So Guys I have been posting lots of questions as of late doing this stroker build.

Anyway what bearing clearances am I shooting for or what do you guys recommend? What "Range" of clearance am I wanting to be in?

What Oil weight? I know lots of different opinions on this.

Daily Driven stroker with smaller to medium Cam. Let me know what you guys think cause im lost!

Other than than Stock GM clearances that is the only guide line I have.

 

A good general rule of thumb is .001" of bearing clearance per 1" of shaft diameter, plus another .0005" for higher power applications.

 

Thanks for the response KCS! Shaft diameter are you referring to diameter of the crank shaft? Or what exactly? Again sorry for the noob ???

Thanks

 

I got my mains in between .0027-.0030. It took me 3 sets ant 2 brands of bearings though. My rods are .0023-.0024. Iron block and a Melling 10296 with the regular spring ,ported by Tony. I'm gonna break in with 10×40 conventional and switch to a 15×40 after. I will adjust accordingly after that.

 

So why 3 sets? Was it because each set u tried had a different clearance?

I bought standard ms2218p mains now will these work or does it just depend on how it measures out?

Chris

 

Yes, diameter of the crankshaft journals. So about .0025" on the mains and about .0021" on the rods should be fine in a performance engine. For a big power adder application, I like to go a little looser. In an aluminum block, you can go tighter on the mains since the aluminum expands more than the iron block does.

 

I originally bought a set of standard King's b4 I got the block machined. Block was line bored/honed so when I got it back I no longer could use the standard size. Next I bought a set of +.001 more clearance King's. They gave me approx .0022- .0024. I wanted more so I grabbed a set of Federal Mogul 152m's +.001 clearance and they got me to the clearance I wanted.

Just goes to show ya that I guess different manufacturers tolerances vary from set to set.

Next build I'm gonna try the ACL's. I've heard very good things about them.

 

Understood! I will def have to check fit everything with the mains i have an go from there.

Any other suggestions on what weight oil to use? 20w-50 seem THICK Never ran anything that heavy. Always been either a 5w30 or 10w30

Chris

 

Hello Guys! Finally got around to measuring my mains an here are my results:

Standard Clevite: MS-2199P

M-1: .0015
M-2: .0018
M-3: .0015
M-4: .0015
M-5: .0018

Those seem tight to me? Do I need to change bearings or just run thinner oil? I have no idea whats the best route to go here. This motor is only going to be NA motor dont plan to add power adders but I want good safe clearances an i know those numbers are tighter than factory clearances.

Suggestions Please! I dont mind swapping to a different bearing if thats what it takes.

Thanks
Chris

 

Are you sure you have the right bearings? MS2218p is a Duramax Diesel bearing set. You might want to look for CB2199.

 

My bad sorry part # on bearings is: MS-2199P

 

You may want to try the CB2199H. It's the high performance set which might be looser but it's also available as CB2199HX for an extra .001" clearance.

 

Sounds like the .001" extra would be spot on no? Question if i did go with those an ended up with even say .0030" that would be fine correct?

 

Subscribed.

In the same boat with my forged 402 build with most of my clearances around .0018 and mine will be turbo. Already buttoned it up and planned to run 40W synthetic but having 2nd thoughts. These are with Clevite H bearings.

 

It would work but your oil pressure would be low with a stock volume pump. As you open up the clearances, it reduces the restriction for oil to flow. It's good for big power applications because more oil is flowing over the bearings to keep them cool but if it's too low, there won't be enough pressure to keep the lifters pumped up. That's when you need to go to a higher volume pump.

 

That's too tight for my comfort. I'm guessing a with a 402, you would be using an LS2 block so tighter main clearances would usually be ok, but I'd still want at least .0025" on the mains and close to .003" on the rods with a turbo or other power adder.

 

The car is going to be high compression NA motor no adders. Still think its to tight if I went with just the H series? Or should i go HX? Or maybe even different bearing all together? Kings?

 

Forgot to mention im going to run high vol. melling pump 10296.

 

I usually use Federal Mogul 152m. They're less expensive and seem to be looser than Clevite bearings. Summit has the FM bearings for $110 vs $140 for the Clevites.

I would want as close to .0025" on the mains and .0022" on the rods as I can get. It's better to be too loose than too tight.

 

Understood... I see its mostly an expensive guessing game trial an error it seems lol. Thanks for the suggestions and help guys. You guys are all awesome on this form helps a ton!

Chris