Vinny P

I just struck a deal with someone for a 2000 HP500EFI. The problem is that Mercruiser doesn't offer a closed cooling kit for this motor. A few guys have told me that Mercs' new HP525EFI closed cooling system will fit the older HP500EFI motors. BUT, after seeing the article in this months Power Boat Magazine, I see that it is not going to work out. According to the article, " The front of the head accomodates the closed cooling. The heat exchanger fluid for the system, actually is housed in the forward portion of each cylinder head casting. That in head design feature enabled Mercury Racing to eliminate a substantial amount of plumbing." Now to me this means that when Mercury and Edelbrock teamed up to make these heads, they created some kind of new style head, possibly with an additional hole in the front allowing the heat exchanger to be sealed directly to the heads, thus eliminating hoses. That means that this exchanger will not fit the older HP500 motors without extensive modifications.
Now comes the part with my question. My current 454 Magnum has closed cooling on it. With the exception of the location of the heat exchanger and plumbing, do you think I can run this system on an HP500? What about the exchangers ability to dissipate the additional heat from the increase in horse power? Any one else running closed cooling on an HP500EFI, if so how did you do it???

Raypanic

Maybe this company can help you out: http://www.i-netmarine.com/fwc/fresh.htm

Vinny P

Anyone else have anything to add?????

Raypanic

I ran across this too, You may want to call Marc at BAM Marine:

http://www.go-fast.com/fwc_sc900.htm

Vinny P

Thanks Ray!!