Clevite vs. Federal Mogul bearings

[72Challenger]

Anyone who has used both have opinions on which are better? I've always used the Clevite 77's, but I'm getting ready to put the 340 back together and noticed that the Sealed Power bearings are a little more expensive. I know that doesn't always mean better, but was hoping some of you professional engine builders may be able to compare the two, from personal experience.

[plydus340]

The guy building my motor was really down on fed. mo. . Said " I wont use them , there made of alum. or something and they wear out too fast" Clevite all the way!

[6 packin]

The tri metal bearing are good. Steel back, copper 2nd layer and babbit/lead coating offers good imbedability. I have used the mogul bearings also. I like the clevite 77 tri metals. But use whats avaliable during assembly.

[72Challenger]

I know the Clevites are good, I've always used them before without a problem. I just have to buy some now, and saw that the FMs were more expensive. Sometimes that means better, sometimes not. Guess I'll stick to what I know in this case. I don't mind trying new things sometimes, but not when it comes to the bottom end of a motor planned for 500+ HP!

[goose69]

Ask the machinist what kind of clearences he set the motor up to have. The clevite brgs. are ever so slightly thinner so it gives you so many more thousanths more clearence. That is what I'm running in the new motor I'm setting up. It'll be pushing 650hp (hopefully, but the dyno will tell) and I needed the extra oil clearence.

[sanborn]

They say "a little knowledge is a dangerous thing", so here goes.

Federal Mogul makes two different types of main bearings(1/2 groove) for a small block 340, a standard replacement bearing and a performance bearing. The performance bearing is a tri-metal bearing. I don't know what the replacement bearing is but it too could be tri-metal with the metals being steel, aluminum and babbit. A lot of standard replacement bearings are. The performance bearing is steel, copper and babbit.

I know of five(5) different Clevite 77, half groove main bearings for a small block Mopar. They are identified by the letter designation after the number. All are tri-metal bearings. They are:
"P"- The most common bearing available. It has a steel backing, copper center material and a moderate thick babbit coating. It is the least expensive of all 77s. Good for street and performance use.
"M"- Steel backing, a thinner copper and a very thick coating of babbit. It is recommended for drag racing only and not recommended for street use.
"H"- A thick steel backing, thinner copper and a thin coating of babbit. Used for serious oval track racing on a very hard crank(billet). Not recommended for street use or stock type cranks.
"V"- Made like the "H" bearing, thinner in width (.030") and the oiling groove is wider. Used as the base bearing by a lot of Nascar engine builders.
"XS"- Made like the "H" bearing but the oiling slots are 3/16" wide and the slots are 90 degrees of the bearing circumference. I'm not even sure if this bearing is available to the public. I have only seen it in some Nascar engine shops.

I have not made a direct comparison between all the 77s in terms of clearance-but I have compared them all to the "P" bearing at one time or another. And, it seems they are all about the same in terms of bearing clearance.

I have made a direct comparison between the 77 "P" bearing and the FM performance this year. It was for my son's GMC(cough) street engine. The 77 "P" bearing was .0004" looser than the FM performance main bearing-direct dial bore comparison-same block within 20 minutes of each other. The engine he was building had too much main clearance(.003")-we were searching for an alternative to tighten it up. The FM got us part of the way but not enough, we ended up using the 77s and having them moly coated. That got us down to .0022", about right.

I forgot to add, the "H,V,M and XS" bearings are only available in .001+, .001- and standard sizes. The other("P") is available in common undersizes.

Hope this helps.

[72Challenger]

Thanks for the comprehensive answer sanborn. Your posts are always enlightening. Since my crank is .010 under, it's either the "P" 77s or the FM performance. It would seem you don't feel that they are inferior in any way to the Clevites, since you were prepared to use them yourself. However, other than the clearance issue, is one superior to the other? I'm not trying to spend more money than I have to, but I want the best I can afford. But I certainly don't want to spend more if I get nothing extra for the money.

[dwc43]

I've used both with good results. Have some FM performance in the last race engine we built. Held up good.

[sanborn]

For a street or mild performance race engine, I think either the Federal Mogul or Clevite 77 would work equally well. I also am hearing good things about a King bearing.

But, for our race engines(high HP/RPM,etc.) I will only use Clevite 77 in one of its various forms.

One of our engines has the "P" bearing. It is .010"/.010" under. Don't have a choice-but it is an all iron, limited engine-about 550HP.

One of our engines uses the "V" bearing. It's new to Clevite and I just wanted to see how well it worked. It's in our 358", all aluminum engine. We have used "H" bearings in the past.

One of our engines uses the "H" bearing. It is in our 408" all aluminum engine and I need all the bearing surface area I can get. We have enough problem with block/crank flex as it is.

The "XS" bearing is slick and already machined for saddle oiling but the price was about $250/set three years ago. No thank you, I will buy a set of "H" and do the machine work myself. We usually must have them moly coated anyway-another $80.