I built a custom 1/8 ply tunnel hull back in college (late 90's). It was my first boat and I built it off the top of my head with some spare wood from my R/C plane hobby. See pics below.
I have a used, complete K/B 7.5 which I got off ebay in 2003 for its piston/sleeve/rod. However, I decided to just use the whole top end on my prather 32 racing tunnel. The bottom end has a tuned pipe, but I think it is too big though I'm used to stock K/B 7.5 engines. I've never run a pipe before.
This engine has a beefy polished rod, a head that is engraved with H.E.W., a lightened flywheel, a trimmed skeg and the tuned pipe. It ran fast without the pipe on the prather 32. So I was thinking of putting this engine on the custom wood tunnel and try the pipe out. I replaced the lower bearing with a barely used stock one, but the top one is making noise and I think it needs replacement asap. I saw the thread on KB bearings so that was helpful. This top housing doesn't have the oiling hole like my other two 7.5 K/B OB's.
What other mods would you all do to this engine? There are no shims on the heads and it loves 35-55% nitro.
I also have a stock 7.5 that broke a conrod which needs a new piston, sleeve and conrod to get going again. Is that a better engine to start modding since it has the oiling hole on the top housing?
I'm running a prather 235 prop right now. I also have a prather 230, octura 447/3, x452 and 1950/3 I can try out on this boat.
The wood blue boat is about pound heavier than my prather 32 fiberglass racing tunnel. It also can handle very rough seas with its crazy sharp sponsons and triangular leading tips. I've submarined it completely underwater (completely as in the entire boat, engine, antenna) dozens of times and it pops up and keeps going. I've run it flat out in 6 inch seas.
I have a used, complete K/B 7.5 which I got off ebay in 2003 for its piston/sleeve/rod. However, I decided to just use the whole top end on my prather 32 racing tunnel. The bottom end has a tuned pipe, but I think it is too big though I'm used to stock K/B 7.5 engines. I've never run a pipe before.
This engine has a beefy polished rod, a head that is engraved with H.E.W., a lightened flywheel, a trimmed skeg and the tuned pipe. It ran fast without the pipe on the prather 32. So I was thinking of putting this engine on the custom wood tunnel and try the pipe out. I replaced the lower bearing with a barely used stock one, but the top one is making noise and I think it needs replacement asap. I saw the thread on KB bearings so that was helpful. This top housing doesn't have the oiling hole like my other two 7.5 K/B OB's.
What other mods would you all do to this engine? There are no shims on the heads and it loves 35-55% nitro.
I also have a stock 7.5 that broke a conrod which needs a new piston, sleeve and conrod to get going again. Is that a better engine to start modding since it has the oiling hole on the top housing?
I'm running a prather 235 prop right now. I also have a prather 230, octura 447/3, x452 and 1950/3 I can try out on this boat.
The wood blue boat is about pound heavier than my prather 32 fiberglass racing tunnel. It also can handle very rough seas with its crazy sharp sponsons and triangular leading tips. I've submarined it completely underwater (completely as in the entire boat, engine, antenna) dozens of times and it pops up and keeps going. I've run it flat out in 6 inch seas.