engine temperatures and glow plug question

[craig911]

ok i got my temp gun yesterday so today after i came home from my LHS i decided to run my kryptonite F4.6, and i would like some info on temps and plugs

after a few minutes i checked my temps and it read around 170C @ the plug,

is this a high temp or is it ok its not running lean its just half a turn leaner than the HPI performance tune so 3 turns from flush on the HSN there is visible blue smoke @ full throttle,

i have checked the temp gun ( boiling water ) and it checked out ok its out by +7C,

it was a sunny day today in england/bristol, so maybe thats the main reason last time i ran it i could not check temps but i could keep my hand on the engine, today i could not ( it was quite warm today )

i run on a Medium Cold plug McCoy MC-9 Glow Plug i use 25% model technics big bang glow fuel ( its actually 20% just checked the bottle i thought i was running 25% )
(model technics oil persentage chart and fuel types
fuel http://www.modeltechnics.com/glowfuel.htm
oil http://www.modeltechnics.com/glowfuel/bigbang.html )

I also have a McCoy MC-8 (Medium Hot) that I'm going to use when my current plug fails

so i know tuning by temps is kinda so so, but is my 170C temps ok ?

also i run a medium plug as i thought it would suit all weather/temps is that correct ?

is it a case of cooler plugs for big engines and hotter for smaller engines ?

also could some one recommend a good cheap fuel thats as easy to get in the UK as model technics and around the same price ( with a good oil mix %10 sounds low )

 

[NitroHawk]

If I recall correctly, the more METHANOL % the hotter the plug and vice versa.

So more nitro = colder plug, less nitro = hotter plug. Hot plugs are easier to start but burn out easily when running high grade fuel.

You temperature on another hand seems to be too high, I would keep it in the 100c to 130c range.

I can't help you with choosing fuel, but Byrons, Tornado and Odonell have always worked well for me.

EDIT: Just checked the HPI site and the manual states 99C to 110c as the safe range, don't know how reliable those figures are but still it's way colder from what you are running.

 

[Extreme RC Mods]

170*C is the same as 338*F and that is way too hot. 135*C would be the max you really want to go with that engine. A MC #8 is a medium plug and is what I would recommend.

 

[Rolex]

170*C is the same as 338*F

WOW!!! Centigrade. I missed that. You are running seriously lean.

 

[craig911]

ok i will richen it out and post back the results

 

[craig911]

170*C is the same as 338*F and that is way too hot. 135*C would be the max you really want to go with that engine. A MC #8 is a medium plug and is what I would recommend.

ok i just finished running it and my temps were between 100-137C and i did not lose any speed with it running richer

thanks guys

also one more question

is this modeltechnics %20 (big bang off road mix ) any good as it is only 10% oil ?

main reason I'm using it as my LHS only stocks this stuff and its pretty cheap P&P almost doubles the price if i order online
1-quart £6-7
half gallon £12-13
1 gallon £17-18

 

[2revo1maxx]

10% oil means cooler temps and a "cleaner" running engine.....it also means you have to be careful with your tuning. With careful tuning you can expect the same engine life or greater than you would with 16% oil.

Remember, when in doubt, go richer, not leaner! You can always lean it back out if you go too rich.