- Joined
- Aug 31, 2004
- Messages
- 1,085
I recently got one of the new OPS .45's and thought I would share some information on it for everyone. I have not run the motor yet, but have taken it apart and took some measurements off of it. This motor is a brand new design by OPS and not a copy of any other motor that was made at one point in time.
Specs (measured in inches):
Bore = .8643
Stroke = .761
Rod Length = 1.376
Boost port timing = 142 deg.
Transfer port timing = 138 deg.
Exhaust timing = 188 deg.
Head volume = .38cc
Engine is 1 piece case and utilizes M6001 and M608 bearings. Bearings have plastic retainers for better wear. Front bearing has seal on outside.
Piston and sleeve fit is tight. It will need a slow break in. The sleeve has 7 intake ports and 1 exhaust port. The boost port has a large opening and there is a big sub port for the transfers. There is a nice size slot in the piston to align with the sub port on the transfers.
Drum rotor assembly is made of a barstock housing with a bushing pressed in and a steel rotor. Bronze bushing is a large enough diameter so that the face of the rotor that runs against it is always touching the bronze and will not rub on the aluminum. Both pieces are machined well.
Crankshaft has 3 slugs in it for balancing. Since I have not run the motor yet I cannot tell you the effect, but it is an obvious attempt to balance the engine as close as possible right from the factory.
Carburetor is machined from barstock and has a .470 bore on it. It also has a mid range adjustment and anodized barrel. It is a big bore for a .45. Carb arm is quite large and may need to be trimmed to fit in some boats, but it is made from solid aluminum. There is no needle valve assembly for the carb provided with the engine.
The water cooled head on the engine does have 4 water fittings on it. Not sure why, but you can loctite a 4mm set screw in the ones you do not want to use. The volume of cooling looks to be the same as most engines on the market. It has a O-ring on the bottom of the water jacket for a seal.
Flywheel assembly is the same OPS assembly that was made for years. It does not have a collet for a flex cable, so you will have to get one. The crank has a 1/4-28 thread on it like most other engines.
The machining on all of the parts are nice and they have done a lot of things on this motor to try and put a competitive product out. The timing is aggressive, so the next step is to get this in a boat and see how it performs.
More to come.
Specs (measured in inches):
Bore = .8643
Stroke = .761
Rod Length = 1.376
Boost port timing = 142 deg.
Transfer port timing = 138 deg.
Exhaust timing = 188 deg.
Head volume = .38cc
Engine is 1 piece case and utilizes M6001 and M608 bearings. Bearings have plastic retainers for better wear. Front bearing has seal on outside.
Piston and sleeve fit is tight. It will need a slow break in. The sleeve has 7 intake ports and 1 exhaust port. The boost port has a large opening and there is a big sub port for the transfers. There is a nice size slot in the piston to align with the sub port on the transfers.
Drum rotor assembly is made of a barstock housing with a bushing pressed in and a steel rotor. Bronze bushing is a large enough diameter so that the face of the rotor that runs against it is always touching the bronze and will not rub on the aluminum. Both pieces are machined well.
Crankshaft has 3 slugs in it for balancing. Since I have not run the motor yet I cannot tell you the effect, but it is an obvious attempt to balance the engine as close as possible right from the factory.
Carburetor is machined from barstock and has a .470 bore on it. It also has a mid range adjustment and anodized barrel. It is a big bore for a .45. Carb arm is quite large and may need to be trimmed to fit in some boats, but it is made from solid aluminum. There is no needle valve assembly for the carb provided with the engine.
The water cooled head on the engine does have 4 water fittings on it. Not sure why, but you can loctite a 4mm set screw in the ones you do not want to use. The volume of cooling looks to be the same as most engines on the market. It has a O-ring on the bottom of the water jacket for a seal.
Flywheel assembly is the same OPS assembly that was made for years. It does not have a collet for a flex cable, so you will have to get one. The crank has a 1/4-28 thread on it like most other engines.
The machining on all of the parts are nice and they have done a lot of things on this motor to try and put a competitive product out. The timing is aggressive, so the next step is to get this in a boat and see how it performs.
More to come.