Thread:

Found a 79 tahiti...wondering about an engine swap

I found someone with a 79 Tahiti 21' for $300.00! with the original trailer. The jet drive is all there but he pulled the 455 for another project. So I was wondering if a 350 chevy swap would work. I only ask because I have a complete 350 cid 350 hp engine that needs a place to go. I'm not looking to win any races just get the boat looking good and on the water for now then down the line up grade to a BB. Any advice?



-Brian

Originally Posted by Addicted_2_boats

I found someone with a 79 Tahiti 21' for $300.00! with the original trailer. The jet drive is all there but he pulled the 455 for another project. So I was wondering if a 350 chevy swap would work. I only ask because I have a complete 350 cid 350 hp engine that needs a place to go. I'm not looking to win any races just get the boat looking good and on the water for now then down the line up grade to a BB. Any advice

-Brian

IF the hull is in decent shape that's almost a no brainer buy! You'll just need the right engine hardware and exhaust system to mount it up, perhaps change out the impeller, though others are better qualified than myself to discuss performance limitations of 350 HP turning what is likely an AA impeller meant for the extra torque/HP of a BB, though likely fine for getting out on the water and having fun till you find a BB...

One thing to consider... if all the original engine mounting hardware and exhaust system comes with the boat, it might well cost you less to find a running 455 than the cost of the swap out hardware.

You might find this recent thread of interest, though it's geared more toward building a fast boat.
21 daytona advice

Sounds alot like how I built my boat. Found it for $325 with the trailer, pump (JC-A), a shit interior and no motor. I got ahold of a 350 for free so I bought a small block front mount plate on here and a bellhousing mount for a big block (same rear bolt pattern) and bolted it on. Had to fab a alternator mount and source a set of small block logs n snails but it's in there and pushes me to about 45mph. Boat originally had a 455.

If you just want to get on the lake, go the route you have. If you want more power and go faster, build a big block. Trust me though, the first time you ride in a friends big block jet, you'll regret putting the anemic 350 in lol.

Originally Posted by Elkidminoltu

Sounds alot like how I built my boat. Found it for $325 with the trailer, pump (JC-A), a shit interior and no motor. I got ahold of a 350 for free so I bought a small block front mount plate on here and a bellhousing mount for a big block (same rear bolt pattern) and bolted it on. Had to fab a alternator mount and source a set of small block logs n snails but it's in there and pushes me to about 45mph. Boat originally had a 455.

If you just want to get on the lake, go the route you have. If you want more power and go faster, build a big block. Trust me though, the first time you ride in a friends big block jet, you'll regret putting the anemic 350 in lol.

I think I may go the SBC to start with. I also was talking to the owner and I may have worked a deal out to trade a generator that I have stashed in the
shed for the boat! I got the gen for free so I'll be getting the boat for free!

What hardware do ytou have left with the project? Motor plates? There is no way I would put a small block chevy in a 21 foot boat. Not even if the thing had 500 hp. That 455 though not an outstanding engine it had a lot a lot of low end power/ torque. Build another if all you need is the motor otherwise a BBC or a Ford.

Originally Posted by Moneypit

Where are you? I have a fresh, (about 12 hours run time), good running 455 Olds in a boat, ready to test on the river tomorrow. Go for a ride, no knocks, no rattles, no bangs, or pops, ready to bolt in your boat and hit the water...... $1200. Flame arrester to pan, (minus exhaust), or $1500. with EVERYTHING you need including the motor mounts, drive line, distributor, plumbing....Even spark plugs and the alternator!!!!! It should bolt right in to your stringers, and fire right up.....
No risk involved as you're going to see ME wring it's neck and it won't blow up!!
Ray 805 300 0012

Thats a killer deal from start to finish.

Originally Posted by Moneypit

Where are you? I have a fresh, (about 12 hours run time), good running 455 Olds in a boat, ready to test on the river tomorrow. Go for a ride, no knocks, no rattles, no bangs, or pops, ready to bolt in your boat and hit the water...... $1200. Flame arrester to pan, (minus exhaust), or $1500. with EVERYTHING you need including the motor mounts, drive line, distributor, plumbing....Even spark plugs and the alternator!!!!! It should bolt right in to your stringers, and fire right up.....
No risk involved as you're going to see ME wring it's neck and it won't blow up!!
Ray 805 300 0012

Ray....that's a great deal. But, money is tight right now unless the "Bank of Ray" is doing payment plans. I would be all over that! I live just a few minutes outside Philadelphia.

-Brian

Originally Posted by md-11mike

What hardware do ytou have left with the project? Motor plates? There is no way I would put a small block chevy in a 21 foot boat. Not even if the thing had 500 hp. That 455 though not an outstanding engine it had a lot a lot of low end power/ torque. Build another if all you need is the motor otherwise a BBC or a Ford.

Mike, Most, if not everything is left from the 455 that wasn't needed. I believe he put the 455 in a car. After researching it a bit more I will most likely
get another 455 for it since everything is there. I'm going to take my time and do it right. I had a 21' Four Winns that after 2 seasons the block cracked. So, I've been searching for a boat that I can work on. I'm an old car guy so I can do alot of the work myself.

Originally Posted by Moneypit

Brian, that would be a bit of a "road trip" to say the least..... I will warn you of a couple of things...
1st, Olds car motors in boat DO NOT LIVE very long..... 2nd, You MUST have a marine pan, 10-12 quarts minimum, and some good internal oil control.... "High volume" pumps may not be best as they put most of the oil up top.......3rd, Additional "skirt to wall" clearance is needed unless you run a "closed" cooling system....Good luck, and let me know if you ever decide to come west....
Ray

Just depends on how you run your boat!

Picked up my day cruiser eight years ago with out a motor. Next day picked up a car on e bay for 500 bucks and drove the toronado to my house. Pulled the motor, put new gaskets on and bolted the sucker up! Probably three years into it I overheated the living crap out of it because of a closed gate valve and never did a thing. That car motor is still in my boat today and is the best running carbed motor I have ever had! The oil pan on it probably holds eight quarts of oil also.

Not to bad for 500 bucks!

Originally Posted by Addicted_2_boats

Mike, Most, if not everything is left from the 455 that wasn't needed. I believe he put the 455 in a car. After researching it a bit more I will most likely
get another 455 for it since everything is there. I'm going to take my time and do it right. I had a 21' Four Winns that after 2 seasons the block cracked. So, I've been searching for a boat that I can work on. I'm an old car guy so I can do alot of the work myself.

The olds isnt the best thing but they did put a lot of them in jet boats ( they were value priced ). Considering you have olds hardware and money is tight sounds like an Olds is the right option. Let me know if you want to piece an engine togather. I have access to a bunch of 455 stuff and my uncle has been building olds engines for a long time.