Honda used roller bearings for the crank in the S600. F1 (IIRC) engines use roller bearings. Why is it that they aren't commonly used in sub 100k cars? Less friction, less worry about oil pressure, etc.

Also what type or roller bearings are used? Trannys use them, but they're a one piece design as you have an open end of the shaft to slide it over. Thats not the case with a journal on the crank.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Aquafina &raquo;</TD></TR><TR><TD CLASS="quote">Why is it that they aren't commonly used in sub 100k cars? Less friction, less worry about oil pressure, etc.
</TD></TR></TABLE>

Cost.

 

Tranny's use them because they are submerged in the oil.
It would take very tight constraints for the block and crank to effectively hold oil pressure with the roller bearings.
Deff not cost effective or even remotely worth it for production cars.

 

Oil pressure isn't as much of an issue with roller bearings.

 

Because Honda performed a $500 million study and found thta street kids with combat wings and bigmouth bodykits would over compress their motor and detonate and shatter the 55+RC hard bearings and then claim that the motor broke while driving 35mph in 4th gear.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Aquafina &raquo;</TD></TR><TR><TD CLASS="quote">Honda used roller bearings for the crank in the S600. F1 (IIRC) engines use roller bearings. Why is it that they aren't commonly used in sub 100k cars? Less friction, less worry about oil pressure, etc.

Also what type or roller bearings are used? Trannys use them, but they're a one piece design as you have an open end of the shaft to slide it over. Thats not the case with a journal on the crank.</TD></TR></TABLE>

I too have thought about that. my dirt bike (07 honda Cr450r) even has roller bearings for the cam, as well as the crank, why dont high power/performance auto engines use this?? it has to really cut down on thermal and frictional loads, right?

 

What is the service life of roller bearings in this application compared to standard bearings?

 

I worded it in a way to mask that I'm thinking about trying out roller bearings in a D15 just to see if they work and if there are any worthwhile gains. Life would be good info to know though.

 

Roller bearings can only take about a 10th of the load of a journal bearing. Also, they tend to have really bad rotordynamics in a 1:1 replacement with journal bearings.

Finally, roller element bearings are less resistant to contamination and wear faster than journal bearings in a equal number of start stops.

 

It would be easier to use 00 weight oil and change your bearings with every oil change.

 

how do you plan on keeping the oil pressure in the rest of the motor when its escaping through the roller bearings?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spun Vtec &raquo;</TD></TR><TR><TD CLASS="quote">how do you plan on keeping the oil pressure in the rest of the motor when its escaping through the roller bearings?</TD></TR></TABLE>

It can be done but it would require a complete rework of the oiling system. Basically, this ideal would only work if this was designed in the motor from day one.

 

lol kinda my point

 

External oil pump, or just a dry sump.

So rollers wouldn't like a long stroke short rod setup?

 

*** it, if you gonna go big go big and use electromagnetic bearings with load control

haha wish

 

Porsche used roller rod bearings in the flat race motors in the 60's. Cup motors use roller(caged needle) bearings on cams now and have been, this is old stuff.

 

I found this roller bearing crankshaft at a garage sale for $15.

Can I use it in my LSVTAK?

 

Huh, so the master of the universe shops at garage sales . . .

Definitely didnt see that one coming . . .

 

Don, do you know what brand bearings they used? Life-span?

I found a bearing company a couple years ago that makes a lot of different needle bearings but I don't think they'd be up to par for engine use.

 

Timkin is good manufucturer of bearings.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mmuller &raquo;</TD></TR><TR><TD CLASS="quote">*** it, if you gonna go big go big and use electromagnetic bearings with load control

haha wish</TD></TR></TABLE>


Magnetic bearings have even less load capability than roller bearings. I believe it is about 100th of a journal bearing.

Honesty in the game of losses, bearings are pretty low, I would look more at pumping losses, etc.

 

throttling seems the biggest (pumping) loss.

 

Throttling pumping losses? I'm having a brainfart and can't decipher that.

 

dont you mean CRF450R? big difference between a CRF and a CR.

 

raise your hand if you can see the irony in this thread.