Cam selection profile for propane use
Cam selection profile for propane use
(OP)
How do you refigure from original cam profile,to regrind specs for propane use.I have a willys F head four cylinder runing on propane now but would like to have the cam reground to optimize the fuel charge.As well as busting the compression ratio.





RE: Cam selection profile for propane use
What is busting the compression and how does cam effect that?
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RE: Cam selection profile for propane use
RE: Cam selection profile for propane use
You can only cut the head so much before it hits the valves at full lift.
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RE: Cam selection profile for propane use
RE: Cam selection profile for propane use
Another hot rodding technique on side valves was to relieve the block in the transfer port area.
This streamlined flow from the side chamber to the piston top.
The trick is to maximise airflow through the valves and chamber, with the minimum volume in the chamber.
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RE: Cam selection profile for propane use
You probably wont help the head gasket problem any but modern fuel qualities can tolerate a CR increase up to the mid 8's or 9's, and like Pat stated, propane works well in the 11:1 range. The higher the compression ratio, the more critical your ignition timing and air-fuel ratio needs to be tuned. Lower compression ratio engines can tolerate a wider range of fuel mixture and timing anomolies.
Franz
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RE: Cam selection profile for propane use
RE: Cam selection profile for propane use
As for the CR, if you had an OHV engine you could take advantage of the higher octane (which would also benefit from a little wilder cam). But since you have an L head you will be limited to around 8:1 for both fuels.
ISZ
RE: Cam selection profile for propane use
Gas is already gas, and therefore has a density much closer to air than does liquid fuel, so air fuel separation and consequential poor mixture distribution and fuel puddling are not such a problem, so gas can tolerate lower air speed and more reversion in the inlet tract and still retain drive ability.
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RE: Cam selection profile for propane use
RE: Cam selection profile for propane use
"For propane, the gas displacement effect is 4%, it means that the displacement of air by propane causes reduction in power of 4 % (volumetric efficiency decrease) from an equilevent gasoline counterpart. Gasoline on the other hand, provides evaporotive cooling of the intake air which increases the intake air density and increases the power. Test results show 6 % less power with propane than with gasoline."
==J.E Sinor Consultants Inc, The Clean Fuels Report, November 1992, Volume 4, No. 5
ISZ