Roller cam bearings

[B Parker]

Originally Posted by Jim Bailey

Not Legal in Stock ,,, correct ?

Jim I was thinking the same thing. Barry

[Signman]

What you may consider is isolating the camshaft by forming a closed tunnel with oil return run directly down to the pan. Cam, lifters and bearings see plenty of oil maybe too much but would not fall into windage with an internal or external oil return line or limit the fall to the rear only for not 100% effect.

When looking at this a few years ago it's difficult with SBC without a lot of work I spent hours cutting and filing PVC tube to fit planning to pin and epoxy but issues with connecting rod clearance made it too much work at that time and became evident sheet metal would have been a better choice.

When searching cases where I could see this actually done this was with a Ford with dry sump much easier to control putting oil in the front and return in the back the tunnel would be filled or nearly.
Great idea to apply to a stocker there would be HP there but the labor cost would be more than most would pay but a crafty guy doing it for himself............

[voltdr]

A very good friend of mine that knows a few things about engine building and find HP told me that when the engine is running, the camshaft is spinning on a film of oil. It isn't dragging against the bearing material.
Dan

[Mark Ugrich]

Thanks to everyone for your comments and insights. I think I’ll stick with Babbitt bearings.

[carl hinkson]

Originally Posted by BILL TAYLOR

My engine guy told me that Jesel experimented with roller cam bearings and the negative harmonics were real bad. That was quite a few years ago, maybe someone found a way to correct?

DING DING DING We have a winner. A few years ago I talked to one of the guys at Grumpy Jenkins shop and they said it was night a day difference between Roller cam bearings and using babbit as roller cam bearings produce a lot of unwanted harmonics.

It takes more power to move all those needle bearings VS the cam sliding on a film of oil.

I blue print bore a lot of blocks for 55MM cam journals for other shops and builders babbit seems like the way to go. Also machine some of the OEM 350 blocks to 2.120 and use the GMP-1 cam bearings for BBC journals.

[HP HUNTER]

Originally Posted by carl hinkson

DING DING DING We have a winner. A few years ago I talked to one of the guys at Grumpy Jenkins shop and they said it was night a day difference between Roller cam bearings and using babbit as roller cam bearings produce a lot of unwanted harmonics.

It takes more power to move all those needle bearings VS the cam sliding on a film of oil.

I blue print bore a lot of blocks for 55MM cam journals for other shops and builders babbit seems like the way to go. Also machine some of the OEM 350 blocks to 2.120 and use the GMP-1 cam bearings for BBC journals.

Carl

Some years back I had a contract to build Winston West 9.1 comp 390 carbed 358 engines. We were quite sucessful and won several races, every engine we built had roller cam bearings, but also were dry sump. I never saw any weird stuff going on in those engines, they made right at 600 HP. Not going to say there was no harmonics, but we never had problems. We also built some with 55 MM babbit, I never saw any difference on the dyno, I did like getting rid of the oil leaks.

[Stewart Way]

Anyone have any experience with roller cam bearings on the street. I have 2 Gen3 hemi aluminum blocks that have been cut for 60mm roller bearings. These are in a cam tunnel so no oil from the top and I don't know if you could put a hole in the bearing cage for oil without hurting the bearing. These are destroked and bored to 305" and Bryant cranks and blocks are cut for LS chevy bearings to get a full thrust bearing for road racing. I was thinking of 1 for a street rod but not sure the bearings would oil enough at low RPM on the street. Any thoughts?

[Glenn Briglio]

Originally Posted by Stewart Way

Anyone have any experience with roller cam bearings on the street. I have 2 Gen3 hemi aluminum blocks that have been cut for 60mm roller bearings. These are in a cam tunnel so no oil from the top and I don't know if you could put a hole in the bearing cage for oil without hurting the bearing. These are destroked and bored to 305" and Bryant cranks and blocks are cut for LS chevy bearings to get a full thrust bearing for road racing. I was thinking of 1 for a street rod but not sure the bearings would oil enough at low RPM on the street. Any thoughts?

Don't let it idle below 1500 rpm.

[SSDiv6]

Originally Posted by HP HUNTER

Carl
Some years back I had a contract to build Winston West 9.1 comp 390 carbed 358 engines. We were quite sucessful and won several races, every engine we built had roller cam bearings, but also were dry sump. I never saw any weird stuff going on in those engines, they made right at 600 HP. Not going to say there was no harmonics, but we never had problems. We also built some with 55 MM babbit, I never saw any difference on the dyno, I did like getting rid of the oil leaks.

NASCAR engine blocks, have closed camshaft tunnels; therefore, the roller cam bearings, camshaft and lifters were always flooded with oil. The initial idea for the use of roller bearings was to reduce friction. Nevertheless, no one expected valvetrain frequencies and harmonics to generate from its use.

[Dwight Southerland]

Isky "Imperial" camshafts.