Best 496 headers?
#61
Jamie
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www.LakesideRestorations.com 570-639-2628
We Make Fast Toys Faster, Cool Toys Cooler and Old Toys New!.. Performance, Custom & OEM Parts & much MORE![/CENTER]
www.LakesideRestorations.com 570-639-2628
We Make Fast Toys Faster, Cool Toys Cooler and Old Toys New!.. Performance, Custom & OEM Parts & much MORE![/CENTER]
#62
Although not for everyone, CMI Headers have proven performance gains and great looks. There are alot of decent exhaust systems out there and many have been mentioned in this thread. If we can help you out with product information or a quote on CMI's, please give us a call. Exhaust systems are expensive, make sure you choose something that perfroms to your expectations and looks like you mean business!!
Kirk
Ateco Engine and Dyno Shop - Your CMI Source
Kirk
Ateco Engine and Dyno Shop - Your CMI Source
Kirk,
I agree CMI is also a good system & has its place in the market without question. It's just good to also have more than one option.. On tighter twin applications the Cmi is the only other good way I know to go when looking for more bling & power.. I also cant say anything bad about the quality of their pipes, every set we have sold or installed to date has been "A ok"..
It's just too bad the pricing is not a little bit better on their products, Although everything everywhere is expensive anymore..
Jamie / Lakeside.
__________________
www.LakesideRestorations.com 570-639-2628
We Make Fast Toys Faster, Cool Toys Cooler and Old Toys New!.. Performance, Custom & OEM Parts & much MORE![/CENTER]
www.LakesideRestorations.com 570-639-2628
We Make Fast Toys Faster, Cool Toys Cooler and Old Toys New!.. Performance, Custom & OEM Parts & much MORE![/CENTER]
#63
At this point if I was buying today, it would be Dana. BUT this thread was asking about headers (not my thread though). Anyway, wouldn't it be great if we could see a comparison between all 496 headers - Stellings, Lightning, CMI, Bassett (any I forgot).
CMI's are around $4500 per set and I believe the Stellings to be similar. Not enough bang for the buck IMO. Lightning can be had for $2000 (mild steel) or $3500 for all stainless polished. Getting a little more realistic IMO. I wonder about the performance in comparison to the others. Bassett, I really don't know anything about including the price.
Anyone with anything further or corrections?
CMI's are around $4500 per set and I believe the Stellings to be similar. Not enough bang for the buck IMO. Lightning can be had for $2000 (mild steel) or $3500 for all stainless polished. Getting a little more realistic IMO. I wonder about the performance in comparison to the others. Bassett, I really don't know anything about including the price.
Anyone with anything further or corrections?
#64
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Joined: Oct 2004
Posts: 1,499
Likes: 48
From: Newbury Park, CA
Just to clarify, the lean condition is not on the top end. The late model 496HO's have a lean condition from 3000 rpm to 3900 rpm. Although the air temperature readings were a little lower at wide open throttle, they were still slightly higher than desired. The 2-3 pounds of fuel pressure is a small change, but this fuel injection system is very sensitive. It fixes the lean condition and does not affect other points of running. Even after our fuel pressure change, it still does not blacken the transom. So idle is not a problem.
Michael
#65
I'll agree that the fuel pressure increase is changing the curve through out the range. I think that's a given. From my experience it does not change it to any negative affect.
We had 3 full days on the dyno with three different 496 engines, and have installed and ran this exhaust on two different boats. By "ran" I mean we've installed and ran for extended periods of time with Mercury scan tools and portable O2 sensor kits installed.
At no time did we have any reason for concern with the 3 pound increase.
This increase was a neccesity on the late model 496 HO's. Without the change, the engine will run dangerously lean.
We had 3 full days on the dyno with three different 496 engines, and have installed and ran this exhaust on two different boats. By "ran" I mean we've installed and ran for extended periods of time with Mercury scan tools and portable O2 sensor kits installed.
At no time did we have any reason for concern with the 3 pound increase.
This increase was a neccesity on the late model 496 HO's. Without the change, the engine will run dangerously lean.
#66
I personally think it is great that Dana Marine has done enough research to know that more fuel is necessary.
I would think that their manifold must be doing something to require more fuel. Either they are producing more HP or TQ (or both) somewhere than others, or the others are running lean. I sure wish we had O2 and EGT sensors with a more sophisticated computer....
The dyno sheets I have seen around here from CMI seem to have some funny things going on with pressure and humidity plus I see it states 92 octane. Maybe those were misprints and sensors not hooked up or whatever,but ?????
Dana Marine Products, can you go ahead and post a dyno sheets of stock versus your manifolds for us (any of the engines)? I have seen other posts where you clearly state the increases along with the baselines. I am not doubting your claims.
I would think that their manifold must be doing something to require more fuel. Either they are producing more HP or TQ (or both) somewhere than others, or the others are running lean. I sure wish we had O2 and EGT sensors with a more sophisticated computer....
The dyno sheets I have seen around here from CMI seem to have some funny things going on with pressure and humidity plus I see it states 92 octane. Maybe those were misprints and sensors not hooked up or whatever,but ?????
Dana Marine Products, can you go ahead and post a dyno sheets of stock versus your manifolds for us (any of the engines)? I have seen other posts where you clearly state the increases along with the baselines. I am not doubting your claims.
#67
I will see if I can dig up somemore info on them like dyno sheets.. I will post it if I can
Jamie / Lakeside
Jamie / Lakeside
__________________
www.LakesideRestorations.com 570-639-2628
We Make Fast Toys Faster, Cool Toys Cooler and Old Toys New!.. Performance, Custom & OEM Parts & much MORE![/CENTER]
www.LakesideRestorations.com 570-639-2628
We Make Fast Toys Faster, Cool Toys Cooler and Old Toys New!.. Performance, Custom & OEM Parts & much MORE![/CENTER]
#68
[QUOTE=Bill 3;2040669]I sure wish we had O2 and EGT sensors with a more sophisticated computer....
[\QUOTE]
Are you sure of that? Get ready for big brother to make it much harder to increase HP....IMO
[\QUOTE]
Are you sure of that? Get ready for big brother to make it much harder to increase HP....IMO
Last edited by tblrklakemo; 02-27-2007 at 02:54 PM.
#69
Kirk,
I agree CMI is also a good system & has its place in the market without question. It's just good to also have more than one option.. On tighter twin applications the Cmi is the only other good way I know to go when looking for more bling & power.. I also cant say anything bad about the quality of their pipes, every set we have sold or installed to date has been "A ok"..
It's just too bad the pricing is not a little bit better on their products, Although everything everywhere is expensive anymore..
Jamie / Lakeside
.
I agree CMI is also a good system & has its place in the market without question. It's just good to also have more than one option.. On tighter twin applications the Cmi is the only other good way I know to go when looking for more bling & power.. I also cant say anything bad about the quality of their pipes, every set we have sold or installed to date has been "A ok"..
It's just too bad the pricing is not a little bit better on their products, Although everything everywhere is expensive anymore..
Jamie / Lakeside.
Last edited by Elite Marine; 02-28-2007 at 08:12 PM.
#70
I would guess that we could make more efficient power if the computer could have more info on what it going on with the motor. Almost like tuning on a dyno. It could get rid of a lean condition, or bad fuel. I don't know, maybe air flow, temp and knock sensors are enough
.And then if we could tune our own motors with the likes of HP Tuners or EFI-Live to make up for small changes such as exhaust instead of going with an across the board fuel pressure increase.



