Standard OEM engine Bearings

[rayhall]

Hello I have a Audi V10 engine from a Audi RS6 The engine is a 5.0L version of the engine in the Audi R8. It is turbocharged from the factory and made 570HP at the flywheel at 6500 rpm. I fitted bigger turbochargers and push the power to 803 HP at 7000 rpm at the wheels on my Hub dyno. At a race track the wrong fuel was put in the tank and damaged one piston. The main and rod bearings were perfect and showed not sign of wear or contact.
I am now rebuilding the engine and cannot get any ACL Racing or King racing bearings for the engine. I will change to E85 fuel an the power should be close to 900HP at 7000 rpm at the wheels. I plan to use Mobil 1 oil 20 -50. Is using the stock new bearing going to be a issue.
Thank you.
Ray.

[Racer71]

Stock bearings should be as good as any.

[rustbucket79]

You’re pushing it pretty hard, my advice would be to do a bearing inspection after a few “spirited” runs to ensure everybody’s getting along well.

[rayhall]

You’re pushing it pretty hard, my advice would be to do a bearing inspection after a few “spirited” runs to ensure everybody’s getting along well.

Than k you for your advice,
That is easy to say but inspecting the bearings is only possible with a complete strip down. Audi designed this engine to make it difficult to do much with out a complete strip down.
Ray.

[rustbucket79]

I assumed you having a hub dyno meant also having a hoist, but I neglected to factor in the likelihood of having to pull the engine to access a few bearings.

How about one of those fancy clearview oil filters? Oh, and the best 20w 50 race oil to help keep the bearings and journals apart.

Good luck, sounds like loads of fun.

[rayhall]

I assumed you having a hub dyno meant also having a hoist, but I neglected to factor in the likelihood of having to pull the engine to access a few bearings.

How about one of those fancy clearview oil filters? Oh, and the best 20w 50 race oil to help keep the bearings and journals apart.

Good luck, sounds like loads of fun.

Yes I have a hoist ,but the engine is dry sump, no single main caps just a full engine girdle that cannot be removed with pulling the reastcof the engine appear first. I should have used a GM LS thing as the engine in the car.
If am looking for metal in a filter and seeing some the engine is toast .
Thanks for your input.

[FloydODB]

be careful with the 20-50. we found it sheared causing excessive oil temps in a 720hp 414ci sbc dirt mod. at one point localized temps and pressures caused the oil to act like a water jet eroding the babbit and tin. these were clevite calico rod bearings set at .0024" and one season at .0028". mains went.0026 and one season at .0032". it was breaking 360 degree gauges. tried everything. switched to a 15-40 and ran 220-240. brand went from valvoline to the schaffers. think it was more to do with viscosity and maybe types and amounts of additives though.

[rebelrouser]

Not sure if they make one to fit an Audi, I like to use a system one oil filter, easy to take apart and look for metal.
One example, had a customer with a 460 Ford pulling truck, engine would blow up about every 10 hooks. He wanted me to figure it out. I told him it is pretty hard to figure out the root cause, when rods are hanging out of the block. I built the engine using same stuff as it had in it. I told him to pull the filter after every hook, hook five, small pieces of metal showed up, took it apart main bearings were delaminating, made some calls got a different design bearing, and the engine is still running three years later.
I don't think the bearing materials are the main issue, will the block and main bearing bedding plate hold up or distort from the extra power? Old muscle car engines were designed with a lot of extra strength, most modern engines are not, just my general experience. Are there any Audi forums or racers you can talk too that have done similar modifications?

[Chris_Hamilton]

Old muscle car engines were designed with a lot of extra strength, most modern engines are not, just my general experience.

I'd say with the exception of cylinder boring limits modern engines are much more durable, stronger and better engineered than stuff from 50 years ago. Honda B and K-blocks Chevy LS, 1000+hp 2JZ Toyota blocks just to name a few. Looking at pics of the Audi V10 I'd say it's limits are pretty high as well.

[Baprace]

Hello I have a Audi V10 engine from a Audi RS6 The engine is a 5.0L version of the engine in the Audi R8. It is turbocharged from the factory and made 570HP at the flywheel at 6500 rpm. I fitted bigger turbochargers and push the power to 803 HP at 7000 rpm at the wheels on my Hub dyno. At a race track the wrong fuel was put in the tank and damaged one piston. The main and rod bearings were perfect and showed not sign of wear or contact.
I am now rebuilding the engine and cannot get any ACL Racing or King racing bearings for the engine. I will change to E85 fuel an the power should be close to 900HP at 7000 rpm at the wheels. I plan to use Mobil 1 oil 20 -50. Is using the stock new bearing going to be a issue.
Thank you.
Ray.

Why not use the bearings over if they look perfect ? You would still be running them if a piston had not failed. I would not change the oil viscosity.

[4vpc]

Hello I have a Audi V10 engine from a Audi RS6 The engine is a 5.0L version of the engine in the Audi R8. It is turbocharged from the factory and made 570HP at the flywheel at 6500 rpm. I fitted bigger turbochargers and push the power to 803 HP at 7000 rpm at the wheels on my Hub dyno. At a race track the wrong fuel was put in the tank and damaged one piston. The main and rod bearings were perfect and showed not sign of wear or contact.
I am now rebuilding the engine and cannot get any ACL Racing or King racing bearings for the engine. I will change to E85 fuel an the power should be close to 900HP at 7000 rpm at the wheels. I plan to use Mobil 1 oil 20 -50. Is using the stock new bearing going to be a issue.
Thank you.
Ray.

Why not use the bearings over if they look perfect ? You would still be running them if a piston had not failed. I would not change the oil viscosity.

Exactly this.
It's quite common to find aftermarket bearings are not as good as the originals.