440 source bears off

Received my 512 stroker kit. Found out the main bearings are .004 clearance, not good in my book. Call 440 source. You think they would check them, they told me now I have to get a hold clevite and deal with them.

So is the main clearance off or are the bearing stamped differently than the box ?

.004 on top side but will work fine. I would much rather have .004 than .002.

Simple, measure the CRANK. If the crank is within spec, this is not 440 Sources issue. And HOW would they check clearance......they don't have your block.

NOT that I am in any way shape or form, a 440 Source supporter, but how about finding out WHAT the problem is before casting aspersions.

I also agree with above.....004 is NOT too much

check the main bores with a dial bore gauge to make sure they're per spec and especially not out of round. the vertical measurement on the last two blocks i checked was awful, the horizontal was in spec; basically egg shaped bores. this will screw up bearing clearance.

Run it

Exactly.............seen WAY more on record setting Pettis motors.

I'm also curious as to how you determined what the clearance is. Obviously parts have to be measured to figure that out. I wouldn't be afraid of .004. Is that what the 440 source said the crank is sized for? Bearings packaged wrong? No other explanation from them other than "Call Clevite"?

I'll give ya $100. for the kit ... CASH. I'll even come and pick it up.

I agree as well. Bearing clearance is dictated by bearing bore housing dimension, bearing thickness and journal diameter.
Doug

Identify the problem accurately first before trying to correct it Take the block (and crank)to a good machine shop if you don't have access to a good dial bore gauge and outside micrometer
I agree with all the other posts about having .004 crank to bearing clearances dry is way better than having .0027 or less dry same thing on the rod clarnaces, a little looser will last a lot longer than a tiny bit to tight will

Took the block and rotating assembly to a machine shop. Block was line bored. They found the same thing, I would like to have.027 clearance than .004.

There is an old saying, kinda applies to your situation, "If your clearances are just a little loose you'll know it, if the are a little tight everyone will know it" go with what you've got, IMHO

Loose is fast!!!

I for one am GLAD that Source cranks seem to be on the low side--You should be happy--FWIW I am just about done with Clevite--King is the Daddy--and the new "black " bearing they have come out with is the best yet!

another thing to try is measuring the thickness of the bearing shells and see if it matches clevite's spec. also, the bearing bores must be measured vertical and horizontal.

I like the aluminum based bearings they had better, the "new black" bearings seem to old school babbit again...

With that said I still love King bearings and will continue to use them in all my builds.

Buying a new set of bearings isn't the biggest problem in the world. I just finished a new short block and we didn't use either the rod bearings or the main bearings that came in the stroker kit. Experienced engine builders typically keep several sets of bearings on hand and they'll split sets to get the correct clearance. It is more of a craft than an assembly line.

WHY?.........that's too tight for anything other than a stock rebuild and I personally wouldn't even do one of those that tight

Is that the standard crank or the lightened crank they now offer?

i ask: why .004" on the mains? i don't agree with .004" on the mains unless it's some kind of extreme racer.

I don't know if I'd shoot for.004" but I'd take it over.0027" for sure.

What did you have for taper? I've run about 6 Source cranks of various strokes - not a one had zero taper. Clearances were acceptible for what the engines were doing but saying everything was perfect would be way off reality.

I didn't say that I would shoot for .004, what I said was that .0027 was too tight.........at least in my opinion anyway. I never put anything up tighter than .003, even a stock rebuild

.004 is a BEAUTIFUL thing. It will live. It will survive momentary starvation. I'm running .030 street bearings at .004 in my 605. 3 years of hard runs (7200) and they still look great. Tight is good some places, not bearing clearances.

RIP

I agree with Monte and sc4400 on the clearances, my small block is at .003 all the way thru.

What was the end result after the trip to the machine shop? If they line bored it, they may have had room to tighten up the main bores a bit, reducing the total clearance on any set of bearings you try. There is a spec for loose to tight, and tight (on the bearing bores, not clearance!) is better for better holding power so the bearings don't spin.
Spec for the main saddle bores is 2.9425 to 2.9430. If your block was at the high side, you can reduce bearing clearance by .0005 by tightening it up to the low side when line boring.
If the block required a fair amount of work to get to spec, the crank to cam distance can change also, requiring a shorter timing chain set. They come in .005 under, and .010 undersizes.