Reversing LP Conversion

[ISU JD]

I have a 720 that has been conveted to LP and have recently had a lot of trouble with the carb and regulator. I have become so frustrated with it I think I want to switch it back to a gas. Has anyone done this and if so can I just drop in a carb and gas tank

 

[BushogPapa]

Assuming the Pistons were changed to "LP" Pistons..

You will need to time the engine carefully..because of the higher compression..to avoid detonation..BUT, they Sound SO GOOD with the higher compression, when they idle..!
Should make a pretty "Stout" 70..!
70 Gas 6.15:1
LP 7.30:1

Ron..

 

[BushogPapa]

OK, I see my mistake..!!
For a 720, the compression ratios are:

Gas: 6.11:1
LP: 8.00:1 might be pushing "regular Gas" a little, if you are gonna work it hard..
May need Hi-Test or more..

Ron..

 

[Nofbdybs]

(quoted from post at 10:19:39 01/27/10)
OK, I see my mistake..!!
For a 720, the compression ratios are:

Gas: 6.11:1
LP: 8.00:1 might be pushing "regular Gas" a little, if you are gonna work it hard..
May need Hi-Test or more..

Ron..

Some 93 octane should fix you right up.

 

[Clint N]

I too am looking at converting my 70 LP to gas, and was told I could add a little diesel to the gas to prevent pre-ignition.

 

[Nofbdybs]

As stated before, with the right timing, and fuel, I bet you could get some good power from an Ex-LP setup converted to gas.

 

[BushogPapa]

I don't think that adding Diesel to gasoline is going to do anything positive to delay per-ignition.
Tje JD 70 LP at least has a lower compression ratio than the 720, and I think the 720 would be ok with proper timing adjustment and (if needed) a minimal amount of leaded racing fuel added...
Just don't let it labor-down..!!
I have been using a small amount (1/2 Pint) of 120 octane racing gas to a tank and have not had any problem at original timing settings..
I wonder if you can just convert the LP tank for gasoline and change to a Gasoline Carb..?
That would work for me..!!

Ron..