replacing Mercruiser 4.3 v6 1993 engine with Chevy s10 4.3 v6 1993

[dlogvine]

I bought a 1993 Bayliner Capri with 4.3 v6 mercruiser engine. originally I thought about taking the outdrive and parting out the rest since the boat with the trailer was very cheap, but after inspecting the boat I realized that the deck and the boat is in a good shape despite having engine water damage. the engine is most likely frozen, I was not able to turn it and carburator was filled with white powder. so I decided to restore the boat and managed to buy an s10 4.3l v6 engine from the same year 1993. now I have a question, what do I need to change on this car engine to make it boat ready. I know I need to change all the gaskets, add new starter and alternator. Looks like the intake is also different and I'm going to use the one from the original mercruiser. anything else? distributor? thank you.

 

[Bondo]

Looks like the intake is also different and I'm going to use the one from the original mercruiser. anything else? distributor?

Ayuh,.... Ya use only the Long Block of the pickup,....

ALL of the accessories come from the boat motor,.....

 

[Scott Danforth]

the white stuff in the carb is long evaporated fuel and deposits. the carb needs a rebuild

I would pull the drive to make sure the motor is frozen prior to swapping.


and the long block will need to have the heads pulled off to install marine head gaskets, and all the steel core plugs replaced with brass core plugs. you will only use the longblock - (block, heads, pistons, crank, etc.)

as Bondo pointed out, all other components come from the boat motor.

this includes the following:

dipstic tube
oil pan
water pump
flywheel
starter
alternator
brackets
gauge sensors
distributor
intake and carburetor
wiring harness

use new brass drain plugs

I personally would also swap the cam, the marine 4.3 cam is a much higher lift than the stock truck 4.3 cam

since you have the motor pulled this far apart, I would also spring for a new timing chain and gears, along with a new oil pump.

test the exhaust manifolds and risers prior to reuising. you may have to buy new

also, the 1993 truck motor will definately have a balance shaft. your 1993 mercruiser SHOULD have a balance shaft. you will want to verify since marine motors sometimes lag the rest of the world by about 6 months to a year.

 

[Rick Stephens]

I personally would also swap the cam, the marine 4.3 cam is a much higher lift than the stock truck 4.3 cam

My bet is the cams are identical.

 

[Scott Danforth]

My bet is the cams are identical.

not if you read the lift at 0.050" for each. however it wouldnt be the first time that one of the published specs are wrong...

 

[dlogvine]

The carb was so frozen, all the valves were solid shut that I had to buy another one. The white powder inside of the carburator is from the water.
Im going to take the boat motor out and then put one motor together out of two. Unfortunately looks like alternator and starter are gone, they are all corroded and most likely need to be replaced.As for the oil pan, it looks pretty close to the one on the mercruiser engine and definitely newer and less corroded. Could I just change the gasket?
And the other question, how can I see if the water pump and fuel pump from mercruiser boat engine are working?

 

[Scott Danforth]

if they are that corroded, you may need to buy new. oil pan may be the same, however the dipstick tube is not. marine dipstick tubes goin the block about 8" to the bottom of the pan so you can suck oil out the tube. car and truck tubes go in the block about 3/4"

you may want to assess all the accessories and what it will cost to replace. then look at craigslist for a running boat with rotten hull. buy the whole thing, part it out and sell the trailer

 

[dlogvine]

We are going to test the replacement engine for compression. Just got a new starter for the engine, will hook it up and crank it. I have specks for mercruiser v6, just wanted to see if the car engine has the same compression, chevy v6 4.3 1993. Thx

 

[Bondo]

I have specks for mercruiser v6, just wanted to see if the car engine has the same compression, chevy v6 4.3 1993.

Ayuh,..... Same motor, same spec's,...

 

[dlogvine]

No Title

cleaned up the piston tops and push rods. Looks like pistons and cylinders are in a decent shape. once the carb deposits were removed there is just one little nick on one of the pistons. The cylinders are also smooth, so hopefully I'll just hone them and change the rings.

 

[Rick Stephens]

One of the harder things to do is to measure diameter. Last time I did a hone and re-ring without a boring, what we did was buy the set of rings and install one the cylinders to measure gap. Here's Hastings ring gap guide. This will let you know you are meeting spec and don't have too much wear.

