IMCO And Dana Exhaust Systems

[Blue Mist '97]

Thinking of upgrading the exhaust manifolds on my completely stock 502 MPI. Mainly because I just hate the clunky look of the OEM manifolds and risers with long pieces of 4" black hose from the risers to the tips. At this time, I am looking to gain some hole shot and mid range, but also thinking about the down the road motor rebuild.

I put a set of IMCO Powerflows on my old Persuader (stock 454 Mag) and they did everything that I thought they would (better hole shot and mid range). However, like an idiot, I sold the boat with the manifolds. I am a big fan of IMCO, so they have been my go to aftermarket exhaust. However, I have become interested in the Dana Flow Torque system and what they bring to the table. I really like the fact that exhaust is separated all the way up into the riser.

Cost wise, trying to compare apples to apples, they are fairly close in price. Performance, IMCO says up to 40 hp, Dana is probably about the same (info solely from other forums as there are no stats on this that I have found). Looks, IMCO still looks good, but somewhat plain (IMO, but I still like them) while Dana has a cool kind of a header look in a manifold (it's growing on me).

So what are your opinions of Dana exhaust systems? Would especially like to hear from anyone who has them now or has had them in the past.

 

[corey331]

I have zero experience with either, but I will say that I see way more sets of IMCO's on boats than I see Dana's, so that tells me something.

 

[check253]

I used the Dana's on my 1700hp twin turbo motor and was totally happy with the performance. They are still on that motor and now have over 500 hours.

 

[SCT]

Check, off topic but did the Punisher get any winter projects? Did she beak 100 last year?

Good luck-

 

[Gimme Fuel]

If it is a stock motor also consider a set of the newer 496 take off manifolds. They are by far the best factory manifold merc has ever made and at stock power levels flow just as good as any after market manifolds. Most dyno tests on 496 engines showed zero gains when upgraded exhaust was installed FWIW.

 

[Blue Mist '97]

If it is a stock motor also consider a set of the newer 496 take off manifolds. They are by far the best factory manifold merc has ever made and at stock power levels flow just as good as any after market manifolds. Most dyno tests on 496 engines showed zero gains when upgraded exhaust was installed FWIW.

We had this same conversation a couple of years ago when I put IMCO's on my Persuader. After you mentioned the 496 manifolds, I looked around and tried to find a set, but couldn't find any at the time, so I gutted up and went with the IMCO's. They were pretty nice. No real speed gains on the stock motor, maybe 1 mph on a good day, but I felt that I got a lot better hole shot and mid range response. At least they looked a hell of a lot better to me than the OEM stuff with the Quick and Quiet system that was on it from the factory. Maybe I am just a glutton for punishment, but I just hate the square block look of those OEM risers sitting on those manifolds.

Thanks for the reminder. I am just in the thinking/planning stage right now and won't do anything until next winter, so I have some time and will look around for some 496 takeoffs. If you happen to run across a nice set, let me know. I would certainly consider a set and they would be a lot less money than IMCO or Dana.

By the way, don't know if you have seen the dyno tests of the 496 with Dana exhaust posted on the Marine West site? Thought it was interesting.

http://www.marineindustrieswest.com/installation/496_Dyno.pdf

 

[Gimme Fuel]

We had this same conversation a couple of years ago when I put IMCO's on my Persuader. After you mentioned the 496 manifolds, I looked around and tried to find a set, but couldn't find any at the time, so I gutted up and went with the IMCO's. They were pretty nice. No real speed gains on the stock motor, maybe 1 mph on a good day, but I felt that I got a lot better hole shot and mid range response. At least they looked a hell of a lot better to me than the OEM stuff with the Quick and Quiet system that was on it from the factory. Maybe I am just a glutton for punishment, but I just hate the square block look of those OEM risers sitting on those manifolds.

Thanks for the reminder. I am just in the thinking/planning stage right now and won't do anything until next winter, so I have some time and will look around for some 496 takeoffs. If you happen to run across a nice set, let me know. I would certainly consider a set and they would be a lot less money than IMCO or Dana.

By the way, don't know if you have seen the dyno tests of the 496 with Dana exhaust posted on the Marine West site? Thought it was interesting.

http://www.marineindustrieswest.com/installation/496_Dyno.pdf

I do have a set of EMI Thunder's with long risers that just happen to come complete with a 548 attached. Pricey though but would've the biggest HP gain from an exhaust swap you have ever seen! Haha!