lead substitute vs. kerosene added to unleaded fue

HarleyBob · May 12, 2003

I have a vintage IH Cub that I have added Lead Substitute
to fuel for past 12 years. The mechanic who works on my tractor (who has owned and operated Cubs for decades) says to add kerosene to the fuel instead. He figures that is what the expensive additive is anyway. Anyone have thoughts on this?

Darren · May 12, 2003

Re: lead substitute vs. kerosene added to unleaded

I'm not sure you need either one. Here's some info.
http://www.morrisminoroc.co.uk/articles/minormatters/The_Lead_Free_Question_Part_Two.htm

OldRedTractors · May 14, 2003

Re: lead substitute vs. kerosene added to unleaded

I agree w/ Darren. My theory is that the old guys are so lightly stressed with how I use them, compared to the 8 hours/day plowing they were designed for, that they will certainly out-last me on the current fuel with no additives.

Doesn anyone have any first-hand experience with damage actually related to current fuel? These engines were llightly stressed to begin with, tend to run cool and slow relative to current engines, and I just can't believe the valve seat problem is a real concern.

Dave

HarleyBob · May 15, 2003

Re: lead substitute vs. kerosene added to unleaded

I do use mine for some heavy work sometime. plowing and disking, not just driving in parades. It was just rebuilt and bored out, so I would like to treat it well. Does kerosene (diesel) help do what the lead or lead substitue does? I have been told that the "lead substitiute" is just kerosene at a higher price. It is not lead, that would be illegal.

Chief · Jun 11, 2003

Re: lead substitute vs. kerosene added to unleaded

Kerosene in any significant proportions will cause the plugs to foul. Solidiers did this at work all the time adding JP-8 to the gas powered flight line tugs by mistake. You probably need no additives except for some fuel system cleaner periodically and maybe some marvel mystery oil for lubrication if you feel you need it.

upgw · Jun 24, 2003

I suppose for lubrication of the cylinder top it could work, however, adding even small amounts of kerosene/diesel to gasoline dramatically lowers (not raises) the effective octane. In air-cooled aircraft engines, this can quickly lead to detonation and a destroyed engine. Agree with other posts, those old engines were slow turning and lightly stressed, I'm sure some of their basic designs probably pre-date leaded fuel, I don't think I'd add anything.

- Patrick