I have been using 100LL in the UL Power 350IS  and have had a leaky valve and only have 60 hrs on the motor.   Started mixing 1/3 100LL to 2/3  premium unleaded 91 octane Auto gas , in hopes that excess lead has built up on the valve and the new mix will clean the valve off.

   Is anyone burning straight 91 octane auto gas or any other  types of auto gas?   

 I have looked all over and cannot find any higher octane gas other then 100LL avgas and 105 octane race gas which is priced at 12$/gallon.

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 The emails are printed out from the previous owner, out at the hangar in build book.  I'll get a copy for you soon.  That one email thread in particular is not very technical; just acknowledges that lots of folks are not using 93, and it's not been an issue.  Besides that talk I did my own research, and am now trying to find the sources.  Lots of reading, and I'm far from understanding it well.  The bottom line I took away is that yeah, 8.7/1 is high compression compared to, seven or eight.  But I'm not operating the engine at the top rated RPM, and temps it's designed to handle, and I don't need the max level of AKI.  Talk more soon.


Thanks for the information, I will wait to hear from you. This is the  first time I  have used the site and appreciate all the help I can get.

 Can I ask you the oil & filter  that your using?  I have been working on getting the oil temp down from the 213F at 2700rpm on a 70 degree morning.  Live up in western ND and only fly in the early mornings .  We have replaced the oil thermostat and replaced the race car cooler with a aero classic, which did not seem to help, even installed a high speed carbon fibre electric fan on cooler , to know avail.   Currently there is a test going on ,with Ams-Oil syn in a 350 , will be interesting to see the results, and whether it will  help drop the oil temp.

        I guess the upside is, early  mornings are the best part of the day..................                                               


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