how much power can stainless marine take
 

have a 4" stainless marine exhaust,will it take 750 hp ?getting conflicting stories.before it goes on the dyno is anyone running this much power thru 4" stuff.its naturally aspirated not blown

I think you should run it on the dyno , with that exhaust, and then dyno headers, and report back on the results. :coolcowboy: Help Full Force Tim out

lol...that's my plan.hoping the stainless works out .we"ll see

yes, very interested in difference, so far I hear 35-40 HP difference from dyno headers to Stainless marine...

Whats the build specs Blownzr1?

Brodix bb2plus heads solid roller single 1050 made around 680-ish with headers I ran gils on it with a 4" dry pipe 90 welded to a flange and it dropped 40hp.

This would of bin like 4.5" dry water jacketed pipes on it.
Forgot 598"

572s,10.5 compression,1050 quick fuel carb,bill miller intake,357 afr,cant remember cam specs right now without looking.bought these used but got dyno sheets saying they made 740-750 hp.were ran with eddie marine thunders on them in other boat with dry exhaust

Any results?

I think we're dynoing one engine this week,went ahead and committed to headers so we wont be testing the stainless marine stuff,dyno is costing enough didn't want to add to it by switching exhaust.i would like to know too but not going that route.

Cool thx bud

Scrap the SM's.

For that I would go with Thunder n Lightning Headers/Manifolds; http://www.diamondperformanceparts.c...cat=282&page=1


A 598" I built with T&L's. https://youtu.be/u-5P0vw1UqQ

Blown the Gen II's are ok with the right pipes but really need Gen III's. NA, the Thunders are the way to go!

On that combo i would guess about 40-50hp difference,the big n/a engines really like headers they really like the big tubes 2 1/8 now if it were a blown 509 making 700 the headers would be good for 20 or so at best

Man those things are Uugly, :helmet: sounds like a swap cam :ernaehrung004:

Good info.

How about a blown 540, making 900-950?

And that's when bling can fuk you.

At 600hp+ level NA it's either this or correctly sized tubular headers.

BT: I've seen these in Merc Racing blue and they look pretty good. Obviously my opinion.

im thinking I don't have enough room between the motors for the 2 1/8 headers....side by side boat

My buddys pro charged 509's have stock HP500 Gils, with boat running 107, they gotta be making 825-850 HP, seems that exhaust is fine for him, he researched it years ago, everyone said with the boost it would not matter much at all... I think boost is a totally different animal..

All about personal preference I suppose.

Headers look like "money" because they cost you "money" and lots of "money headaches" down the road.

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I personally dont think those thunder n lightning manifolds look bad. I mean sure,stainless tube headers look cooler, but its not like the GIL or SM regular manifolds are pure sex. At least imo.

According to pipemax, a build like that maxing at 6000 rpm, making 750ish hp

For low to mid range power, a 2.06 to 2.131 diameter primary, with 18.8 inch x 3.829 to 4.079 diameter collector.

For mid to upper rpm power, a 2.206 to 2.331 diameter primary, with 18.8 inch x 4.079 to 4.579 diameter collector.

Thats a mile, wait, 10 miles, away from a typical stainless marine standard manifold. In the car world, if you stuffed a 750hp 572ci big block in your car, and ran a 1 7/8" shorty header, with a 3" inch collector, someone would smack you across the cheek. :cartman:

I believe MER Performance recently dynoed a 650ish hp 509 build. Made close to 640 with the 2.25 dyno headers. Bolting the stainless marine manfolds on, it made right about 600hp, and lost a bunch of torque as well. About 30ft lbs I think at peak tq .

no disrespect Panther, all good

None taken, it's all good!

I still think we need to do an exhaust shootout on a N/A 700hp build. That seems to be the norm these days. 15 years ago, 550-600hp was the goals. What worked then, may not work now.

Maybe we can round up some exhaust, to try on Full Force's 540. We have his Stainless Marines. Vintage Chromoly offered up his Lightning headers for testing. Be cool to see some thunder & lightnings tested, and maybe some CMI big tubes, on a combo like this.

Didn't raylar do a bunch of testing or was that on lower 500-550 hp builds

If you guys do an exhaust shoot out, and they are not on my boat yet, I can send a set of Thunder and Lightning's to test.

Raylar's testing was all done in the 496 HO engine

That would work, since you are local . I can always meet up with ya before hand and get them, and bring them home after. Im sure nobodys gonna wanna ship exhaust around. Not to mention, the chances of them getting damaged in transit the way our carriers are these days

Let me know when you guys plan to dyno. If I can just give them to you, that would be the best!

Ive got the big tube CMI's, but Im a long ways away and not sure when the new engines will go in the boat.

We are going to need more beer....

Fountain did a test years ago -

It be nice to see that test done, on an engine that actually has some overlap, and turns some rpm. I think your product will really shine there, as opposed to a low rpm 500hp minimal overlap cam

Collector length means a ton ! Max hp doesn;t really change, but if you would see the torque and hp difference's from mid to upper mid rpm you may schit yourself - especially between worst lengths and best lengths.

Just keep your Gil's... Might just keep you from getting t-boned. Remember house sold. GC next. Don't fk with me. Lol. Just kidding. I think those exhaust are awesome not only power but looks. See them in person and they grow on you real quick. They look even better in a twin app. Did you ck measurements yet. Warm this weekend.

I'm coming up this weekend. I need to pull my drives and if possible, pull the other 3 Gil manifolds.

Endeavour32, call me if you get a chance, for some reason I cannot send out a PM