Raylar's 496 Exhaust mods??
10-26-2006, 01:52 PM
#1
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Raylar's 496 Exhaust mods??
Ray,
In a thread that is a few years old now, you wrote about modifying the stock 496 exhaust for better flow. You were going to eventually start offering this service. Since we've seen nothing of this, I'm assuming you just decided it wasn't worth doing???
If you've given up on making a profit on the idea, would you mind letting the rest of us in on the mods you made, and what you got out of them?
I'm all for giving an innovative fellow his due profits, but if it's not going to happen, maybe you could help the rest of us out.
Thanks
In a thread that is a few years old now, you wrote about modifying the stock 496 exhaust for better flow. You were going to eventually start offering this service. Since we've seen nothing of this, I'm assuming you just decided it wasn't worth doing???
If you've given up on making a profit on the idea, would you mind letting the rest of us in on the mods you made, and what you got out of them?
I'm all for giving an innovative fellow his due profits, but if it's not going to happen, maybe you could help the rest of us out.
Thanks
10-26-2006, 05:18 PM
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Re: Raylar's 496 Exhaust mods??
I asked Raylar here on the forums, about the ported manifolds, and never got a response, but here is a copy of a response about the 496 manifolds that Raylar posted a couple of weeks ago:
Just to clear the air here a little (PUN)! Removing the turbulators on a stock 496HO yields about 10HP and yes we didi dyno pulls to confirm it. We have never recommended porting the stock Mercruiser manifolds on stock 496's because the benefits would be nominal. Stock 496's don't breathe well enough at WOT to take real advantage of big exhaust only changes. Also the stock valves in the stock 496's are steel and they rust easily when exposed to a lot of moisture, especially in salt water, sans the reason for turbulator plates to cook off this condensation. We do give some clean up porting tricks on the manifolds to our kit purchasers that do help the motor because after the kit install ,it benefits from exhaust side deep breathing and we use stainless nitirided valves that don't rust. We saw about 10-15HP at WOT on these mods. If you really want to see a Raylar HO525 or a HO600 deep breathe then install a good set of headers like the CMI's and yould see overall numbers around 560-570 HP and 625-630 HP on the HO600. Yes we dynoed those to confirm. Our Raylar/LaveyCraft race boat has our HO525 engine with 496/CMI's and I can only say that it outruns the same hull with a HP525 blue motor. It will be running this weekend in the OSS/OPA races at Lake Mead outside Las Vegas. There should be some surprised looks when the weekends over!
Just to clear the air here a little (PUN)! Removing the turbulators on a stock 496HO yields about 10HP and yes we didi dyno pulls to confirm it. We have never recommended porting the stock Mercruiser manifolds on stock 496's because the benefits would be nominal. Stock 496's don't breathe well enough at WOT to take real advantage of big exhaust only changes. Also the stock valves in the stock 496's are steel and they rust easily when exposed to a lot of moisture, especially in salt water, sans the reason for turbulator plates to cook off this condensation. We do give some clean up porting tricks on the manifolds to our kit purchasers that do help the motor because after the kit install ,it benefits from exhaust side deep breathing and we use stainless nitirided valves that don't rust. We saw about 10-15HP at WOT on these mods. If you really want to see a Raylar HO525 or a HO600 deep breathe then install a good set of headers like the CMI's and yould see overall numbers around 560-570 HP and 625-630 HP on the HO600. Yes we dynoed those to confirm. Our Raylar/LaveyCraft race boat has our HO525 engine with 496/CMI's and I can only say that it outruns the same hull with a HP525 blue motor. It will be running this weekend in the OSS/OPA races at Lake Mead outside Las Vegas. There should be some surprised looks when the weekends over!
10-26-2006, 06:22 PM
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Re: Raylar's 496 Exhaust mods??
thanks phebus.
I don't blame him for keeping quite if it's something he's integrating into his kits.
Normally I'm pretty good at looking at raw castings and seeing where changes need to be made. I really can't see anything obvious, and have no desire to ruin a set for trial and error.
I don't blame him for keeping quite if it's something he's integrating into his kits.
Normally I'm pretty good at looking at raw castings and seeing where changes need to be made. I really can't see anything obvious, and have no desire to ruin a set for trial and error.
