Originally Posted by Sydwayz (Post 2037636)

Fred at Trick has switch from CMI to Stellings for his distributorship.

I also know that Basset is now producing a set of 496 headers. They are working on the accessory adjustment kit.

Originally Posted by Undertaker (Post 2037964)

Purchased mine from Jaime @ Lakeside Restorations a sponsor on here give him a call he is very knowlegeable and willing to answer any questions IMO. Good luck

Originally Posted by DONZI33 (Post 2038036)

Thanks.. :)

Your manifolds & risers arrived on friday.. Bling bling! The tips are still on the way.. :D

Btw: I believe I said labor to install the manifolds is a minimum of 3-4 hrs depending on application, not including the tips.. ;)
The Cmi system takes even more time to do due to line mods & other relocations.. :)

Jamie / Lakeside

Originally Posted by tblrklakemo (Post 2038165)

Sweet....let us know how the dana product turns out. I am very close to buying something like that. What is needed for install besides nut drivers and a torque wrench? Any special tools?

Originally Posted by Undertaker (Post 2038144)

Cool when we gettin those bad boys installed..... 3-4, 5 hrs whatever they are a lot less than CMI'S thats what I was trying to say.

Undertaker

Originally Posted by Undertaker (Post 2038466)

Cool....talk to ya later...

Originally Posted by Undertaker (Post 2037963)

Just ordered the new Dana Marine exhaust for my Donzi 22 classic w/ 496 HO was told 40-45 hp gains about 3 hrs install time and if ya put there new exhaust tips on you will notice a VERY NICE sound.....can not wait for spring

Originally Posted by tblrklakemo (Post 2039023)

If anything, loseing the 80lbs of iron in the back will help my slug get on plane.

Originally Posted by DONZI33 (Post 2039014)

While the factory system on its own is not bad, it still is not as good as it can be.. The DMP exhaust has long internal runners, and has runners that carry into the risers. There after exiting thru a venturi they call a vortex. The venturi helps to speed up the exiting exhaust more than many collectors in headers. This also helps to draw in more air fuel mixture into the engine. This requires an adjustable fuel pressure regulator to enrich the fuel delivery slightly. That's how the power is gained with this system.

In reference to Ray @ Raylar he has dynoed the engines with these kits & he has substantiated these gains & the need for the fuel pressure regulator on the Mag Ho applications with the modular fuel pump system.. We are a dealer/installer for his products as well. I have personally talked to him about these systems. Unless I misunderstood Ray, then even though many of the engines you see in his ads have CMI, he said that the DMP systems also compliment his products nicley..

BTW: Ray has if my memory serves me correctly said that the factory exhaust was good for a merc stock part. However Ray himself was able to improve upon it & used to offer that service at one time. He felt that the DMP was superior to doing that, especially with the manifolds going back to cast iron.

As far as the cheapest bangs for the buck, this is one of them..

I hope this helps to shed some more light on the subject for you guys. :)

Jamie / Lakeside

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Originally Posted by Bill 3 (Post 2039092)

Thanks for the info Donz33. Thanks,
Bill

Originally Posted by Raylar (Post 1575038)

I thought I might chime in here to kind of even out the questions of horsepower and torque gains from exhaust upgrades on 496's. First, keep in mind that for any motor to gain horsepower or torque it must basically get more efficient. Obviously any things changed on a motor that increase the volumetric efficiency can increase power. There are basically three types of marine exhaust manifolds,

1. The tradtional old mercruiser log manofolds that came on the 350 thru 502 carburated and MPI motors from 60's thru mid 90's. these manifolds because of their log (all exhaust ports dump close to the head into a long square chamber and then exit a back end up thru a small vertical riser entrance) are very innefficient, heavy (iron) and were poor at letting the motor develop hp and torque.

2. The aftermarket and new Mercury (Gil) short runner, center riser manifolds. These are aluminum units like Eddie,, Revolution Imco, Gil, CMI E-tops and 496 Merc., etc. they all have similar short runners 8" - 10" that merge into center riser openings and definitly flow better than the old log type most boaters have been use to. They will definitly make more power and torque than the old log manifolds.

