I have a friend that put Whipple's intercoolers on a roots blower (like the 575SC's blowers. Whipple's are much lower profile and are copper nickel. Super Chillers are aluminum (like Prochargers intercoolers) and WILL NOT last 2 years in salt water hence the closed cooling system mentioned above. Buy the Whipples.

Adding intercoolers by themselves does not produce more HP. Intercoolers allow you to run more boost without detonating, more boost means more O2 so you can add more fuel so you get more HP. The 575 SC is essentially a 500HP with a blower and TBI. Why not whipple 500EFI's for much less money? The Whipple 500EFI kit is intercooled and will fit on twin applications. If you add an intercooler to a 575SC, you will increase the blower overdrive to increase the boost to get the added HP SO you will also have to change the TBI settings (aftermarket reprogrammer) to get more fuel. IMHO you are still entering unknown territory by getting away from the standard/stock Merc setup by intercooling 575SC's just as you would have to with the Whipples and 500EFI's. So, why not do it for less money by Whippling the 500EFIs? It looks like the reliability risk is equal for both setups to me.

Jassman,

Another thought, why don't you call Mark Boos at Precision Marine in New Orleans. He built the 572 inch naturally aspirated motors for the GNO Cyclery PowerPlay (see GCOffshore.com) that dusted my a** in Ponchartrain this year. Mark could build you two 572 cu in motors for less than the 575's that will produce 700-750 HP with better reliability than supercharged motors.

Buy the 37 with good drives and 502EFI's or whatever the smallest big blocks you can get, sell the stock motor and have Precision Marine put in some monster naturally aspirated motors. I think you would come out ahead in more ways than one.

Tom

Thunderstruck, Is it true that the 575's are simply 500hp's with a blower ? I thought there was more to it than that.

I also think intercooling does more than reduce detonation. It actually lowers the temperatures in the top end of the engine. This does more than just reduce detonation. As far as I am concerned that is a positive by product not a reason to use the aftercooler (as they are called in my business) we're talking valves, pistons, heads, blocks, etc. As you mention both the setups (500's whippled or 575's aftercooles) require more fuel (or risk a lean burn situation) and require re-mapping.

The reason I think the 575's are a better way to go is 1) I thought they had some internal changes that typically are made to supercharged engines versus the 500's(PowerBoat article)and 2) the whipples are around $6500 per engine while the intercoolers run around $2,000-$2500

I thought I read that Jassman could get a deal on some 575's. That's what made the whole thing work.

I could be wrong about all this stuff, I've never done any of this stuff to a boat motor before. Industrial engines & equipment, yes, pleasure boats, no

H2O, after checking part numbers on mercruserparts.com, the 575 does have different pistons and camshaft. The valves and rocker arms are the same. The pistons are probably dished to reduce the compression to prevent detonation and the cam will take advantage of the blower setup. You are right the deal would make the difference, but if you have to put a closed cooling system on for the aluminum intercooler you add a bunch of bucks. Also, the whipple intercoolers can be used with raw water but they are ~$3500-4000. You get the intercooler with the $6500 whipple kit and you get their customer service and the kit will fit under a normal hatch. It would have to be a heck of a deal to go with 575's I had one of the old prochargers on a 502EFI and never broke any hard parts, the intercooler prevented detonation and I was careful with the A/F. The aluminum intercooler rusted out in <2 yrs.

Hey Catman, how the hell are you, you'r right
I was plastered, my wife surprised me when I got home, all my buddys were here, and their wives, parents, and some blond chick with Bodacious Ta Tas from stripogram came at 10pm. It was a great party, hard to get up though, my head hurt till noon. I have decided to go with the Whipples, but like H20 says: I will let you know by the weekend

Thanks H20 for the info, very educating

Hey Thunderstruck, I also apprieciate the info, I received your email and sent you one back, get those motors ready buddy, Im gona spank ya at the Tickfa

I represent that remark

Im just bustin your balls,

Well life on the farm is kinda laid back

My name is Dan Lawler and Im sleepin in the sack

I can't post a reply cause I'm way too tired

I wish I were like Jassman who is always real wired.

Its bad enough that I have to do John Denver ****, where the hell are you tonight.