Main Engine Bearing Sizes

[bonhamsurf]

Hi fellow Primers,

I have a 1991 NSX and am having to replace the main engine bearings in my engine. I am running a Brian Crower 3.5L stroker kit and recently spun a bearing.
We had to have some slightly oversized custom pistons made, replace the crank shaft and also need new engine bearings.

I know that the main bearings come in different colors, and each color is a different size.

But I cannot find anything anywhere that tells me what size each color is. I need to find out exact size each color bearing is.
Does anyone have this information please?

Thank you!

 

[Mac Attack]

Sorry I can't help you, but I'm surprised you use OEM aluminum bearings on the stroker crank. I would talk with the popular bearing manufacturers about making better ones for your application. If you're at 800 WHP you need something that can support a higher load.

Sorry I don't have measurements for the OEM main bearings. I do have measurements for the OEM rod bearings because during my motor rebuild I measured a bunch and they were shockingly inconsistent (there are two suppliers and they both seem to have had quality issues. I have a thread somewhere here on this). I have a small fortune in OEM rod bearings I will never use.

Just to be clear, did you spin a rod bearing or a main bearing?

 

[bonhamsurf]

Sorry I can't help you, but I'm surprised you use OEM aluminum bearings on the stroker crank. I would talk with the popular bearing manufacturers about making better ones for your application. If you're at 800 WHP you need something that can support a higher load.

Sorry I don't have measurements for the OEM main bearings. I do have measurements for the OEM rod bearings because during my motor rebuild I measured a bunch and they were shockingly inconsistent (there are two suppliers and they both seem to have had quality issues. I have a thread somewhere here on this). I have a small fortune in OEM rod bearings I will never use.

Just to be clear, did you spin a rod bearing or a main bearing?

I wish I could find an aftermarket bearing manufacturer. I have been searching for over 6 months for one. I would love to upgrade the bearings. I am speaking about the main bearings. I lifted a head which then spun a bearing.
This thread is about the MAIN engine bearings. I'm actually replacing the connecting rod bearings too, but they are from Brian Crower.

I actually have another thread specifically looking for other options for main engine bearings at http://www.nsxprime.com/forum/newreply.php?do=newreply&p=1982387

Here's what I just posted in that thread

"I have contacted King Bearings and they do not do NSX bearings. I also tried another bearing manufacturer, no luck.

I spoke with Science of Speed and they told me they are not aware of anyone who makes aftermarket bearings for the NSX. They told me that they are comfortable using the OEM bearings up to 850hp AT THE CRANK. I'm just a little over 850hp at the crank, but I am going to detune the car to lesser power for more reliability.

Does anyone have any other suggestions for an aftermarket bearing manufacturer?"

 

[Stephen@NCAutoUSA]

I wish I could find an aftermarket bearing manufacturer. I have been searching for over 6 months for one. I would love to upgrade the bearings. I am speaking about the main bearings. I lifted a head which then spun a bearing.
This thread is about the MAIN engine bearings. I'm actually replacing the connecting rod bearings too, but they are from Brian Crower.

I actually have another thread specifically looking for other options for main engine bearings at http://www.nsxprime.com/forum/newreply.php?do=newreply&p=1982387

Here's what I just posted in that thread

"I have contacted King Bearings and they do not do NSX bearings. I also tried another bearing manufacturer, no luck.

I spoke with Science of Speed and they told me they are not aware of anyone who makes aftermarket bearings for the NSX. They told me that they are comfortable using the OEM bearings up to 850hp AT THE CRANK. I'm just a little over 850hp at the crank, but I am going to detune the car to lesser power for more reliability.

Does anyone have any other suggestions for an aftermarket bearing manufacturer?"

I could be wrong but I thought one of the advantages of going with a Brian crower crank is that you can spec different or larger bearings. Or if something happens you can resize the bearings. I’m not a technical person when it comes to engines so I can probably be completely wrong.

I’m sure someone should be able to chime in. There’s a few running setups like yours I believe throughout the years.

I also see you have some lovefab items. Maybe reach out to Cody. I see he’s back up selling limited items.

 

[Mac Attack]

Ah, gotcha.

