I just got a 4.6L interceptor police car engine. I wanted to see if they can be used for a small 18 ft jet boat. I see the 5.3L gm being used. Has anyone tried this or can help if it would work. I have a limited supply of 15 engines with transmissions. I have computer and harness. The one I have has 21k miles on it . others vary from 50-110k .
sure anything can be done. they're VERY wide though in comparison to a bbf/bbc though. im not too sure how you'll adapt the cooling system to a pump though... ive seen a few of the LS motor guys use a heat exchanger so tehy can keep the closed loop cooling system and keep the engine at a 160* temp...
i think the biggest issue will be a full marine sized pan. the mod motors are notorious for running low on oil, especially the 32v. they'll suck a pan dry easily.
I haven't seen it, and honestly I wouldn't think it would be the "best fit" for a jet boat. But...I was told the same thing when I put an LSx into my boat. I would think a 5.4 (especially a Lightning engine) would be a better fit. BUT, if you have access to "cheap" motors, then more power to you! Let's take Mustang vs F-body to the water!
I'd just go with a heat exchanger, if I were you. I can keep at 500+hp 383 LSx cool with one that measures 16.5"x3.25". Keeping a modern engine like the LSx or the Mod at it's designed operating temp is critical to keeping power and longevity in them, and you can retain your thermostat with a heat exchanger. It's EASY to plumb, too.
2nd, you'll need to have a PTO adapter made. I'm not a Ford enthusiast, so maybe you share some kind of crank/flywheel pattern with another motor to make this easy. If not, it's still not *that* much money.
3rd, you'll need motor mounts. Just use front/rear motor plates from place like swracecars...it's easy that way.
4th, exhaust. For your first swap, go cheap - that way if it doesn't work out you didn't break the bank on headers. IF you have ~$1000 burning a hole in your pocket, then get Rewarder to custom build you some.
5th, the oil issue. I can't help you here as I'm not a Mod motor guy....but I do know from some of my Mustang buddies they don't sustain high RPM without oil starvation. I would suggest some research here before you do it.
6th, fuel. You'll either need to go to a high pressure return line fuel system (if you have 2 tanks, you need a selector valve); or go with a carb type manifold and an MSD for Mod motor.
i thought id give it a shot. work on it on some spare time here and there. the hull is a good sanger sprint jet that i was goint to cut up but figured ill use it as a mock up. going carb is 700.00 bucks. i thought if i can do a low budget engine swap id try it. ya it faces alot of issues but i thought lets give it a shot.
I have a customer in LV thats done a couple of these we have custom cut impellers for him , He even makes an intake adaptor for them , says they run very well let me know and I'll put you in touch with him Tom