Crazyhorse

Tonto has a nice pair of 420 engines for sale and you can buy his for less than you can rebuild yours.
You might want to look real close at the blowers if they've got a lot of time on them. Pull the carbs off and look at the rotors to see if they've been rubbing on each other. If you can see any evidence of this you'll need to get them serviced. I just had Holley do one of mine for $550.

Infomaniac

I know of brand new 522 C.I.D. long blocks blower ready for just under 10K each. Perfect for smaller blowers.

Dart, Callies, J&E, Comp roller valve train with the new Isky heavy duty hydraulic roller lifters, Edelbrock Marine heads. Just over 800 HP and 850 ft.lbs with 8 lbs of boost. 750 HP and over 800 ft/lbs at 6 lbs.

jaybird

The blowers are at the Blower Shop getting reworked now.

I looked around, didn't see a listing for Tonto's motors here. Tonto - if you see this, PM me if interested in selling.

I called around today looking for long blocks, and most people seem to steer me towards 502's. I have heard though the 174's are too small for a 502 - need at least a 250. Also, I just had my carbs setup for the 454's, not sure if they would need at least a re-jet or more. Probably looking to stay close to what I have because the boat is quick enough for me already, and I don't want to start blowing trannies and drives (already lost one lower gear set on my first season!)

Crazyhorse

Jaybird, look in the Apache section for one of Tonto's posts and e-mail him from from there. Or you can look in "boats for sale", find the 35 Cafe Racer he has for sale and reach him that way. Or you can just throw a post up in the general discussion section and I'm sure he'll see it and reply to you.

RMPRam

iTrader: (1)

One other thing to consider. I noticed that you have TRS drives. Do you have the stock Mercury dual cooler bellhousings? If so, and you are using 1 of the coolers to cool the engine oil, you may want to pressure check that cooler to see if it is leaking oil into the water and it "may" want to "suck" water back into the oil, creating your milky oil cond.
Just a thought.

jaybird

Yes, I have the stock dual cooler system. Thanks for the suggestion - I will check it. I believe that the oil cooler on that engine is the one that cools both the oil and power steering fluid.

Is there a simple way to test a cooler (air compressor with low pressure?), or should it be sent out?

While discussing coolers, is it really neccessary to add an oil thermostat to the system? It's not part of the stock system, but I have heard it mentioned. If so, one more thing... I am thinking about adding that newer Merc water pressure relief valve to the cooling system too. I never put a pressure gauge in the system, but a lot of people here feel strongly about this issue. Just wondering if oil temp is as big of a problem.

mcollinstn

If the same tstat works fine in one engine, but not in the other, then it is going to be a restriction somewhere in the cooling system.

If you have not tried it yet, drill airbleed holes (about 1/8 dia) into the tstat plates. You need bleed holes on crossover motors. Didn't know you were running crossovers or I'd have said something earlier.

If you're buying blocks, of COURSE go with a 502 block.

Sure 174's are small for a 502, but you already got em and they will work. Just don't expect to be able to pulley it for over 5 pounds of boost.

carb jetting will be close but will need tweaked a tiny bit. Nothing major.

RMPRam

iTrader: (1)

I doubt that "the" cooler on that engine cools both the oil and the P.S. If it is a dual cooler bellhousing, then one of the coolers may cool the transmission and the other does the engine oil. Usually there is a separate "in-line" cooler for the P.S.

jaybird

Sorry if my previous post was confusing. That engine has 2 "in-line" coolers. One does the transmission, the other does both the oil and the power steering.

PatriYacht

Has this boat been in salt water it's entire life? If so, even with regular flushing, all castings that have water flowing through them are suspect. Also all coolers should be tested. You can test them with a garden hose and some fittings. Just plug one end and connect the hose to the other. If any water leaks anywhere replace.