I have an old 74 Orrion Trihull boat that I sport in the summer. Its 19' long with an open seating arrangment. 8 people can all have a place to sit and to boat still does alright!

Problem is it has an old 302-A Wakesha ford V8 mated to a Volvo Penta 270 outdrive. I was told that you can run these outdrives at full throttle reverse, so I would really like to swap in a FI 302 from a Mustang.

Has anyone had troubles with breaking their outdrives by putting too much power into them? And what is the danger behind not water cooling the exhaust? Thanks!

 

First off, why would ANYONE want to go full throttle in reverse??? I would think the 302 to 302 would be no problem. No water to the exhaust means you burn up your pipes faster. You might get by ceramic coating the pipes. Just my 2 cents.

 

By what I've observed the marine engine run opposite spin as an automotive engine. So to make the boat go forward I need to repin the gear select cam in the outdrive. It would essentially be driving in reverse, but in opposite spin, so it would forward.

Burn up your pipes? That doesn't sound good. I'm sure I would have to make holes in my transome to vent it out as well right?

 

the best thing to do is to buy a reverse rotation timing chain and camshaft and you wouldnt have any problems. you can usually get the stuff from a local parts store for fairly inexpensive.

 

You can run over the transom headers and then not worry about burning the glass, but even running water in the headers, it doesn't take much, 15 lbs of water psi will do, but , even then they will turn blue of you don't get them cool enough. No water when you are at idle. 2000 rpm your ball "T" valve should open and water flow. You'll get water out the pipe ends as well as the weep holes.

 

If I'm not worried about keeping the pipes shiney, what would be the safest way to run them? I want to put a sun deck in the back so the engine would be covered up. Should I keep a fan going like the bilge blower?

I'll look into the reverse cam and chain. What about the outdrive power handling? Are most of the high power boats a direct drive?

 

What exhaust do you have now? If you have an enclosed engine you MUST run a blower running. It's the law. USCG

 

your outdrive is just like a transmission it will handle power to an extent. if you run a stock 302 FI your outdrive sould handle it, but it it wont last as long as it would if it had the stock engine in it.

 

The 270 is the weakest of the vollvo drives I run a 290 on my sutphen and it is suposed to be one of the strongest drives out there.
They made the 270 280 and 290 as well as other variations.
The problem is it(the 290) soaks up a lot of HP.
It is also hard to find performance props for them.

The 270 is not a bad drive just not super strong.

Why not run water in the exhaust. its easy even with turbos. all you need to do is run a typical merc manifold. cap it with an adaptor plate, isolate the turbo, Run water around the turbo then off the turbo outlet run a double walled SS tube and run the water inside that pipe. You can even run a liquid cooled ceter section for the turbo.

Run a blow through carb and hat. Air to water intercooler with fresh water plumbed from the cooling system and it will make plenty of power.

Its not very hard really.

It can be done on a budget too.

 

I know that I have to run a blower and I have one. Like you said, its the law. I was saying that if I didn't have water cooled exhaust that I would have to run it all the time to keep the bilge cool.

The exhaust now is the marine manifolds. They run up and then down into the outdrive. It comes out of the tip of the outdrive right where the prop is. Speaking of the prop, its really hard and expensive for a new one! I was lucky and have 4 props that came with the boat. One of which is a 21" with 15" pitch. Fricken torque monster it is. Stops the engine dead in its tracks when doing hole shots. Motor has enough torque to pull my 230lb friend out of the water with a wakeboard though, but not much more.

Good to know bad69. I didn't know that about the 270. This is my first boat so I've learned a lot! It didn't run when I got it, so I rebuilt the carb, made the blower work, redid the fuel lines, rebuilt the outdrive tip assembly, and rewired a bunch of stuff.

There's a pic of it at Lake Sammish this last summer.

 

It's not there to keep the bilge cool, it's there to keep the gases from building up and exploding on you.

Won't the old exhaust connect back to the replacement motor? If they are both small block Fords, they should and you don't have a problem there.

Maybe you're wanting something more out of the little boat than it's capable of handling. Take it out and have fun and then maybe look for something like a "V" drive or Jet driven boat to hot rod. You'll get hole shots that will stand you on your tail.

 

The boat is old, still in good shape. Think i'm asking it to do more than intended? Lol, I put a home built wakeboarding cage on it. Its a learner and I hope to get a decent boat someday. Its fun for now though. I've never found anyone who knows anything about boats so posting here was awesome for me. Especially since there is a lot of mustang people posting.

I'm not even asking for much, but a bit more power and reliability would be nice. I want to run a FI 302 so I thought I'd have to change the manifolds to run the o2's. Or I could run without o2's. The engine hasn't had its oil changed since the mid 80's so I figured it could use a break.

I also thought of running a Chevy TBI unit on top of the existing SBF just to manage the fuel. I have the TBI, wiring, and ECM sitting in my attic.

 

Maybe you should just get this one running as is and then look for a "Project Boat" to hotrod. A couple of good boat sites are:

http://www.socaljetboats.com
http://www.justjetboats.com/forum/index.php

Don't let the names fool you. Just about everything boating is covered.

Once again, just my 2 cents. Good luck on whatever you decide to do.

 

Blue, I knew you didn't want to hear that, but that's what I would do if I were you. Have fun with what you have until you can build up what you want.

 

i second that motion, no sence in fixing what aint broken. just take your time and do it right rather that jumping right into something your not sure about.


Jeston

 

Its okay man. No worries. I was mainly just wanting this boat to run a little better and more consistent. I don't want it to be a super boat, its just a run about party barge!

 

Hey Blue,

Check out Craigslist for your area and you'll find a nice project boat to hotrod. Might even get a turn key that won't need much work. Get your little party boat tuned up and running and go have fun. Jut my 2 cents, again. A couple more of these and I'll have sent a dime.

Greg

 

Dont spend all that money in one place GAWnCA......


Jeston