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Discussion Starter #1
I run a HP500EFI but my buddy has the carb version. Were trying to think of ways to get more HP without spending lots of course.
The first thing we know we have to do is replace the manifolds with headers, but after that without going to a Wipple we think changing the cam would be our next step. But we don't want to go changing valve springs etc. can it be done. looking for at least 50 HP or so. Does anyone know of any experiments on this engine??:confused:
 

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I though the 500's came with Gil headers already???? If thats all you looking for you could get close with an adjustable fuel regulator, and ecm remap,,, something llike the "smart charge" kit,,,, also Arizona speed and marine already has the parts out to make the 500 EFI into the new 525 EFI. PLus I'm sure there is some cheap HP in the heads in the way of porting. You should not have to hard of a time, your HP wants are very realistic for small budget mods,,,, except the headers,,,, there are several thousand dollars there, and like I said,,, I think they came with Gils from the factory.
 

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Discussion Starter #3
It wasn't the EFI I was looking at playing with it was the Carb version, they only came with manifolds.
 

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Discussion Starter #5
We know we have to change exhaust for sure, but that alone won't give us enough to go up a size at the prop. I didn't know if anybody has worked with this engine before without supercharging.
 

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Discussion Starter #6
Hey Obnoxus, how do I get in touch with Arizona Speed. That souds like something I could to mine if it's not a big deal.
 

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Discussion Starter #9
I'd be surprised if he jumped a size because I run the same size prop, I've got headers on a EFI, unless he goes with a set like lightning or some other big tubes maybe then.
 

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You might want to check this little item out also (with the proper amount of caution, I may add) --

Remove your gas tank fill cap and see if you pick up any top end. On SOME boats, there is not adequate ventilation on the tank, and at high speeds (especially if you are pumping a large amount of fuel down your carbs) a vacumn does result in the tank, effectively starving the engine. Most tank manufacturers will swear this will not happen, but it does (happened to a friend on a race boat - lost the cap, picked up some speed).

If you do pick up some speed, you can change the vent hose diameter and thru-hull fitting to a larger size to provide the needed ventilation.

Needless to say, don't run around with the cap off for too long!
 

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Ihad a carbed one before i put a 420 mega blower on it. You can go up a size on the cam and not change anything else, but make shure its a true 500hp, with a roller cam, stainless marine has a good deal on headers, and try a canfield spacer plate. nothing but nothing compares to a blower, you can get 650hp for about 4500 bucks, if you want you can call me at 513 4076206
 

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Discussion Starter #12
That cam sounds like what we are looking for, do Stainless Marine have a web site? We priced out wipples for his and mine but the way our dollar is we are looking at $14000 installed! Thats pretty dear. If we can change the exhaust and throw a mildly upgraded cam in this maybe we'll have our 50HP for under $6000 CDN!
 

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Discussion Starter #14
The blower shop 250 is for sure an option, been talking to them about it. I don't think they have much testing with it yet, were as Whipple has proven themselves. It doesn't look like we can achieve our wanted HP gain without spending over $10000. Maybe next summer!
 

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Jeff, how would you like to buy a 12 hour Whipple Charged 454 blower motor (625 HP) for $7,500.

This engine has all the goodies and the most radical hydraulic roller cam you can get and it was dynoed and tuned at Dean Nickerson's in Bristol, Pa.

That's a lot less than $10,000

If you're interested - email me.

I've got killer engine that's hardly broken in with GIL's on it.

- jeff
 

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Discussion Starter #16
Hey Jeff, that sounds good to me, but my buddy doesn't want to change engines. Also keep in mind were dealing with CDN funds here, your $7500 is our $12000. For that price we can blow it and have more HP. Thanks for the option.
 
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