CMI 496 Sport Tube
#11
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Re: CMI 496 Sport Tube
Originally Posted by C_Spray
Playing with the calculator, I get something like a 48 hp increase.....
#13
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Re: CMI 496 Sport Tube
Nice pics Oh-Deere,
It's hard to tell by the pics but do the headers add any additional height or length to the motor? It looks like the oil filter assembly might of moved forward a bit. I have VERY LITTLE room to go up or forward in my engine compartment. If anything sticks out past the flame arrestor it won't work for me.
Dave M.
It's hard to tell by the pics but do the headers add any additional height or length to the motor? It looks like the oil filter assembly might of moved forward a bit. I have VERY LITTLE room to go up or forward in my engine compartment. If anything sticks out past the flame arrestor it won't work for me.
Dave M.
#14
Re: CMI 496 Sport Tube
I have tried a few different prop setups and have found that 496 with headers performs best at higher RPM's (5050+). Tried more pitch which ran @ 5000 RPM, but found that the smaller wheel felt better all around. In my opinion, if someone is currently running 4900 RPM or less, they may not need to make a prop change and will gain the MPH through increased RPM. Fine tuning of their current prop may be all that is needed. I may stay with the labbed 28 and just have the ECU reprogrammed to keep me out of the rev limiter and perhaps gain a bit there. Will have to play with it a bit more in the Spring. All things considered, they worked for me.
#16
Re: CMI 496 Sport Tube
Dave,
I will take some height measurements from a common point on the motor this weekend. Even with the 3" spacer for the cowling, I did choose to trim it a bit, as you can see in the previous pics. The highest point would be the forward header on each side. The cowling could be set lower, with additional trimming and shorter spacers, so that should not be an issue. You should have no problem with forward space, as you can see in this pic.
I will take some height measurements from a common point on the motor this weekend. Even with the 3" spacer for the cowling, I did choose to trim it a bit, as you can see in the previous pics. The highest point would be the forward header on each side. The cowling could be set lower, with additional trimming and shorter spacers, so that should not be an issue. You should have no problem with forward space, as you can see in this pic.
#17
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Re: CMI 496 Sport Tube
Shorter, narrower, wider, straight back, down turned, above swim deck, below, with the right measurement input, you can have headers any way you want them.
#18
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Re: CMI 496 Sport Tube
Oh Deere,
I have been reading your posts and congrats on your success with these headers.
Sean H,
I do not believe anybody including myself said 4more mph sucked. I think that this is very impressive to be honest with you and I am very much considering adding them to my boat. As my post read I have not been able to find other threads other than this one to base any type of real numbers and opinions. As you know many different boats have different setups so this could definitely change the performance from boat to boat.
jrz,
I am not insinuating anything. If you would have read my post a little closer you would have noticed that I asked if there were other threads that had any real numbers and opinions. I am only looking for info and not trying to bad talk the product.
I have been reading your posts and congrats on your success with these headers.
Sean H,
I do not believe anybody including myself said 4more mph sucked. I think that this is very impressive to be honest with you and I am very much considering adding them to my boat. As my post read I have not been able to find other threads other than this one to base any type of real numbers and opinions. As you know many different boats have different setups so this could definitely change the performance from boat to boat.
jrz,
I am not insinuating anything. If you would have read my post a little closer you would have noticed that I asked if there were other threads that had any real numbers and opinions. I am only looking for info and not trying to bad talk the product.
#19
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Re: CMI 496 Sport Tube
Joe I ran my outerlimits (finally) the headers and mufflers worked perfect, waiting for the weather to try different props and rotation
Gary told me you got a new boat, hows it running?
Brooks
Gary told me you got a new boat, hows it running?
Brooks
#20
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Re: CMI 496 Sport Tube
Hi Brooks. I was wondering who the Wisconsin/Florida Outerlimits owner was. I bought a used 38 Fountain with Staggered 525's. Other than the better air why did you wait until October to start testing? I might try larger ID headers, ECU's, 2" shorter sportmasters, and Herring 5 blades. Just to keep it stock.