I have a 1986 Starcraft Supersport 210 (aluminum, 21' open bow) with an OMC Cobra 4.3L 205HP engine. About two years ago, I forgot to drain the block before I deployed for the winter and it froze hard while I was gone. The block cracked. Bad. Everywhere. One of the heads cracked. One of the exhaust manifolds cracked. The power steering pump split wide open. It was a total mess. I was sick. This had been my grandpa's boat since the 80's and it had been babied its entire life. The engine couldn't have had more than 300 easy hours on Minnesota lakes on it.
I was about to buy a Rapido long block when a last minute search on craigslist yielded a 1987 (I think) 4.3 OMC Cobra engine with exhaust manifolds for $500 complete with everything to the transom coupler. It was in a boat that was falling apart, but it ran (poorly on 5 year old gas). The guy who was selling it had bought the boat for the outdrive and wasn't interested in the engine. The accessories on it weren't in as good of shape as mine were. The other big negative - it was the 175HP version with the 2 barrel carb.
My big question is, can I swap the 4bbl carb and intake on to this motor without changing the cam and still get _almost_ 205HP? Will it run right? I feel like the boat is big and heavy enough that it needs all the power it can get.
I pretty much have to swap the intake and carb to properly interface with the controls on my boat, I'm just hoping to avoid the work (cost) of swapping the cam. My experience with work inside engines is pretty slim. I can attempt most anything on a car until I get to engine insides. When people start talking about roller cams vs tappets etc I get lost. I know the basics of what makes an engine operate, I just don't know all the nuances that can be different on each specific part.
I have swayed back and forth between spending $1500 to get this engine re-manufactured before I put it back in the boat, but it would sure be nice if I could avoid spending that money and still have a decently operating engine for a few years. So my biggest question is can I swap the carb/intake without swapping the cam and will it have similar results?
Thanks in advance!
Ryan
I was about to buy a Rapido long block when a last minute search on craigslist yielded a 1987 (I think) 4.3 OMC Cobra engine with exhaust manifolds for $500 complete with everything to the transom coupler. It was in a boat that was falling apart, but it ran (poorly on 5 year old gas). The guy who was selling it had bought the boat for the outdrive and wasn't interested in the engine. The accessories on it weren't in as good of shape as mine were. The other big negative - it was the 175HP version with the 2 barrel carb.
My big question is, can I swap the 4bbl carb and intake on to this motor without changing the cam and still get _almost_ 205HP? Will it run right? I feel like the boat is big and heavy enough that it needs all the power it can get.
I pretty much have to swap the intake and carb to properly interface with the controls on my boat, I'm just hoping to avoid the work (cost) of swapping the cam. My experience with work inside engines is pretty slim. I can attempt most anything on a car until I get to engine insides. When people start talking about roller cams vs tappets etc I get lost. I know the basics of what makes an engine operate, I just don't know all the nuances that can be different on each specific part.
I have swayed back and forth between spending $1500 to get this engine re-manufactured before I put it back in the boat, but it would sure be nice if I could avoid spending that money and still have a decently operating engine for a few years. So my biggest question is can I swap the carb/intake without swapping the cam and will it have similar results?
Thanks in advance!
Ryan
