Just read the link. Seems to me that it was just a freak thing. Although Judge Ito has a point. What happened to IHOR is almost exactly what happened to another friend of mine who also owns a silver 93. Basically the car just stopped running when not under load. I hope this doesn't cost anything.

I thought there were no side effects of using leaded gas???(beyond o2 & cats)

Thats what I thought too. If it raises the egt's high enough to actually blow the motor, it kinda defeats the purpose of using it.

Exactly. How does that make sense though? Doesn't raising EGTs, mean your running lean? How would running leaded gas do that?

I'm guessing it wasn't anything to do with lean conditions. Probably has more to do with bad apex seals and bad luck.

Yeah. But didn't 7mech say that leaded high octane gas raises egts?

So the presumed cause of this failure is what? Silver, what is your full setup exactly? specifically, your fuel sytem, and ignition ? What were you doing when it let go? is this a problem inherent with the turbo, or did you suck a seal through your turbo? TIA, Carl

Sorry for your loss https://www.nopistons.com/forums/pub...IR#>/dunno.gif

Damage like that comes from a seal (or some foreign object) going through the turbine.



Ihor, do you have a filter on the turbo?

1Revvin7 and 94 touring the reason I believe that high octane leaded or unleaded gas causes higher egt's is that it burns better and you don't get that unspent fuel going through the exh. As we all know unburnt fuel has a cooling affect, and without having some unburnt fuel passing through your exh. you don't get that cooling affect(hense higher egt's). This is my own theory and is not a proven fact, so take as you may. Sorry if I'm wrong and for any confusion I may have caused.

13bAce I didn't know there was a filter made that you could put in your turbo manifold that would block things like broken apex seals. Please give me some more info on this, like where I can get one and how much it cost.

Actually, Leaded race gas runs cooler at the same (fuel map settings) as pump gas because the density of leaded fuel is higher than pump gas. Generally, when you run leaded (race gas) your a/f ratio drops approximately by 1 point. ex. 12:1 a/f ratio on pump gas will drop to 11:1 a/f ratio on race gas using identical fuel map. EGT will also run cooler because the a/f ratio is lower. The advantage of running race gas is that you can get away by running leaner a/f ratio w/o experiencing detonation. The reason being is that race gas tends to burn slower thus, reducing any chances of predetonation at higher boost level or more advancing timing. EGT can also get higher because of leaner a/f ratio. Just by running leaded gas (race gas) doesn't make the car run hotter. It has the opposite effect.



Steve K