Mercruiser 4.3l 1990s parts question

[jamesdgreen2016]

Would the parts for a mercruiser 4.3l from 1991 be interchangable with a mercruiser 4.3l from 1993? Generally is everything similar in terms of fit?

 

[tpenfield]

You can check the Mercruiser serial numbers of donor and recipient engine to be sure . . . but generally, they don't change much, if any year-to-year, except at major changes of the base engine from GM.

 

[jamesdgreen2016]

What about putting a 1993 gen 2 v6 in place of a 1991 gen 1 v6. How big a deal is this? Will it fit in boat?

 

[jamesdgreen2016]

Here is my issue: I have a 1993 gen ii v6 mercruiser engine sitting in my garage. I have a 1991 gen 1 mercruiser v6 broken engine sitting in my boat. I would like to take the one in the garage and install it into the one in the boat. I am told there could be gear ration issues, or even physical mounting issues because the one in the garage might not "fit". I know anything can be done, but there might need to be some modifications to make it work. Im trying to figure out what those modifications might be? What other parts might be needed in terms of mounting the engine from the garage in place of the engine in the boat.

 

[jamesdgreen2016]

No Title

 

[jamesdgreen2016]

Block of new engine is 10105867 and serial number of old engine is 0D685578 if that helps. Im trying to see if those two are more or less interchangable because I want to replace the old with the new one.

 

[alldodge]

10105867 = 1989 to 1990 Fuel Injection, roller tappet with knock sensor.
0D685578 = is for an Alpha 1 Gen 2 drive

In any case, the 4.3 will fit where another 4.3 was. Issues may be a mechanical fuel pump.

Edit: are talking complete motors right?

 

[jamesdgreen2016]

Complete engines yes. Except they both have carbs. So its doable. The one engine is in parts and has to be put together then put in boat in the place of the other one.

 

[alldodge]

Complete engines yes. Except they both have carbs. So its doable. The one engine is in parts and has to be put together then put in boat in the place of the other one.

So long as the carb is a "marine" carb and not one from a car/truck then good to go. Same goes for alternator, starter, distributor.

 

[jamesdgreen2016]

The replacement engine is mercruiser with all the parts looks just like the one in the boat except 4 barrel carb in new one 2 barrel in boat. Otherwise both are boat engines.

 

[alldodge]

I don't see an issue :thumb:

 

[jamesdgreen2016]

No Title

 

[jamesdgreen2016]

Right on thanks!

 

[alldodge]

Looks like a basket case ound: :sorry: I'm bad

 

[jamesdgreen2016]

Ha!

 

[Fun Times]

See if the info below can help you out at all too,
MerCruiser GM Engine Identification
MCM 4.3L, 4.3LX Alpha
V6 AND V8 THERMOSTAT HOUSINGS

 

[Bondo]

Ayuh,.... You keep goin' on 'bout Gen.I, 'n Gen.II,..??..??

That's got Nothin' to do with the motors,.....

The '91, Could be an Alpha 1, as it's the transition year, 'n the '93 is no doubt a Gen.II Outdrive,...

 

[Scott Danforth]

92 was a transition year to balance shafted motors. Pre balance shaft motors have squishy mounts. Balance shaft motors have same mounts as 5.0 and 5.7 motors

82 was also the transition year for the drive as mentioned

 

[jamesdgreen2016]

Does it matter which outdrive i have? Will the new motor have a problem working with the boat if its the alpha one rather than the gen 2?

 

[Fun Times]

Does it matter which outdrive i have? Will the new motor have a problem working with the boat if its the alpha one rather than the gen 2?

As for cooling systems concerns between a gen 1 and gen 2 style drive, yes it could matter for potential overheating issues. That's a reason I posted the V6 AND V8 THERMOSTAT HOUSINGS above as you'll need to check what thermostat housing designs you have/going to use on what drive model.

If one/any of the engines you have were to of been an "inline" engine then the drive input shaft length would of been one issue of a few....But with the engines and drives you've mentioned, there shouldn't be any issues for the engine Coupler/Flywheel assembly vs drive shaft lengths....Again just potential cooling issues depended on what T/housing design you use as you may have both types in the parts boxes, etc..

The new housing, P/N 16413A9, can be used as a direct replacement for the older one with check balls EXCEPT on certain model. The reason for this is that the by-pass hole inside the housing is sized for a certain minimum seawater pump output and some older models don?t meet this requirement. If the new housing is put on these older models, the engine will overheat at idle or low engine RPM.
P/N 16413A3 Thermostat Housing WITH Check Balls. Must be used on all V6 or V8 engines that use an R, MR or Alpha One stern drives with the smaller water pump impeller.
P/N 16413A9 Thermostat Housing WITHOUT Check Balls. Can be used on all V6 or V8 engines that use Alpha One Gen II stern drive with the ?floppy vane? water pump impeller. Also, it can be used on any V8 engine that uses a belt driven seawater pickup pump which includes all Bravo and inboard engines.