i decided to volunteer my car for the testing with the smaller pulley and bigger injectors(sorry can't give the sizes of either) with the high octane maps running...first pull on a conservative map put out some pretty damn snazzy numbers.... second pull got to about 6000 rpm and blew a head gasket (atleast that's all we think is wrong with it right now)

brian of course sat back laughing and immatating me he said " well ricerboy, i guess you gotta pay to play" cause i always tell other people that lol I don't guess i'm allowed to be mad cause they told me that map was a bit extreme for having no supporting engine work... but hey atleast it was only the gasket and not a piston

 

Knock on wood

 

well everything looks fine, and there was very little water in the cylinder, i'm just hoping it didn't warp or crack something that we won't see until it's running again

 

Ouch!! After research (which I'm sure you have done now) do you know of a good company for seals and gaskets? I want to prep my motor before I start messing with more boost and put the stage III on it.

ps the pistons in the SS S/C are forged so hopefully they held up

 

the pistons aren't forged

 

The rods and crank are forged, not the pistons. I believe they are hypereutectic.

 

forged pistons are egg shaped and round out when hot, and they have plenty piston wall clearance, HT pistons collect more heat, area super tight fit, and are round and barely expand (if at all).

forged was in the 60s, 70, 80s, and a few morons in the 90's. used them

 

whats an HT piston?

 

WHAT ARE YOU TALKING ABOUT??!! A forged piston is stronger and is not going to burn up as easily in an engine with the chance of detonation. the down side to a forged piston is that they tend to be heavier.

Cast pistons are in your cars less prone to detination because higher heat in forced induction, nitrous, and higher compression ratio engine cause them to burn up faster.

Forged pistons are defin. better than a cast piston in higher performance applications i can assure you a top fuel car making near 8000 horsepower dosen't run a cast piston.!

 

Can you say if it was smaller then a 2.7" and bigger then 42lb injectors???

And how are you changing the maps and what HP numbers were you seeing???

 

there's an aftermarket system installed on the car, you can upload new maps to it with a laptop

the size of the pulley wasn't what blew the gasket... it was us being stupid

 

So your using the SMT-6

 

So if you have someone playing with your fuel mapping, does that mean we may have some sort of PCM access soon?

 

So if you have someone playing with your fuel mapping, does that mean we may have some sort of PCM access soon?
So if you have someone playing with your fuel mapping, does that mean we may have some sort of PCM access soon?
So if you have someone playing with your fuel mapping, does that mean we may have some sort of PCM access soon?
So if you have someone playing with your fuel mapping, does that mean we may have some sort of PCM access soon?
So if you have someone playing with your fuel mapping, does that mean we may have some sort of PCM access soon?
So if you have someone playing with your fuel mapping, does that mean we may have some sort of PCM access soon?

Well does it?

 

Are you changing your calibration? What stupid thing did you do ?
As for editing the PCM there are several companies that have software thats going to be able to do it very very soon. Like as in a matter of weeks.

I think selfinfliction has been teasing us long enough and needs to let us know what he is up to

 

sorry man.. me and brian would both love to tell everyone, everything we've been through the last 2 months but we just can't.


on the topic of the calibration, we were running one that shouldn't be run on a stock motor (or at least not safely... appearently)

 

Is that possible to know what have been done so this way I won't blow my headgasket with the HPTuners software ... PM me !

 

hmmm somebody got carried away a little

as long as you monitor your af and knocks, and aren't pushing your luck, it's prety freaking hard to break something...if you start geting knocks and or lean out, then get out of it fast.... basically don't be stupid about it and you'll be fine, regarding of the set up (stock car or highly moded).

a word on pistons: Hyper pistons have a nasty tendancy to shater as opposed to forged that will crack first...it is all a matter of tuning, if you don't knock, then pistons will be fine, I believe the Keith Black pistons where proven at the track to hold a 500 shot on a mustang, with a safe tune...knock, lean out and boost will eff up any piston, regardless. Hyper pistons make for a "better" street motor, less blowby, tighter tolerences, a little more power...but if you don't want to worry about pistons, and you knwo you'r going to turn serious rpms or serious forced/nitrous set up, go forged.

 

yeah keep the boost and whp under 300 whp on stock motor. Or throw tons of fuel at it and get owned by rising gas prices

 

Very well put. The other down side to forged pistons is, that they expand and contract more to twmperature changes. You have to leave a much bigger tolerance which leads to sloppy piston fit until they are warm. This is especially true for cold morning starts, where the piston will slap around inside the cylinder and tear up your rings.

For daily drivers, use hypereutectic. For high hp track cars that are constantly being rebuilt, use forged.

 

I don't believe that forged metal expension rate is linear tho, so the only time you'd have loose tolerences would be on start up, but the piston itself will heat up really fast (faster than your coulant will) so it is taken off quite fast, but regardless, it does expend alot more than cast or hyper. The effect of a piston rocking in the the bore can alse be reduced with the placement of the piston pin. Piston pins located closer to the crown will make for a more stable piston in general. I think cost ends up being a big part of the decision: 280 bucks or 600 (i'm talking V8 figures --sorry not as knowledgeable on 4 cylinders parts).

 

Seriously tell us how you blew your head gasket.

 

I will guess: high boost and knocks

 

and everyone was so quick to kill me when I said "tune with care"

 

I have the Wiseco forged aluminum reduced compression pistons in my Ecotec. My engine now sounds like a small diesel. It is louder after a cold start, normal. The diesel sound comes from the concave dish shape of the top of the piston. Also normal I'm told. Since the Ecotec is a smaller bore engine (compared to a big V-8), there isn't as much of a problem with the thermal expansion issues, but they still exist.

I also use ARP head studs instead of bolts. I would certainly recommend switching to those if you haven't already since you will be removing your head.