Engine Assembly

OK I've had all the parts sitting here for about 3 months to assemble my new short block. I've been busy building new kitchen cabinets and helping my 9 year old win the pinwood derby (see attached pic).

Anyhow I installed the crank and just checked three of the main jornals with plastigage. I came up with a reading of .003 on all three journals. I have two chiltons manuals that say it should be .0008 to .0015. The back of the bearings say .25mm and the tag on the crank said that it was turned 10/10. Am I missing something or could the crank be turned 20?

Try the pic again http://natomessageboard.com/uploads/0000...winner.jpg

Did you measure the crank to see if it was actually turned 10 under?

The nominal size was 2.399 to 2.3982"
.0008 to .0015. are the correct clearances

No, I don't have a mic.
The machine shop I use is just a block & 1/2 away but of course he's closed for the weekend. I even had him provide the bearings. He's usually pretty good, but my block and crank sat there for 3 months until I gave up on getting TRW pistons.

Originally posted by Dan Hahn:
Try the pic again http://natomessageboard.com/uploads/0000...winner.jpg

That looks awesome.

Took the crank out and up to the machine shop. I told him that my two Chilton's manuals said the clearance should be .0008 to .0015 and he said they lie. Then he checked on his computer and said well I'll be darned it does say that. Then he said that industry standards on bearing clearances are .002 to .003.
He also said that he wanted to mic. it again when it was warm. He said that he keeps his shop between 74 and 78 degrees 24/7 at a monthly cost of over $2000 for heating alone just for that reason. My shop was 65 degrees for 24 hours when I checked it. He said that's not warm enough to be accurate. This is probably the first engine I have built in cold weather so who knows.
He said that if it were his engine he would go with it but also gave me the option of turning the crank to a tight 20/20.
Twenty years ago when we raced the 2300 we had an authorized Ford re-builder building our short blocks to our specs. According to one of the guys that was on our crew who is still involved in oval track racing, he says we had them give us .001 to .002 on the mains and rods but I honestly can't remember if we ever checked them. We also replaced our short blocks every 6 to 8 races mainly because they were free and we could. He said that .003 might be OK for a qualifying engine but not for a turbo street motor.

So whatdouall think?

Thanks, Cracker137

Dan, the clearances I quoted above are from Ford's Service Manual.