Header Choices
 

I'm a little confused on what headers to run on a new setup. There is a lot of two sided views on the same product on this site. You hear the horror stories along with nothing but good things on similar setups.

I have an old pair of Stainless Marine manifolds that I intended to run on a new pair of 572cu in w/ 420 megablowers. Problem is, they are used, and have been in salt water all their life. I will take reliability over HP and would like a little advice from experienced users. I am a little nervous to use these, not worth it if there is a catastrophe. Also, I'm very nervous to buy a new set as I have heard of major catastrophes.

Any advice?

If you can't get hold of some KE headers, (the best IHMO:)) then go with either IMCO Power flow PLUS, or the SM Gen III manifolds.

Thanks for the advice. Are you saying the Stellings are not a good choice? I would almost rather have manifold style if they are on the safe side vs. a true header design that I have read about coming apart, leaking, etc.

we had a blown 502 whit stylings on them and bought it make 750 hp for a few years after rebuilding it at the same specs we get it on a super flow dyno and only see 675 hp ! Now the part you won't believe ,we swapped the stylings for a pair cast KE and we maked 800+ Hp after a few hours fine tuning it almost maked 900hp :eek drop:

We set it at 850 to keep it save but it was unbelievable U have to been there to believe it

I wish the made a set for ls small block !

On a 572 cubic inch well equipped blower engine the Stainless Marine HiTorque III system works very well also and a lot of performance boaters and big dollar boats have been using them successfully for years with good results and reasonable cost. The Kieth Eickert cast sweeper headers are great units too and as said here develop great power and torque, they just cost a little more with special tips and all.
Neither have a problem with leakage or breakage and seem very long lived with good maintenance and care.
You couldn't go wrong with either.

Best Regards,
Ray @ Raylar

stainless marine gen III manifolds with 5" tails! Very nice!

You mean these Ray? I will advise this when selecting the KE cast exhaust, be very selective on your hardware for bolting to your heads. The large casting area around the mounting holes does not have alot of clearance. Had to grind off some of the hex area to clear the casting. Thinking using a SS allen head bolt instead. Drilled for safety wiring of course!!

The KE cutaway pic is the old original header. Note in mine, KE no longer uses two water exit points. The rear boss area is left untouched. BTW. Having bungs welded into the tails for O2 sensors.

rotax is right on the KEs, I had to grind off the arp studs on the lower middle 2 fasteners to get the headers to clear. They are fine now though and I agree after almost 10yrs of running 2 sets of KEs they are the catz azz.

Yes, those are the KE headers I was referring to. I realize many cast manifolds and manifold headers will usually have a problem with clearance height on lower head row of ARP type studs as studs on this row are taller than head bolts and require more clearance that most all brands of cast manifolds do not have versus flange style tubular headers which generally do not have a head stud clearance problem at the same point. As you said the solution if pretty simple to keep existing studs or new ones in use on your engines. Glad to hear KE cleaned up the water transfer points near the tails is obviously looks cleaner on the new style.

Best Regards,
Ray @ Raylar

What's the difference in performance between the Stainless Marine or KE and Lightning tubular headers? My Lightnings lasted 14 years, how does that compare to the Stainless Marine or KE?

Like Ray and Mild Thunders says. Stainless Marine Gen III :) This is my first pair of SM. But done CMI Sport Tubes, CMI Big Tubes and Stellings Big Tubes before. With mixxed experience....

Jerry and Letty at Stainless Marine are great people with lots of knowledge and good service :)

Just in the rigging process so don't mind the mess.


Mange

I also had to grind down the arp head bolts to clear, not just the studs. I never tried it but have heard tale of the SM exhaust actually working better than a header on a blower engine. No facts on that just heresay.

On a big horsepower normally aspirated engine generally the KE's and tubular long tube headers will make more torque and power than the manifold(Stainless, etc. ) and E-top types. Normally aspirated engines perform better with longer individual tubes to scavenge the exhaust out better.
On a blower engine with higher boost levels (7-25psi)setup the stainless Marine Hi-Torque III and big tube E-tops and big tube (2-1/4" -2-1/2" ID) tubular will work best as your are trying harder on these engines to get the increased volume of exhaust gas out quickly. You still must be careful though to keep your torque and power up and consider how much of the time you are in boost and at what boost levels, as the rest of the time you are still operating as a normally aspirated engine not in boost or at very low boost levels (1-3psi). At these non-boost or very low boost areas, big tube headers or some larger passage manifolds can actually kill some of the lower rpm torque and power developed with scavenging and will negatively affect acceleration and mid-rpm performance. The KE's cast sweepers are pretty big passage units and probably work just as well , just have never had an opportunity to test or run a blower engine with them.

Nice set-up Mange, beautifully built & rigged and looks like that is gonna be one fast cat!

Best Regards,
Ray @ Raylar