3.6 rebuild. No, not the 964/993 3.6

[Shuie]

anyone ever built a 3.6 using a 76mm 964 or 993 crank, rods, & JEs on 3.2 case with with 100mm cylinders (the 3.5 cylinders) with the type 930 stud spacing)? The 3.2 heads are good to 300hp, right? Seems like it could work. Or am I totally misinformed or off base in thinking that a 964/993 crank can work in a 3.2 case?

I know it wouldnt be cheap, but Im thinking about the possibilities. I saw a 964 crank with rods for sale recently that made me think of this. Its nothing more than curiousity, Im not thinking of doing it or anything. Yet

TIA

[strokher racing]

I have a 3.3 based turbo engine with a 964 crank and 98's in it. Why not go with a 3.7 cylinder from Charles at Lnengineering. You can find his link on my signature. They will work great for NA motors. You want the 964 crank and rods if you go the other route instead of the 993 stuff.

Eric Hood

[IrocMan]

It will be fun to modify both crank and crankcase

In my opinion, you will spend so much time and money to have an engine finally less performant and reliable than a gently tuned 964 or 993...

[Carrera3.5L]

Originally posted by Shuie
anyone ever built a 3.6 using a 76mm 964 or 993 crank, rods, & JEs on 3.2 case with with 100mm cylinders (the 3.5 cylinders) with the type 930 stud spacing)? The 3.2 heads are good to 300hp, right? Seems like it could work. Or am I totally misinformed or off base in thinking that a 964/993 crank can work in a 3.2 case?

I know it wouldnt be cheap, but Im thinking about the possibilities. I saw a 964 crank with rods for sale recently that made me think of this. Its nothing more than curiousity, Im not thinking of doing it or anything. Yet

TIA

Nope, not off base at all. Been done many, many times in the past on 3.0L/3.2L cases before 3.6L conversions were both affordable and figured out.

You will need to modify the Mahle 3.5L 100mm pistons though to work with the 3.6L 964 crank and 3.2L rods (you don't need the 964 rods for this conversion). I do have the piston mod drawing if you end up doing it. I'm sure JE can make some pistons to work as well. Case spigot bores need to be enlarged to 105mm from 103mm as well.

A 102mm p/c combo for a 3.7L will need the case to be enlarged ANOTHER 2mm to 107mm. Not really sure how durable that is in the long run. Andial uses Carillo rods with that conversion and they use Mahle pistons/cylinders with a 3.2L crank!

IrocMan does have a valid point. Unless you get the 100mm pistons/cylinders and 964 crank for REAL cheap, it isn't a cost effective conversion compared to a 3.6L transplant, both in price and in power and probably durability as well. Remember, add in the extra cost of twin-plugging with the 100mm bore. No knock sensors.

Ralph

P.S. - Hey IrocMan, do you have an english version of your site so I can read about your projects?

[Wayne 962]

Do a search in this forum, 100mm is not really recommended for the -89 cases - the cylinder walls really get to be very thin. Although, I have not seen Charles' 100mm cylinders up close...

-Wayne

[asphaltgambler]

Another issue is that that the 3.6 crank needs the dual-mass flywheel and clutch to control harmonics.

[strokher racing]

964 cranks really should be checked for straightness. They solved that problem with the 993 cranks, but they are not as good. You will not need the big heavy pulley or the dual mass setup. I am not using either one.

Eric Hood

[Carrera3.5L]

Andial includes a special crank pulley with their 3.6L conversion package that alleviates any harmonics problem. No need to run the dual-mass clutch set-up either.

I still don't think that it is cost effective to go this 3.6L route but I'm sure that they would sell the crank pulley to you separately if you needed it.

Ralph

[dwightp]

"anyone ever built a 3.6 using a 76mm 964 or 993 crank, rods, & JEs on 3.2 case with with 100mm cylinders (the 3.5 cylinders) with the type 930 stud spacing)?"

Oh yes.

"The 3.2 heads are good to 300hp, right?"

Unsure about stock heads. Modified, yes and over 300hp capable.

"Seems like it could work. Or am I totally misinformed or off base in thinking that a 964/993 crank can work in a 3.2 case?"

Not off base (993 crank). No exprience with 964 crank but I imagine it would work also as spoken above.

[aturboman]

My engine is a "3.6" turbo built as you described. Based on a 3.3 it has 964 crank and 100mm 3.5 Mahle pistons & cyls. The longer stroke provides a nice increase in comprseesion. I've had the crank carefully balanced and made a custom pulley from a 964 unit. The rest is as usual 964 cams, ported heads ,twin plug etc... It can done and I have no douts about reliability, but it ain't cheap.

[asphaltgambler]

Is the pulley from Andial more for harmonics or just to have the right offset to drive the accesories??