krustyCrab
Cadet
- Joined
- Jul 1, 2014
- Messages
- 27
1986 OMC 4.3l V6
So I finally got the boat on the water and after leaving the harbor I pushed the throttle and alot of white smoke/vapor was coming out of both the PVC valves on the valve covers. I would say it was more steam than smoke as when I throttled down the steam dissipated but I could clearly see a liquid drip coming from the hose. While at an idle there is a slight smoke that comes from those hoses but not like what was happening when I opened her up. I assume im dealing with either a cracked block or a bad head gasket. I am pretty sure its going to end up being a cracked block, why wouldnt it right LOL. I also verified I have good compression.
Changing the oil: When I first changed the oil it appeared fine up until about the last once or so which then appeared watery/slight milk. The boat had been sitting for at least three years so I thought well maybe its just due to that. I changed the oil before I took her out, when I came back to shore because of the steam issue I decided to pump out the oil again to see what the condition was, it looked perfectly fine with no sign of water.
Facts to help: When I purchased the boat I did so with full knowledge that this was going to be a project. Something to note here is both exhaust elbows and manifolds had slight cracks, I replaced them… While I had them off I did my very best to identify any cracks or issues with the block externally, I found nothing. I do understand that if the exhaust was cracked theres a good chance the block is as well, but most likely internally on a cylinder wall or multiple cylinder walls.
Rigged stuff: Please dont crucify me for this but when I first got the motor running I noticed a slight leak of an oil substance coming from the intake manifold gasket on the front of the block, I tossed some JB Weld on it and no more leak there, however I then noticed another leak where the oil pan gasket and timing cover meet, more jb weld, no more oil in the bilge. What does any of that tell me? Besides im an asshat for rigging it in such a way.
The Question:
I am fairly certain its going to be a cracked block, I can get a new block and heads for just under 2k. I was really wondering if I could source a 4.3l v6 block from a salvage yard maybe off an astro van or something, as this was a fairly common motor for a very long time. If that block will work am I looking at a huge project retrofitting it to a marine application or can this be done just like anything?
*** Also I cant seem to get the motor past 140f, which strikes me as odd because the thermostat should open at 160, no cooling to the exhaust manifold?
So I finally got the boat on the water and after leaving the harbor I pushed the throttle and alot of white smoke/vapor was coming out of both the PVC valves on the valve covers. I would say it was more steam than smoke as when I throttled down the steam dissipated but I could clearly see a liquid drip coming from the hose. While at an idle there is a slight smoke that comes from those hoses but not like what was happening when I opened her up. I assume im dealing with either a cracked block or a bad head gasket. I am pretty sure its going to end up being a cracked block, why wouldnt it right LOL. I also verified I have good compression.
Changing the oil: When I first changed the oil it appeared fine up until about the last once or so which then appeared watery/slight milk. The boat had been sitting for at least three years so I thought well maybe its just due to that. I changed the oil before I took her out, when I came back to shore because of the steam issue I decided to pump out the oil again to see what the condition was, it looked perfectly fine with no sign of water.
Facts to help: When I purchased the boat I did so with full knowledge that this was going to be a project. Something to note here is both exhaust elbows and manifolds had slight cracks, I replaced them… While I had them off I did my very best to identify any cracks or issues with the block externally, I found nothing. I do understand that if the exhaust was cracked theres a good chance the block is as well, but most likely internally on a cylinder wall or multiple cylinder walls.
Rigged stuff: Please dont crucify me for this but when I first got the motor running I noticed a slight leak of an oil substance coming from the intake manifold gasket on the front of the block, I tossed some JB Weld on it and no more leak there, however I then noticed another leak where the oil pan gasket and timing cover meet, more jb weld, no more oil in the bilge. What does any of that tell me? Besides im an asshat for rigging it in such a way.
The Question:
I am fairly certain its going to be a cracked block, I can get a new block and heads for just under 2k. I was really wondering if I could source a 4.3l v6 block from a salvage yard maybe off an astro van or something, as this was a fairly common motor for a very long time. If that block will work am I looking at a huge project retrofitting it to a marine application or can this be done just like anything?
*** Also I cant seem to get the motor past 140f, which strikes me as odd because the thermostat should open at 160, no cooling to the exhaust manifold?
