Basket case 4.3, gonna have some questions

[Bumperlt12]

Bought a new to me 91 Maxum. 4.3 alpha one. Quadrajet.

I'll post a picture of current below. I've already bought a new longblock. 4.3 non-balance draft pre-vortec, because that's what I should have. Well, I don't because there's a balance shaft.. has 12 bolt intake manifold so if my research is accurate I have a pre-vortec with balance shafts.

Will my manifold fit on a non-balance shaft engine?? If so, im just going to proceed like I never saw the balance shaft.

Next concern is thermostat housing. The one that came with boat is quite rusted. However after researching the cost of new, I might try and salvage it. I also don't have most of the associated hoses... which sucks.



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[Scott Danforth]

if it has a balance shaft and 12 bolt heads, the motor is a 93-95

the intake manifold is different than the 85, 86-88 and 89-92 motors

balance shaft motors also do not use the same mounts as the non-balance shaft motors (squishy mounts)

soak the T-stat housing in a solution of oxalic acid for a week (attacks rust, not base metal), then neutralize and paint with epoxy...... then get new check balls and springs.

 

[Rick Stephens]

I have a frankenmotor non-balance shaft w/Vortec heads motor. With non-Balance Shaft you can use any old timing cover of any old small block chevy. Your 12 bolt intake will fit as long as you have non-Vortec heads. You will need squishy mounts.

So yeah, go to it.

The motor in the pics is a beaut!

 

[Bumperlt12]

Got a good deal on a reman 4.3. After I paid, I went to get the intake manifold to clean it up and there was a balance shaft! in my 91! I decided to pretend I didn't see it.

So I will have a pre balance shaft 4.3, 12 bolt intake manifold, and a quadrajet carburetor

Other things have come up. I have no thermostat housing or associated plumbing, I looked briefly at parts / cost and that ish is expensive and I got lost in a sea of part numbers. it looks like the housing I have currently isn't made anynmore. So I was going to buy (what appears to be) its replacement:
https://www.amazon.com/MERCRUISER-THERMOSTAT-HOUSING-GLM-Number/dp/B004AQQANQ

I have no plumbing hoses except the large diameter hose from pump to housing. Is there a universal hose I can cut to length for the remaining runs? I'm not trying to pay $30+ per hose.

I'm planning on plugs/wires/cap, is there any other things I should do now, while I'm putting the engine components together?

 

[Rick Stephens]

Salvage the old housings.

No way for anyone to tell you what is good. Follow the Merc manual and go to building. Don't forget to install brass core plugs and marine water pump. Auto version of either won't last with plain water running through them.

 

[Bumperlt12]

The engine I bought is a marine engine.

Im really torn about about using therm housing because by the time I buy all the other stuff to use it, I could have bought a brand new one with the hook and everything.

 

[Bumperlt12]

I've decided to just buy a new thermostat housing. I need help confirming I am getting the right items.

This is the thermostat housing I have, which is seemingly out of productoin.
https://www.nlamarine.com/products/...3-4-3l-5-7l-v6-v8-305-350?variant=10339249285

This is the replacement part, I think.
http://ww2.iboats.com/Thermostat-Ho...9454736--session_id.859473918--view_id.172934

But it's missing 2 hose ports, so do I use this as the "cap"?
http://ww2.iboats.com/Thermostat-Ho...9454736--session_id.859473918--view_id.173121

Or do I just buy this...?
https://www.amazon.com/gp/product/B004AQQANQ/ref=ox_sc_saved_title_2?smid=A1AOMQWLSRNOND&psc=1

 

[Bumperlt12]

Pulled the old motor today, and noticed more surprises!

The thermostat housing I purchased is for a 6 hose set up, but the exhaust manifolds that came with the boat appear to be for a 4 hose set up. I have no idea what is original and what is not at this point. At this point I'm just trying to be correct to a 1991 build. To that end, what's the best solution to this mis-match? Can I just add nipples to the manifolds and hook em up??

 

[Bumperlt12]

I must not be posting correctly...

 

[Rick Stephens]

I'd answer you, but it'd be a WAG. You'd do as well doing a wild @$$ guess of your own.

 

[achris]

This is how the 91 was originally set up.

(BTW, what's the drive? Gen I or Gen II?)

Chris............

 

[Bumperlt12]

THANK YOU FOR HELPING.

Drive serial number is 0D465459, which I believe makes is a gen 1.

As far as the cooling situation, is there any reason I can't just pull the plugs on the riser and add nipples? Im wondering if the casting is different some how that my solution wont work?

Also.. why so many cooling variations and thermo housings?? it's exhausting.

 

[achris]

The plugs are there so you can remove them and put nipples in....

Chris...

 

[Bumperlt12]

UPDATE

Boat is 91. New long block is pre-balance shaft. Existing bolt ons are 94. Replacement bolts ons are mishmash of 94 and 91.

Made some good progress the other day.

I need to get some torx sockets so I can remove the rear seal cap....thing off the old motor.

I was thinking about not using the extra 2 hoses and going with just 4 hose cooling system. Mostly because its all plugged now. Does it make a difference?? Its just hot water out the exhaust right..? Although as I type this I'm thinking about how I need a hot water source for bow heater. Hmm

PO stripped a 90 into the manifold.

Because existing motor was from a 94 with electric fuel pump, boat is currently equipped with an aftermarket fuel pump. I think I need to switch back to mechanical.

 

[kirkll]

I’m no mechanic by a long shot, but why would you go back to a mechanical fuel pump over an electric? Just curious on your reasoning here, as I’m having my fuel pump replaced right now myself. Kirk

 

[Bumperlt12]

Because in order to do it properly, you have to add some electrical components that I dont feel like trying to figure out... lol.

 

[Rick Stephens]

If I am not mistaken, heater water comes right off the plugged port on the side of the engine water pump.

It is NOT hard to figure out the electrical plumbing for a proper electric fuel pump.

 

[Bumperlt12]

Is it easy to cap off the mechanical pump hole? I haven't researched it, I will now

 

[Bumperlt12]

UPDATE

Got new carb.

Snapped an old bolt for the rear seal cap inside the block. Sweet..

Cross threaded manifold drain i inherited snapped while trying to remove. Sweet..

 

[Rick Stephens]

Last time I busted a drain I drilled it, and bought a 1/4 pipe tap and rethreaded. Carefully - you aren't cutting threads but removing the remnants of the old pipe threads.