Tired of the 3.7L Shenanigans (3.7L to 4.3L Swap)

[actaeon9]

Hi All,

As some of you may have followed I have been chasing a "Running Too Warm" issue on my 88 3.7L (Newer style 470) - Alpha One Gen I combo ALL season long (going back to about March here in FL).

SO after spending way too much money and even MORE time on this motor, I've decided over the winter I am going to swap it out for a 4.3L V6 from Rapido (they come with High recomendations, and are pretty close to me). It's going in an '88 Wellcraft 190 Classic Bowrider w/plenty of room in the engine compartment.

SO, my question is before diving in, has anyone here completed this swap and have any advice to offer or issues that I will run into?

TIA!

Dale

 

[natemoore]

Re: Tired of the 3.7L Shenanigans (3.7L to 4.3L Swap)

Hey Dale,
I found that site last night while I was contemplating the exact same thing.

You can read my two current posts and see pictures of the condition of my engine. I'm looking at a complete rebuild. So, I'm thinking about putting that money toward a different engine.

It sucks that you spent all that money and time and still have engine problems.

I've got an '87 Four Winns Horizon 170. The hull is in super shape and it looks like a new boat, so I'd like to salvage this bad experience.

Are those complete engines or long blocks? If so, you'd still have to find the manifolds, carb, starter, alt,etc, which will add up quickly.

What were we thinking when we bought these boats????

Nate

 

[actaeon9]

Re: Tired of the 3.7L Shenanigans (3.7L to 4.3L Swap)

Mine was a gift from my dad...I'm starting to think he didn't like me very much

In any case - I read your post and feel for ya. I know ~exactly~ what your talked about when your looking at something with the fam and "There's someone coming to look at it right after you"...Been there many a time.

I spent 2k this spring on having the oil pan brazed (Had to remove motor, and mounts all had to be replaced etc..) It didn't run warm last year at all and compression was good so I thought it was worth it. Oops - this year we've spent the whole year looking for a ghost. I've just had it, and don't have the experience (nor the tools) to rebuild myself. Being that I've already paid a large amount of my mechanic's kids college tuition, I'm sorta out of options other than to replace. I think the rapido prices are just the block and heads..accessories are extra...I think they also installed for like 800 or so..not bad. Like you, I'd rather save and do it as we can afford it, than have to finance 15K over 6 years and end up paying 19K with the same problems in 6 years.

Where abouts in FL are you? I'd love to check out your project sometime.

 

[Don S]

Re: Tired of the 3.7L Shenanigans (3.7L to 4.3L Swap)

Rapido sells long blocks. You would still have to buy the full exhaust system, intake manifold, carb, ignition system, shift interrupt system, starters, wiring harness, circulation pump, belts pulleys, alternators, motor mounts, coupler, flywheel, flywheel cover with engine mounts. All this if you can find a Y exhaust pipe that will bolt up to your transom shield. If that isn't enough, you have to have stringers for the V6 to sit on. It doesn't have the front mount like the 470 does.

Buying all those OTHER parts is going to cost a fortune.
IF, and that is a big if, the Y pipe were to match up something like this would be the way to go.
http://www.marinepowerservice.com/BoatingStore/browse_detail3.cfm/productID/23368.cfm

If you really-really, like and want to keep the boat, then maybe this would be an option.
http://www.marinepowerservice.com/BoatingStore/browse_detail3.cfm/productID/23392.cfm

 

[stonyloam]

Re: Tired of the 3.7L Shenanigans (3.7L to 4.3L Swap)

Are those complete engines or long blocks?
Nate

I think those are just long blocks, to repower you would need the complete engine, intakes, carb, manifolds, y pipe etc. would be best to look for a setup out of a salvage boat.

Anyway, I feel your pain, I thought about doing the same thing (1987 FourWinns 190), but decided against it. First expense, too much money to put into a 20+ year old boat. Secondly, and really more important to me, was the weight. I am set up with a outdrive trolling motor and 2 class 27 batteries in the stern, so added weight was a concern. The 4.3 with the alpha drive weighs in at about 850 pounds, while the 3.7 comes in at about 600 pounds (460# motor plus about 150# for the alpha). That was too much for me. I pulled the head for a valve job, and now it runs really nice. So I'm sticking with my 470.

 

[natemoore]

Re: Tired of the 3.7L Shenanigans (3.7L to 4.3L Swap)

After my head stops spinning....I'll go gently carass my 470.

 

[actaeon9]

Re: Tired of the 3.7L Shenanigans (3.7L to 4.3L Swap)

Wow - same here.

All of a sudden a possible head gasket doesn't sound so bad.

Thanks Don and Stonyloam

 

[Don S]

Re: Tired of the 3.7L Shenanigans (3.7L to 4.3L Swap)

Go looking for an old dead boat with a Mercruiser V6 with an Alpha I Gen I outdrive or older. maybe with a frozen engine and the drive missing. Then replace the transom shield and Y pipe from the doner boat, get a short block from Rapido or somewhere, new manifolds and risers, use all the other accessories off the doner boat, use your drive, and part out the rest on ebay to recover some of your money.