Whatever to do???

[wca_tim]

OK, not my first rodeo but I could use some input on this. I dragged a wellcraft 19.6 home the other week. I like the hull and am going to set it up for cruising and fishing in the sound and inshore. It currently has a mercruiser 470 in it that recently seized up. no water in the oil and it was properly winterized from what I can tell. I'm assuming before taking it apart that a manifold leaked water into a cylinder or cylinders and it rusted in place. I've pulled the drive and checked it out. It pressure fine and seems to be in decent shape. I'm considering 2 options:

1. Tear the 4 cylinder apart and rebuild it using an aluminum ford head, new manifold assembly, 4bbl carb, add an external alternator kit, etc... This kind of sounds like fun and I like the idea of the lightweight engine back there. It also sounds like it could become a relatively expensive proposition pretty quickly.

2. I know where I can pick up a "project boat" that has a serviceable 4.3 with low hours and an alpha drive for under a grand. The boat hull is damaged and would go to the dump. I also have another use for some of the drive gimbal and bell housing parts. I'm leaning this direction overall especially since I have spare alpha drives and parts, spare alternator, starter, etc, etc, etc... for 5.7 / 4.3 alpha set up. a couple specific questions:

Aside from having to build structure under the engine mounts in the wellcraft for the 4.3, what else would I have to change? Is there any way I can use the 470 drive and transom assembly with the 4.3? I'd love to not have to tear everything apart if I don't have to.

How much heavier is a 4.3 than a 470? I've got a good handle on the 4.3, but don't know about the 4 cyl.

Thanks for any input or experience you have to share!

 

[Don S]

Re: Whatever to do???

2. I know where I can pick up a "project boat" that has a serviceable 4.3 with low hours and an alpha drive for under a grand

That would be your best bet. Use all of it, engine, transom shield, and drive. You may also have to add stringers for the motor mounts if your boat doesn't have them already.
Too many inherent problems with the 470 worth rebuilding and upgrading.
Cam seal failure, open deck design, outboard charging system, points ignition.

 

[wca_tim]

Re: Whatever to do???

Thanks Don, That was my impression regarding the 470 from what I read before posting, and the direction I'm leaning...

I haven't measure carefully, but it doesn't look like I'll have to add very much to have solid structure in the right place for 4.3 engine mounts. Either way, that's an easily addressed issue with materials I have on hand.

Is there any way I can use use the drive that is on the boat? It looks as if the boat was in use fairly recently, bellows are in good shape, no sign of leaks, gimbal bearing is smooth, u-joints go drive shifts easily, lube clean, upper gears look very good, external looks great, etc... Seems a shame not to use it. it's a 1979 model...

Anyhow, thanks again for the input... Cheers

 

[sharkin95]

Re: Whatever to do???

the 470 and 4.3 both use the same gears 1.81 for the older models and 1.84 for the newer. I did this change about 6 yr's ago, main thing is front motor mounts and dual exhaust which wasn't too difficult at all.

 

[Augie56]

Re: Whatever to do???

I've got a '79 Wellcraft Sunhatch (small cuddy runabout), and it has the 5.0 litre GM 305 mercruiser. It's a little arse-heavy, but it's tuned very well and it sure gets out of the hole quickly without any struggle. These boats are solid, heavy boats...I wouldn't want to be without my V8. The 4.3 might weigh about the same, just something to consider.

Good luck and post some pics soon. I love the solid, old Wellcrafts. They were built right, and the ride very nice in chop. Fortunately, mine was taken care of it's whole life, and it's a reliable fun boat at 33 years old. Good luck!

 

[wca_tim]

Re: Whatever to do???

Thanks! that's exactly the model boat it is and seems like it will be a great boat for the sound where the water can get pretty rough. The boat hull is very solid and it doesn't look like it is going to need a full major overhaul. I have a spare set of trim tabs laying around as well as a pile of props.. and alpha drives, mercruiser parts, etc... Getting out of the hole is about propshaft torque and prop pitch / design. I'm not worrying about top speed on this boat so would underprop it a little bit. Moving motor mounts is no biggie - blocks of wood, glass mat and resin. I've got a couple gallons of MAS epoxy sitting on the shelf that should do the trick.


