HCT1080
07-13-2015, 04:42 PM
Hello all,
Newb questions here. Sorry if posted in incorrect area, please move if necessary.
Long story short: Built a small hydro with my dad when I was young. Used it. Then later the 9.8 merc **** out. Rebuilt Merc. Never got the hydro back out after motor rebuild. Sat for years. Got it out 2 years ago, had a blast trying to get as much speed out of it. This last year redid some fiber glass work as well as modifying the lower gear case to increase the hydrodynamics. The water pickup was also relocated to a hull pickup. All this to move the motor up to aid in the use of a cleaver prop.
Engine: 1967 Mercury 110, 9.8 HP, 6 spline. Rebuilt in 2003 with a few hours after rebuild. No modifications, just freshened up.
Boat: Clark craft, Bobcat.
My main objective is to go fast in a strait line on a small lake when it is calm. I’m not looking to compete or anything of that nature, as I know my hull and boat design is old and dated. This is just a fun thing for me.
Last year, with messing with the motor height and trim I was able to reach a speed of 29 mph. This was with a factory 9” diameter 10” pitch, stump prop. Doing the calculations assuming no slip, the old Merc was spinning 6124.8 RPM. As per the Merc manual full throttle RPM should be 5000-5400 RPM. I need more prop. This year with the modifications I made with the same prop I just got over 30.
Question: Where can you source performance props for older engines? That being a 6 spline Mercury cleaver? I have been scouring the internet and it looks as if something like this is a custom made deal. But who do you go to? Also like to mention I have an extra female 6 spine hub. Thinking this could be pressed into an existing prop with proper machining. Thus broaching of splines could be avoided.
Newb questions here. Sorry if posted in incorrect area, please move if necessary.
Long story short: Built a small hydro with my dad when I was young. Used it. Then later the 9.8 merc **** out. Rebuilt Merc. Never got the hydro back out after motor rebuild. Sat for years. Got it out 2 years ago, had a blast trying to get as much speed out of it. This last year redid some fiber glass work as well as modifying the lower gear case to increase the hydrodynamics. The water pickup was also relocated to a hull pickup. All this to move the motor up to aid in the use of a cleaver prop.
Engine: 1967 Mercury 110, 9.8 HP, 6 spline. Rebuilt in 2003 with a few hours after rebuild. No modifications, just freshened up.
Boat: Clark craft, Bobcat.
My main objective is to go fast in a strait line on a small lake when it is calm. I’m not looking to compete or anything of that nature, as I know my hull and boat design is old and dated. This is just a fun thing for me.
Last year, with messing with the motor height and trim I was able to reach a speed of 29 mph. This was with a factory 9” diameter 10” pitch, stump prop. Doing the calculations assuming no slip, the old Merc was spinning 6124.8 RPM. As per the Merc manual full throttle RPM should be 5000-5400 RPM. I need more prop. This year with the modifications I made with the same prop I just got over 30.
Question: Where can you source performance props for older engines? That being a 6 spline Mercury cleaver? I have been scouring the internet and it looks as if something like this is a custom made deal. But who do you go to? Also like to mention I have an extra female 6 spine hub. Thinking this could be pressed into an existing prop with proper machining. Thus broaching of splines could be avoided.