3. The tubular stainless and special cast units with long 18" to 24" semi-equal length with good merge collectors, like CMI, IMCO Super Powerflo, Stellings, Eichert Bassett, Dana, etc. will generally flow exhaust more efficiently than either of the two other types.

The real question here is the 496 engine. The stock 496 Merc (GIL) aluminum manifolds (type 2) are really pretty good units when compared to other (type 2) manifolds. Their individual runners and merge into the stainless steel round big radius risers with merge collectors can do a very good job of helping the 496 develop its great torque and good power. ESPECIALLY WHEN THEY ARE GIVEN EVER SO SLIGHT MODIFICATONS! If you were to take the turbulator plates alone out of the 496HO and dyno the motor you will see about a 15HP increase alone! So if you compare certain aftermarket manifolds (not type 3 tube headers) you will in most cases see no significant power increases from stock 496 manifolds.
If you are looking for more Bling, polish or paint the Mercury 496 manifolds, polish the stainless risers and you have some good look'in aluminum manifolds that work well and you will save yourself about $1500 minimum.
If your 496 is stock and you choose to step up to a good (type 3) header system you will probably see about 25-40HP net increase over the stock exhaust manifolds and risers with the "turbulators" removed, depending on your boats riser to transom configuration and muffler use if applicable.

Trust me when I say that Raylar has probably made more dyno pulls on stock and modified 496's with many combinations of exhaust than probably anybody in the industry short of GM and I have the dyno sheets to prove it! We have made over 525HP on a normally aspirated 496 with stock Mercury 496 exhaust manifolds (turbulators removed and manifold riser openings lightly ported.) This is about the limit, normally aspirated, for these stock manifolds.

If your plans are to go above 525HP with a 496 either normally aspirated or supercharged 496, then invest in a good set of (type 3) real headers or manifolds, you won't get there without them.
I am not trying to endorse or critisize any aftermarket exhaust manufacturers here, I am just trying to get the real world results of their use on stock 496's where I have my expertise.
Remember engines increase power from increased breathing and efficent use of fuel. The 496's need to breathe better on the intake side to make more power above 450HP and this will only come from improvements in heads, cams and intake manifolds, supercharger or turbo charger addtions . You are not going to get a 475HP from a stock 496 from just installing any set of headers and especially not from a set of $2000 manifolds. If you do, let me know how you did it.

Just some real world facts!

Best Regards,

Ray @ Raylar

Originally Posted by Michael1 (Post 2039157)

Just increasing fuel pressure for full throttle is going to put the engine too rich at every other operating point. That's a rather crude way of tuning.

Also be careful of these horsepower claims. You can easily show huge horsepower gains, by putting on a new,shiny set of valve covers, and "correcting" to a more favorable set of standard pressure and temperature conditions for the dyno run. That's a very common cheat.

Michael

Originally Posted by Bill 3 (Post 2039171)

Question. I looked on Dana's website and found the manifold. If I understand it right the 496 kit ($2550) comes with all needed. But it comes with "tube style" risers and to get the hp gains we would like wouldn't we need to get the "vortex *" risers which are $1060. Not sure about an exchange of the "tube style" for the "vortex *" riser $. Regardless we are getting real close to header money if not over and they have more bling factor to go with the hp.

Don't be offended by my (our) skepticism. There are a lot of exhaust systems for sale. If you can go ahead and post the dyno numbers. I am sure several of us would like to see them.

PM or email me with pricing. I am currently having my hull blueprinted, and depending on how that goes ($), I may be interested in more "go fast" stuff.

Thanks,
Bill

Originally Posted by Michael1 (Post 2039157)

Just increasing fuel pressure for full throttle is going to put the engine too rich at every other operating point. That's a rather crude way of tuning.

Also be careful of these horsepower claims. You can easily show huge horsepower gains, by putting on a new,shiny set of valve covers, and "correcting" to a more favorable set of standard pressure and temperature conditions for the dyno run. That's a very common cheat.

Michael