Shiv,

Saw the latest Best Motoring visdeo and you guys had a bad head gasket and couldn't compete in the Amercian Touge. Props to the top secret Civic....guy is a spectator from Chicago, Tsuchiya and orido decide to race his car and it kicks ***!

Damn, the worst of luck not having BMI review a Vishnu evo....

 

the evo would have won by 3 seconds or more... looook what car had the fastest time. i was pissed that i didnt get to see Tsuchiya and Orido driving the car though.

 

still want to know how the gasket went bad....

 

Hiya,
It turned out that it wasn't the headgasket. Instead, a too aggressively ported intake port developed a crack which was deep enough to penetrate into a coolant passage. Under heavy vaccum, the coolant would be pulled into that cylinder and burn off. Under boost, the cooling system would pressurize. The reason it cracked was because that head saw one hell of a thermal cycle back in December right after the 25Hr race because we yanked the AC and belts off of the shop car in order to keep the 25Hr car going. Without these parts, the water pump doesn't spin. So the act of simply driving the red car on to the trailer and leaving it idling for a short period of time (which I suspect the towing guys did without knowing any better) generated more heat than that head was capable of sustaining. The entire head was tossed and replaced with a stock head soon thereafter. This explains why we couldn't find any sign of leakage on the headgasket when we did the last minute gasket swap the night prior to the show. It does truly suck that we didn't run the car. The car needed to be driven 350 miles home so we didn't want to strand ourselves in Willow Springs of all places

Cheers,
Shiv

 

From what I understand the 4G63 head is pretty sensitive to porting, as Shiv said the walls can be over done to the point where they are pretty thin. Without the over heating event there may not have been a problem, but the same thing has happened to other 4G63 heads before. I do not know how much opening up the ports really helps anyway, I can see where cleaning up and smoothing the bowls helps, but if you look at the ports on the 4G63 compared to other four cylider heads they are huge to begin with. I do not know this for a fact, but I would guess that if the ports on the 4G63 head were opened up too much more you would loose a lot of velocity. While forced induction does make up for this somewhat, it will hurt the lower end off boost conditions considerably. I guess that everything is a trade off and you just have to look at the detriments as compared to the advantages.

It is a shame that they could not finish the contest, but Sh*t happens to the best of them.