3.5 w/3.0 turbo case

gumba · 09-09-2006, 07:43 AM

I have a 3.0 turbo case, 3.5 (7:1 comp) turbo p&c's (mahle cylinders w/JE pistons, and 46mm Webers? Is there some motor combo I can make with all the spare parts?

Facey · Facey's Garage

not sure what you mean by "3.5 (7:1 comp) turbo p&c's"

here is my guess
you have either 100, or 102mm bore pistons from JE, with matching mahle cyclinders. and at some point there were used in combo to make a 7.1 comp ratio.

however, the problem is, that we need more info then given to tell u what u actually have.

i am unaware ( don't remember if the turbo was the same as the n/a)of the stock 3L crank, my guess is 70.9mm, with this combo and the 100mm = 3.3L
and if u have the ~74mm crank with the 102mm pistons u have a 3.6L

and discplacement of 3.5L is reached by using the 100mm pistons, with the ~74mm crank.

any of these setups are a nice start to a engine, however if the c/r is actually only 7:1, then your bascially throwing away lots of hp in an N/A application, you bascially should use those to build a forced induction engine.

i am using the 74mm crank, with mahle 100mm P&C's to get a over sqaure (short stroke) 3.5L, the c/r is somthing like 12.8:1, it is twin plugged, electromotive ignition, and i am even using another item u named, the 46mm webber IDA's.... this configuration makes some serious hp.

now you would be looking at even more with a forced induction setup, however, i have been told that the webbers would be all but wasted.

so a little more info, and someone smarter then myself and you'll be set.

i'm sure there is a possiblity to do somethign with what ya got.

gumba · 09-09-2006, 09:21 AM

The 3.5's (JE & Mahle) are out of my 3.5 twin plug turbo motor, so a 74 mm crank. I'm replacing these with a set of Mahle 3.5's (7:1) for the turbo. I'm assuming the JE/Mahles were about the same c/r.

I was going to sell the set of JE/Mahles. But since I have a 3.0 turbo case and a set of Webers I was wondering if I could build something fun with this combo.

Jeff Alton · 09-09-2006, 09:51 AM

Sure you could, but not with the pistons. Get some higher CR pitsons and have the case spigots openned up to take the cylinders and you are on your way.

Cheers

MBEngineering · 09-10-2006, 09:54 AM

HI if you actually have a 3.0Lt turbo case???? then you will have a 70.4 mm crank and a 74.4mm crank will not fit, engine No' and the type No' of the case would be good, just to confirm which case you have.

regards mike

gumba · 09-10-2006, 10:36 AM

Yes it's a 3.0 turbo case I bought last year. Case only, no crank. The 3.5 p&c's are out of my 3.5 turbo motor w/74mm crank.

Lukesportsman · 09-17-2006, 06:36 AM

Wouldn't custom rods be able to solve this issue? Mike, is this what your implying or are you suggesting that the block would need clearancing or the larger stroke? I've never heard the latter.

As a racer, but certainly not a P-car expert, seems that you could get with very precise measuring a custom rod that compensates. In domestic engines, we consider this a long rod/short piston design. No this is not optimizing anything except the parts on your shelf. You'd be just as well or ahead costwise to use stock type rods and new JE pistons.

Henry Schmidt · Henry Schmidt's Garage

Even though you could build an engine from the parts you have, selling the 3.0 case and buying a later 3.0-3.3 case would make more sense. The 3.0 turbo case is magic in that you can put a 66 mm crank in it making a very short stoke engine. That crank will not fit in a later case (9 bolt).

There is no benefit is using a 3.0 case for any engine with a 70.4 crank or larger. In fact the case has limits in that the 6 bolt crank is considerably weaker than a standard 3.0 SC crank