strangezz

Hi guys, i have a '99 Evo 6 GSR and i'm looking for some feedback on what might have caused piston No.4 to melt on me.

This is the stuff i had in my car when it went: Evo6 TME TD-05HRA turbo, HKS 272 camshafts, sprockets and valve springs, Power direct fit fuel pump(flows either 220 or 230, i cant remember), stock injectors and an autronics ecu. i also have the HKS racing suction kit and Hiper exhaust with front pipe.

The car had just been fitted with the camshafts and there was some mild porting done. While on the dyno(of all places), piston no.4 decided to give up and went on only the 2nd dyno run. When we took apart the engine, we found no.4 was melted. There was no other damage to the engine or the turbo other than no.4 piston, the con rod and scorching in no.4. there was apparently no warning this was going to happen on either the dyno read-out or the laptop monitoring the ecu.

Im currently rebuilding the engine but i thot i'd get some feedback to find the cause and prevent this from happening again. The injectors were flow-tested after the incident and were okay.

So far, the biggest suspect is the fuel pump. Any ideas?

Sorry for the long post!
Strangezz

okitenik

Sound like you were probably maxing out your injectors and hence the fuel pump. Maybe it gave up under the strain?

Are you rebuilding with stock internals or forged/stroker kit?

CuGSX

Have you done any datalogging? It's kinda-sorta difficult to tell what the problem is if you don't show what your O2 sensor, knock sum while underload are.

Mike L.

strangezz

All the data is in the tuner's laptop..i can't remember the figures off-hand but im pretty sure the duty cycle for the injectors were still within a "safe" zone.

I'm just going to use 86.0 JE forged pistons and HKS conrods...leaving the crank standard. I would loved to hav a JUN stoker kit but its too expensive for my blood!

AndyF_RSX

A few questions,

What boost level were you running?
Have you checked the fuel filter to see if it was blocked in any way?
Did you flow test all of the injectors after it went pop and was no.4 injector flowing OK?

Andy

strangezz

Andy,

I was running 1.4 Bar, the fuel filter was okay and all 4 injectors were flow-tested after the incident and came up okay.

AndyF_RSX

Must agree that it sounds like a dodgy fuel pump then.

Standard injectors are 560 cc/min and should be more than up to the job of coping with 1.4 bar boost and some head work and cams.

Do you know what the specific flowrate of the pump is at various pressures. This will determine if the pump was big enough for the job or if it may have stopeed working, causing the problem.

Andy

more EVOlved

Could it have been your cam selection? A cam with less valve overlap/higher duration with a turbo will end up boosting the actual cylinder pressure. like having too much boost.

what were the differences between the new cam and the stock one?

evo_artist

Happened to me 2 days ago on my evo 4
installed a mines Ecu and on first run 14-15psi stock engine (air induction kit and half exhaust) at even 150 kmh SUCKS
#4 melted
I have a new post at the engine forum and check it out "a detonation problem?"

very disssssssssapointed and angry

evo_artist

so another #4 melted piston and should raise a lot of question marks to tuners
its the 3rd case of #4 melted piston that i hear in the forum

evo 8 ya

iTrader: (31)

I'm not suprized. On the old 4g63's #4 would melt first.

2GDSM

evo8ya is right on the #4 piston melting first. I had the #4 piston melt on my old 1G eclipse on TWO seperate occassions. Both times I noticed a lower than normal fuel pressure at the rail. I believe that the #4 injector ran low thus causing a lean condition and a melted piston. Found out that the stupid pump wasnt getting a high enough voltage to run correctly.

2GDSM

by any chance, was it more melted on the intake valve side or the exhaust valve side? Both times, my exhaust side of the #4 was melted through the ring lands much more than the intake side.

patsevo8

dude it doesnt sound like it has anything to do with your fuel pump. if that was the case you probably would have fried all 4 pistons not to mention not being able to drive at all.
I have a good idea that it might have been either your fuel injector or possibly the line going into your injector..

projekzero

no actualy theres an old thread on dsm.org about changing out the power supply wire to the fuel pump with a larger gauge wire, supposedly alot of people werent gettign the 12 volts to the pump and causing a lean condition. maybe this same inherit problem exists with the evo/