GregBBRD

He's got Chevy rod bearings with different crank oiling....

That's what makes some of this so funny!

GregBBRD

I did.

I said that your experience is somewhat unique.

S4ordie

MK, you speak of the importance of making sure your car is fully warmed up before getting on the track. Can you share your process here? I'm truly interested in what it is you do.

Sorry for the hijack.

justaguy

That is probabaly the funniest thing I've ever read on here.

milkman383

Great thread... I own a 928, but I build Chebbie motors, and so many of the problems and solutions are the same.

Which chevy bearings is Mark running?

And Greg, beautiful stuff. I love me some Carillo's. Are you using the parent company, CP, for your pistons? There aren't words to describe how great those pistons are.

I don't know a lot about the architecture of the "famous" 6.5l strokers, I guess I should ask Marc Thomas, I'm old old friends with his wife Susan. Next time they're in NC I need to buy them some drinks and chat. BUT does anyone do a block with more bore? Can you bore the stock block more than a few thousandths? Greg, you talk about big end journal size, and making it smaller, like Honda journal small? And are you narrowing the rod so that you can piston guide it or is that just the stock architecture?

I'm sure many people who have been both smart and lucky have not had bearing issues even with track use, if you keep the oil fresh, cool and plentiful and don't have detonation and keep the revs low enough, then they'll last forever. Any of those things not true, then you fall back on the strength of the bearing, which is what Greg seems to be addressing according to my read. Since others have used a hooker analogy I guess I'll use one too. The stock bearings are hiring a pro and only using 1 rubber. That will work fine as long as you're smart and lucky, but 2 is safer. :-)

Great stuff!!
-jeff

namasgt

I thought you were joking Greg. Then why all this questioning and engine surviving thing?


Mark,

I understand your original Holbert engine survived track abuse, but that engine was assembled by Porsche to go to the salt flats. There is no telling how much time and attention to detail they paid into assembling that engine compared to the ones that were used for the assembly production line. Also, that was a ~320 HP engine. Greg is making these parts for higher out put engines that are going to rev much higher than a stock factory crank. Hence the use of stronger bearings. How many ~400 HP 928 engines you know with stock internals (more specifically factory bearings) that have survived track abuse?

GregBBRD

I didn't assemble his engine, so I can't say which brand/type of bearings are in there.

Hilton

MK's bottom end was assembled by Todd in Green Bay - then shipped to MK and he slapped his own heads on it with, if I recall rightly, a cometic gasket.

Fabio421

I have nothing to add here other than this.........using two condoms at once is LESS safe than using one at a time. Carry on

milkman383

This is NOT good news!!

IcemanG17

I follow the same process, so I can answer for MK.....basically its this.....get the oil up to 180F BEFORE you run hard......which can take a while on a cold day....but is usually achieved during the warm up lap (for me anyway)...

I want my temp gauge (factory) at the 1st white bar or higher....

dcrasta

I would think this would be common sense for any car. At least give the thermostat a chance to open and the ECU to get out of warmup mode before you go hammering on the car..

As far as condoms, if you have to double bag, is it even worth the price of engagement ?

dr bob

For those paying at home, this is an almost mandatory practice for street driving too. Beyond the bearing issues, pistons grow faster/bigger than the holes in the blocks when heating is way uneven.

Back to the crank discussion...

SeanR

But but but, my car runs its best just after I start it up and it's cold.

mark kibort

the stroker used USED main bearings too! (stock used porsche)
dont know the rod bearings, but i can find out

funny, how?? the 84 I ran with 2 engines, ran stock porsche OE rod bearings. scots, now Petty, all used the stock stuff.

we pulled the engine if you remember, and nothing was modded on the bottomend. alll looked very stock and rough. bearings were perfect after 10 years of racing and 20 yearrs of uknown abuse. it seemed to be a stock block, non squirter

Yep, thats it. even used main bearings were used and it was an 85 block to boot.

its more than that. its heat soaking the engine parts too. ie, heating it up and letting it sit if possible. then re heating and you are safe.

Most dont do this , almost no one does this and i see all sorts of engines blowing up around me at the track. ask me how many vets and camaros ive seen with rod knocks and new engines by the next event. (or later) ask me how many issues ive had in 15 years of beating up the 928. always shifting at near redline, ever shift for hours and hours and hours!!

then, there must be a reason, because it span for over more than 5 engines all running extremely hard at the track in all conditions and speeds. the only think i havent done is open road racing where this might be a problem, but, keep in mind, i have no breathers, no extra oil coolers, no mods what so ever. scot doesnt even have a factory oil cooler . you see all my rear cam video, ever see a puff of smoke? yet, you hear the rev limiter getting hit occasionally!

No spacers, no baffels, no old pickups, etc etc.

1:36.1 and beating the GMG Sofro GT3 race car conversion on slicks to boot with a mild pro at the wheel. just maybe you might want to look closer at what im doing instead of calling it voodo
and by the way, ive dont nothing much differnet than Joe has done with your build cars too. yet, how many things that were modded were pulled off and gone back to stock?? (besides your engine mods of course)