crank shaft question

[Mach 5]

So I got an idea and my plan is to destroke a 3500 for a 3100 turbo build while keeping my factory gen 2 top end. This is for my 89 turbo grand prix. I wanted this crank because its forged. My question are there any 3100 that came with forged cranks?

I dont want to hear about how much better the 3x00 top ends flow or that its a waste of time. This build is strickly for getting the most I can out of the 3.1L. I will be running high boost 20+psi and I want to hit close to 500

oh and Im also looking for a pic of the oil squirters from the bottom end on a 3500

Thanks for your help!

-Jarek

[geoffinbc]

No there are no forged 3100 cranks. Good Luck!

[Superdave]

The best 3.31" stroke crank (aside from the 3500) is the stock one from a Turbo 3.1.

[geoffinbc]

As far as I have seen the rumors of it being a "stronger crank" are just that. Rumors. There would have been no need to fortify the crank so why would they bother.

[Superdave]

As far as I have seen the rumors of it being a "stronger crank" are just that. Rumors. There would have been no need to fortify the crank so why would they bother.

I wouldn't say it's stronger.. just a bit lighter. I have acces to one, if i get the chance i'll snap some pics before the engine goes together.

[Mach 5]

I always thought the 3.1 LG5 turbo cranks were cast but hardened..?? If you could get a pic of the 3500 bottom end that would be awesome!! Im also tryign to find the journal and stroke spec of the 3500 crank vs a 3.1 crank..

-Jarek

[geoffinbc]

its in the specification section

[Mach 5]

Im gonna have to look again I had trouble trying to search before.. thanx

[geoffinbc]

Your right I cannot find it either. Here ya go http://members.shaw.ca/betterthanyou...ifications.htm I keep my backups on that server. Specs for all the motors are in that folder.

[bszopi]

Not all specs have been put back up. When I was doing it after we switched to the newer version of the software, I ran into issues with the length of some of the specs and not everything getting displayed, so I stopped. And have yet to start back up...

[Mach 5]

awesome!! Thanks! Do you by chance have either 3.1L specs or 3100 specs, or both as well?? mainly the 3100 specs as I have a factory service manual for the 3.1L

[Superdave]

the FWD 3.1, 3.4 DOHC, 3100 and 3400 all use the exact same crank.

[Mach 5]

ok so after looking over the specs I see that the stroke and main bearing journal size are the same. The rod journal size is different -1/4inch larger-. This is a good thing because now I can have this crank stroked-