Thanks a lot for the info. I was hoping the drive and transom assembly would work with the 4.3, but a little too lazy to go out and pull everything apart. part of me is still sort of thinking of parting this out instead... oh well, no worries. Hope everyone has a GREAT day! I'm gonna put the drive back on the other boat (off for routine service checks) so I can take the kids skiing this weekend. cheers!

 

[sharkin95]

Re: Whatever to do???

4.3 weighs about 665 lbs...... 5.0 about 750 lbs. My 1989 IMP Sportsman 220 cc is also a solid boat 21 ft @ 3200lbs loaded she turns 38-40 mph, and I have had her out in 7-8 ft sea's too bad but they stopped making them at of Iola Kansas. good luck on whatever you choose!!!!

 

[wca_tim]

Re: Whatever to do???

I ran across a possible option to pick up a mercruiser 165 - the straight 6 250 version for very reasonable money. I had a similar engine in a pickup years ago that was absolutely bullet proof. Other than relocating the engine mounts, is there any reason not to go this route? It comes complete water pump to bell housing (including alternator, wiring harness, exhaust, etc, etc, etc...) and I'm assuming that between the 470 that's in the boat and the parts on the new engine I can put together everything that's needed. I don't need a ton of power, just want to wind up with something dependable, reasonable fuel economy that has enough power for cruising and fishing the sounds and near shore on clear days. Thanks again for any input. Cheers!

 

[Scott Danforth]

Re: Whatever to do???

Its big, its heavy, and the power to weight ratio is not there like it is in the 4.3

your best bet so far is the 4.3 for under a grand, then sell off the 470 stuff and the drive to those that are trying to keep the 3.7 liter 4-banger together.

 

[slicksboat]

Re: Whatever to do???

well your motor mounts will no matter what will have to be build the pic is how i made mine it wasnt hard and they work great the 3.7s are just to costly for repairs cause they are junk and to get anything that fixs them is a arm and a leg they quit making them for a reason!!! the block is gm aluminum and rest is 460 pistions rods and cast iron head my vote is save your self the money and go with 4.3 it has options a 2bbl and 4bbl depending on year if its under 92 a 2bbl has it at 175hp and 4 bbl is 205 92 a nd up are 190 with 2bbl but anyways the acceleration is the only thing that a v8 has to offer. speed has nothing to do with it because of the alpha one out drive gearing the are designed to propel the boat at 55mph max most dont get to go that fast cause the engines arnt proped right or burning effiecently the gears are different for the different engines due to the fact of torque and over and under spining a prop so dont worry if youll be fast enough with it youll be plenty fast might not hit top speed as fast as a big engine. but if you want higher speeds a bravo 2 is designed for 100mph and can handle it the the bravo 1 is 65 and the brovo 3 is 65 but it has dual propellers on one shaft and gets a new realm of propusion but none of that is worth the money

 

[wca_tim]

Re: Whatever to do???

Thanks for the replies! I was thinking of the weight with the inline 6 as well. I missed the one 4.3, someone bought it before I had the time to go and get it. I'm not in a big hurry, but want to do this boat on the cheap for a beater to fish through the winter with. I'm thinking if I can hit mid 30's and cruise upper 20's that'll be good enough. anything beyond that is a bonus. Who knows, it may get a small block if that's what I run across in a donor boat or for cheap first. I'm looking for something that has a complete and usable exhaust to avoid having to spend the cash for that right out of the gate. I probably have plenty of pieces to put together a drive gear ratio / prop combo on hand at the house now.

I have a smaller boat (17 ft) 383/alpha that easily runs deep into the 80's when loaded light and propped right. especially when I've got the shorter ss drive on it. it's not a lot slower than that with a standard alpha 1.8 gear drive on it. it would run 60 with a 4.3 (non balance shaft, roller motor with vortec heads, edelbrock intake and 4-barre, etc...l) before I got silly and shoehorned the 383 into that little engine compartment...

Anyhow, thanks again for input. still pondering this one... Hope everyone has a great weekend!