Tony Mamo @ AFR

iTrader: (13)

Well guys...

Yesterday was a somber day....

I headed to the track with ideas I might put my 224 cammed C5 in the tens with some aggressive launch RPM and the help of the new lightweight 17" frontrunners I just fabricated (thanks Guy!), but the GM stock shortblock finally gave out on me in the burnout box on my first attempt to get down the track. I noticed an intermitent loud tapping noise coming out of the water (which I was hoping was valvetrain related), but upon further inspection last night, I speculate a piston ring land might have broken and was getting banged around a bit (closed up the #7 spark plug). The valvetrain looked OK, but I havent had the opportunity to actually pull and disassmemble the engine to verify additional damage etc.

Anyway, considering the long life (52K) and it's recent job as a 205 cylinder head test mule, I must say this engine doesn't owe me a penney (400 verified dyno pulls including the testing I did before the AFR H/C package, a handful of track events, MANY passes in the middle of the night, etc.) I wish it would have hung on a little longer as I wanted to pluck it and use it as a "baseline" for future testing. I've got a 383 shortblock in the works and planned on doing some 205 versus 225 testing and a couple of cam swaps as well. Looks like I will have to take every component of of my current hurt engine and try to duplicate it using another stock GM shortblock....I would expect the numbers to be close assuming a decent leak down on the donor shortblock (I'll make sure the cam is installed exactly how it comes out of my current shortblock, etc.)

By the way, I'm not posting this information in search of a bunch of sympathy and all that BS....I'm a big boy and I know I have been pushing this engine well beyond it's intended means for quite some time. I knew this information would ultimately get into the public domain and I wanted to be the one to share it with you. May she rest in peace and I hope to have as successful a project with the 383 that's now on deck....

I will keep you guys appraised of that information as well as the official autopsy report on the 346 when I finally get it out of the car. I'm just glad I had the opportunity to get that recent "in car" track video most of you saw already when it was alive and running well (redlight and all!!).

Regards,
Tony M.

silverbeast

iTrader: (16)

Well atleast she went out with her boots on..... in the water box! Good luck with your next motor Tony.

pdd

iTrader: (3)

good luck with the next build up tony

Patrick G

iTrader: (14)

Don't stay down for long Tony. We always look forward to your new tests.

slo-vette

Thanks for the update and good luck on the 383.

BrentB@TEA

I lost my first stock shortblock at the track also...top of third gear....old #7 came apart...closed the gap etc.
Price we pay..
why not go 402 since you may need a block also?

Tony Mamo @ AFR

iTrader: (13)

Many projects are in the works....a 408 build up will also see the light of day in the near future as well....We are making a pitstop at 383 inches along the way. Lots of good tech content in the works with various AFR headed combinations....engine and chassis dyno information to follow.

CHRISPY

Sorry to hear the bad luck If a piston came apart it was likely from lean detonation.

I think an LS2 402 with AFR 225's would be nice.

gomer

iTrader: (13)

Damn, that makes me worry about my stock shortblock. It has 30k on it now and has been modified internally since 800 miles. At last count it had over 10 sets of heads and getting close to 20 cams in it. Probably close to 200 or so dyno pulls too.. and a few track runs. I'm installing a set of Bo White's 241's on it right now and have a MS3 cam I want to stick in it within the next few weeks.. maybe the ol' bitch will hang on a little longer. Sorry about the engine Tony, but it just opens the door for bigger and better things.

slow trap

iTrader: (22)

is it just me or is # 7 prone to going lean ?

TJ

iTrader: (10)

is it vettes, or an LSx thing altogther. ive seen more #7's come apart then anything.

XLR8NSS

iTrader: (4)

LSX think in general.

mike c.

iTrader: (1)

hay tony,love my 205 heads not only did i gain 52rwhp but i gained about 4 tenths on a slipping clutch that died at the track on the 3rd run. anyway...i lost a motor too,so i feel you bro. goodluck with the new set up,looking forward to the new testing. mike c.

JZ'sTA

iTrader: (23)

My number 7 had a nice quater size hole in the middle last year.
Everything else looked good.
That damn #7 piston.
A guy that tunes down here sometimes tunes by each cylinder, and said he see's the #7 cylinder lean more often then the other one's.
Weird.

gomer

iTrader: (13)

LOL, I'm going to stick me a cold *** plug in #7 after reading all of this. 7 Tr6's and 1 polar circle plug

BrentB@TEA

the reason #7 burns up first is because it gets the most air due to GM's intake design. The back wall of the intake angles right to the number 7 cylinder. So #7 gets the most air and same amount of fuel. so when cylinders 1-6 are set on kill...it can kill 7 and sometimes 8

BrentB@TEA

maybe just a slightly larger injector on #7

jrp

iTrader: (16)

good thing i didnt make the trip up to bako just to see your car

what was the turn out like?

PREDATOR-Z

That is why ITP systems should be develloped and marketed a a decent price for max effort systems.
Not to mention their ability to accept tight lsa cams that idle like a 224

PREDATOR-Z

That is what I did, but not a bigger injector just 2 that flowed the highest out of the 2 sets I got.