MC951

Engine back in after rebuild and it cranks but seems to have too much resistance like it's tight bearings or something.

Anyone ever run across this?

everything was torqued to spec along the way

The mechanic is going to pull the motor back out and check everything over.

xtaC

Silly question, but did you make sure your battery and starter were up to the charged/up to the task?

carlege

Pull the engine back out with out doing anything?

MC951

I'm pretty sure that my mechanic checked the obvious (battery, starter etc..). I don't know all that he's done to troubleshoot so far, but he said that he checked the belts and everything in front and all seemed good there. He went to hand crank the engine and it was giving a lot (excessive) resistance.
He thinks something is too tight like some bearings? This is were my lack of knowledge with these things comes in. I'm just wondering if the bearings thing is a possibility. This mechanic has built more than a few 944/951 motors and I trust him to get it right. I agree that pulling the motor seems extreme but he's said that he wants to do it to ensure that all of the tolerances are set right. on his dime of course

lart951

may I ask who is your mechanic or the shop's name?

MC951

Ryan @ RSR Autosport in San Diego

333pg333

.........

Chris White

Its pretty hard to get the bearing clearances too tight if you are using a stock used crank and new bearings. It would be more likely that the rings are incorrect or the crank is slightly bent.

A band new engine can be a little ‘tight’ until is run in. How did it run?

It does seem a little strange that the engine was not turned over by wrench before it was installed. The mechanic should have done that when he was installing and tensioning the belts with the engine on a stand. If he didn’t notice anything odd at that time installing it in the car would not change anything.

dillon410021

is the clutch not working and the car is in gear?

Jfrahm

Yeah how do you even get the cam timing and belt tension set if the bottom end is stiff when assembled. It could have stiff balance shafts or a ring problem. Otherwise if the bottom end was stiff the final assembly would have to be done while aware of this problem and the mechanic would have to be hoping it'd loosen up once run in. Crazy.

MC951

Here's the latest plan - engine still in and we don't want to use the starter any more until the crank turns smoothly by hand (he did turn over by wrench before install). He's going to pull both the balance and timing belts and turn each shaft seperately, cam crank and both balance shafts, in hopes to isolate the issue and go from there.

carlege

That sounds like a more logical plan

Tom M'Guinn

Balance shafts can bind up pretty tight if you are not careful with the nose pieces.

alxdgr8

Did you change the rod bearings? If you did, make sure the caps were put on the right direction. I had one wrong and the engine would hardly turn with a 2' breaker bar (with the plugs out). Fixed it and it spun nice and easy.

J1720

+1 on Balance shaft housing