LP Performance vs. Race Fuel

[Mopower]

Hey YT fellas, seriously considering fueling my new project MM U with Propane instead of "race" fuel. "LW" has me leaning torwards LP. This is a NATPA Div3/4 setup. From internet research I've read how there are different grades (ex. HD-5) of LP. Different sources say 105-118 octane. Obviously there is some scientific fudging going on. I understand the basics of LP but I have a few questions:

1. What different types of LP are available, at what octanes, and does it really matter?

2. LP is in a gas state resistant to any detonation (spark knock). So what compression ratio yields the best power for high grade LP?

3. For pulling, is it better to run off liquid or vapor?

4. Are some fuel delivery setups superior to others?

5. There are some hot propane turbo machines out there. Does LP have any cool performance tricks up its sleeve for a normal antique puller?

 

[Bottlefarts]

One cool trick for LP...Can I build a grille to mount on the end of your weight bracket so we can cook out at fowler?

 

[guido]

Hello Mopower.
LP is very clean burning, better than pump gas.
118 octane equivalent is a bit high. its about 108 octane equivalent. The set up is the same as a gas motor with a carburetor. The propane from the tank goes into a pressure regulator/vaporizer, vapor propane is then piped to the carburetor.
No liguid is used to feed the engine in a normal set-up. A friend of mine runs in the antique class with a MM on propane, very strong! Its a 403 running in stock class.
Guido.

 

[Anonymous-0]

Genius and feasible. Bring the meat. Digger can handle the beer. Marky will bring the gals.

 

[Mopower]

I've been impressed with Henderson's 6cyl setups. Also considering converting Dad's 403 UB. Is the pressurizer/regulator best fed with liquid from the bottom or gas from the top of the tank? 108 octane and no atomization worries? Why doesn't everyone do it?

 

[Anonymous-0]

I run a henderson 4 cylinder lp cranking out over 200 horse easy and it's safe to say that it runs better on lp than
Racing fuel cuz we beat tractors with the same amount of cubes bad. It's always a good conversation started too

 

[Mopower]

Henderson is doing my block work. 5.1875 X 7 at 591 cubes in a 4500# UTN. 10A4232 heads. Probably tune for 5-star RPM although most pulling will be speed limit at 10-20% over U RPM. Not as big as I wanna be but still oughta be fun. Maybe someday... 728?