Sanding a lower unit for speed
10-07-2012, 10:23 AM
#22
Registered
iTrader: (4)
Interesting, most of us just keep adding HP
Curious to see if any DIY'ers on this site have trued a lower unit themselves.
10-07-2012, 12:20 PM
#24
Registered
iTrader: (1)
http://www.proboat.com/blueprint-for-speed.html
Interesting, most of us just keep adding HP
Curious to see if any DIY'ers on this site have trued a lower unit themselves.
Interesting, most of us just keep adding HP
Curious to see if any DIY'ers on this site have trued a lower unit themselves.
10-08-2012, 08:50 PM
#27
Having a true straight lower on a twin engine appllication is beneficial but i don't think this is the case on a single engine app.
Outboard drag racers have been sanding/profiling lower units for many, many years, and straight was not what they were after. Running a high x dim will result in increased speed but on a single it will try to prop walk. Prop walk will cause the driver to crab the lower to keep the boat in a straight line. Look at the skeg mounted torque tabs on the fastest of outboard drag boats and you wouldn't believe the curve. Drag boat skegs running right hand rotation props will have the stbd leading edge ground on back to mid skeg. On the port side, from mid skeg back to the trailing edge is ground on. This curved skeg is the fastest setup on a single engine.
Outboard drag racers have been sanding/profiling lower units for many, many years, and straight was not what they were after. Running a high x dim will result in increased speed but on a single it will try to prop walk. Prop walk will cause the driver to crab the lower to keep the boat in a straight line. Look at the skeg mounted torque tabs on the fastest of outboard drag boats and you wouldn't believe the curve. Drag boat skegs running right hand rotation props will have the stbd leading edge ground on back to mid skeg. On the port side, from mid skeg back to the trailing edge is ground on. This curved skeg is the fastest setup on a single engine.
10-08-2012, 09:05 PM
#28
VIP Member
Having a true straight lower on a twin engine appllication is beneficial but i don't think this is the case on a single engine app.
Outboard drag racers have been sanding/profiling lower units for many, many years, and straight was not what they were after. Running a high x dim will result in increased speed but on a single it will try to prop walk. Prop walk will cause the driver to crab the lower to keep the boat in a straight line. Look at the skeg mounted torque tabs on the fastest of outboard drag boats and you wouldn't believe the curve. Drag boat skegs running right hand rotation props will have the stbd leading edge ground on back to mid skeg. On the port side, from mid skeg back to the trailing edge is ground on. This curved skeg is the fastest setup on a single engine.
Outboard drag racers have been sanding/profiling lower units for many, many years, and straight was not what they were after. Running a high x dim will result in increased speed but on a single it will try to prop walk. Prop walk will cause the driver to crab the lower to keep the boat in a straight line. Look at the skeg mounted torque tabs on the fastest of outboard drag boats and you wouldn't believe the curve. Drag boat skegs running right hand rotation props will have the stbd leading edge ground on back to mid skeg. On the port side, from mid skeg back to the trailing edge is ground on. This curved skeg is the fastest setup on a single engine.
__________________
Throttles- Cleveland Construction 377 Talon
08 OPA Class 1 National Champion
08 Class 1 Geico Triple Crown Champion
08 OPA High Points Champion
10 OPA Class 1 National Champion ( happy now Ed! )
Throttles- Cleveland Construction 377 Talon
08 OPA Class 1 National Champion
08 Class 1 Geico Triple Crown Champion
08 OPA High Points Champion
10 OPA Class 1 National Champion ( happy now Ed! )
10-08-2012, 09:40 PM
#29
Registered
Having a true straight lower on a twin engine appllication is beneficial but i don't think this is the case on a single engine app.
Outboard drag racers have been sanding/profiling lower units for many, many years, and straight was not what they were after. Running a high x dim will result in increased speed but on a single it will try to prop walk. Prop walk will cause the driver to crab the lower to keep the boat in a straight line. Look at the skeg mounted torque tabs on the fastest of outboard drag boats and you wouldn't believe the curve. Drag boat skegs running right hand rotation props will have the stbd leading edge ground on back to mid skeg. On the port side, from mid skeg back to the trailing edge is ground on. This curved skeg is the fastest setup on a single engine.
Outboard drag racers have been sanding/profiling lower units for many, many years, and straight was not what they were after. Running a high x dim will result in increased speed but on a single it will try to prop walk. Prop walk will cause the driver to crab the lower to keep the boat in a straight line. Look at the skeg mounted torque tabs on the fastest of outboard drag boats and you wouldn't believe the curve. Drag boat skegs running right hand rotation props will have the stbd leading edge ground on back to mid skeg. On the port side, from mid skeg back to the trailing edge is ground on. This curved skeg is the fastest setup on a single engine.
10-09-2012, 05:09 AM
#30
Registered
iTrader: (1)
Having a true straight lower on a twin engine appllication is beneficial but i don't think this is the case on a single engine app.
Outboard drag racers have been sanding/profiling lower units for many, many years, and straight was not what they were after. Running a high x dim will result in increased speed but on a single it will try to prop walk. Prop walk will cause the driver to crab the lower to keep the boat in a straight line. Look at the skeg mounted torque tabs on the fastest of outboard drag boats and you wouldn't believe the curve. Drag boat skegs running right hand rotation props will have the stbd leading edge ground on back to mid skeg. On the port side, from mid skeg back to the trailing edge is ground on. This curved skeg is the fastest setup on a single engine.
Outboard drag racers have been sanding/profiling lower units for many, many years, and straight was not what they were after. Running a high x dim will result in increased speed but on a single it will try to prop walk. Prop walk will cause the driver to crab the lower to keep the boat in a straight line. Look at the skeg mounted torque tabs on the fastest of outboard drag boats and you wouldn't believe the curve. Drag boat skegs running right hand rotation props will have the stbd leading edge ground on back to mid skeg. On the port side, from mid skeg back to the trailing edge is ground on. This curved skeg is the fastest setup on a single engine.
