Mercruiser 4.3 Repower

seadogmike

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Jun 26, 2015
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Well I'm Finally getting started on the repower of the Renken 2000 Classic.

Started disconnecting everything and am about ready to pull the old engine. It had threw a rod, so going to get a replacement engine. Will pick up the engine on Wednesday. Will want to go through it before installing it in the boat, and will be parts chasing, No doubt. The old 4.3 from what I can decipher is an 1985. (block stamping T05182KD). It does have roller rockers, but not the counterbalance shaft.


The new engine is a 1992 Vortex. I'm not sure what parts I will be swapping, But I know some parts are different.
Oil Pan- Not sure because I have not been able to determine if the old block has a 1 piece or 2 piece oil seal.
Exhaust manifolds- I believe these should fit, but I will have to replace 1 of them.
Throttle Linkage- Don't know about this one either. The old one had a 2 barrel New engine is equipped with a 4 barrel edelbrock.
Ignition- Hoping I can still use the Thunderbolt IV.
The Old engine already was converted to an electric fuel pump.
Flywheel and coupler. I know the flywheels are different The old has a 12 3/4" I believe, and the new one will have a 14".

Thoughts/Opinions???

 

NHGuy

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I am not well informed on all the parts differences but I can say that you really ought to run the replacement motor on the ground before you put it in the boat. I do know you can use the TB IV ignition, and the same exhaust manifolds. You will probably need a different coupler and rear engine housing mounting cover. If the replacement engine has a marine fuel pump on it just save the electric pump for another day. If not you will need to swap over the pump opening cover from the old engine. That should be the same, but you'll want a gasket.
Is the 4 barrel a marine one? Needs to be or you're not legal and safe from fuel spills, and vapor build up. Both of those can create conditions that end with boom.

Keep an eye out here, folks who know the conversion will be along soon.
 

seadogmike

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It is my intent to run the new Mill on the ground before installing. Yes the carb is a marine. It is my understanding that the later blocks (vortec) used an electric fuel pump and there is no provision for a manual pump on the block.

It's hot Hot hot here in SC. Work is slow, Garage is like a Tin Can, even with the fans going full bore and the doors open. Hoping for some cooler weather for the weekend. Maybe will get something done.
 

NHGuy

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I feel you on the temps. I am way up in New Hampshire and it even feels hot here. I have a car in pieces out in the yard. When I get home at 7 pm I'm good for about 40 or 50 minutes before I get hot or tired or bitten by bugs.
 

seadogmike

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Jun 26, 2015
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I am looking for some info to connect a temporary starter switch to the replacement motor in order to run it on the ground before installation.
Have a 3 position starter switch with 3 terminals marked B, I, S.
B for battery (got it)
I for ignition- (to the plus side of the coil?)
S for starter ( which terminal on starter solenoid?)
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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the terminal that had the yellow stripped wire connected to it prior. it should be a little post connection on the solenoid.
 

Bondo

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I am looking for some info to connect a temporary starter switch to the replacement motor in order to run it on the ground before installation.
Have a 3 position starter switch with 3 terminals marked B, I, S.
B for battery (got it)
I for ignition- (to the plus side of the coil?)
S for starter ( which terminal on starter solenoid?)

Ayuh,..... Welcome Aboard,..... Ya don't need no switch,... just a set of jumper cables, 'n a couple of 14ga. jumper wires,......

Connect the jumper cables (-) battery, to the block, 'n the (+) from the battery, to the battery lug on the starter's solenoid,.....

With a long jumper wire, connect from the (+) power, to the coil's (+) terminal,.....
With a short jumper wire, jump from the solenoid's battery lug, to the tiny terminal closest to the block, to activate the starter,....

When it Starts, Pull the short jumper off the starter,.....

To kill the motor, remove the long jumper powerin' the coil,....
 

seadogmike

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Jun 26, 2015
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Kewl Beans!
Thanks for the info.
Engine will be here tomorrow.
Have to set up to unload it. Looks like it's gonna be a 2 beer job.
 

seadogmike

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So I got the replacement engine home yesterday.
It came with a new 4 barrel intake and a New Edlebrock carb. (1413). This is a non-marine carb. The guy told me that he accidentally ordered the wrong one.
Several things I am going to need.....
14" flywheel and coupler
The correct carb, (edlebrock 1409) or a 2 barrel intake and carb.

The new engine has the serpentine pulley on the crank. I'm hoping that my v-belt pulley will bolt up, or I will have to change out all of the pulleys on the circulating water pump, alternator and power steering pump.

