Anyone here see this? Pretty crazy!!

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Nov 10, 2006 | 01:02 PM

#16

Beertestr

Registered User

Joined: Sep 2001

Posts: 115

From: MI

Quote:

Originally Posted by captaindbol

Not sure where where you heard this or if its a typo that i didn't see, but the MAINS are not 2.1" nor have they ever been. LSX mains are bigger than a traditional small block. The RODS are still sbc size but that in itself is overkill with good parts. Honda rod journal 1.880" is the racing industry standard and seems to hold up pretty well. The winston cup guys have been playing with a BMW journal in the 1.7XX range for some time now. As long as the crank is designed properly, a smaller main is also more desirable at high RPM since there is less area to try to keep oiled. As far as durability is concerned, my shop has a BBC 4.6" bore, 3.75" stroke turning 9200 (1100HP) that one of our customers set the gas modified roadster record with at bonniville. It runs a shelf crower crank with 2" rod journals. They run the thing WFO for 5 miles then basically hot lap the thing back the other way in order to back up the record. You still might need to sell crack to afford it

but there are shelf parts out there that can get the job done at the street car level. If you decided to break from the norm and base a 10.5 outlaw/pro-mod car on this platform then parts availability could get interesting.

Yeah, mistype, I meant rod throws are essentially 2.1" like the old small block. If you want to get technical, the range spec is 53.318mmm-53.338mm for a rod throw.

All my comments around ultimate strength revolve around building the engine to its potential of 2500 HP. The rotating components will be heavily taxed, and IMO would not be there for longevity. Even the WFO 5 mile setup is not a very long time. I recently won a bet running a 318 for 4 minutes without oil.. Not sure what kind of comparison that is, but it seemed neat to say

When you consider a production engine is validated to 400 HOURS of peak torque to peak power sweeps, wondering how a 2500 HP engine on the same rod and main bearing diameters would hold up. It's not a matter of if, it's how long before it blows.

No arguement on smaller is better for oil film thickness and high rpm, but my comments were based on collateral damage and longevity, RPM independent.

Overall, it's killer that there is a new block on the market, I just see people jumping on it and totally under utilizing it.

Anybody know the highest output shops are getting out of a production 6.0L iron block? I know BMR has a seriously fast 4" x 4" iron block, but I don't know what the numbers were. How about forced induction?

Nov 11, 2006 | 12:32 AM

#17

captaindbol

Registered User

Joined: Nov 2004

Posts: 377

From: La Porte, TX

Glad that was a mistype. It's clear you know whats going on. I just know how the internet has a way of becoming gospel and I didn't want anyone to be confused. I used the bonniville engine as a example because I know of few things that can replicate that kind of stress on a engine. The bobweight is hundreds of grams heavier than anything else I know of turning 9000+, and all the endurance applications I know of making that kind of power do so at much less RPM. Congrats on the 318 BTW. There will always be tradeoffs between power and reliablility but I still stand by my statement that the journal size is not the weak link. When pushed to the limits, pistons will still get stress cracks, wrist pins will still distort, and rod bolts ( bolt threads in AL) rods will still fail irregardless of journal size.

I hear you all the way on the block being under utilized. The people that can actually apply 2000+ hp and go down the track are years away from embracing such new technology. And the fast streetcars/dyno queens can't take advantage of the power already available to them. All in all its still great to see the factory steping up like this though.