Marinette Boat Forum

Hi guys I was wondering if a Chrysler 360 would bolt right in place for a 318. My port motor is bad and a 360 re-builds cost nearly the same as a 318 but have more HP. THANKS

I'm not a motorhead but wonder whether mismatched engines will give you less (or more headaches) than you need.

At wot it might be an issue. Your props are usually set up for the hp you're running currently. More hp would make the rpm too high at wot. Might void the warranty on the new motor.

The 318 is internally balanced, the 360 is externally balanced. You will have to have the flywheel and the balancer for the 360. Everything else will work. Joe

I was wondering if the motor mounts would be exactly the same so as to have no mods needed for the 360. The starboard motor runs fine but has poor oil pressure (12-15psi) and is probably not long for this world, that's how the WOT issues will eventually be addressed . If I were to do this up grade I would be starting with a 360 long blocks and have to use as many of my 318 parts to finish out the long blocks as possible. I think I can use the intake and exhaust manifolds, but what about the water pump, fuel pump and oil pan. Thanks

Maybe the experts at an engine rebuilding company such as Jasper can answer your question definitively and then you can relay the answer to the community

They bolt up the same, they do not weigh the same, you can mix them if you want, but not recommended. Internally and externally balanced means different fly wheels, pulleys, and harmonic balancers. If you are only changing 1 motor stay with the same displacement. Props, rpm powerband , fuel use, carb and timing settings would all be different for 360 vs 318. Would not be smart in my eyes. - your call.
I swapped out my original 318's and installed 360's simply because I found 2 of them and rebuilt them complete with out having to pull the running engines from the boat.
Boat performs about the same with either setup. Water pump, fuel pump and oil pan will work.

..."Boat performs about the same with either setup. "

It has to unless you propped up. The 360s used another 2 inches of pitch.

Jeff

Went from 14x9 to 14x11- 1:1 velvet drives Could only get 3400rpm on the 11's went back to the 9's had them cupped and he reworked the pitch angle .Back to 3900 rpm about 20mph top speed Generator , A/C flybridge Heavy load of gear. Jumps out of the water. Cruise mostly at 1700rpm @10mph. 360's made 250 HP on the dyno at 4000rpm. Staying conservative on the engine load, I hope.
Any input always welcomed.

barefoot99 wrote:. Cruise mostly at 1700rpm @10mph. 360's made 250 HP on the dyno at 4000rpm.

Are you sure you're on plane at 1700 rpm/10 mph? Sounds kinda low on both numbers. Do you have trim tabs?