Also I believe that the starter is different. The new engine has staggered mounting holes (1996) and the old one (I believe) has parallel holes for mounting. (1986).
So off to ebay for parts search, unless someone on here has a better Idea.
I am considering bolting up the intake and using the 1413 Carb for the "on the floor" run test. Thoughts/ Ideas?

My intent is to make the engine as close to plug and play as possible before installing it in the boat.

I know it's going to be a slow project. It's hot, working long hours, family duties, but hoping that progress will be made soon.
 

Bondo

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I am considering bolting up the intake and using the 1413 Carb for the "on the floor" run test. Thoughts/ Ideas?

Ayuh,..... Trade it for the 1409,......

Which coupler is 'tween the old motor, 'n drive,..?? crank mounted, or flywheel mounted,..??

If crank mounted, get the retrofit, as the flywheel mounted probably won't clear the flywheel cover,...

Yes, ya need the staggered bolt starter, for the 14" flywheel,...
If the old motor has the 12" flywheel, that may also present problems with the flywheel cover,...
Might need a later model cover,...
 

seadogmike

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In order to cut the costs for startup, I am thinking about using an adapter plate for the new Intake to adapt to the mercarb 2 barrel. I haven't found anyone who wants to trade the 1413 for a 1409, but I can sell the carb to help pay for the other parts I need. Then later, I when I can locate a 1409, it should be an easy swapout.

The old engine (1986) has the 12" flywheel and flywheel mounted coupler. I know I will need a new flywheel, coupler and I am guessing I will need a housing. I have located a source for those parts, but wanted to wait until I pull the engine tomorrow, just to make sure.

Will replace the starter with a new one.

The previous owner had "rigged" the fuel lines. The steel tubing that comes from the carb was cut about 3 inches from the carb, and the fuel line was slipped over this stub and clamped. then a marine grade fuel hose was ran from this point to the electric fuel pump. I know that this isn't right, but not sure yet how to approach this. I would want to use the correct fittings between the carb and fuel pump, and still stay within CG regulations, besides that, I had rather not open my hatch ans see fuel in the bilge, or worse "KABOOM". Any suggestions would be appreciated.

Old motor comes out tomorrow. Will start assembly of the new engine next week.

Am I correct in assuming that the recommended sealer for the Intake would be quicksilver perfect seal? (I have to locate some).
 

Bondo

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I know that this isn't right, but not sure yet how to approach this. I would want to use the correct fittings between the carb and fuel pump, and still stay within CG regulations, besides that, I had rather not open my hatch ans see fuel in the bilge, or worse "KABOOM". Any suggestions would be appreciated.

Ayuh,..... 3/8" steel brake line is the same size, same fittin's as the original fuel line,....

A brake line, 'n a tubin' bender is all it takes to build a new factory lookin' fuel line,....
 

seadogmike

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Ok, Got the old engine out on Saturday. It's now a matter of changing everything over to the new engine. So as I am comparing differences between the engines, here are a couple of things that I noticed:
The Old engine had the 14" flywheel. Looks like I am good to go there. This means that My coupler, rear housing and starter should all fit. Old engine had staggered bolt holes for the starter as well.

The old engine did not have an engine oil cooler. The new one has the Oil lines that come out of the engine just above the oil filter.
So this brings me to several questions.
1. Since the old engine didn't have one does the new engine have to have one. I realize that there are no major issues with adding it, except... the cost of the cooler and some hardware.
2. if one is necessary, where would it be added in the cooling system? (I assume that it would be mounted in the same hose as the power steering cooler.) before the power steering cooler or after?
3. Would this work or do I need to get a special "Oil Cooler"?

Picked up the intake gasket set this morning at Napa. (Fel-Pro). I think they are about the best quality.
 

Bondo

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1. Since the old engine didn't have one does the new engine have to have one. I realize that there are no major issues with adding it, except... the cost of the cooler and some hardware.
2. if one is necessary, where would it be added in the cooling system? (I assume that it would be mounted in the same hose as the power steering cooler.) before the power steering cooler or after?
3. Would this work or do I need to get a special "Oil Cooler"?

Ayuh,..... Are ya sure it's for a Cooler, 'n not for the remote filter,..??

As ya note, it ain't Necessary, but a nice addition,....
Yes, in-line with the P/S cooler, where ever it fits in,.... 'n no it ain't the same as a P/S cooler, but close,...
 

seadogmike

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Jun 26, 2015
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Thanks Bondo,
I am sure, because the Oil filter is mounted just below the 2 lines.
It has 2 bolts holding it on that you can see when you take the oil filter off.
I haven't removed it yet, but I'm pretty sure that when you take it off, the oil filter will screw in it's place.
Will try to get some pics when I go back to the garage.
 
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