Well if your car is over heating than you can cause a hot spot inside the cylinder. Or the hot spot on your piston cause the coolant to heat up much faster than it can get rid of the heat. Those ideas can explain why your coolant was so hot.




keV

 

I have had cast pistons melt like that twice. i put my faith in a "professional" that was not able to notice that my injectors max out at WOT. the car ran great untill extended periods of time at WOT on the freeway. it was lean got too hot and did the exact same thing. Get your injectors flow tested to make sure and check the resistance on your injector clips to make sure you dont have any wiring issues then get some forged pistons and rods and retune that thing. Spend some time with a wideband on the freeway and see if your afr's change at WOT on the freeway for long periods of time. freeway driving is kinda hard on built motors and you wanna make sure things are right.

 

I don't think 15* is too much. How much is a regular LS or GSR? 12-16* I imagine. Do you have any pictures of the valves for cylinder 2? I don't think it was retarded too much either since it is on the intake side. I like the idea that the injector and/or wiring could be the culprit for this mishap.

 

My nitrous motor looked like that after I ran it lean one night. Thats what my senses say. Looked exactly the same as yours.

 

Correct me if I'm wrong, but lean conditions cause hotter cylinders and melt pistons. Too much timing also increases cylinder pressures, but the consequences are usually catastrophic (i.e. snapped rod, lifted head, cylinder crack). I think that the results from lean conditions are heat related, but results from timing are shock related.

 

Thanks for the replies. I know my injectors were not maxed out, i'm confident fuel pressure was good, the walbro 255 was not maxed out either. I am still looking for the best place to buy pistons and rods.

So far the cheapest place i've found is a store on ebay, $790 (US) for eagle rods with arp s, wiseco pistons including rings.

I know lots of people are using oem honda bearings, are the acl bearings worth the $150-200?

 

I think you have that backwards, alot of peopel run acl's but are hondas worth the 220 bucks. nothing beats oem but acl's get the job done very well. Just see what bearing codes you have in your engine and get the proper spec acl's theres standard, thiner, and thicker ones. you can find them on ebay rods mains and thrusts for 70 shipped from this place in puertorico, not sure of the sellers name but ive got a few sets from them. fast shipping and best prices ive found

 

I just bought rods, mains, and thrust bearings for 45 shipped. They were kings though, I got em off of ebay and the guy said they'd be either kings or acl, whichever he had in stock. I dont think they offer different bearing codes like oem does. You can either get standard or oversized. Just check your clearances with plastiguage.

 

So oem ones from honda are around 220? I will definitely plastigage them.

Here are some more pictures.

 

get the injectors flow tested, cleaned.

How long has it been running before?

 

I drove it about 500kms.

 

miles please

What brand of wideband was it tuned on?

 

Just estimate. i'm guessing about 220 miles.

i was using an aem uego.

 

Talking to the owner of a machine shop, he works mostly on v8s.

After looking at my piston and headgasket, he says the compression ring heated up enough to close the gap. Causing increased cylinder pressures, leading to detonation.

It seems to make sense to me, has anyone seen this before? What are you guys with built motors running for ring gaps?