I'll check them and maybe as eficker also said, i'm not 100% sure it was directly a rod problem, maybe it was another thing like a preignition due to any fuel system failure, but i dont want to investigate why it broke.
BTW eric, why when i enter to the online store, it appears in spanish and all messed up. I'll apretiate if you post any info and some pics of the oliver rods.
Thanks a lot.

 

I'd send the rod back to Crower and have them inspect it. Crowers are very strong rods and are rated for much higher HP that you were running, but there's always a remote chance that you had a metal failure of some sort. It sure does not hurt to find out what the issue was and learn from it. Pauter rods are extremely beefy as well.

Six bolt 4g63 motors came in the 1990-1992 DSMs. They are the motor of choice for DSMs, but obviously don't fit Evos. ( Opposite orientation in the engine compartment) The "six bolt" refers to the number of bolts holding the flywheel to the crankshaft; the 6 bolt rods are different in width and in their small end diameters.

 

What are you running for engine management? Any logs ??

 

Then there is a good chance it will break again. You really should figure out what happened to determine if there is another issue that needs your attention before you build a new motor and grenade that one as well.

 

Is your engine management setup to pull timing and add fuel when it detects knock. One of the problems with having such a stout engine (4g63) is that there is no weak link like a head gasket that will fail prior to a catastrophic failure like yours. In most applications detonation would eventually cause you to blow a head gasket. On ours we break rods and pistons.

 

have you established that the failure was actually the rod or was it caused by a bolt failure? Most times in a blow up like this the bolts are what fail.

 

This seems a bit too lean for what I would consider as best practices. It's not going to do much for you except create virtually no room for error at 550whp. In short, it's unnecessary, and I'd hedge my bets it's at least part of the reason why that rod broke. There are quite a few persons who've generated the same level of power with factory rods (gulp), and we don't see breakage. But then again, they are running richer, safer mixtures.

This is just a (wise) suggestion, so take it FWIW.

 

12.5-13.0 is not something I would run. Its hard to believe that it wasn't knocking.
Even on 110 its too lean IMO. I would go ~12.0-12.5 on c16 but not 110.

 

It has a GEMS ECU, it pulls out timing and adds fuel when theres knock.

It wanst a bolt failure, the rod is still bolted to the cranck and looks ok.

When i said i didnt want to investigate i meant that i dont want to blame anybody, just want to fix everything and go on, of course i'll check why the rod broke.
So, as recomendation, what AFR's are safe for 550whp with 110 octane fuel?
I setted to 12.5:1 cause it was only 1/8 mile race.
Thanks all you guys for your replies.
cheers

 

Oops! Glad I didn't get Crower

 

12.5-13 on just 110 is lean but with alky you made it even worse. stoich levels for alky are lower than gasoline. How much were you injecting? I wouldn't go near 12's with alky....

 

Its a 100 times more likely a piece of the pistons broke off. When this piece wedges in between the piston and cylinder head at rpm there is enough force to snap ANY rod. Dont blame the rod. look at the side of piston for signs of detonation then report back.

 

11:5 - 12:0 is a wiser choice.


Crower's track record is very respectable. If the breakage is not the fault of the rod (and it probably isn't) , it doesn't matter who made it, it will break just the same.


It doesn't work that way. Stoichiometric for methanol is 6.4:1, but that reads as "14.7:1" on your meter. In other words, a wideband sensor isn't telling you what the mixture is, it's just giving the free oxygen equivalent. So, if one tunes to 12:1 with methanol, it's the same effective mixture as 12:1 with gasoline.

FYI

 

you might need to go into the cart and reset your preferences. you might of accidentally hit spanish as a defaul language. If you email mark@amsperformance.com your login information he can probably switch it for you.

We dont really have the oliver rods in the cart but you can call in to inquire about them
847 709-0530

Eric

 

Buschur runs Crower rods also and had no probs...ive been running the Crower Pro rods with no probs also
check to see if the cylinder walls are a different color (darker) good way to see if ya been running lean