Question regarding swapping of engines

[lmorefield41]

I know this isn't really a repair question, however it has to do with my original problem which is from this thread, http://forums.iboats.com/showthread.php?t=519268 Some of you may remember me from this thread. To make a long story short, I had a crap mercruiser 140 that had multiple cracks and was seized. I've found a mercruiser 120, that has no cracks, and starts, no water in the oil, looks almost too good to be true. The price is super reasonable. My question is would this engine work with my outdrive and the 140's wires, and if 120 hp is enough power for my 19ft Four Winns Open Bow Horizon? Both engines are 1984's. Thanks for the info guys.

 

[duped]

Re: Question regarding swapping of engines

Yes, it is a direct swap. It's my opinion that it's probably underpowered with a 140, let alone a 120, but it would depend on what you plan on doing with the boat...

 

[achris]

Re: Question regarding swapping of engines

I've done a few 120 out, 140 in, on 18' half cabins. The results were astounding. So pulling a 140 out of a 19' to put a 120 in, I think, is not such a great idea. It's not just 20 horsepower different, it's the torque, and it's torque that turns a propeller... More of that you got, the better. There should be plenty of 3.0 litre engines around that you could get, surely... But in a 19', now you have the opportunity, get a 4.3 litre V6 in there man! I GUARANTEE you will not regret it.... Everything better, and you'll probably use less fuel.

Chris.....

 

[lmorefield41]

Re: Question regarding swapping of engines

I definitely want to get a bigger engine, however, there's not a lot of room for one. An inline 6 is about 12 inches too long. I found a few of these as well. I plan to mainly fish in Lake Erie with it, also do a little skiing, but mainly fish and relax on it. What's your guy's thoughts on fitting a bigger engine in there?

 

[duped]

Re: Question regarding swapping of engines

I-6 would be backtracking quite a bit, that engine was long dead in '84. Dont.

It's really up to you on the engine swap as far as what time, money and effort you have to put in. A 4.3 would probably be worth it if the boat around it is nice, but its considerably more involved, and expensive. I would find another 140 and call it a day, but I'm getting lazy in my old age.

 

[lmorefield41]

Re: Question regarding swapping of engines

I-6 would be backtracking quite a bit, that engine was long dead in '84. Dont.

It's really up to you on the engine swap as far as what time, money and effort you have to put in. A 4.3 would probably be worth it if the boat around it is nice, but its considerably more involved, and expensive. I would find another 140 and call it a day, but I'm getting lazy in my old age.

Thanks for you honesty. I appreciate it.

But in a 19', now you have the opportunity, get a 4.3 litre V6 in there man! I GUARANTEE you will not regret it.... Everything better, and you'll probably use less fuel.

How would I go about this? Is a 4.3 litre V6 an inline 6? If not, will it fit in my small space?

 

[Oshkosh1]

Re: Question regarding swapping of engines

A 4.3L V6 is just that...a "V" shape motor, 3 cylinders left/3 right and at an angle (hence the "V") above the crankshaft. It's considerably shorter than an inline 6...which is all six cylinders in a row..all directly above the crankshaft. Lenghtwise it's probably about the same as an inline 4 cylinder...width-wise it does require more clearance though. The 4.3L is basically just a GM 350(5.7L) V8 minus two cylinders.

 

[thumpar]

Re: Question regarding swapping of engines

I have a 120 in my little boat and wish I had more power. Someday I will find a 140 for a good price and swap it.

 

[stonyloam]

Re: Question regarding swapping of engines

I have practically the same boat (87 H190 with 165 470 engine). IMHO the 120 would be seriously underpowered. The easiest would be to find another 140. A 4.3 V6 would give you added power, but you would need the whole engine including exhaust, have to fabricate front mounts and your outdrive gear ratio would be wrong. Good luck.

 

[lmorefield41]

Re: Question regarding swapping of engines

I have practically the same boat (87 H190 with 165 470 engine). IMHO the 120 would be seriously underpowered. The easiest would be to find another 140. A 4.3 V6 would give you added power, but you would need the whole engine including exhaust, have to fabricate front mounts and your outdrive gear ratio would be wrong. Good luck.

There is a guy who has a 470 4 cylinder engine with the matching outdrive. He's the same guy that has the other motors, which all are in working condition, without any cracks. I'm going to look at them again tomorrow. I'm in no rush to buy a motor, as the season won't be around again until late March, early April, however, his prices are crazy low. Is your 165 470 a 4 cylinder Stony?

 

[achris]

Re: Question regarding swapping of engines

T.... Is your 165 470 a 4 cylinder Stony?

Yes it is.... and 'Run away!'.. If you are not familiar with these engine, and have the opportunity to get something else, do so. As good as these engines are, they are now getting old, and parts are getting increasingly difficult to find. They have some quite peculiar quirks and unless you have a lot of time and patience you will be very frustrated with it. Even most 470 owners will advise you to 'move away from the strange engine'.... This is NOT a 470 bash, I actually like them, but understand they are a 'problem child' for most people....

Chris......

 

[stonyloam]

Re: Question regarding swapping of engines

Yeah Chris is right, you don't want the 470. I really like mine, but it also would not be a drop in. Sounds like the guy with the engines might have some connections. Might be able to help you find a 140. Nice thing about another 140 is that it is a drop in, and a great learning experience. As you said, it is a long winter.

 

[lmorefield41]

Re: Question regarding swapping of engines

Would you guys recommend getting an engine from a car and converting it to a marine engine at all?

 

[Bondo]

Re: Question regarding swapping of engines

Would you guys recommend getting an engine from a car and converting it to a marine engine at all?

Ayuh,.... There ain't any that fit yer application...

 

[lmorefield41]

Re: Question regarding swapping of engines

Haha, so the search for a drop in 140 begins. Thanks for all the info guys. I will just take it easy and get a dependable 140.

 

[1980Coronado]

Re: Question regarding swapping of engines

You have the number