[barnett]

I know this is not a nitrous question. But alot of people on this forum have alot of knowledge about pistons. This is a friend of mines from work 2.3 svo turbo ford motor. That he races in mub bog compeitions. This happened about 20-30 seconds into the run. This was on 15lbs boost with regular 93 octane. The spark plug looked rich and still had the electrod and didnt show signs of detination. Just want some info on what other people think.

 

[Monte Smith]

Looks like too much timing, although hard to tell in that pic.

Monte

 

[Collinsautomotive]

Looks like it got lean and detonated a bit. I would agree with Mikes assesment of to much timing as well.

 

[barnett]

This was with stock timing of 10 degrees. Maybe he should pull some timing out. Sorry about the pics their the best ones I have. Thanks guys keep the info coming

 

[Collinsautomotive]

I am gonna go with lean and hot. 10btdc does not seem very aggresive aside from the fact that the engine is on power for a long time. I would suggest check for bad injectors and clogged fuel filters and pump flow and definately get some picture of the plugs up ASAP !

 

[Monte Smith]

Lean usually does not nibble on the edges like that. If it was that lean, the top of the piston should be really clean and the entire top deformed from excessive heat. Slightly overtimed will detonate, rock the piston in the bore, let some oil by the rings and nibble on the edges of the piston. A piston that has that type burn is usually always an oil burn...now what let the oil into the chamber is what you have to figure out.

 

[Collinsautomotive]

I would tend to agree with you. but being lean on a FI motor causes knock. I typically see that on low timed motors starving for fuel. either way I want to see some plugs before condeming much of anything. 10* is not much timming unless its is a pump gas motor. If it is He is about to get an earful.

93 octane quality about straight sucks right now.

Lean usually does not nibble on the edges like that. If it was that lean, the top of the piston should be really clean and the entire top deformed from excessive heat. Slightly overtimed will detonate, rock the piston in the bore, let some oil by the rings and nibble on the edges of the piston. A piston that has that type burn is usually always an oil burn...now what let the oil into the chamber is what you have to figure out.

 

[Kayzen]

Rich, not enough octane, and to much lead. first off he races this thing in mud bog conditions,with 93 octane and 15 pounds of boost. This isn't a street car. The motor works much harder in those conditions. With the increased load he needs more octane or less timing.

 

[barnett]

Thanks so much guys for the replys. I also thought it was oil and a timing issue. We have been very worried about heat as sometimes he is on the throttle for 30-60 seconds. We are in the works of Intercooling the engine. We flowed all 4 injectors and decided to replaced them anyways as the flow in spec and we are going to run a higher octane fuel. Will see if I cant get a pic of the plug. Again guys thanks so much

 

[Sam Vincent]

10* is probably base timing. Remember the ECU advances the timing above that. Example: A 5.0 mustang with 10* base timing ( which is stock) has about 28*-30* total timing. sure with a turbo it will have less than that total timing, but you get the idea.

 

[barnett]

Yes it has a base timing of 10 degrees which is controled by the ECU. Sorry I should have been more specific. Thanks Sam

 

[punisher#1]

Rich, not enough octane, and to much lead. first off he races this thing in mud bog conditions,with 93 octane and 15 pounds of boost. This isn't a street car. The motor works much harder in those conditions. With the increased load he needs more octane or less timing.

X2

 

[barnett]

John aka Punisher#1. Is the austin gang coming to run Extreme at HMP this weekend???