Hi Ric, thanks for the answer. we see a dark attack on the valves, it looks like a fine tar-like deposit, that makes the valve doesn't close properly after a while and we loose a lot of power on the engine.
We cannot explain this phenomena, but it caused already 2 times a lot of motor overhaul. Br, Peter From: "Ric Sutton" <[email protected]> To: "peter clymans" <[email protected]> Sent: Sunday, February 2, 2020 3:57:23 PM Subject: Re: MOGas or AVGAs hi peter i vaguely recall this topic being mentioned several times before on this forum but my experience is thus- i run 95 mogas when i can. i am often faced with only having the choice of 98, however i believe that the volatiles evaporate more readily(in my part of australia at least). not very good if you are not planning using a whole tank. i have encountered pinging (detonation/preignition) as a result of this. there is an airworthiness directive that speaks of the effect of some fuel blends on the fiber glass fuel tank. performance wise- have noted very little difference between fresh 98(or 95)mogas and avgas. through some........ circumstances shall we say, a rebuild was necessay. this was after running on avgas. on pulling down the engine i found lead deposits every where. is that a problem? you can decide. as it was a little while between tearing down and reassembly (6 ish months) the valve seats were badly corroded. after speaking with people that know much more than i, i am lead (geddit) to believe that chemical reactions with some of the additives in avgas may have been instrumental in this and wouldnt be as prevalent running on mogas. i have heard of some retarding the timing to settle the pinging. i am undertaking a protracted exercise to collect vibration data and carry out some very rudimentary analysis before i commit to the same. this is my two cents is there anything specific you are trying to ascertain. cheers Ric. From: [email protected] <[email protected]> on behalf of [email protected] <[email protected]> Sent: Saturday, February 1, 2020 5:50 PM To: dog <[email protected]> Subject: [DOG mailing list] MOGas or AVGAs Dear all, we are flying a Dimona H36 with Limbach L2000 and had a discussion using MOGas or AVGas. Any opinions to this ? What are you using currently ? Appreciate your feedback. Peter Clymans - KAC Weelde - Belgium