 

[dlogvine]

One of the harder things to do is to measure diameter. Last time I did a hone and re-ring without a boring, what we did was buy the set of rings and install one the cylinders to measure gap. Here's Hastings ring gap guide. This will let you know you are meeting spec and don't have too much wear.

Im going to take the engine to the shop to magnaflux it and mike the pistons and cylinders. I dont have proper micrometers and dont want to do something im not really familiar with, that can cause the engine problems later. Anyways im planning on grinding the shaft, maybe taking about 0.001mm, since the engine had at least 100k miles on it.

 

[dlogvine]

We started taking apart the Mercruiser engine on the boat. Despite plenty of rust on the outside the heads inside looked very clean and not worn at all. If magnaflux will show that the heads are sound and no cracks I'll just use the ones from the boat. Looks like the valves are in great condition, bright and clean.
There were a couple problems I discovered so far. The thermostat housing did not have a thermostat inside, and the risers were almost completely clogged with rust and some gunk. What could have caused this much dirt and rust inside of the risers? Exhaust manifolds were much cleaner and besides some rust on the outside, pretty intact inside.
I'll make pictures as soon as we pull the engine outside of the boat. Planning on doing it later today.

 

[Rick Stephens]

If you are dragging the block to a machinist, take the heads and let him inspect them. If you got a good one, it takes very little to check valve seats and install new seals. I had mine reground for very few dollars. If you purchase your gasket set before you take the heads in (I got FelPro marine gaskets from Summit Racing, they are the best) Then you can take your valve seals in as well and have him install them when he inspects the seats.

I'm lucky, I have a small local machine shop with an owner who is totally anal and loves doing it right. He enjoyed working on my engine and made everything perfect for me.

As far as manifolds, this boat EVER in salt water? If so, life span for them is not that long.

 

[dlogvine]

If you are dragging the block to a machinist, take the heads and let him inspect them. If you got a good one, it takes very little to check valve seats and install new seals. I had mine reground for very few dollars. If you purchase your gasket set before you take the heads in (I got FelPro marine gaskets from Summit Racing, they are the best) Then you can take your valve seals in as well and have him install them when he inspects the seats.

I'm lucky, I have a small local machine shop with an owner who is totally anal and loves doing it right. He enjoyed working on my engine and made everything perfect for me.

As far as manifolds, this boat EVER in salt water? If so, life span for them is not that long.

Absolutely, I want the heads to be magnafluxed, on my other rebuild engine the problem was in the cracked head, the water got into the engine and froze it shut. As for the shop, all the shops I looked for in Phoenix area are pretty expensive and some have also bad reviews. It cost me almost $1700 to bore the cylinders, do the valve job, grind the shaft and replace the pistons, with new gasket sets. And it was with me doing all disassembly and assembly.
As for the salt water, I'm guessing yes, the boat was most likely used in the ocean, original registration is in California and the zink plates on the outdrive are all pretty corroded. Still I have not seen the riser passages so clogged. I wonder if the clogged riser could have caused the engine overheating and possible failure?

 

[Senior B]

Clogged Risers have been the culprit of many over heating problems. Between risers and manifolds, risers are always the first to go as they don't stay full of water like manifolds do so the corrosion process attacks them much more aggressively. If the gasket surfaces look good, you may be able to have the set boiled out and get more life out of them, but for all the work you've put into this craft thus far I would get new. If you're only going to be in fresh water, a new set will last the life of the boat..

 

[achris]

If you are in salt and want to change manifolds, go to the 'dry-joint' manifolds.

 

[dlogvine]

I am in arizona, so it will be fresh water only, and I have a set of almost new risers to replace these ones. started cleaning valves on the replacement engine, very dirty but surfaces flat, no holes. was surprised to find a couple missing valve stem seals, but I'll replace them all. Looks like heads could be completely restored if they have no cracks and structural damage.

 

[dlogvine]

No Title

Today I took apart and cleaned both heads and valves. Valve pistons had a lot of carbon deposits on the surface and there was plenty of old grease and gunk inside the valves.

 

[dlogvine]

No Title

Started with cleaning valve pistons surfaces, used a wire brush on the drill and cleaned up carbon deposits. takes a while to remove it. however found out that after initial dirt and gunk is removed from the surface , 3M polishing pad removes carbon buildup much faster