I have a pair of Whippled 525 EFI motors that I am getting freshioned up at a very reputabil shop. When it is all said and done the motors will have a complete over haul minus the cam(he said didn't need) it will be .060 over with new JE pistons running about 6-7 lbs boost, he thought 740-775 HP on dyno. My issue is I want to get rid of the closed cooling system but I want to run a thermostat. I was told to do this we would need to reenvent the wheel. I wave a pair of cross overs with the pullie to keep my surpentine belt but still no thermostat. I am scared that no thermostat will affect the fuel curve since the water in Iowa doesn't warm up until July- August. He said he could change the computer to do what ever we need. Which is the best way to go here?

What is your specific reason for wanting to get rid of the closed system?? Is it not doing what you need it too???

I'd leave it on.....nothing like
being a guenea pig.


How do you plan on dealing with the different
coolant routing these things have ?

x2. Leave it closed cooling and spend the money and time on some other part of the boat. Can't you just put a t-stat in under the water neck in the manifold? My crossovers have t-stats. If you're worried about the exahust, drill a couple small holes in the t-stat and be done.

There isn't a water outlet on the manifold in the
traditional sense, there is an outlet on each end
of the cylinder head.


http://www.mercruiserparts.com/Show_...sed+Cooling%29


http://www.mercruiserparts.com/Show_...28Sea+Water%29

Ahhhhh, thanks for clearing that up for me. Then I have no solution.

It was suggested by the motor builder and I don't see any real advantage to a close cooling system running in fresh water. It will also make the motors look nicer.

The biggest issue is finding a crossover to use with a serpentine belt, that I can afford. I did find a pair but at just under $2200.00 I need a different idea.
Is it possible to remove the impeller from a stock water pump and use it as a crossover? It already has a pulley on it that I need. Has anyone ever tried this?

Someone makes a cheaper alternative. I have the link on my laptop at the office. I'll get it for you tomorrow.

Thanks!

So my brain storming idea to remove the impeller from a stock recirculation pump and use it as a crossover with the pulley isn't such a good idea after all?