Nola Mike's 3.7/470 --> 4.3L swap thread

[nola mike]

I'm sure that this will be a saga, so starting a new thread. Just picked up an '89 Glastron donor with a 4.3. I'm planning on refurbing the engine and adding a 4bbl carb and vortec heads. I'm going to start on the engine in a bit, and then swap it in the fall after the season.

1st question already:

I don't particularly need/want power steering and don't have it currently. If I swap it, do I need the whole steering system off the donor, including the cable? Hadn't planned on pulling it from the donor, but need to know if it's necessary before I junk the hull. Is it possible to just keep my current system and delete the PS pump on the donor?

 

[alldodge]

Yes you will want PS, there is a lot more torque from the 4.3 then the 470

 

[PatinIdaho]

PERFECT thread for me to watch. Im going to do about the exact same swap next winter.
I have the PS setup from the 3.7 and the 4.3 so ill be keeping it.

 

[nola mike]

I want able to find a thread about someone doing this... Are there any out there?
​​​​​​Also, AllDodge , if I keep the ps what do I need to remove from the donor?

 

[stonyloam]

Say it ain’t so Mike LOL! Yeah transplant the whole power steering setup.

 

[nola mike]

That's what it takes to get a post out of you these days, eh? I've been threatening to do it for years. .. you'll be laughing at me when I realize that this was way more work than I thought it would be. Already starting to miss the 3.7 a bit. Manifolds and risers are expensive and you need 2. Plugs and oil filter are a pita to get to.

 

[alldodge]

I want able to find a thread about someone doing this... Are there any out there?
​​​​​​Also, AllDodge , if I keep the ps what do I need to remove from the donor?

The pump and line, also the steering ram that is attached to the transom plate

 

[porscheguy]

Moving the power steering over is no big deal. As I said in your other thread. Take EVERYTHING related to the engine and drive. Take the controls, wiring, cables, etc. Everything means everything. Most of it isn’t hard to extract and you’ll be glad you did.

 

[harringtondav]

Earlier you mentioned handling the PS leakage when you pull the 4.3. If you haven't already pulled it, disconnect the steering cable from the PS cylinder and the cable pin from the clevis, remove the Jesus bolt from the cyl and transom plate, remove the cyl pin from the steering tiller arm and tie the PS cyl onto the engine and keep it as a package. No leaks removing the engine, and no leaks when you run the engine on the stand.

 

[nola mike]

And we're off!


I managed to remove the steering, disconnected cable from the helm and from the transom plate via the 2 clevis pins. Finally got an opportunity to see how the system works. I neglected to say that I was unable to turn the wheel at all when everything was hooked up, and have no idea if the ram/cable is any good. So still hesitant to put it in. I'll be able to use my current system and not touch it, which is appealing. For the life of me I was unable to get the the transom plate off or separate the gimbel housing from the outside. Tried to saw it out, but ran out of juice on my sawzall before getting it out. The transom is *rock solid* btw. Ugh.
Also still can't remove the damn control box from the trim panel. Can anybody help? I can't get the handle off, it appears just pressed on, but I don't want to start prying.

Ran out of time to finish everything today. Next week need to finish up the transom and control box, remove the gas tank and junk the hull.

 

[stonyloam]

Use the sawsall to cut the panel to remove the control, just don’t cut the cables. You might want to saw out the section of the inner hull that has the front motor mounts so you can duplicate them.
p.s. Have fun winterizing LOL

 

[nola mike]

Well yeah, a sawzall removes anything. I'd like to actually take it apart though the way God intended--I'll need to do that at some point anyways...
And yeah, I'm kind of bummed about winterizing.

 

[nola mike]

OK, so the old motor is pulled. Ready to get going on rebuilding the new one. I have to find a machine shop to do the rebuild, not sure about how to find one. I don't know any mechanics or whatever in town. I've asked around with no luck. Need to start sourcing parts as well. So far I need:
1. Gimbal bearing and unis for the outdrive, bellows, shift cable
2. Intake manifold; these should all the same for vortec heads, right? Looking for aluminum, 4bbl carb
3. Exhaust manis/risers. This looked to be a freshwater donor, any chance to reuse, or just bite the bullet?
4. Carb: Should I look for a used QJet/rochester? I assume they're jetted different for v6/v8? Rick Stephens said that I'll need an adapter if I go with a stock carb, but that an Edelbrock 1409 is direct fit?
5. Motor mounts. Seems like a good thing to replace

Any other "while I'm in there" items? Maybe oil drain plug/hose? What else sucks to replace once the engine's back in?

Lastly, I can't seem to find dimensions for the motor; I need to get some info on if/where I need to glass in some new mounts. Also need to figure out how that's done...

