W8N2SQZ

iTrader: (6)

Hey everyone,

I have had an issue in the past where my 347 would use a little coolant upon some spirited driving. So I changed the gaskets (GM MLS) and things were good again.

Now the radiator cap is tough to twist off and once I rotate it over it gvies a gerber baby food "POP" and there is an inch + of coolant gone.

I am not to terribly worried. The block has a good 20K + miles on it @ about 575 @ the tires. I have self taught myself how to tune (still don't know a whole lot) and through this I have boosted the car with a lot of timing which resulted in pinging.... well you get the idea. In other words, the motor I am sure is still good, but has also seen its days. I have replaced the gaskets before due to a loss of coolant, but I have never had the radiator cap POP before.

Anyone else experience this?

Thanks,
Glenn

Blownramair

I've had this problem last year running 15-17psi on my D1... 347cid like yours... what happened is my gaskets started leaking and under boost -- the heads lifted off just enough to pressurize my cooling system casuing the radiator cap to pop... After ripping the heads off, I had 3 cyclinders leaking on the left bank... hope this helps...

Jay

W8N2SQZ

iTrader: (6)

Thanks Jay,

I have come to the realization that the heads have lifted again. I have a 6 liter iron block I am working on. I will just have to speed it up!

I guess part of me was hoping that it would be in the radiator cap. This would buy me some time on the other build I am doing.

Glenn

Blownramair

get some arp head bolts or studs if your gonna run high psi and of course the gm mls gaskets... what heads you running?

J

W8N2SQZ

iTrader: (6)

ARP studs, unported 317 heads, and GM MLS 6 liter gaskets.

Talked to my engine builder today and he has 4 LSX blocks in stock. Who know what will happen

Glenn

mahhddgtp

I'd have it tuned by someone who knows what they're doing... Too much of that "ping" can cause you to be reposting this topic

W8N2SQZ

iTrader: (6)

Trust me, I have learned my lesson