New to the forum but not to boats.. Nissan V8 in a Chris-Craft.

Hello fellow watercraft enthusiasts. First off, ive spent the greater share of the afternoon with a hot bowl of chili reading these posts after I found your forum.. There will be others that will pay for this decision besides myself!

Anyway, ive been around boats all my life. Ive been told I could drive a boat before I could ride a bike! Ill try and skip to the important stuff. My Grandpa started a marina up here on Lake Wawasee, and we are the oldest dealer of Mecury outboards IN THE WORLD, and for a while were one of the oldest dealers of Correct Craft boats.

Heres what we have to deal with: I have a late 60s (im pretty sure its a 1968, i feel stupid I dont even know the year of my boat without thinking twice! ) Chris-Craft Commander 23 in fiberglass... Great old boat, interior has been redone, the body is solid but some bruises from being run into seawalls or the engine stalling when trying to dock. You know the drill...

Anyway, the low point about this boat is the motor. The 327 that chris-craft gave me is getting tired. It hasnt been overhauled once in the 600 hours this thing has on it. Not bad for a GM motor!! I took it out ont the water today, and its just going to be like feeding a dead horse... Ran so bad (but started up no problem) that i decided to take it out of the water, winterize it and put it in the barn for the winter...

So, its either rebuild this motor or put in a new one. Well, as you may notice, im not a huge fan of GM, and im a really big fan of Nissan/Infiniti. I am thinking about putting the 4.5L V8 from an early Infiniti Q45 into the chris craft. Here are the benefits I see..

1. The engine is all aluminum 32 valve- perfect for sustained RPMs which is what boating is all about. Also, im sure Ill be losing a couple hundred pounds (the Nissan V8 only weighs about 500-600lbs, the SBC probably weighs upwards of 800)
2. The motor is on par with most other boosted Nissan motors as far as the level of construction. IN short, people have taken these motors up to 450HP on a completely stock motor with just a slight retuned ECU, and ive seen 800HP on one with a stock short block, with only minor modifications (mainly cam and lowered compression). This engine LOVES high RPM and has no problems staying there for a while.
3. The motor puts out about 300HP at like 6000 RPM, but 320ft/lbs at 4000RPM, and about 280ft/lbs at 2000 RPM so it should be able to get this big boat moving reasonably well... Probably wont be pulling any skiers behind this boat, but its got some low end grunt.
4. The boat itself sets up well for a swap. The SBC and infiniti V8 have similar dimensions and the engine bay is HUGE, so space shouldnt be an issue, and thus it should be easy to keep it ventilated so that things dont get too hot in there.
5. I have a lot of experience and parts for this motor, as well as some ability to fabricate stuff, so it shouldnt be a real big deal to get that done.

Just so everyone knows, this is a gasoline EFI motor.

Heres sort of what im up against. I would appreciate any feedback on this.
1. Exhaust- obviously no one makes risers and wet manifolds for an infiniti V8, so that will mean im most likely going to run a dry exhaust... Im not sure how that would work, and if id be able to keep the same outlets on the transom... Id really like to not modify the exterior of the boat if at all possible.

2. Cooling- I assume running a heat exchanger would be best. an aluminum block even with freshwater doesnt like corrosion too mcuh plus if you run cold water right into the engine the ECU is gonna get thrown off as it will never technically warm up.

I think i would probably use some sort of electric pump to pump fresh water inot the heat exchanger, possibly thermostatically activated so that I can run it when the water is really cold....

3. After reading on the forum, it appears that I will want to somehow "flame proof" the alternator and starter, as the engine uses coil on plug so no sparks from the distributor to worry about. However, since I cant go out and just buy that, i think ill need to figure out a way to do that.

I know that going out and buying a marine ready motor is going to be the easiest way to get this thing back to terrorizing the waters, but itd be something i could really be proud of....

Sorry for the long post, and if this thread is incorrectly placed please move it so... ill find it

 

The cooling requirements will need a pump belted off the engine, electric is too whimpy for a big heat exchanger.

The exhaust can be wrapped with insulation , or better the run to the transom jacketed outside , so no exhaust risers are needed.

W-C used to make a fine monel fitting that jacketed the exhaust thru the transom , keeping wood boats from burning.

The fitting even sprayed some water into the exhaust stream , reducing noise and smell.



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