Rod and Main Bearings

[Ernie GN]

I have new set up I’m buying bearings for
I have attached pictures of the bearings I’d like to use.
The rod bearings has a note that they are for a steel crank.
I have 4340 forged Crank and rods.
Can someone please look over and let me know that the type of Bearings will work?

Thank you in advance

 

[750H.P.V6]

Those are what I use. If the crank you're using is wide journal you should be fine. If it's a narrow journal crank you'll want to double check the bearing doesn't interfere with the rod radius. If it does you can chamfer the edge of the rod bearing.

Neal

 

[Ernie GN]

Thank you for the help
I ordered them just now

My crank is a narrow bearing

Seems like there isn’t to many good options for the rod bearings for Turbo Buick
Except for these

 

[Ernie GN]

Those are what I use. If the crank you're using is wide journal you should be fine. If it's a narrow journal crank you'll want to double check the bearing doesn't interfere with the rod radius. If it does you can chamfer the edge of the rod bearing.

Neal

Do you use the same main bearings as well?

 

[Ernie GN]

 

[750H.P.V6]

Yes I use both of the bearings you show above. I used to run Clevite bearings but they don't seem to make a performance main bearing for our application any longer. The rod bearings were still available last I checked. The Speed Pro / Sealed power bearings work well and I can usually get them in short order from Summit Racing.

Neal

 

[Ernie GN]

Nice

I spent probably 4 to 5 hours today calling places in searching the Internet for performance bearings for these turbo Buick’s.

Not too many options out there

 

[pacecarta]

calico (acl) cb61228 for the rods on steel crank

 

[earlbrown]

Use rod bearings for the newer 3800 series Buicks. They're not skinnier than the rod like the 3.8 bearings are.

 

[turbodave231]

The 107M Mains are also available in sets of -.001". These are extremely useful. They can be used with the standard main bearings to tighten up clearances.

Earl, The 3800 bearing are Aluminum bi-metal or babbit based tri-metal? I never used these before. I stick with the Clevite 1228P and 1398H's (and V's if I can get them)

 

[Steve V]

There are 3 types of bearings available(sizes not MFG), standard, .001(used to tighten up), and Hx these are used to loosen things up. I have seen the X bearings available in King and Mahle brands. I use them often to get .0015-.002 on the main/rods. I am not a fan of tri-metal bearings on the mains, I have used an upper on the piston side of the rod and a P bearing on the cap. I am with Earl on the wider bearings and of course sometimes they need to be chamfered.

 

[earlbrown]

Earl, The 3800 bearing are Aluminum bi-metal or babbit based tri-metal? I never used these before. I stick with the Clevite 1228P and 1398H's (and V's if I can get them)

Depends on which one's you get. I always use the FM A-series aluminum on my builds for a 95 Park Ave. I'm really amazed that part number hasn't been superseded to the older 3.8's and 4.1's. They are literally the 'right' size for our stock rods (and journals).


If you were to lay out a two dot rod along with a 3.8 bearing and a 3800 bearings, a competent engine builder (with no Buick experience) would say the 3800 is the correct part.


I did the math years ago with load area and it was pretty significant. I also did the math with a stock length rod, .010" journal and .001"/.0015"/.002" clearance concerning lateral little end 'sway'.... and it was VERY significant. Since we run an offset rod relative to the centerline, I'll take all the extra stability and play elimination I can take.

 

[tsm3089]

sometimes you find some old stuff.

 

[ShawnR]

Use rod bearings for the newer 3800 series Buicks. They're not skinnier than the rod like the 3.8 bearings are.

Can you narrow down what years exactly to look for? Maybe even a part # if you would have that handy.

 

[dank GN]

Can you narrow down what years exactly to look for? Maybe even a part # if you would have that handy.

It’s posted in the tread read the response before yours or better yet use the search function I know for a fact that the part number has been posted countless times

 

[dank GN]

Can you narrow down what years exactly to look for? Maybe even a part # if you would have that handy.

It’s posted in the tread read the response before yours or better yet use the search function I know for a fact that the part number has been posted countless times

 

[ShawnR]

It’s posted in the tread read the response before yours or better yet use the search function I know for a fact that the part number has been posted countless times

Specifically, I was wondering about what years of 3800 rod bearings Earl recommended for the 3.8 because they were the full width of the rod end. The info / part numbers listed above was for 3.8.

The search phrase "3800 rod bearings" yields no useful information.

 

[dank GN]

Specifically, I was wondering about what years of 3800 rod bearings Earl recommended for the 3.8 because they were the full width of the rod end. The info / part numbers listed above was for 3.8.

The search phrase "3800 rod bearings" yields no useful information.

Depends on which one's you get. I always use the FM A-series aluminum on my builds for a 95 Park Ave. I'm really amazed that part number hasn't been superseded to the older 3.8's and 4.1's. They are literally the 'right' size for our stock rods (and journals).


If you were to lay out a two dot rod along with a 3.8 bearing and a 3800 bearings, a competent engine builder (with no Buick experience) would say the 3800 is the correct part.


I did the math years ago with load area and it was pretty significant. I also did the math with a stock length rod, .010" journal and .001"/.0015"/.002" clearance concerning lateral little end 'sway'.... and it was VERY significant. Since we run an offset rod relative to the centerline, I'll take all the extra stability and play elimination I can take.

 

[dank GN]

https://www.turbobuick.com/threads/widest-rod-bearing-for-stock-crank.400875/#post-3272657

 

[ShawnR]

https://www.turbobuick.com/threads/widest-rod-bearing-for-stock-crank.400875/#post-3272657

Bingo. That is exactly what I was hoping for. Thank you!

The bearing numbers are 6760A for sealed power, CB1443P or A for clevite, CR6664AM for king, 6B1443P or A for ACL. The acl P will be an extremely hard to find. If using a steel crankshaft, use sealed power 6-7120CH.