I have seen these roller cam bearings used in dirt track engines because of the high valve spring pressures they run . A concept that would render this conversation moot if they were available to replace the other bearings in high HP apps. . http://www.summitracing.com/parts/cc...O7waAm2G8P8HAQ

Both foreign and domestic... Anything that was built in the last 5 years you better get used to checking the oil every 1000 miles or you will be replacing a engine now...

5 quart capacity that has an allowable usage of 1 quart every 600 miles. This same motor has a recommended change interval of 10,000 miles.... Do the math. Less than half way through your oil change you could be replacing your engine instead of the oil. 0w-20 is like antifreeze consistency.

I went through oiling issues years ago with my 454's...ran the "loose clearances" with standard pumps that many on oso said would be fine, 55psi cold at idle.... I wiped out mains on both engines at less then 3 hours... and even after a rebuild people still said the pumps and pressures were ok... then another wiped main, people here and other places blamed Fram filters ( I use K&N) so not sure why that was said to me lol, they blamed the factory merc 90 degree brass fittings...the been there 20+ years on EVERY BOAT OUT THERE, not the best but work fine..people blamed the bearings.... everything.....of course I never listened to my best buddy Lake Effect.... and I should have...

we redid engines one last time, I bought new cranks because I didnt want cut ones, #1-4 mains were .003 and #5 was .0035 we used HV pumps shimmed for 80 psi (trick from Dean Gellner) and reassembled engines...had 80 psi cold at idle, 40-50 hot idle, temps never went over 240 tops with Valvoline V! racing oil 20-50

I beat them engines for 5 seasons with zero issues ever again, so my personal experiance I say the loose clearance and high pressure is the key, along with a thick GOOD oil...

I am going to set up new engines the same way that I am building this winter...

Someone I know very, very, very well (wink) decided when 0w-20 / 5W-20 was spec'd on certain cars that came in, they still used 5W-30 synthetic. And have never seen the oil usage issues that you two mention. I'll tell him to give himself a pat on the back for just saying No. LOL.

Workes fine in his -20F or so winter starts ups, so why go lighter ?

I've done the math believe me I've even called the manufacturers. Yes 1qt 600 miles is the acceptable threshold. You gotta b kidding me. Sad thing is the general public doesn't have a clue what junk the are buying.

Helmet boy, I've been doing the same thing for 5 years. I'd say great minds think alike but I'd never compare myself to someone that sits in a corner with a helmet on.

To many harmonics! Everyone has gone away from them. Amazing how new things come out and everyone jumps on the wagon for awhile but eventually they get back off.

I'm no engine assembler but someone once told me .001 per inch of journal diameter.
I realize that's pretty generic but it popped into my noodle.

in a marine bbc i like ,0027-.003 on the rods and .003-0035 on the mains.for a street car subtract .0005.i have done it this way for 35 plus years and im not changing now.i have seen bearing failure from to tight clearance but not from a little loose.just my opinion.i also like 15w50 or 20w50 oil in them.

That is how I fix there oil consumption problems when the factory says its within
"ACCEPTABLE LIMITS".