Questions on how to mod a crankshaft open b
Moderator: hbartel
Questions on how to mod a crankshaft open b
I'm trying to get a little more power on my 25's, my os fx's are fearly new and are tac'n at 1780 and some at over 1800 with a 9x4 MA prop header and a can , I have been reading on the turbo cranckshafts that novarossi has on there engines, and I am wondering how does this crank help on the performance?, what does this do? has anybody tried turbo'in a regular crankshaft?
heres a picture on a turbo crankshaft of a novarossi
http://www.planethobby.com/image.php?type=P&id=556
[:p]I just like how flying open make my heart rate go up[:D]
heres a picture on a turbo crankshaft of a novarossi
http://www.planethobby.com/image.php?type=P&id=556
[:p]I just like how flying open make my heart rate go up[:D]
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Gil, the cut out on the left side of the crank counterweight area seems to be to reduce drag. That is the "leading edge" of the counterweight part of the crank when it is rotating. It may also serve to "scrape any fuel mixture in that area and throw it back and up, helping it to enter the ports.
The other cutout which comes out of the center hole does two things. One thing it does is to "throw" or "sling" fuel out of the crank. Also, when the crank pin is at bottom dead center the connecting rod blocks fuel from coming out of the crank hole. This cutout helps eliminate the point at which the rod blocks the fuel.
The best thing that you can do to increase rpm is to take the crank out of the engine and increase the intake hole in the crank about 1/16" on both the opening and closing side. No more than 1/16". This will increase the length of time that your crank allows fuel and air to enter the engine. It`s like putting a higher "lift" camshaft in a car engine.
This should give you over 19k. But be careful or you may blow the engine up. I`ve found that the OS connecting rod isn`t good for much more than that without breaking.
The other cutout which comes out of the center hole does two things. One thing it does is to "throw" or "sling" fuel out of the crank. Also, when the crank pin is at bottom dead center the connecting rod blocks fuel from coming out of the crank hole. This cutout helps eliminate the point at which the rod blocks the fuel.
The best thing that you can do to increase rpm is to take the crank out of the engine and increase the intake hole in the crank about 1/16" on both the opening and closing side. No more than 1/16". This will increase the length of time that your crank allows fuel and air to enter the engine. It`s like putting a higher "lift" camshaft in a car engine.
This should give you over 19k. But be careful or you may blow the engine up. I`ve found that the OS connecting rod isn`t good for much more than that without breaking.
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