Shoptalkforums.com

Every 2" journal crank I've ever seen has had the correct journal width and chamfer for an out-of-the-box 610P to fit fine. Obviously there are some out there for which even the 610 is too wide, if you have one of those you'll either have to modify the crank or find a different bearing, quite possibly you'll need to carve the edges to clear the fillet radius. P (as in Performance, NOT as in Passenger) are the better bearings for extreme duty - the H is a good bearing too but I wouldn't say that it's "much better", especially for high-RPM duty. If you could find an "H" for a Buick V6 it'd probably have ample fillet radius clearance for any crank, but the 745H is too wide for any VW application without major modification. What's the 1238P supposed to be for, Pete? I've never heard of that one before, sounds like it's worth looking into.

H
( http://www.flatlanderracing.com/clevmrbearings.html ):
Clevite/77 Engine Bearings -- H-Series Race
These bearings were developed primarily for use in NASCAR type racing but are suitable for all types of competition engines. H bearings have a medium level eccentricity. They feature a high crush capacity. Enlarged chambers for greater crankshaft fillet clearance. These bearings are made w/o flash plating for better seating. Use H bearings w/aftermarket performance steel crankshafts that have oversize fillets & where engines run in medium to high rpm range. If you buy a new crank with .125 radii these bearings are a must for rod clearances.

P
( http://www.flatlanderracing.com/clevmrbearings.html ):
Clevite/77 Engine Bearings - Performance
The P-Series bearings is Clevite's performance series. Since their development in 1929 these bearings have set the standards that other bearings copy. These bearings are designed to provide winning results, and are used in INDY, NASCAR, ARSA, NHRA and IHRA. Our recommendation is NEVER skimp on bearings.
( http://engineparts.com/motorhead/techst ... selec.html ):
These are not to be confused with the standard passenger car and light truck parts for the same applications which also have a "P" suffix letter. These high performance parts have unique core part numbers different from the standard parts for the same application.
The Clevite 77® marking alone does not necessarily mean the bearing is optimum for high performance. We make Clevite 77® Engine Bearings for passenger cars too.

The 745 H is not that difficult to cut to size and re-champfer. For those that can't do this type of work, there's always the possiblity of ordering them direct from Pauter Machine already machined and with the correct champfer added. This is what Pauter uses in their own Big block Flat-4 aftermarket engines.

The H series bearing offers 3-4 times the life of the 610P (passenger) bearing especially in applications with lots of compression and the use of a two step for launching the car.

After switching to the "H" series I would never go back to the 610P. There is nothing wrong with running the "P" Series bearing, but they just aren't as tough. Street and "milder drag" applications they are fine. Lot's of comp (14 or higher), boost, etc.. switch to the 745 H, you won't regret it.

One thing else to remember with any bearing is that the harder the surface area is the less wear will appear. Note of caution to anyone deciding to run a 745 H series bearing, always check the bearing width before running and then again upon rod bearing inspection after running, as they will get wider and this in turn will increase the ID of the bearing. A 610 P will do this as well, but wear on the bearing face is very noticable at this point.

Marc wrote: What's the 1238P supposed to be for, Pete? I've never heard of that one before, sounds like it's worth looking into.

i don't know what the 1238's cross reference to.

the first set of bearing i bought had a black finish to them. they were said to be "flame hardened". are those the H coded bearings?

i'm thinking of getting a set from pauter to see what/supposed to look like.

i will try to see if i can find my old bearings and take a few pics. i know i have some 1238's around, maybe the 610's, and the blackened set.

later,
pete

Got a set for my 2332cc W/11.5 to 1 (Static) C/Ratio. Still driving that engine! Couldn't tell you what brand now but, at the time, 2003, bought them from Bernie Bergman in Escondido with a repaired 84 stroke full circle "Lite" Crank. Believe still have box for bearings, No adjustment was necessary to bearings though, anybody ever try Silverline Bearings??
JL has the Empi, Clevite/ Mahle bearings Like 45 Bucks, going to see if any Reviews online. If someone has bought a new set recently and had Good wear and fitting from this brand or better brand, I did look up the 635p or 685p I believe, said they were for 2.1" rods in the information, at AA Performance, they have the same Clevite/Mahle for under 40.00. Appreciate it Guys.