Gearing up Temp effects and plugs
 

Hi guys
just curious about my os tr 5 port.

on a saturday i ran my motor with a p7(average temp) plug and got it to run consistantly at around 240 F
with the gearing of 21/51

then installed 23/50 same plug
and it ran at the end of the race at 270 F

so does this mean with higher gearing your engine will run hotter? with the same setting for the screws.

does the engine run hot if it reaches top speed and stays there for abit or does it just wear out quicker ?

also would a colder plug run cooler compared to an average temp plug?
any comments appreciated thanks!

Gas or electric motors will run hotter is they are under geared or over geared, but if you are within a tuning window then it might run cooler if you were to gear up but maybe just not make as drastic change as you did. A colder plug will run "cooler", b/c they do not glow as hot so it's just not as hot or rataining heat as well. So since when people temp their engines they shoot it at the glow plug it will temp cooler, but that doesn't mean engine is running cooler or isn't running on lean side. Colder plug will give you more torque, less top end, not as good idle/start up quality, usually requires leaner main needle and bottom needle might richen a little.

thanks slobbatech

ill try this weekend with smaller tyres ( a quicker change to lower the gearing :P) and see how my temps go :)

will have to go back to the average temp plug if cold plug gives less top end power. i was told it would give more top end as the ignition is retarded. im running single speed so i need the most top end i can get :p

also a question about pipes.
picture the pipe where it has the muffler stay connected to the front of the pipe. My question is if the section has been pushed in a bit will that effect the pipes pressure system? making the engine lean itself off during the race?

Cold plug = retarded timing is right but effects of it is backwards, advance timing means more top end power, colder more low end power. Just with hotter plugs the coil is thinner and not as physically durable so you might be restricted on what plugs you can run whether or not they will finish a race, the main, a whole race day, or a few week of running, the factor depends on which one of those is acceptable to you for when it's time to change out the plug. I'm not really sure exactly where that dent in your pipe is from your description but I wouldn't think that it would make the engine run dfferently/worse throughout a race unless it was something that should be fixed. If you had the dented pipe and a new pipe of same make/model brand new the tune for each one might differ a little from the dent and the one with the dent might change power characteristics of it some but I really don't know for sure b/c I usually will fix the pipe asap or put a new one on asap.

thanks slobbatech

i actually tried the smaller tires during the week, and it felt like the gearing was perfect! so i may have to go down a gear.

about the temp i fixed the problem! i dunno wether it was lower gearing (small tires) or the fact that i dropped my body down by to body post holes front and rear. when i did this my car seemed faster and the temps i was running were around 220. and speed was satisfactory to me. it was running like at the same speed on race day with a temp of 270... so might be the body and gearing at the same time. as i can also now see through my front window the the wind will be blownig towards the bottom of the engine as well. instead of the 1st-3rd fin of the cylinder head.

thanks for all your help slobbatech :)