4.3 motor swap

[Berezy24]

have 1993 4.3 lx alpha one engine that needs replacing. Found a tbi 4.3 from a van of same year, can I swap intake and distributor to this engine and will it work??

 

[alldodge]

NO :nono:
Auto stuff is not ignition protected, and to use it can turn your boat into a bomb

 

[nola mike]

AllDodge , think he's asking if he can swap his old dizzy and intake to the new longblock. That should be fine, that vintage you might still have a mechanical fuel pump.

 

[Berezy24]

Correct, wanting to swap my intake, carb and distributor to the new engine.

 

[Rick Stephens]

That should work perfectly.

 

[jimmbo]

I doubt you will be happy with the performance

 

[Scott Danforth]

first, you need to pull the heads and install marine head gaskets and you need to knock out the steel core plugs and install brass or stainless

the base motor in a truck is the same block, heads, rotating assembly in your boat. the cam profile is slightly different, however not enough to worry about

then after you get the long-block re-assembled, switch everything else over from your marine motor. all accessory drive brackets, pulleys, etc. the starter, alternator, intake, and ignition.

if the van was a manual transmission, no need to swap that, however if it was an automatic, you will need to swap over the flywheel.

keep in mind, 93 was a cross-over year. make sure your motors have the exact same block casting number. the motor in your boat may be older

 

[Berezy24]

Thanks for the replies. Casting numbers ARE different. Ours is a 10224535. Engine I’ve found was a GM crate engine, block 10105867. GM part number 12361243.

 

[Scott Danforth]

some light reading

https://forums.iboats.com/forum/eng...history-of-the-4-3-liter-with-casting-numbers

10224535 is a balance shaft engine

the engine you found is a NON- Balance shaft engine with block 10105867

find a balance shaft motor, or if you go backwards to a non-balance shaft motor, you need a whole lot more stuff than what you have.

 

[Berezy24]

Thank you Scott. Slightly more confused now! Can you provide more info on what stuff I would need to run the non-balanced shaft motor? Would in need a different flywheel and damper?

 

[Scott Danforth]

different flywheel and damper (because the non-balance shaft motors are balanced different)
different intake because the intake changed for balance shaft clearance
accessory drive and brackets (because that was part of the change)
different mounts as the non-balance shaft motors used the fluid filled mounts (squishy to allow the motor to shake like a dog passing a peach pit)

as I stated, get a balance shaft motor

 

[Rick Stephens]

different flywheel and damper (because the non-balance shaft motors are balanced different)
different intake because the intake changed for balance shaft clearance
accessory drive and brackets (because that was part of the change)
different mounts as the non-balance shaft motors used the fluid filled mounts (squishy to allow the motor to shake like a dog passing a peach pit)

as I stated, get a balance shaft motor

Scott, I'm sure glad you posted on this. I thought 94 was the change year. You just saved the OP a bunch of heartache!

 

[Berezy24]

Appreciate your expertise!
Are the newer 4.3’s useable in my boat. Trouble finding one with my casting. Seems to be plenty of the 1997-2002 era truck engines. Vortec I guess? Saw 2 with block number 14099090, looks like a balance shaft engine but can it work for me??

 

[Berezy24]

Appreciate your expertise!
Are the newer 4.3’s useable in my boat. Trouble finding one with my casting. Seems to be plenty of the 1997-2002 era truck engines. Vortec I guess? Saw 2 with block number 14099090, looks like a balance shaft engine but can it work for me??

 

[Bondo]

but can it work for me??

Ayuh,..... Welcome Aboard,..... Sure,.... it'll work with slight up-dates,.....

 

[Scott Danforth]

Appreciate your expertise!
Are the newer 4.3’s useable in my boat. Trouble finding one with my casting. Seems to be plenty of the 1997-2002 era truck engines. Vortec I guess? Saw 2 with block number 14099090, looks like a balance shaft engine but can it work for me??

newer motors are better from a variety of views. the vortec heads provide over 20hp alone

however.

not a single accessory drive piece you have will bolt up and you will need a vortec intake for the 1996 and newer motors

your starter, alternator, ignition, flywheel and exhaust will transfer over.

you will need the following:
marine head gaskets
brass core plugs
vortec marine intake
vortec marine water pump (circulating pump) - do not use the automotive one.
new crank pulley for serpentine setup (potential to use the automotive one)
new water pump pulley (potential to use the automotive one)
new mercruisers brackets (serpentine setup)
new mercruiser belt tensioner
new hoses

your motor is a 93-95 balance shaft motor

 

[berezy]

Will my existing accessories and brackets not bolt onto the newer engine if I change out the damper/pulley from old block and use v-belt??

 

[berezy]

newer motors are better from a variety of views. the vortec heads provide over 20hp alone

however.

not a single accessory drive piece you have will bolt up and you will need a vortec intake for the 1996 and newer motors

your starter, alternator, ignition, flywheel and exhaust will transfer over.

you will need the following:
marine head gaskets
brass core plugs
vortec marine intake
vortec marine water pump (circulating pump) - do not use the automotive one.
new crank pulley for serpentine setup (potential to use the automotive one)
new water pump pulley (potential to use the automotive one)
new mercruisers brackets (serpentine setup)
new mercruiser belt tensioner
new hoses

your motor is a 93-95 balance shaft motor

Will my existing accessories and brackets not bolt onto the newer engine if I change out the damper/pulley from old block and use v-belt??

 

[Scott Danforth]

No, you will need the new brackets, etc for a serpentine setup. That would be the easiest.

if you want to stick with V-belts, you will need to modify, fab and add/make a variety of spacers, however you can not simply bolt them on.

the damper sticks out further from the block face, the water pump is different, etc.

 

[Rick Stephens]

It would be a very difficult task taking a late model Vortec and fitting with v-belts. All custom, unfortunately. This means making your own brackets and spacers with the hardest finding the right shiv for the water pump to line up with whatever shiv you found to bolt up to the harmonic balancer. Worst part is, you end up with a morphodite bastard motor that no one can work on. Just not worth it. Cost wise would be cheaper to just go get a complete Vortec motor with all the parts off a donor boat.

Note, I have a bastard motor. I have a non-balance shaft 4.3L block with no mechanical fuel pump port and Vortec heads. All the accessories are v-belt from being a pre-Vortec motor. Top end is all later year. Just buying gaskets is a PITA since bottom end is all pre-Vortec and top end is all later.When I buy parts I have to use two different era parts lists. Added to that mix, the Tbolt IV ignition module died and I replaced the ignition with EST Voyager. Since I built the thing, I can keep it running. I feel for the poor soul who gets this boat when I kick the bucket.