Inboard inline drive transmission ratio

"Given the OMC 302 and an inli

"Given the OMC 302 and an inline drive set up, is there a rule of thumb to determine the transmission ratio? before I leap out there and buy one I would like to know what the plus and minus is to 1:1 vs 1.5:1 etc. The boat is a 17' classic glass runabout"

"What was in it before? I saw

"What was in it before? I saw the other post about the motor but depending on how fast you want to go (top end) and how quick you want it to get out of the hole, that motor will need a 1.5:1. Tournament ski boats use 1:1 or 1.26:1 in most cases now because the motors in them put out over 300 HP, and more torque than yours will.

What's the story behind the boat and why does it sound like you're trying to make something work that this boat was never designed for?"

"Jim,
The boat is a 1957 Skag

"Jim,
The boat is a 1957 Skagit that typically came from the factory with this size engine. Along the line someone put a 413CID in it and the engine is just too much. The guy I bought the boat from is taking the 413 engine and transmission out for sale. I bought the 302 engine alone and am trying to refit the boat. The shaft and coupler are still there. I need everything inbetween. Current 413 set up

"Wow,.......

Sounds like a

"Wow,.......

Sounds like a Fun Refit.....

I do Outdrive stuff,.... Little or No Inboard experince here,....
But a couple of Thoughts anyways,....

Even at the Inflated price of Free,....
That OMC probably is about the Worst Choice Possible......

The Ford based marine engines haven't been used by Any of the Big Name Marinizers in Years,....
Mercruiser Quit using them back in the 70s,.... OMC in the 80s,.... And even Volvo has stopped using them.....

Basically,.... The Marine Power Market is All Chevy based Power,.....
Popularity means that replacement,+ Used parts are Abundant,+ Easy to Find......Lots of "Good Deal" Parts if you know Where to Look....

The fact that all the Marine Goodies that are bolted on to that Ford motor are OMC is Another Bad Thing,.....

OMC is Gone,... No More Factory Support,... Just the Aftermarket suppliers.... Finding some parts is already getting abit Tough,.... It'll get nothing but Worse in the future.....
Exhaust Manifolds,+ Riser for your Ford will set you back nearly Twice as much as a set for a Chevy motor,......"

"Too much what? Power, gas guz

"Too much what? Power, gas guzzled, fun?

If it's too much motor, you can limit the throttle so it only goes to a set RPM or add a plate like the ones on NASCAR motors, to limit how fast it can go. A whole lot easier than re-fitting every part of the drive train. That 418 is a nice looking motor and if it's original to the boat,....oh well, it's your boat after all.

I would secure that fuel line, though. I assume it's not where it will live, right?"

It rains here alot but that me

It rains here alot but that message from Bondo was a frog strangler. So it sounds like I am better off giving the guy who sold me the boat another grand to leave the 413 in there and dump the 302. Worst case you saved me a lot of time trying to get the 302 up to par. I will secure the gas line when I get the boat. Thanks

"Ask what the motor needed tha

"Ask what the motor needed that made him repaint it. It may have been just dingy looking/oily/paint flaking, etc or it needed a rebuild. When I look at boats, I go through it thoroughly- compression test, check all fluids, make sure there are no leaks and run it. Basically, a complete survey unless the price is so low that even it it's a worst case scenario, I'll still be OK."

"I do not quite agree with Bon

"I do not quite agree with Bondo in this case. The only 'marine' parts You would need is in general manifolds, and does not have to be OMC, there is no drive and casted exhaust pipes to fit them to. The only extra costs would be manifold and flywheel housing. With a free engine , you may spend quite some on a manifold set before it equals up.
As for transmission ratio, it might depend a lot of the propeller You want to use and propeller space available. Contact a prop distributor, Michigan?, and give the specs of what You have. He should be able to recommend both prop and gear ratio for Your set up. Personally I would try to go for a 4-blade to get vibrations down and blade area up which will give a much better economy. Might loose a percent or so in top end, but gain a lot on cruising."

ACME is a good prop and they h

ACME is a good prop and they have CNC cut models that are even better. They can add or subtract hook and do all kinds of mods to tailor the prop to the boat and motor.

"My $.02 worth. looking at cur

"My $.02 worth. looking at current set up (borg-warner) 1.5:1 will not fit. in such a small boat,(unless reeeaaly heavy) 302/1:1 aughta work fine. gonna have to research props though. good luck."

"I could be way off base here

"I could be way off base here but to the best of my knowledge, the only 413 cu in motor I have ever heard of was one that was put out by chrysler in the late 50`s and was referred to as a semi-hemi??? Can`t say I`ve ever heard of one of these as a marine engine if that`s what it actually is."

"The 413 is similar to the pop

"The 413 is similar to the popular 440, and it's a pure wedge motor.

Why is this engine unsuccessful in this boat? Certainly, it does not suffer from a lack of power! Please clarify. I suspect a prop mismatch is in efect here.

Jeff"

The 413 remains along with the

The 413 remains along with the 1:1 Velvet Drive. I have renegotiated the deal and left the drive train intact. I suspect it is not an M413 as there is nothing to indicate such. I did get a marine carb for it and and Performer 440 manifold to match.
I appreciate your time and input on this. You have all saved me a great deal of time and trouble. Now back to the carb swap.