Main Engine Bearings for 1991 NSX list please

[bonhamsurf]

Aloha Prime Family,
I need to replace all of the main engine bearings in my NSX except for the connecting rod bearings.

I know there's different colors and some colors take different amounts of bearings than others.

Can anyone please either

Provide me with a link that lists all of the main engine bearings with their part numbers and how many of each bearing for a 1991 NSX? Again, don't need the connecting rod bearings, but all other main engine bearings.

Or just reply with the details of these bearings for me to order from Delray Acura or another vendor?

Thank you!

 

[Mac Attack]

There are a total of 8 main bearings.

Look in the SM beginning on page 7-4. The bearings aren't stamped with a thickness, they are instead color-coded on the sides to let you know some "nominal" thickness. You won't know what thicknesses the original Honda engine assemblers used until you either pull out the old ones and look at the colors, or decipher the hieroglyphics on the block and crank and determine the colors on page 7-8 of the SM. Be careful just looking at the colors because sometimes the colors may have faded or the red looks like a brown, the pink looks like a faded red, etc.

You really need to use the block and crank to ensure you order the correct replacement bearings for your engine. Honda assembled these with very tight tolerances and unless you know precisely what you are doing, then it is best to just duplicate what they originally did. Going a step further, you or your engine builder should measure all the dimensions and calculate the clearances yourself.

Therefore, unless you want to have a small fortune in main bearings buying eight of all possible colors before doing the rebuild, then you'll need to wait and order them after you disassemble the engine and see what was previously used. You may have to use amayama.com or use this online parts store as a guide on prices:
https://www.acuraautomotiveparts.org/


Was this on your 741 WHP engine? If so, why not replace the rod bearings as a contingency while you're in there? Also, having OEM bearings hold up at that level is impressive. They are weak aluminum. I would use aftermarket if possible. Good luck!

 

[bonhamsurf]

Thank you

Thank you very much Mac Attack for your helpful reply.
I agree the OEM bearings are not strong enough for my car. It's actually tuned to 714whp/605wtq on pump and 795whp/633wtq on Enthanol.
I am using the Brian Crower bearings for the connecting rod bearings as it's a 3.5L Brian Crower stroked engine (the smaller of the 2 bore sizes from Brian Crower)
I would like to go with something stronger for the rest of the bearings as well. I will check out the links you sent.
Any suggestions on aftermarket bearings for the rest of the main engine bearings to handle my car's power?
Thanks again...

There are a total of 8 main bearings.

Look in the SM beginning on page 7-4. The bearings aren't stamped with a thickness, they are instead color-coded on the sides to let you know some "nominal" thickness. You won't know what thicknesses the original Honda engine assemblers used until you either pull out the old ones and look at the colors, or decipher the hieroglyphics on the block and crank and determine the colors on page 7-8 of the SM. Be careful just looking at the colors because sometimes the colors may have faded or the red looks like a brown, the pink looks like a faded red, etc.

You really need to use the block and crank to ensure you order the correct replacement bearings for your engine. Honda assembled these with very tight tolerances and unless you know precisely what you are doing, then it is best to just duplicate what they originally did. Going a step further, you or your engine builder should measure all the dimensions and calculate the clearances yourself.

Therefore, unless you want to have a small fortune in main bearings buying eight of all possible colors before doing the rebuild, then you'll need to wait and order them after you disassemble the engine and see what was previously used. You may have to use amayama.com or use this online parts store as a guide on prices:
https://www.acuraautomotiveparts.org/


Was this on your 741 WHP engine? If so, why not replace the rod bearings as a contingency while you're in there? Also, having OEM bearings hold up at that level is impressive. They are weak aluminum. I would use aftermarket if possible. Good luck!

 

[Mac Attack]

Wow, nice engine. I'm not familiar with the strokers though. IIRC, some people were using aftermarket Chevy bearings for the mains after the proper machining.

There are a lot of good bearing manufacturers out there. I like King bearings.

If your main bearings are OEM, King should have an application. Or, my main and rod bearings may have been a one-off custom set. Either way, they should have the OEM measurements on file if that's what you need.

 

[bonhamsurf]

Thanks for the info. I will be contacting King Bearings.

Wow, nice engine. I'm not familiar with the strokers though. IIRC, some people were using aftermarket Chevy bearings for the mains after the proper machining.

There are a lot of good bearing manufacturers out there. I like King bearings.

If your main bearings are OEM, King should have an application. Or, my main and rod bearings may have been a one-off custom set. Either way, they should have the OEM measurements on file if that's what you need.

 

[bonhamsurf]

Wow, nice engine. I'm not familiar with the strokers though. IIRC, some people were using aftermarket Chevy bearings for the mains after the proper machining.

There are a lot of good bearing manufacturers out there. I like King bearings.

If your main bearings are OEM, King should have an application. Or, my main and rod bearings may have been a one-off custom set. Either way, they should have the OEM measurements on file if that's what you need.

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?

Thanks!

 

[Mac Attack]

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.