Ya'll are probably going to get tired of hearing from me but the info is great that yall post. started playing with the scat crank in my stroker motor. couple odd things even though i am only slightly into this--I set the crank in on all 5 bearings just to measure endply as it sat for what that is worth. It was .035--kinda tight--got to messing around and noticed the crank was rocking with thrust bearing the high point--the thrust was really difficult to push onto the saddle--took the crank out--swapped the thrust for the other half--went in saddle much easier and the rocking was gone. endplay for what it is worth was .040--is this a possible problem with thrust bearing?--by the way my last 2nd compression ring i measured befor file fitting was ABOUT 1/4 INCH GAP!!--kinda disapointed in that i guess scat will ship me another but makes you wonder about QC-- I also went to the trouble to tap the freeze plug holes--lot of trouble but the screw ins look really heavy duty/performance like--thanks again
messed up my numbers---it was .004---left out a zero---any way the main concern was the rocking of the crank with the first thrust half i tried and wondered if something wrong with the bearing??-of course the ring was wrong size that was just a comment toward quality control at SCAT--maybe it is a common occurrence with all ring manufacturers and i guess it would not be SCATS fault since the rings were in original packaging from MAHLE---I know that mains need to be torqued to measure endplay I was just wondering if anything can be learned from endplay with the crank just sitting on the bottom half of the bearings
What block are you using?
What bearings are you using?
Usually you should see thrust numbers between .008 and .012. I like them on the tight side, but you don't usually get to "choose". Be sure to lever that crank hard back and then hard forward before tightening the thrust cap.
Sometimes the width of the block's thrust can be on the wide side and deform the bearing. More often an issue with aftermarket blocks....some need the side chamfer enlarged by about a mile.
The thrust cannot be measured until all the caps are torqued up - the block deforms a bunch. I've had ones that scared me because the crank would not spin - until torqued and then it spun smooth as glass.
Anybody can have a bad day in packing rings. Mahle normally makes nice enough parts. Notice that rings have no part numbers on them - easy to miss a goof in packaging.
Check your rod side clearance carefully - I'll tell you how to fix that problem if/when it arises....
needs to match the block at the thrust surface of the brg. ...some blocks (64/earlier) have a different dia. undercut for the brg. to fit over...will result in tight brg.
This block is a C1 part number (a 352 bored out to .030 390 )--if thrust bearing not correct for block are the correct ones available-or modify bearing? or machine block?
and your solution. You have an early block which takes a different bearing part number as John pointed out. The F-M race bearings I use in my kits have a reduced thrust diameter which usually - not always - fits both blocks. The passenger bearings will not interchange and you are going to need F-M p/n 4020M or the Clevite equivalent.
