According to Mahle-Aftermarket's documentation, 3/4 groove bearings promote less HP loss and don't suffer any lubrication loss vs. Full Groove bearings.

Is there any reason to not use 3/4 groove bearings in a BB Mopar stroker engine? Or any better reason(s) to use Full Groove instead of the 3/4-groove?

I have a pretty good reason for not using 3/4 groove in my BB.

400 Mains.

That being said, the regular ol 876P full groove bearings I am replacing in my engine were put in it in 2018, and I could reused the rod bearings if I wanted to at 800+ hp.

And they have a LOT of passes on them. Like 200 a year except for covid year when I only put 110 on it.

Man, that's awesome! Glad they held up that well for you!

Yeah, guess I should have said RB based stroker...

Do you want oil pressure to your rods full time or not?
I do , I use the ruck narrow full groove main bearings, not the wide full groove race bearings

Oil does two things in our motors, lubricate and cool, I like cool cranks

Are those the same as the MS-1277HG Clevite 77's?

I can't answer that sorry. I use to use the Seal Power part number M4500 for the RB motors and their M4400 for the B motors, I think they discontinued the M 4400 several years back
I prefer to build the 400 blocks over the 440 blocks due to the thicker main webbing

Ok, I get ya. I think they are the same bearing. I have a '78 440 and I think it is similar to the 400's in that respect.

I use 3/4 groove if I can find them. Sometimes it is really hard to find bearings these days so you just live with what you can get. In the old days when parts were available we used 3/4 groove on everything.

I like the Speed Pro 119M 3/4-groove main (although they're really more like a 5/8 with a wide groove if you look closely). That said, I wouldn't think twice about running a traditional full-groove, which I have in the past. I know Cab is a big proponent of the narrow-type full-groove and I'd consider those if I couldn't get my preferred 119Ms.

I was just commenting for the sake of the full groove 3/4 groove debate.

I would probably run a 3/4 groove if it was an option but it isn't.

And I never had any problems I could link to full.

I've run Clevite 3/4 groove in my 4.5 stroke motor to 7200. 11 years 1000 passes. They've been fine

Here is the info from Clevite with the attached Graphs

Iget it, but what about the the effects on the rod bearing.

I know that the 1/2 grove is best for the main wedge/film but I more concerned about the rod.

Yep, that's the info I was referring to. Good research on their part.

That is the way I am going. The 3/4 groove set wound up fitting much better across all of the mains than the full groove set did.

Thanks for all the replies, all!

So what are people opinions of 3/4 groove Speed pro 119M vs. Clevite MS-2233HG ?

Also, Has anyone ever measured bearing eccentricity ? I'm dial boring my engine bearings now to calculate clearance and don't know what to expect.

AG.

Bearings can be hard to find these days so you should feel lucky that you have a couple of sets to pick from.

If both of them fit (meaning no interference with the radius or the block) I would run the ones that gave me closest to the clearance I wanted.

I like the 119m .....they are typically cheaper.