I just tossed out my TT39 that would never tune properley and replaced it with an OS37 in my Raptor 30 V2. It runs great and I couldn't be happier. However I am a bit paranoid about my engine after all the hassle I had with the TT39. At one point I thought I had over-heated the TT39 and that that had caused all my tuning problems, but I am not convinced.

Anyway, I got a temperature guage and tried to monitor the temperature of the new OS37. It seems to run quite hot though. When running the best, i.e. lots of power/response to increased collective, no apparent overheating (i.e. no loss of power after a while), lots of smoke, etc. it seems to run at about 135 degrees celsius. Someone on the Raptor/ThunderTiger forum told me that a 30 size engine should run at about 112 degrees. I am using 15% nitro with 18% oil (50/50 castor and synthetic). I have tried to richen it up to drop the temperature and it works, it will drop to about 115 degrees. The only problem is the response to the collective drops significantly and the general power loss is too much to be acceptable.

So, my question is, if all seems to be well and the engine runs hot (according to the guage), is that still okay, in other words, should you ignore the temperature guage? I just do not want to end up with a bum engine again. Any suggestions or comments?

I reckon you should try to run it cooler (richer) while it is still new and weaken it out when you've put some good amount of fuel through it. My experience with OS is that they are cracking engines and don't need too much early cycling for "running in" but they don't settle to their best for a while but even like this they are great.

once you got about a couple of gallons or so through it, tune it to the settings you had before, the temperature your measuring may not be right, and the engine was running best slightly hotter so keep it that way, if your really paranoid, get the settings back so it's giving you the best power and then put a new glow plug in and go for 2 or 3 flights, after the flights are up take the glow plug out and examine it carefully, if your threads are dry and the element has gone slightly white and looks a tiny bit pitted you are lean, if the threads are wet and the coil still looks a shiny silver your just fine, re-insert glow plug and go fly, this is why i dont use temperature gauges.

Gareth

Thanks guys. Sounds like good advice all around. Will definitely put more fuel through it with it rich until the engine is nice and settled. Once I have done that I will try your suggestion, Darksider, and see what the glow plug looks like. Sometimes I tend to get too involved with the numbers instead of the physical reality of the situation.

Thanks again.