salt water in single cylinder

[Lou C]

It’s because the engine companies look to save money any way they can & much of the USA is freshwater so it’s not a drawback. A closed system now a days adds over 2 grand USD to repower cost.
If I repowered with a reman 4.3 sure I’d add it. But it is close to 2 grand!

 

[Mc Tool]

It’s because the engine companies look to save money any way they can & much of the USA is freshwater so it’s not a drawback. A closed system now a days adds over 2 grand USD to repower cost.
If I repowered with a reman 4.3 sure I’d add it. But it is close to 2 grand!

I guess it makes sense to wait for a re-power and do the job . These new automotive electric water pumps would make life easier in that you dont need to locate any extra pumps near an existing pulley system .
I can handle thinking about outboards in salt water coz they are sorta made for it but Id be leary of a cast block in even fresh water as I think that repeated wet / dry cycles or leaving it half full of water cant be good for them .... we all have seen the colour of straight water in a cast block ..... megga rusty .

 

[Lou C]

Cast iron components in most fresh water last indefinitely. You should see boats from the USA used only in fresh water regions. The engines look like new, same with outdrives. We in the salt, change our elbows/manifolds every 5-7 years, at least the elbows, in fresh water, some last indefinitely!
I don't think that outboards always have longer life in the salt. My 1988 original short block hasn't rotted through yet. Here you see Yamaha F-150s rotting through right by the 'stat housing and in the exhaust midsection, sometimes in less than 10 years. My engine gets filled with my own mix of Sierra PG antifreeze and water every fall. Not much flaking rust at all. Only parts like the elbows, and 'stat housing that aren't totally full of AF in the off season seem to have flaking rust. But yeah if I spend the cash for a nice reman 4.3 Vortec, no way am I running salt water through it.

 

[cyclops222]

Salt is bad enough. Add in INDUSTRIAL chemical dumping. Like Paper Mills or battery recyclers ? Eat metals alive quickly.
A large sewage plant can dump some large amounts at night. Why are my underwater metal parts so PITTED ? Then add in dangerous 120 vac leakage currents from power outlets ? CHOMP CHOMP most metals.

 

[beruken]

I know that some will dispute this but after running my present boat in Long Island salt water (23 seasons) I have seen that winterizing using proper antifreeze (PG but with corrosion inhibitors) seems to prolong the life of certain components…for example after 23 seasons in the salt I have changed the thermostat housing a few times but still have the original intake and I do pull the stat housing to check the inner passage in the intake when I winterize. Otherwise I found that the cyl head cooling passages were getting eroded after about 15 years and some seepage around the head gaskets was already happening before my overheat back in 2016. How do I know that? Oil analysis. It showed up way back in 2011, and after in 2015. Nothing showed on the dipstick till the head gaskets let water in a cyl (2013). Replaced cyl heads due to cracks from overheat. Exhaust has been replaced on schedule every 6/7 years. I had 3 sets of OMC batwings & converted to the later 2 piece when I replaced the heads.

Well I can't def say the head gasket was blown but from these pics of the 0 compression #6 and the # 2 rusty cyl something may have been wrong before my water intrusion. Family was stating noise coming from the engine week before and my investigation of it may have led to the water intrusion, but the piston issues look like been that way for a while. Possible boat was running on 5 and I didn't realize it. I couldn't really tell just running it to do the compression test the other day. Did seem like it didn't have the same top end for some time it had in prev years. Hey Lou, my playground was Fishers Island sound/LI too.

 

[Scott06]

Well I can't def say the head gasket was blown but from these pics of the 0 compression #6 and the # 2 rusty cyl something may have been wrong before my water intrusion. Family was stating noise coming from the engine week before and my investigation of it may have led to the water intrusion, but the piston issues look like been that way for a while. Possible boat was running on 5 and I didn't realize it. I couldn't really tell just running it to do the compression test the other day. Did seem like it didn't have the same top end for some time it had in prev years. Hey Lou, my playground was Fishers Island sound/LI too.

