I have said for 30+ years good instruments can save expensive engine repairs and this week I can really thank Barry Deeth (my friend who discovered KSA at Oshkosh) and Bill Simkinson (the maker) for KSA CHT1DT over temp alert and shock cooling alert.
I guess 50%+ of glider tow planes in AUS have KSA1DT instruments fitted to prevent shock cooling on decent after a aerotow. More recently I have introduced same into motorgliders (these days with L&R switch) as I re engined same and this week it sure paid off. After 50hours of perfect temperatures on every climb all of a sudden RH side rapidly rose above my setting of 175deg C while LH was 25-30degC lower - normally there is 3 to 4 degC difference between L and R side. After 3 such flights and at a friends advice I checked the inlet manifold gasket at head. Yes copper gasket was crushed more than it should be. Down to George the local VW man and he found the gasket ($1 for 2!!) and guess what next flight was perfect within 3 degC. I am certain if I only have single (say VDO CHT) I would not have picked up the problem and would have had burnt valves in 50 hours time costing $500. I can not speak highly enough of good simple engine instruments. I look on fitting same which costs less much than $500 as one off engine insurance policy. The other little trick I use in any aircraft if I see CHT rising more than it should then I apply say 30% to 50% Carby heat and immediately down comes CHT temp due to the richer mixture. If instead I bring back throttle just a little UP goes the CHT even more. I just love giving every engine full power as fuel is cheap compared to repairs and the latent heat of vaporization does cool the engine. The other instrument I like in motorgliders is dual cheap EGT. On full power EGT must fall a little from backing off throttle a small amount which shows you are running rich of peak. Around the go cart track it is always true that the cart engine never ever goes better then just before the engine blows up!!!! That is they were running it lean and then it ceased. For those with Limbachs Tech Bull 53 remarks 4 reads "The engine temperatures should be kept at the lowest possible level. Ideal is less than 180degC in a climb. In this context see Tech Bull 44" This is for L1700, L2000 and L2400 and as far as I am concerned every other 2 stroke Rotax and Jabiru engine as well and infact I say 175degC. We in our PIK20E have a Rotax 501 which is 29 years old and has never been rebuilt and Bert Flood Imports inform me it is the oldest Rotax in Australia still going!! I could recommend reading of Tech Bull 44 (latter 11 page version) Sorry for the add but I am so glad problem was found and fixed Ian McPhee 0428847642. Skype <macca304>
