noonzor

iTrader: (1)

ive currently got a set of clevitte high performance "p" style main and rod bearings for a turbo motor im building. the engine shop says i should upgrade to a better bearing. should i? motor will push roughly 800hp on 15lbs of boost in a c10 pickup.

LS1-450

iTrader: (33)

Am not sure which are the "p" style. If I were building an 800 HP engine & the engine builder told me to upgrade bearings, it would be done.

Sales2@Texas-speed

iTrader: (5)

Those bearings are fine for that power level! You could buy their coated bearings, but honestly you do not need it and will not see any benefit so long as the machining is up to par and everything is assembled correctly.

*waiting for someone to come in and say the H bearings are better*

KCS

iTrader: (20)

What are the part numbers for the bearings you have?

Clevite has two different "P Series" bearings, one style is for light duty passenger cars and have a 663P or 2199P part number. The other is the high performance style which use a different part number completely, but the last time I looked they weren't offered for LSx engines.

If you have the passenger car bearings, I would switch to the H Series. Passenger car bearings are designed to compliment the loads seen on mostly stock engines, so they typically have a low eccentricity profile and a lower amount of bearing crush. The H Series, however, are designed to compliment engines with higher loads and would be very happy in an 800hp turbo motor. They typically have a high amount of crush and a medium eccentricity profile, both desirable characteristics in a performance engine.

JPH

iTrader: (2)

^^ I agree with Matt on this.

Sales2@Texas-speed

iTrader: (5)

I knew someone would come in recommending the H's! The H bearings for the LSx engine are made of the same material, same composition, use the same core number, etc. The difference is the the 2199H bearings have a larger chamfer for the aftermarket/fileted cranks and are made without flash plating for better seating. The 663HN bearings are also narrowed. There is no material advantage there, per Mahle/Clevite, only eccentricity and chamfer changes.

H's can also be substituted when the contact patterns are too narrow with the P bearings (due to slight changes in eccentricity). On the flip side of that, with a stock crank if your contact pattern is too wide, you can switch to an H bearing from the P to help correct that issue.

Mahle/Clevite has a free catalog that can be downloaded which has page after page after page of useful information on the topic for anyone who has a tough time getting to sleep at night!

KCS

iTrader: (20)

My recommendation has nothing to do with material advantage.

Read my post, eccentricity is the reason I suggested the H series. Not because of flash plating, material, or a chamfer. Eccentricity.

When you double the power of an engine or significantly increase the operating RPM range, you place more load on the main and connecting rod bores. The parting line on the connecting rods, for example, are notorious for pinching in an decreasing that clearance area which is detrimental to maintaining that hydrodynamic wedge keeping the journal from contacting the bearing. This is a common cause for spun rod bearings.

H series bearings have more clearance at the parting line that the P series passenger car bearings for this reason. The ACL Race bearings I put in my engine went from a clearance of .0020" to over .0050" as you measured closer to the parting line. P series typically have half that eccentricity.

Everything I just said is in the catalog as well.

LS1-450

iTrader: (33)

Like I said, if an experienced engine builder, who is taking responsibility for the engine build, wants different bearings, why question his request?