Courtholl

I have a new engine being built and need to figure out my exhaust. My old engine froze and the block cracked. I have what appear to be older dry gil exhaust manifolds and SS pipes. The manifolds are polished aluminum and I have not seen any online that look like these. We are scrapping these, as they might have cracked and my mechanic here hates them and says they are old. The exhaust pipes are still good and are dry pipes.

I am having a 454 stroked and bored to a 496. Engine builder is thinking it will pull 500-525 hp. He does have a big cam in the engine and he likes to try to go to dry exhaust to eliminate the possibility of reversion. He is going to have it idling at 800 RPMs and said at idle the big cam could pull water back in, etc. I am not sure how concerned I should be about this. I am trying to figure out 3 different options for our exhaust set up.

One would be to buy gil replacement manifolds and use my existing pipes (stick with complete dry system that I already had on the 502). Or go with 2 different EMI options. One he has EMI build a complete dry exhaust for about $2,500.00. The other is EMI with the water jetted towards the back when it is introduced into the exhaust – he has it introduced later and force back towards the transom (about $2,100.00). Would be able to use some flexible tubing in the second EMI option, but the first would be a solid dry pipe like I had with the 502. I wanted to try to use my existing Gil pipes, but will not be able to, as they said it would cost more to modify everything to use those (if just get gil replacement manifolds, then would be able to use them). Gill replacement manifolds alone are around $2,000.00.

My questions are: Should I be worried about reversion? What is my best option? My engine builder and my local mechanic come from two different schools of HP. Builder likes big cams with good intake, and my local guy focuses on intakes for big HP gains. Any feedback would be greatly appreciated. Oh yea, this will be going in a 24 pantera (89).

basic info on engine:
Dart Cast Iron heads 345

2.30 intake valves
1.88 on the exhaust

Cam is hydraulic roller
547 lift
230 intake
236 exhaust

Griff

What is the lobe sep on the cam?????? That is really not a very big cam.

I ran a bigger cam on my 525sc/454 and never had a hint of reversion with wet exhaust. I ran CMI Unitops.