 

[Scott Danforth]

permission to come aboard..........never mind...... Im a pirate and just boarded.....

regarding the intake, if you boat in brine and do not plan on a HX (recommended), you need either a cast iron intake or a dedicated aluminum marine intake with bronze water passages.

if you had the 4" HX on your 470, PM me some pics of the existing HX and I will advise how to plumb it for a half system on the V6

no problem if you have a pair of fresh water castings. toss in a vat of oxalic acid for a week, then pressure wash. they will look flawless.

go with a 1409, then tune properly. the 1485 kit is close, however needs tweaking.

add the oil drain hose with the motor out. you will thank yourself.

easiest way to figure out where the mounts go is to hang the new motor while having the rear mounts bolted, have the alignment bar in place, then measure

clean and paint the bilge with the motor out.

 

[Scott Danforth]

just out of curiosity sake, what are you doing with the 470? ......

Hint....... has to do with post #11 https://forums.iboats.com/forum/oth...billique-florida-2020?p=10834481#post10834481

 

[Rick Stephens]

Your carb choice will be somewhat determinate on what intake, or vice-versi. If you are going to drop a 4 barrel on it, then you can either choose a 4 barrel iron mani or a 4 barrel aluminum like the square bore Performa I installed. I got an all aluminum intake because I'm a long ways from salt. You will need to get one with brass lining for salt water. If you go with the Performa, then just get a 1409.

 

[nola mike]

permission to come aboard..........never mind...... Im a pirate and just boarded.....

regarding the intake, if you boat in brine and do not plan on a HX (recommended), you need either a cast iron intake or a dedicated aluminum marine intake with bronze water passages.

if you had the 4" HX on your 470, PM me some pics of the existing HX and I will advise how to plumb it for a half system on the V6

no problem if you have a pair of fresh water castings. toss in a vat of oxalic acid for a week, then pressure wash. they will look flawless.

go with a 1409, then tune properly. the 1485 kit is close, however needs tweaking.

add the oil drain hose with the motor out. you will thank yourself.

easiest way to figure out where the mounts go is to hang the new motor while having the rear mounts bolted, have the alignment bar in place, then measure

clean and paint the bilge with the motor out.

Wasn't planning on trying to keep FWC, I'm brackish and after 12 years it looks more like it's been fresh boating than brine. The system is just the stock 4" HX--what were you looking for specifically?

So no aluminum unless FWC, guess that's why it was in the 470 to begin with. Presumably the standard alum intakes don't have the bronze passages? Sounds like the 1409 is the way to go, but no prob with a stock 4 bbl if I come across one?

Good to know about the exhaust. Forgot to ask if that's the same between the non-vortec (old) and vortec (new) heads. IIRC only the intake is different.

I'll need to get the actual mounts glassed in before I hang the engine, so I just need a ballpark initially. I'll fine tune it when it's ready to go. There's going to be some time before the engine's ready, so I want to just plop it in when ready.

Are you just looking for a bare short block? I know your disdain for the iron head. I actually have another 470 sitting in the yard as well that ran about 4-5 years ago and has been sitting under a tarp since. Had planned on rebuilding when this one crapped out, but decided on the 4.3 instead.

 

[Lou C]

On the 4.3 if in salt/brackish you can easily find cast iron 4bbl Vortec intakes (8 bolt), the pre Vortec (12 bolt) ones are tougher to find in good shape. When I did my top end overhaul 3 years ago I just got a set of reman heads with the same casting #s as my originals so no surprises with re-assembling; I know I could have picked up 20 hp going to Vortec though.
Exhaust manis & elbows are the same pre Vortec or Vortec no worries there if your present exhaust is good.
carbs, I use a Qjet, good cores are hard to find though so going with the Edelbrock 1409 will be less risky or a Holley 4160 which OMC and Volvo both used on thee after GM quit making Q jets. The Edelbrock appears to fit without an adapter but the Holley for sure needs in on the cast iron intake.
Winterizing isn’t that bad but when I eventually re power I will be going with an engine clean enough inside for a half closed system and a remote oil filter mount. Just makes winterizing way easier that way. On mine I pull out the back seats and it’s wide open but they get heavier as I get older lol!
in all these 4.3s are good compact engines for small boats. The pre balance shaft ones don’t run as smooth as a V8 but are more pleasant sounding than a big 4 cyl. Personally my ideal engine in a boat with an I/O would be a GM 250 cu in straight six (easy maintenance better balanced too) but those days are long passed.....

 

[Rick Stephens]

I built a jig out of plywood that worked perfectly to set height on my new V6 motor mounts. It was based on the Mercruiser drawing for the Alpha 4.3L 1996-01 2 piece exh. And the main thing is that all Merc transom plates set the motor at 13º down from the transom angle. With that as the centerline for the motor, the glassed in motor mount height is exactly 4 inches below top of the motor mount ears on the transom plate.

 

[Scott06]

https://samerwebapp01apncus01.azuree...-865108r89.pdf

this will show the install dimensions fir the front motor mounts

sorry didn’t see the link to same dwg in Rick post