I have a new 4.250 crank not ground under size
for my 496 (454 BB) . this is what i came up with

TQ the bolts down to 95 foot pounds with oil
on threads, this is what the mains on the crank mic.out to
#1 2.748
#2 2.748
#3 2.748
#4 2.748
#5 2.7474
THEN I USED THE MIC. TO SET MY DAIL BORE MIC USEING 2.748 FOR THE FOUR
#1 .0038
#2 .0037
#3 .0038
#4 .0038
#5 .0035
AND USING 2.7474 TO CHECK #5 SEEING THAT IT MIC. SMALLER THAT THE REST
DOSE THIS SOUND LIKE THE CORRECT CLEARANCE

LET ME KNOW IF THING ARE OK OR WHAT SHOULD I CHANCE OR FIX????

yOUR MEASUREMENT ARE JUST A TAD ON THE TIGHT SIDE BUT NOT ENOUGH TO BE WORRIED ABOUT. HOWEVER, YOU MEASURED ENOGH CLEARANCE FOR A 10,000 RPM MOTOR, IS THAT WHAT YOUR BUILDING?

I'm shooting for a 7000 rpm street racing TQ monster , its A 5140 steel crank that is external balnced making a 396 sleeper look HEHEHE
what is the ideal bearing cleance for a 496 bb
on the street ????

Originally posted by Robert G:
I'm shooting for a 7000 rpm street racing TQ monster , its A 5140 steel crank that is external balnced making a 396 sleeper look HEHEHE
what is the ideal bearing cleance for a 496 bb
on the street ???? =
I prefer .0022-.0025 & feel .0020 to .003 is within a runable range.
You can run that much clearance but I would buy a set of .001 under bearings & close it up if I were doing it. That should put you closer to .0025.
If you don't do this a lot, I would suggest double-checking your readings with plastigage just to be sure,,, ;)

I'M KINDA STUCK WITH BREARINGS FOR NOW SEEING THAT I JUST GOT THEM H CLEVITE , so will this work or is this going to be future rebuild???
ONCE AGAIN WHAT IS THE CORRECT CLEARANECE TO RUN??? THE LOW AND THE HIGH???

I WILL ALSO CHECK WITH PLASTIC GAGE ASAP

OK RAT MAKER STATES I'M ON THE TIGHT SIDE, BUT OK
AND WOLFPLACE IS SAYING TO BUY UNDERSIZE BEARING
TO GET CLOSER TO .002-.0025???????
NOW I'M LOST

Robert,
Please turn your caps off it implies you are yelling ;)
I read what Rat Maker posted & am not sure what the tight part was but I doubt it was the bearing clearance as he finished the post telling you you had a lot of clearance.

Yes the clearances will work but I would not run them unless you are planning on running 50 wgt oil,,,
Buy some bearings & do it right now,, it is a hell of a lot cheaper than fixing it later. :D

Robert:
Sorry I was trying to say your main journals are on the min side with the range ideally 2.7481 to 2.7490 for 1-4 & 2.7476 to 2.7486 on 5. It's not a problem by any means. However, I'm curious about how you came to get such clearance, assuming your meas are correct. What are the numbers on the bearings your using which you indicate are Clevite and are they new out of the box? PlastiGage would give a little more indcation if your meas are close but it's never as dependable as the mic in skilled hands and since you haven't indicated how versed you are at this I will assume your a litle unsure?

If your clearances are as you measured you would do well to follow Mike's advice! At a minimum take it to someone in your community who can determine if the motor had previously been line bored and your undersize may be related?

I work as an inspector in a cnc shop i do this for a living , so my numbers are correct
I will look to see if i can return the bearings if not then i will sell them and buy the correct ones -.oo1 I think

thanks