CMI headers vs. Stainless Marine Gen III

ASD-6 · 06-26-2002, 04:01 PM

Fellas,
I read the pro's and con's of headers vs. manifolds, each has it's benefits and drawbacks.

I'm in process of installing a 509ci BBC with radical roller cam and 10:1 compression. With that said, I could use the cylinder scavenging benefits of a full 32" runner. Stainless Marine makes a (in my opinion) a bullet proof Gen. III manifold, riser and stainless tail pipe, however the 15" runner scares me. Is it worth spending a little extra $$ for CMI's 32" runner header? (and yes, I know the headers look kick a$$ and probably sound a little better)

My friend has the GEN III's on his Falcon, and they have worked flawlessly.

Oh yeah, the boat is a 1971 Donzi GT (looks like a Classic, but is beamier) and will utilize Arneson's extension box and #6 drive in salt water.

bajabob38 · 06-26-2002, 04:05 PM

If you have the $$$$$ go with the CMI. Just got them on my boat. They do look KICK ASS !!!!!!!!

Dean Ferry · 06-26-2002, 04:13 PM

Looks aside, The KE Manifold/header is by far the best HEADER, (Full 32" runners) and is manifold TOUGH, (No leaks!) on the market. I have run my set on my HP500 for 4+ years in the Atlantic ocean and have no problems. Plus, I don't have the H2O reversion problem either with my KE's! The only down side is they are not the eye-candy that some people perfer, and they are alittle loud! I put Shotgun III's mufflers on them also, again, with no problems.
Hope this helps,
MD

06-26-2002, 04:19 PM

I can't vouch for Stainless Marine, but I will say that CMI has been nothing but helpful in setting up my exhaust. Got the wrong tailpipes (my fault), no problem, had custom ones made in a week and 1/2 - a perfect fit. I couldn't measure from the outside of the boat for custom tailpipes (Formula with Silent thunder platform), so they helped me figure out dimensions from the inside. Tore a header gasket adjusting rockers, no problem, overnighted me a new pair. They've been great.

Just my experiance.

Scott

blueamerican · 06-26-2002, 08:22 PM

Tried both types on my naturally aspirated full roller, 10:1 compression, 588inch tall deck. The Gen III pulled 5 more HP above 5,000. The CMI's are prettier, but the Gen III's work, besides, Iam starting my 4th boating season, and they still look brand new.

jollyroger · 06-26-2002, 09:16 PM

Nate...

Do the rest of your Donzi brothers know what you are up to?? Good thing I'm putting a 'Hawk on mine. I'll need to just to keep up!!

Woodsy

36spectre · 06-26-2002, 09:28 PM

CMI all the way. I bought a set with the "cool collars" and they perform flawlessly. Also I found out a trick that makes them last years longer in salt water apps. On the runner, remove the rear cap and replace them with an adapter and a 1/4 inch hose. Run the hose out of the hull just above the water line thus allowing them to drain automatically after each use. I also think the CMI's have a lifetime time warrenty. Otto

Jassman · 06-26-2002, 10:30 PM

Pat at Active Thunder is putting CMI on my KE675's, I have them also on my Sonic, never have had a problem, 88 hours and no leaks.

Jassman · 06-26-2002, 11:14 PM

Troutly, You can see your reflection in them, eye candy it is.

Dean Ferry · 06-27-2002, 08:17 AM

Troutly,
I'm just an "Enginerd" by trade/schooling, therefore I make most of buying decisions based on performance/reliability data, (Enginerd's curse!), just like @ work! It's funny, when I look @ KE's headers, I see a BEAUTIFUL example of ENGINEERING/DESIGN and reliability, but, hey thats' the curse I mentioned earlier.

I would like my next set(s)? of KE headers to be coated the Mercury Racing Blue, if he can do that? I wonder if KE will polish them, that would improve the "Eye Candy factor"? Hmmmm?
MD