PDA

View Full Version : Exhaust



courtholl
07-25-2010, 02:45 PM
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 gil exhaust. They are dry. The manifolds are polished aluminum and I have not seen any online like 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 us 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. Ooh yea, this will be going in a 24 pantera (89).

stormrider
07-26-2010, 04:17 PM
Reversion, imo, should be avoided at all costs.
As far as the exhuast, i'd look at stainless marine.