3100 crank in a 3.1L

[Ortie666]

Hey, can you fit the 3100 crank anywere the 3.1l one can go? the crank sensors dont matter with this application, juss will it fit the same with the 3.1L rods

[bszopi]

Yes. In fact, they may even be the same part.

[Ortie666]

sweet thanks man!!

[Superdave]

yes, the crank is the same between the 3.1, 3100 and 3400

[GPRacer]

yes, the crank is the same between the 3.1, 3100 and 3400

I'm not calling you out on this, but at the same time, i don't think that's completely true.

In fact i think the 3100 crank has another reluctor type ring that the 3.1 doesn't, but that might just be me. I've also checked on part #'s between the 3100 and 3400, in which they didn't match up.

[IsaacHayes]

the reluctor ring is on the balancer pulley

[XLR8ING]

The cranks may be different part numbers from GM, but the casting numbers on the crankshafts are all the same on the 3.1, 3100, 3400 and 3.4 DOHC.

[Superdave]

I'm not calling you out on this, but at the same time, i don't think that's completely true.

In fact i think the 3100 crank has another reluctor type ring that the 3.1 doesn't, but that might just be me. I've also checked on part #'s between the 3100 and 3400, in which they didn't match up.

that's odd.. considering the crank i just pulled from my 3400 had a big 'ol "3.1 L" Stamped on it lol

same stroke, same 981 casting, same 7x crank trigger, same bearing sizes etc... like IsaacHayes said, that trigger is on the inside of the balancer pully. I had forgotten about that since i ripped it off when i first got the engine.

The cranks may be different part numbers from GM, but the casting numbers on the crankshafts are all the same on the 3.1, 3100, 3400 and 3.4 DOHC.

exactly.

[Ortie666]

wicked Dealy.. super thanks to everyone.. I actualy wound up getting one out of a 3400. It was laying on the ground already, outa the car and off the tranny. for 60$can..opposed to 120$ for a regrind

[Superdave]

wicked Dealy.. super thanks to everyone.. I actualy wound up getting one out of a 3400. It was laying on the ground already, outa the car and off the tranny. for 60$can..opposed to 120$ for a regrind

Have it checked out by a machine shop, it dosen't take much to mess one up... you might wanna get it polished as well, the extra $50 could save you a few hundred when a bearing fails... take it from a guy that had it happen

[Ortie666]

Ya, im going to get the new 3400 one pollished, prolly take it down a thou, or so.. give a little more space for oil.. and then prolly resize and new bolts for the rods.. i was workin for a high-performance engine building shop, so i will get a killer price if i go there, or mabye ill juss do it my self..