Mystery Bolts from Engine that was Pulled_Can Someone ID??

[Paul C.]

Had someone pull my engine at the bell housing and am cleaning all the bolts. I have 6 x 3/8 x 1 inch black phosphate hex head bolts with sb grade 5 head markings. The have threads halfway up the bolt. Engine is at the rebuilder and he can't figure out where they came from when pulling the engine. The guy who pulled the engine had them labeled intake bolts--that I know is incorrect. Can someone help me solve the mstery?

[Michael L.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

Can you tell me what year/engine they're from? What options? What tranny? thoughts that come to mind are Pressure plate to flywheel bolts, which would also explain why the builder can't figure out where they go, since bolting on the pressure plate usually isn't part of a rebuild. They're are six of those bolts and that's the right thread/length IIRC.

Mike

[Edward J.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

Paul , I agree with Mike They appear to the bolts that hold the pressure plate to flywheel.

[David B.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

I have things apart at the moment, so I just checked my baggie of pressure plate bolts. The dimensions look similar, but I've got grade 8s (which I assume are correct), not grade 5s.

Is it possible they're from the side motor mounts? (I have a C1, so don't know anything about those).

[Paul C.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

It is a 1971 LT-1, 4-speed.
Here's a picture of the engine out of the car.

[Michael L.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

Motor mount bolts are another def possibility.

[Michael L.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

I'm headed to my shop in a bit I will check my pressure plate bolts to see what they are.

[Patrick B.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

The pressure plate to flywheel bolts shoud be grade 8 and only partially threaded. That is what you have.

[Joe L.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

I have things apart at the moment, so I just checked my baggie of pressure plate bolts. The dimensions look similar, but I've got grade 8s (which I assume are correct), not grade 5s.

Is it possible they're from the side motor mounts? (I have a C1, so don't know anything about those).

David-------


Motor mount bolts are all thread. These bolts would not even work for that application since the un-threaded shank is too long. In other words, you'd never be able to tighten them against the motor mount. I'm pretty confident these are pressure plate-to-flywheel bolts. Some of these are grade 5 (3 lines).

[David B.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

...and that's why I shouldn't "assume". Thanks, Joe.

[Edward J.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

Paul check the head marks on both sets of bolts. this may give some in site on the bolts of that era.

[Paul C.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

The guy who pulled the engine didn't remove the clutch or flywheel and the motor mounts are still on the engine. Now I'm really at a loss for where they came from.

[Stephen L.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

Bellhousing to block???????????????????????

[Thomas J.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

I have two 71 with 4 speeds pulled bolt from each bell housing bolt is 1 1/4 long threaded all the way grade 8 sounds like what you have are bell housing bolts someone changed out

[Paul C.]

Re: Mystery Bolts from Engine that was Pulled_Can Someone ID??

The bell housing bolts are threaded the entire length and I have those in a bag. I'm stumped.