Mahle 94 stroker piston- differences?

[dieters]

In process of rebuilding a customers stroker engine (82x94), problem is the new Mahle cylinders don't fit the engine case. The Mahle 94's we took out fit. The base shims fit the old cylinders but not the new ones (approx.030"difference) part # for the new pistons 311-198-069-94s. The sleeves fit the head fine, just not the case (same case) What gives? Disassemble the short block and have it opened up the rest of the way? What do I do for shims? Thanks!

[dieters]

So they are actually 96mm (old pistons) and 97 mm new pistons. At the case side of the cylinder. Our supplier shows base shims at 96 and 98 mm. Are the old pistons (smaller) like a slip in to fit a hole for a 90.5/92?

[modok]

the bottom diameter of the mahle 94mm cylinder has not changed in 20+ years, it should be 97.3mm

the old cylinders were modified by somebody to fit the case

[SRP1]

Sounds like the cylinders are not Mahle maybe???
AA?

[dieters]

I thought the cylinder lip looked real thin, like the slip in 88's, like you could shave with them. So is 96mm on the case the size for a 90.5/92. I've got quite a few cyl base shims that diameter. The heads fit the new cylinders(thicker) fine, could I put 92's in instead?, or are the heads too big to fit them?

[modok]

yes, 96 is for 90.5/92

AJ Sims has been selling 94 sets turned down like yours, maybe you could get some from him?

[mxracer]

[dieters]

Thanks mxracer. I guess I already knew what my options were, just looking for an easier way out, guess there is not. Also thanks for the breakdown on sizes, a nice thing to know!

[wbbbbbbb]

I purchased most of a NOS 2180cc, internals are Scat 82mm crank & Scat h-beam rods! It came with Clyde Berg GB 865 heads bored for 94mm, but has Cima / Mahle 92mm pistons and jugs that were power sleeved by Rimco back in the day! Power sleeved means that the top of the cylinders had a ring of iron press fit and machined to 94mm for increased rigidity on thin wall 92mm cylinders! Essentially Thick wall tops and thin wall bottoms.

All these parts are originally from 2006! We will see if this works when I slap that puppy together! I need to contact Clyde Berg and get his recommendation on a camshaft? It came with a NOS GB-310, basically an Engle K8! I always ask my head porter for their recommendations on cam, carburetion, and exhaust.

Your might be best off boring the case for thick wall 92mm or 94mm cylinders? It might be the most economical route?$?
Sleeve the heads instead of cylinders if that’s a thing?



I will put 2180 in my 64 with Benco “Overhauling” transaxle.

[Axitech]

I have a stupid question, maybe.
My case and heads were machined for 94’s (AA brand P&C’s). Looking at ordering new P&C’s (Mahle forged units)from ACN and the ad says :

“Case must be machined! Thicker cylinder walls give ultra-reliable power. When used properly, these will give 50K miles of life before needing attention. Gives BIG displacement increase to your engine. This cylinder set fits a 97.25mm case opening, and a 101.1mm head opening”.

I’m on the road in Virginia this week, and have to stay here because gas is in short supply, so can’t travel home to measure anything. Is 97.25mm case, and 101.1mm head opening the ‘standard’ for 94mm P&C kits?

I need to know before completing the order. Thanks for the help, Gents!
Bob
_________________
He said to them, “But now if you have a purse, take it, and also a bag; and if you don’t have a sword, sell your cloak and buy one. Luke 22:36


The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.-Thomas Jefferson

[Axitech]

I have a stupid question, maybe.
My case and heads were machined for 94’s (AA brand P&C’s). Looking at ordering new P&C’s (Mahle forged units)from ACN and the ad says :

“Case must be machined! Thicker cylinder walls give ultra-reliable power. When used properly, these will give 50K miles of life before needing attention. Gives BIG displacement increase to your engine. This cylinder set fits a 97.25mm case opening, and a 101.1mm head opening”.

I’m on the road in Virginia this week, and have to stay here because gas is in short supply, so can’t travel home to measure anything. Is 97.25mm case, and 101.1mm head opening the ‘standard’ for 94mm P&C kits?

I need to know before completing the order. Thanks for the help, Gents!
Bob
_________________
He said to them, “But now if you have a purse, take it, and also a bag; and if you don’t have a sword, sell your cloak and buy one. Luke 22:36


The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.-Thomas Jefferson

[mark tucker]

some guys were machining the 94 cylinders to the 92 size to have more meat at the case savors.

[modok]

Not exactly but close enough

Cima's spec sheet says the top of the cylinder was 101mm, bottom ledge 97.3
And that's the MAX sizes of cylinder itself.