Theoretical engine build.

[YoungPUP]

While doing 12oz curls with a few friends Saturday nite, a theoretical build that we've talked about for years came up again, so I thought I'd see if it was possible.  We keep bringing up the idea of a FULL, Complete  roller bearing motor.  Replace ALL the bimetal bearings with roller or ball bearings. They already make needle bearings to replace cam bearings on the 350 and 351 Chevys and Fords.  I know its being done with motorcycle and snowmobile engines, but those have modular crankshafts. Could races be machined into the mains and the rod journals turned down to accept roller or ball bearings?  Waaaay not a Valk topic, but then again it is Cabin fever season!

[Patrick]

Roller bearing engines have been around for years, even back in the very early days.

[Hooter]

ANYTHING can be done with enough money. Sometimes bar napkins and 12 oz curles can cost you a lot of money!

[Reb]

A PHD student and I are in the process of engineering a 5 stroke engine. Theoretically works well on computer. A British company has already designed one but has yet to put it into something. As much as I'd like to make things go fast, the world is in need of more fuel efficiency. 

[Dogg]

All inline 4cyl bike motors are bearings, not slide bearings. My gs i raced for years had solid h beam rods, a bearing was pressed into the rod, then pressed on the crank then the crankshaft was pressed together and welded. Then balanced. 16,000 rpms on that old 8 valve motor...

[Patrick]

5 cycle ?  Ed Iskenderian used to make 5 cycle camshafts back in the 50s. When asked what was different or special about them, he would just smile.

[PharmBoy]

Over 50 years ago the 4 cylinder Mercury 2-cycle outboard engines had all needle bearings on the crank shaft.  Unfortunately, I got the pleasure of rebuilding one of the little monsters as a teen.  Thankfully, it even ran when I was finished...Jim

[MarkT]

I could be CFOS, but IIRC, sleeve bearings supporting a pressurized film of oil have advantages, besides lower cost - they can take higher pressures, and they are lower weight, reducing power loss of reciprocating mass.  I invite discussion on these points from anyone knowing facts or having opinions...

[Patrick]

I don't know whether I can help or hinder. More and more parts in 4 stroke engines are using roller bearings such as rockers, followers and wrist pins. But crank bearings remain inserts. Inserts on the crank big end certainly are lighter and cheaper to make and maintain. They also work well as long as the oil film is maintained.
Its always appeared to me that roller bearings on cranks were mostly on 2 strokes due to the ability of them to survive with less lubrication.

[czuch]

Smokey Yunic could have figured it out, and still passed tech.
I have no idea but I'll buy one when you do.

[Patrick]

Smokey ?!  I watched him drill a small hole in the bend of each exhaust header. I asked why, he just smiled. Later and after a couple he said it reduced turbulence and therefore helped with scavenging. Sharp man.

[hal47]

Harley's use them on the crank and rods.

[Tailgate Tommy]

Had a 1975 Kawasaki 900 that had a pressed together roller bearing crank. Racers welded them to prevent them from twisting, especially when turbocharged.

[YoungPUP]

The talk has been to try and do the bearing setup on a car engine like a 350 Chevy.  I understand its been used for Marine and motorsport motors for years. HOw hard would it be to do with a V8???

[hal47]

Why would you want to do it any way?

[YoungPUP]

Beer was involved and it seems like a good idea for longevity of the engine.

[musclehead]

I poked my head in, sniffed around and said "this is far to slide ruley for my shade tree knowledge" and slinked away to a political thread