I posted in your other thread that Shad at DA has apparently used Chevy bearings as mains with stroker cranks. I don't have any experience with those, but I do know that if I wiped a main bearing I would be trying to find out why before rebuilding. Do you know the cause? Assembly error, foreign material, overloaded, overtemperature, insufficient oil supply?

Also, I do know that one of the major bearing manufacturers made me a custom set of rod bearings. It's been about seven years, but I'm pretty sure it was King. Our engines are very similar to the Honda B-series, so they started with their B-series designs.

 

[bonhamsurf]

I could be wrong but I thought one of the advantages of going with a Brian crower crank is that you can spec different or larger bearings. Or if something happens you can resize the bearings. I’m not a technical person when it comes to engines so I can probably be completely wrong.

I’m sure someone should be able to chime in. There’s a few running setups like yours I believe throughout the years.

I also see you have some lovefab items. Maybe reach out to Cody. I see he’s back up selling limited items.

Cody is a good idea, if he'll answer his damn phone!
The Brian Crower kit actually comes with connecting rod bearings, so those are after market. It's the main bearings I can't find anyone to make.
Do you know who else was running my kind of power or similar setup?
Thanks

 

[bonhamsurf]

Ah, gotcha.

I posted in your other thread that Shad at DA has apparently used Chevy bearings as mains with stroker cranks. I don't have any experience with those, but I do know that if I wiped a main bearing I would be trying to find out why before rebuilding. Do you know the cause? Assembly error, foreign material, overloaded, overtemperature, insufficient oil supply?

Also, I do know that one of the major bearing manufacturers made me a custom set of rod bearings. It's been about seven years, but I'm pretty sure it was King. Our engines are very similar to the Honda B-series, so they started with their B-series designs.

P(COPIED FROM OTHER THREAD)
Per my post #4 above, I went back and searched for those using Chevy bearings.

You should contact Shad at Driving Ambition. Apparently he uses, or has used, Chevy bearings for our mains.

I believe I did contact Shad and he didn't have a solution. That was several months ago. I will try him again. Thank you. As I just mentioned, the Brian Crower kit comes with their aftermarket connecting rod bearings, and I am replacing those.

My mechanic thinks it could have been the machine shop I used for the Brian Crower kit. He had a couple of other cars that had work done from them have issues at the same time. I'm using a different machine shop now. Either that or it could have happened when we were tuning. When I was tuning the car, the main engine coolant line popped off. I run 2 separate cooling systems. One for the main system and one for the turbo kit. I run different color coolants in them so I know which is leaking if one leaks, and it was definitely the main cooling system. My car actually could have made more power than it did, but the ignition coils couldn't keep up.
I'm definitely going to de-tune the car down. It's too much power for the rest of the mechanics and I'd rather have it reliable than over powered. THere's always faster cars out there.


I'm going to try Driving Ambition and see what they say as well as Cody. If anyone knows of another Prime member that is running a setup like mine, please let me know their UN.
Thanks everyone for your help!

 

[bonhamsurf]

So I just talked to SHad at Driving Ambition. He was very helpful and informative. He explained how he uses the Chevy bearings. I'm not quite sure I can do this with my setup, but I'm definitely going to try!

 

[Mac Attack]

Good deal! I hope you can adapt the aftermarket main bearings for Chevys - They are far superior technology to the cheap OEM aluminum bearings.

 

[bonhamsurf]

Good deal! I hope you can adapt the aftermarket main bearings for Chevys - They are far superior technology to the cheap OEM aluminum bearings.

@

Me too. After talking to my mechanic and also Cody Loveland, I doubt this will happen, but I'm going to try and find out today.
Thanks!

 

[bonhamsurf]

So I cannot use the Clevite/Chevy bearings. The Brian Crower crankshaft uses the same pin size as OEM, and the Clevite/Chevy bearings require a larger pin size.

However, I did speak for about 30 minutes to Brian Crower himself. He was VERY informative and helpful. He has had zero issues using OEM bearings an any race NSX he's ever built. He says the OEM Bearings are totally good over 1000hp. In fact when I said my car was 795whp, he said, "Do you have something more powerful than fucking NASA car? Because I've built an NSX for NASA well over 1000hp on OEM Bearings and it's still running today."
He was funny but also very, very intelligent. Could have talked to him for hours. He was giving me all of the information on bearing sizes and preferred clearance down to 1/10000 of an inch.