also done and so are the lifters too. Can the lifters be reworked? Pics of the second session. This engine did not have many miles after the last rebuid with new bearings. What do you say about those spots on mine?

Anyway, it will need a fresh start. Pistons and cylinders are pretty fresh 86mm units. What would be good cam if I'm aiming for around 100hp, without sacrificing reliability? Any suggestions? Do you have experience on Pelican or Stoddard cams? Or can I get cam from Germany?

antporter · Post by **antporter** » Tue Sep 02, 2008 10:56 pm

Hmmm... I can see why that engine made some odd noises. What's the damage to the crank?

Tipi_dwl · Post by **Tipi_dwl** » Wed Sep 03, 2008 7:14 am

Guide pin holes are f*cked up, as you can see here:
http://dwl.fi/tipi/muut/912/motor/block ... 20022.html

Mr Pharmacist · Post by **Mr Pharmacist** » Wed Sep 03, 2008 3:46 pm

You'll find some of the best advice in the Harry Pellow books & DVD's:

http://www.hcpresearch.com/books.html

Good luck

old_skool · Post by **old_skool** » Thu Sep 04, 2008 7:20 am

industrial engines have lower compression. so head height might be different? for 2nd hand engine parts i use a guy in the states (Mike Boyer vwpartsmaninc@yahoo.com)

912uk · Post by **912uk** » Thu Sep 04, 2008 8:55 am

interesting stuff
the bearings don't look too bad but that cam and the followers don't

I would have said your going to need to look for a new crank

either way doing it on the cheap you will find the bill could amount to £3000 before you know it.

I'm £4000 in and I am only just about to start to put it togeather, again a 69 motor.

But the list of parts for mine is long!!

reground crank
NOS bearings
NOS rod bearings
New RSR0012 Disy
New SX1 Cam shaft
New lightweight pully
New Ali Oil cooler
New oil by pass sytem
Heads total re work with new valve guides
New Exhaust Valves NOS
New Intake Valves NOS
New valve springs
New Shasta's
New Bursch
CSP Delux gasket set

the list goes on....

Tipi_dwl · Post by **Tipi_dwl** » Thu Sep 04, 2008 11:48 am

Atleast industrial engine pistons are machined for lower compression (the top end is turned). I have a good industrial engine crank, but I'll try get original fixed as it has counterweights, which industrial crank does not have.

Scheiße! For £3000 I'll build VW Stroker with double amount of power than OEM engine!

How about the generator? Mine has a Beetle generator. But some 356/912 had also thinner generator and different generator stand? Does these go by year model or how? I have spare thin Porsche generator I'd like to use, but I need a spacer or another stand. I got also eight spare Ø86mm pistons and cylinders from industrial engine. Maybe this stash I scored two years ago, will help my wallet a bit?

912uk · Post by **912uk** » Thu Sep 04, 2008 12:43 pm

every thing helps...I am sure you could get the crank repaired but it's a big job. You would have to weigh up the cost of the crank re pair v another one..

old_skool · Post by **old_skool** » Fri Sep 05, 2008 9:42 am

Tipi_dwl wrote:Scheiße! For £3000 I'll build VW Stroker with double amount of power than OEM engine!

thats what im doing. keeping the porsche engine to one side (which is running ok). and doing a stroker type 1 for every day useage. or you could use a 2lt type 4 with an upright conversion.

http://www.geocities.com/clarkblumberg/ ... page9.html

Tipi_dwl · Post by **Tipi_dwl** » Fri Nov 28, 2008 11:45 am

The Pelican flew from California with some vital parts for the engine. And I hope the really loose shifter/stifting will be stiffer with new bushings.

Cam is the WebCam 86a which is a notch wilder than the original. Now I can start rebuilding the engine.

My friend welded and machined the flywheel and crank to original spec, so I avoided sourcing new ones, and saved me going bankcrupt

Tipi_dwl · Post by **Tipi_dwl** » Wed Jan 07, 2009 9:08 am

Block is now cleaned, but I'm still waiting for the crank and fly wheel from the machining shop. I cleaned the oil gallery's like it was instructed in the Owners Workshop manual. Any pointers at this phase?

I bought another set of Solex PII-40 carbs, as the other carb of the pair I had, has a little melt down problem because the cylinder 3 fire. This 'new' pair was actually restored by me seven years ago for my '54 VW Oval 1,7l engine.
Pics

912uk · Post by **912uk** » Wed Jan 07, 2009 10:46 am

Well as long as you stick to the tollerances as you go stage by stage then you should end up ok..

Now you have with the crank made sure it has been ground ( if this is the case ) with a radius as per the factory specs?

if you grind a crank with a 90 degree angle like a modern crank it will in time crack there. So make sure you have that right..

Now would be a good time to check all your parts to make sure you have every thing you think you have eg it is 912 and not a mix of 912 and 356 as has happened in the past..

atomman · Post by **atomman** » Wed Jan 07, 2009 11:26 am

just rebuilding my engine aswell

like Mark said just make sure you check all the tolerances and measure every thing as you go, its good to keep a log so you dont lose track to,and make sure every thing is real clean.oh and make sure the oil plungers are clean and move freely/

Put my new my barrels and pistons on the other night

and got one head on now just need to torque the other one down tonight.

912uk · Post by **912uk** » Wed Jan 07, 2009 1:22 pm

I must admit I have one area I need to learn about

Compression..

There was a good artical in the 356 reg mag about it some where..

Tipi_dwl · Post by **Tipi_dwl** » Wed Jan 07, 2009 2:01 pm

Which part of the crank are talking about, the radius I mean? Connecting rod or main bearing journals? These won't be machined if in tolerances. My friend is machining the guidepin holes, which needed to be welded shut...