Crank end play

Is .003 to tight for a drag only motor.

Ace

Yes.

.004-.008. lightly sand the sidemof the thrust and open it up.

.004 to .008 is desired.

So sanding the thrust side of the bearings is acceptable ? And what do you recommend I use for the operation?

Ace

personally I would sand the non thrust side only.

A nice piece of 1/4" plate glass works ok for a flat surface if you dont have acces to like a granite test block or some such.

Lay a piece of fine sand paper or emery cloth on the flat surface face up.

Place the bearing shell face down on the paper and gently move it in a figure 8 pattern while applying gentle pressure.

a Shot of WD 40 may help keep the paper from plugging up during this process.

Check the clearance often.

Kinda like filing rings... rub a bit, test, rub some more test again.

  

dkp

Ive had to do this on the last couple builds ^^^^^^ works fine

I prefer not to be less than .005". It helps to figure out if the block or cap 1/2 is the bigger issue.

Lem Evans wrote:I prefer not to be less than .005". It helps to figure out if the block or cap 1/2 is the bigger issue.

It an Ohio crank and I'm betting its tight. I have not contacted my crank guy as he may have rushed through this and missed it. He was leaving for Xmas vacation. I have not even paid him yet. Also Lem it's a stock block using the Kingb5242hp bearing I got from you a while back


Ace

The brand of bearing does not seem to matter. Most of the Scat cranks seem to be about .003" too.

Lem Evans wrote:The brand of bearing does not seem to matter. Most of the Scat cranks seem to be about .003" too.

So I'll massages the thrust side of the Bearings to get .005.an I'm getting old lifting this thing in and out. Next crank will be a super lite deal

Ace

You did "seat"the cap didn't you? If not you may not need to sand the bearing.

Good tips all around. Boss posted a good procedure. I use wet/dry auto body paper with solvent or WD for lube.
600 grit helps make for a tedious..controlled removal.
Cool's tip about seating the bearing is another good point. That can pick up at least a thou in most cases.
That is...with the bearings installed and the cap tightened...then backed off to snug...
Use a big dead blow mallet and give the center of the rear crank flange a good whack or 2. You can also carefully use a chunk of brass to protect the crank and a regular hammer.
Just lines up the shells...
I like .007" end play.
.005" will work.
Keith

Wheelie58 wrote:Good tips all around. Boss posted a good procedure. I use wet/dry auto body paper with solvent or WD for lube.
600 grit helps make for a tedious..controlled removal.
Cool's tip about seating the bearing is another good point. That can pick up at least a thou in most cases.
That is...with the bearings installed and the cap tightened...then backed off to snug...
Use a big dead blow mallet and give the center of the rear crank flange a good whack or 2. You can also carefully use a chunk of brass to protect the crank and a regular hammer.
Just lines up the shells...
I like .007" end play.
.005" will work.
Keith

OK. Pretty much did it all. and we ended up at .006. so its all good. i will now check deck height using 4 piston in each corner with out the rings measuring at the center or just above the pin. and then file fit the rings per hole and mount them on the pistons. not sure ho much i'll get done here as there some kind of football game on today day thats getting a lot attention .  

Ace

Seating the cap is a good idea but, with the doweled caps like an A460 block, there is little to get.....unlike the typical production blocks.

"I like .007" end play."

That's a good place to be with the really big engines.

I've owned 2 Scat Billet cranks and both were tight on the thrust by about .003-.004. The block was a DIVE with the splayed Engine Systems 4 bolt main caps on the center 3. Only throwing that out there for the fact that the billet seemed no better than the cast in that respect. Personally I would rather have it on the tight side so you can customize the tolerance to your needs............ hard to add to it when you need it ( if it was on the large side to begin with )