496 cmi e-tops
11-15-2011, 09:24 PM
#1
496 cmi e-tops
i know this is a loaded gun question, but i'm looking for some feedback on these, search really didn't turn up much. i'm torn between the e-tops, lightning and dana, i've had the dana's before and was very happy with them but i do really like the look of a "true" tube style header as the 496 needs all the help it can get in the looks department. do the tube style require more attention to prevent cracking? i've read countless threads about cmi's cracking after a few years or less, this is a freshwater only boat and is stored indoors climate control year round, thanks in advance
11-16-2011, 07:49 AM
#3
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For what its worth I think the cracking happens mostly on stock Merc 525 headers manufactured by CMI. This is typical more so than headers manufactured by CMI for specific applications.
That being said, I think the Danas get more power and are a work horse that you wont ever have problems with.
That being said, I think the Danas get more power and are a work horse that you wont ever have problems with.
11-16-2011, 12:02 PM
#4
i've seen that alot were the 525's, but there was also quite abit of 500's and big blocks in general, also read that guys put drains on them so they can drain water, just sketchy about forking out all that money and having to worry about my headers all the time, what about the lightnings? not too much info on those what little i've read people seem pretty happy
11-16-2011, 10:23 PM
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For what its worth I think the cracking happens mostly on stock Merc 525 headers manufactured by CMI. This is typical more so than headers manufactured by CMI for specific applications.
That being said, I think the Danas get more power and are a work horse that you wont ever have problems with.
That being said, I think the Danas get more power and are a work horse that you wont ever have problems with.
11-16-2011, 11:09 PM
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Not all headers look and work the same ??
Don't get to worked up on just looks when considering headers or header manifolds. How they are actually configured will have a big affect on how much added power they will develop on a Merc 496 engine.
The CMI-Etops for 496's are not having any problems I have heard of in the last three years with cracking. The only other thing to think about though is that E-tops are not a long tube collector tuned true header, but short tube single 90 degree riser short header. The CMI Sporttube headers for 496's are more of a longer tube tuned head and as such make about 40-45 more horsepower than the stock merc manifolds. They are also about $1500 more per set than the E-top. We have tested the 496's with both E-tops and the Dana header manifolds which internally are real 4 tube, long runner headers with a tuned merge collector in the end of the riser. The E-tops make about 22HP over stock 496 Merc manifolds and the Dana Header Flo-torque header manifolds make about 45HP over stock 496 Merc manifolds. Raylar has not tested Lightning headers and so I cannot attest to their horsepower increase over stock manifolds, but I believe Bob at Full throttle did some dyno tests before and after on stock 496" with Lightning headers and I believe that result was posted in his post for 496's he tested about two years ago.
As for draining or flushing headers, it is important to flush stainless headers or aluminum headers or manifolds and drain them especially if they will sit for long periods. After salt water use stainless headers can rust and corrode at the weld areas with salt water, long standing fresh water or high mineral content - brackish water and aluminum will corrode quickly if left with salt water in the header without fresh water flush. The Dana's can be hard anodized to slow corrosion in salt water use but then they have to be powdercoated to covet the aluminum discoloring from anodizing.
Bottom line if the look is more important then go with +20-22HP E-Top shorty headers which cost between $2800-$3500 per set, go with all stainless long tube Sporttube style long tube headers that run about $5000 per set for about +40-45HP increase. If the Polished Dana header manifolds will get an OK for looks,then their +40-45HP increase can be had for about $2600 per set. I don't have any pricing on the Lightning headers or their power increase so that's for others to supply here. Hope this info helps make your considerations and decisions a little easier to make.
Best Regards,
Ray @ Raylar
The CMI-Etops for 496's are not having any problems I have heard of in the last three years with cracking. The only other thing to think about though is that E-tops are not a long tube collector tuned true header, but short tube single 90 degree riser short header. The CMI Sporttube headers for 496's are more of a longer tube tuned head and as such make about 40-45 more horsepower than the stock merc manifolds. They are also about $1500 more per set than the E-top. We have tested the 496's with both E-tops and the Dana header manifolds which internally are real 4 tube, long runner headers with a tuned merge collector in the end of the riser. The E-tops make about 22HP over stock 496 Merc manifolds and the Dana Header Flo-torque header manifolds make about 45HP over stock 496 Merc manifolds. Raylar has not tested Lightning headers and so I cannot attest to their horsepower increase over stock manifolds, but I believe Bob at Full throttle did some dyno tests before and after on stock 496" with Lightning headers and I believe that result was posted in his post for 496's he tested about two years ago.
As for draining or flushing headers, it is important to flush stainless headers or aluminum headers or manifolds and drain them especially if they will sit for long periods. After salt water use stainless headers can rust and corrode at the weld areas with salt water, long standing fresh water or high mineral content - brackish water and aluminum will corrode quickly if left with salt water in the header without fresh water flush. The Dana's can be hard anodized to slow corrosion in salt water use but then they have to be powdercoated to covet the aluminum discoloring from anodizing.
Bottom line if the look is more important then go with +20-22HP E-Top shorty headers which cost between $2800-$3500 per set, go with all stainless long tube Sporttube style long tube headers that run about $5000 per set for about +40-45HP increase. If the Polished Dana header manifolds will get an OK for looks,then their +40-45HP increase can be had for about $2600 per set. I don't have any pricing on the Lightning headers or their power increase so that's for others to supply here. Hope this info helps make your considerations and decisions a little easier to make.
Best Regards,
Ray @ Raylar
11-17-2011, 05:41 PM
#7
thanks ray thats exactly the info i was looking for, performance def is more of a concern over looks by all means, just have not heard any numbers on the e-tops and their longevity, i've used the dana's on a 454 before and was very happy with results, quality and price, not to mention the install was fairly easy, dana seems to pop out again over these others i mentioned so its looking like these are it, i've read that you only need about 3psi more of fuel pressure to cure the lean issue in the 3-4k rpm band, thanks again for your insite
