musselman
Active member
I know there has been a few posts on oil cable setting lately but I have a slightly different question. The throttle/oil cable I am using now is from an 04 mtn viper and it's the 2 into 1 style. What should my measurement be since vipers are 18 to 19mm and redheads are 22-24mm I think? I'm not sure if the cable is different or just that vipers need more oil. Thanks
Stock specs are 20.5 for Vipers, and 22 for Redheads (at least for several later years). The actual mixture calibration is inside the oil pump and they are not all the same. The Viper is calibrated smaller on the low end, and the ramp up is different. I haven't seen the actual chart in some time, but I remember that it is considerably leaner than the redheads.
Some on here like to adust the oil on a Viper to start the ramp up sooner. They may have good reasons for this. My opinion is that the stock setting is fine, and even too rich if you are running an oil that flows significantly faster than 2S.
For what it's worth . . .
The gap (freeplay) in the cable determines how far the throttle can be opened before the oil pump arm starts to activate. The oil pump arm (when activated) changes the size of the hole that oil flows through from a smaller size to a larger size. This not only increases the oil in the mixture, but it also overcomes the natural tendency for less oil to mix as speed increases because of it's lower flow rate than gasoline (as rpms increase the fuel flow rate increases faster than oil).
At all resonable settings (gap) the oil mix is at the small setting at lower throttle range, and the max for the pump calibration at anything over 3/4 throttle or so. The gap only affects the mid range oil mixture unless it is set way out of spec.
Though you may be curious to see how this works, don't take the oil pump apart to see. Don't ask me how I now that . . .
Some on here like to adust the oil on a Viper to start the ramp up sooner. They may have good reasons for this. My opinion is that the stock setting is fine, and even too rich if you are running an oil that flows significantly faster than 2S.
For what it's worth . . .
The gap (freeplay) in the cable determines how far the throttle can be opened before the oil pump arm starts to activate. The oil pump arm (when activated) changes the size of the hole that oil flows through from a smaller size to a larger size. This not only increases the oil in the mixture, but it also overcomes the natural tendency for less oil to mix as speed increases because of it's lower flow rate than gasoline (as rpms increase the fuel flow rate increases faster than oil).
At all resonable settings (gap) the oil mix is at the small setting at lower throttle range, and the max for the pump calibration at anything over 3/4 throttle or so. The gap only affects the mid range oil mixture unless it is set way out of spec.
Though you may be curious to see how this works, don't take the oil pump apart to see. Don't ask me how I now that . . .
musselman
Active member
Thanks Ding that gave me a great understanding of the concept. Right now I have the gap set at 18mm so I will try it there and slowly change it closer to 21 or 22 if I notice i'm using too much. I just didn't want it to run low on oil since the engine is freshly rebuilt. Thanks again