Broken Diamond Piston. Pics why????

[87we410877]

hmmm.. who built the motor 2 times ??? What were the ring gaps ??? Ya sure do have some "cool guy" parts .. Do you see knock on a Fast system ??? (just wondering.. we r still on a chip)

FAST never picked up any knock ever.

Motor was built once, the first time by myself. After this bull, im sending it to RPE to take care of it. He'll probably tell me the crank and block is no good yada yada 10 grand. You can see my build and all teh specs including ring gap if you search "complete engine build" in general tech". It was pre-engine tech.

And yes i know, everyone has a stock rod stock crank stock ECU, 8445 heads with alky running 9's on a 2004R full weight 3700lb GN. Im becoming a firm believer of KISS (keep it simple stupid). Ditch the fast and the ALKY run a turbo tweek chip and 116 with a good tune.

 

[krom]

(keep it simple stupid). Ditch the fast and the ALKY run a turbo tweek chip and 116 with a good tune.

I agree with dumping the alky. Seems lately that all the broken motor threads have the same common denominator (alky).

 

[Mr.Spool]

i wouldn't blame the fuel to many variables but i can say you won't be disappionted with rpe.more than happy with the motor,and it does have diamond pistons and alky with a tt chip at 23psi it hit .97 g's on the g teck with a 62/65 turbo.

 

[87we410877]

It seems the only other noticable detonation was on #2 and #3. I took a pic of the worst rod. The worst bearings correspond to the pistons w/ no detonation. The pics are in order from piston #1 to piston #5 then back down from #5 to #1 at the different angle.

 

[87we410877]

#4 on

 

[87we410877]

2, 1 rod

 

[Grumpy]

well by the look of the bearing you def had detonation ..

And yes i know, everyone has a stock rod stock crank stock ECU, 8445 heads with alky running 9's on a 2004R full weight 3700lb GN. Im becoming a firm believer of KISS (keep it simple stupid). Ditch the fast and the ALKY run a turbo tweek chip and 116 with a good tune.

absolutely NOT !! look at a lot of guys that copied her set up.. They are not there. Personally I'd go with a chip and slowly LEARN the tune.. **** happeneds fast with a 10 sec car!! once ya have a handle on the car and its flying then go back to the Fast if ya want . Rome wasn't built in a day.. So get the thing fixed and move on.. Can't dwell on it now. pissed off.. hell ya !! Oh were you running alky ??? Bobby builds a mean motor!!

 

[TurboBuRick]

Do all the bearings look like that?

No matter what kind of fuel you run, there will always be something that can fail. Don't blame the alky.

What kind of fuel pump are you running? I would be taking a close look at it and do some testing.

Also test that map sensor. If you were having problems with the tune, maybe it's a flaky clone.

 

[Grumpy]

Oh forgot to ask.. Where is the piece of the piston ???

 

[Jeff Rand]

What fuel are you using to run 9's and how much boost? Someone once told me that when an engine detonates, it increases the force by 200 times. I have also built a few street engines with Diamond pistons and have not had a problem but I have to admit they have not been pushed into the nines. I know Kenny D uses Diamond pistons as well as CP's.

Jeff

 

[BEATAV8]

Id be more concerned about where the piece of the piston went. Better check your turbine wheel. I think youre going to be sad.

And the valve seats and valves...

Where ever that chunkie went it will leave it's mark.

 

[BEATAV8]

FAST never picked up any knock ever.

Better look into that. Maybe the sensor is dead or has a bad connection, or the transfer function / sensitivity in FAST is set incorrect.

 

[87we410877]

Do all the bearings look like that?

No matter what kind of fuel you run, there will always be something that can fail. Don't blame the alky.

What kind of fuel pump are you running? I would be taking a close look at it and do some testing.

Also test that map sensor. If you were having problems with the tune, maybe it's a flaky clone.

Aermotive A1000 and AN-8 line all the way up from the cell.

Grumpy, the chip is MIA. I looked at the cyliner walls and the heads and everything looks fine. Miraculously the thing may have made a clean pass out the exhaust.

Yes im running alky and a FAST.

 

[turbobitt]

Looking a the rod bearing I would think that something is bent, out of round, or tappered.
I still think the little pits in the piston are from the floating debris. It's not uncommon to have mterial carry over from one cylindr to the next after a failure. I wonder if the detonation could have occured after the damage due to the hot molten piston debris floating around ?
Allan G.

 

[BEATAV8]

Looking a the rod bearing I would think that something is bent, out of round, or tappered.

Aside from the seriously high severity of the wear, the lopsided pattern looks fairly typical for an off-center motor, doesn't it?

 

[V6gofast]

Id be more concerned about where the piece of the piston went. Better check your turbine wheel. I think youre going to be sad.

I would be willing to bet that the aluminum left the cylinder as molten
particles . Some of it will likely be on the exhaust valve and guide . And it
doesn't matter whose piston it is the ring placement is incorrect for a turbo
application.

 

[turbobitt]

Aside from the seriously high severity of the wear, the lopsided pattern looks fairly typical for an off-center motor, doesn't it?

Ok, here is another thing you can check. Usually after bad detonation, the rod bearings get pounded out of shape until they no longer hold themselfs in the rod. If you unbolt the cap, does the bearing fall out ?

I would say that the wear pattern is extreamly excessive for an off center motor. It has bearing material on one side with a fairly large wear pattern on the other. Looks fishy to me.

 

[ChrisChow]

big time detonation ... I also didn't care the way they are cut so close to the edge BUT we have been pounding the hell out of them for $15k+ with NO DETONATION Oh IF ya detonate the crap out of it you are goin to get the same results . Oh what does the top rod bearing look like ??

I agree. The first thing that came it to mind was LEAN and/or too much timing. Make sure you get a good WideBand to measure A/F on your next rebuild. What fuel injectors/pump are you using?

 

[87we410877]

I agree. The first thing that came it to mind was LEAN and/or too much timing. Make sure you get a good WideBand to measure A/F on your next rebuild. What fuel injectors/pump are you using?

Its whatever wideband comes with the FAST unit. it was like $370. Injectors are siemans 83lb and a aermotive A1000 pump. The tune was fine. Very conservative. 20* timing at 24 lbs and A/FR's at about 11.3 showing no knock. i think this fast and alky needs to come out.

 

[ChrisChow]

Hmm, did you verify timing using an external timing gun? It's a good way to make sure what you type on the laptop is going to be the same as what you have out in the field.

I'm still using a Gen 6 DFI with one of my turboBuicks . Found out my trusty laptop couldn't connect because the hard drive controller broke on it and looking to upgrade to another ECU...but that's another story.

At 15 psi of boost and 66lb Siemans injectors I'm running 11.5 AF on pump gas at a very conservative 15 degrees of timing.

Its whatever wideband comes with the FAST unit. it was like $370. Injectors are siemans 83lb and a aermotive A1000 pump. The tune was fine. Very conservative. 20* timing at 24 lbs and A/FR's at about 11.3 showing no knock. i think this fast and alky needs to come out.