Would think the last one is related to detonation

 

[Lou C]

Agreed that’s what the last pic looks like. When you get it back together (or get a reman) be careful with where you set the timing. Apparently the 4.3s are more prone to detonation and I’m not sure what Merc’s specs are but OMC specified only 12* of centrifugal advance and base timing was 1* if using regular fuel and 6* if using 89 octane. I always used at least 89 & never had detonation. I finally got a new advance timing light to replace my old Sears Craftsman unit because I questioned how accurate it was.. I got the OTC one and very easy to use nice bright light. Better to set it in the water where you can set total timing advance at the specified RPM. For mine it’s 18* @ 3200 rpm.
About the water intrusion does that engine still have the one piece batwing exhaust? If so that might be the source. These were hard to cast with consistent wall thickness and many leaked water back into the engine. The other possible source is the intake gaskets with the Vortec intake manifold…the old pre Vortec 12 bolt manifolds very rarely if ever leaked….I think GM goofed with the first run of gaskets on the Vortec…...I had the OMC version of the Batwings on mine for about 15 years (replaced 2x over that time) & never had water in a cyl from that. When they became NLA I converted to the 2 piece exhaust using Barr aftermarket & V/P parts (same as OMCs original design except they don’t sell those parts any more)….
What’s your plan for this engine?
My boating area is far west of yours Huntington & Northport….same salty water!

 

[beruken]

Agreed that’s what the last pic looks like. When you get it back together (or get a reman) be careful with where you set the timing. Apparently the 4.3s are more prone to detonation and I’m not sure what Merc’s specs are but OMC specified only 12* of centrifugal advance and base timing was 1* if using regular fuel and 6* if using 89 octane. I always used at least 89 & never had detonation. I finally got a new advance timing light to replace my old Sears Craftsman unit because I questioned how accurate it was.. I got the OTC one and very easy to use nice bright light. Better to set it in the water where you can set total timing advance at the specified RPM. For mine it’s 18* @ 3200 rpm.
About the water intrusion does that engine still have the one piece batwing exhaust? If so that might be the source. These were hard to cast with consistent wall thickness and many leaked water back into the engine. The other possible source is the intake gaskets with the Vortec intake manifold…the old pre Vortec 12 bolt manifolds very rarely if ever leaked….I think GM goofed with the first run of gaskets on the Vortec…...I had the OMC version of the Batwings on mine for about 15 years (replaced 2x over that time) & never had water in a cyl from that. When they became NLA I converted to the 2 piece exhaust using Barr aftermarket & V/P parts (same as OMCs original design except they don’t sell those parts any more)….
What’s your plan for this engine?
My boating area is far west of yours Huntington & Northport….same salty water!

I don't know what part the thunderboat ignition plays in this but I never set the timing and one time I thought of checking the light didn't work. Not sure what to do with it yet. I guess get an estimate to have the heads looked over and the block redone first. Reman's are costly even at 4-5 grand. water jackets look good so far. I think

 

[nola mike]

I don't know what part the thunderboat ignition plays in this but I never set the timing and one time I thought of checking the light didn't work. Not sure what to do with it yet. I guess get an estimate to have the heads looked over and the block redone first. Reman's are costly even at 4-5 grand. water jackets look good so far. I think

4.3 auto blocks are cheap

 

[stresspoint]

start looking for a split in the engine block.

hey there Lou ....

 

[Lou C]

Hey there long time no see!

 

[stresspoint]

Hey there long time no see!

yea mate , busy being single !

OP , test the block and head for a crack , , test the exhaust and inlet port on that cylinder , they have a tendency to rot around the stem area .

 

[Lou C]

When I had blown HGs on mine I found that both V6 heads had cracks in the valve seat area of the center cylinders. No cracks in the block though. Past overheat damage….