348 power quest... head rebiuld

I am not so sure about that. I have never CC'd one but the cranking compression does lend creedence to the 10.4 claimed and there was only one piston part number until very late in production when some variants had 10.8.

 

The piston in the above pic is scuffed at the skirt and needs to be replaced. Stock pistons are fine, but JE are also very good and much more reasonable @ around $1200 a set with rings and pins

 

BTW the 355 rods are only 390 gr.

 

Verified, you have the ball bearing, not the early roller bearing that is prone to failure.

The H manifold Ernie speaks of
Image Unavailable, Please Login

 

If there was any question,

HC OEM on left, Std. CR OEM of right and Stupid CR Cosworth slug in the back
Image Unavailable, Please Login

 

Spacers fabricated by gothspeed engineering using plate aluminum and waterjet cutter. Don't ask me if it does anything by itself. It's part of a package of mods we made that do work, but who's to say if it's one thing, all of them or something else?

Note: You will have to work up something to elongate the shaft for the balancing butterfly in the center of the upper plenum. With gaskets it's about .375" taller. Also note spacers at throttle bodies to free room for the throttle linkage to function without binding.
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

Wouldn't it be cool if somebody had a few of those cast?
Could probably be done in some of today's plastics.

 

It would have to be a package because of all the other stuff involved: throttle bodies moved outboard; longer Allen head bolts; extra gaskets; butterfly valve shaft extension. I suppose goth could come up with something. The risk to me is that we could not tell you if these mods alone yield any benefit. Add ported and polished runners along with completely smoothed upper plenum surfaces and bored throttle bodies, and yes, you will get more performance.

 

I still need to get my coffee straws ported, er..... I mean, the throttle bodies.

On second thought, scratch that. I need to get this pile of crap running right........if that will ever happen???????

 

The reliefs are cut with 35/30 cutters. I had to pocket them a bit deeper for the Sprint engine cams. Its a heavy slug but made to live at very high CR's and abuse levels. Sy's LM and my IMSA are both running the same Cosworth pistons but he is running sans head gasket with a fully Cooper Ringed head thus giving even higher CR figures.

I am in full agreement with you regarding the OEM pistons. A wonderful blend of longevity and high performance that is quite hard to improve upon. Ferrari chose to stick with the identical design through the F50, 355, 360... only changing the crown design for the 5 valves.

Somewhere in the stacks of parts I have an unaltered H manifold I can flow to get some base numbers for your research if that helps. If I can find my old files from years ago I flowed a good many of the intakes. On one of the H manifolds I installed stacks inside much like the 550/360 design but never had time to flow it or study it further. I believe that showed a good deal of promise to be built upon.

 

Excellent work, Daniel.

 

Hey, cool thread - I can't believe I've not noticed it before!

Forgive me if this comes out sounding confused, but is that a timing chain to replace the timing belts and so improve longevity between majors or is that timing chain completely separate from the famous timing belt?

All the best,
Andrew.

 

Good job Daniel,
Did you keep the hour glass shape runner whan you ported them, or did you make them more cylindrical? Also, what size are you planning to port the Throttle body?

 

Andrew, this is something completely different than the timing belt that run the four cams on the 348 - this timing chain is for the oil pump inside the gearbox.