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Old 08-13-2007, 10:23 AM   #1
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Default Anyone every tried computer heatsink grease on nitro engines?

I was taking apart my C6 yesterday and I was thinking about putting a thin layer of heatsink grease between the cooling head and engine button for better heat transfer. Anyone ever tried this before? Guess I can try it on my old nova first to see if it lowers engine temps.
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Old 08-13-2007, 11:05 AM   #2
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I think it's useless .... why ?? because you always set the operating temperatures within 100 - 126 degree celcius. In computer yes, you want to absorb the heat as much as you can and release it quickly.... but not in engine.

Secondly, that grease makes your underhead stick to cooling head ( hard to remove ), and I think it gonna be messy and risky.

You can lower the engine temp by using colder plug, lower nitro, or simply use bigger heatsink.
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Old 08-13-2007, 06:14 PM   #3
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Originally Posted by magbarn View Post
I was taking apart my C6 yesterday and I was thinking about putting a thin layer of heatsink grease between the cooling head and engine button for better heat transfer. Anyone ever tried this before? Guess I can try it on my old nova first to see if it lowers engine temps.
I've tried, I put Arctic silver but nothing improved, and engine will look messy after a while, after it mixed with dripped after run oils WD-40 etc..why computer need it? it's because the heatsink only hold by it's retainer clip, so not much pressure applied between heatsink and processor so you'll need to fill the gap. you shouldn't put thermal paste to engine it's because direct metal to metal contact is better in tranferring heat since the heatsink contact with button and sleeve is damn firm. just my 2 cents.
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Old 08-13-2007, 08:57 PM   #4
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I wouldn't use it. Any gains would be minimal as heat sink grease is really only meant to fill gaps that would hinder heat transfer. Cylinder to button would be out of the question, and button to head already has a very tight fit.
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Old 08-13-2007, 10:09 PM   #5
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i wouldnt use it, dont seal and will most likely cause a leak after it dries out.

FYI higher nitor %s should cause Lower temps, while lower %s cause more heat in MOST cases.
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Old 08-13-2007, 10:22 PM   #6
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i wouldnt use it, dont seal and will most likely cause a leak after it dries out.

FYI higher nitor %s should cause Lower temps, while lower %s cause more heat in MOST cases.
Are you sure higher nitro means cooler ??

I think you got it wrong.
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Old 08-14-2007, 04:53 AM   #7
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Think of it this way, the more oil that is in the fuel the harder the engine needs to run to burn it off (oil does not burn well) = higher engine temps. Less oil in fuel = higher burning temp = engine works less = lower engine temp.

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Old 08-14-2007, 05:24 AM   #8
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higher nitro raises engine temps unless you take action on tuning the engine. to compensate for this you need to richen the needles. if you leave the needles alone and go from 20% to 30% let me know how long before your engines performance degrades. If you're already on the edge with 20%, you'll detonate the engine for sure going to 30% without richening the engine.

Nitromethane provides more oxygen to the engine as it atomizes and the more oxygen you give going from 20% to 30%, the leaner (hotter) your engine will run unless you richen the needle. Higher nitro fuels also have a narrower tuning range. With 20% you may be good within 1/4 turn on the top end needle.... 30% you will need to be within 1/8 turn or less (numbers just for example- not exact).
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Old 08-14-2007, 08:47 AM   #9
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higher nitro raises engine temps unless you take action on tuning the engine. to compensate for this you need to richen the needles. if you leave the needles alone and go from 20% to 30% let me know how long before your engines performance degrades. If you're already on the edge with 20%, you'll detonate the engine for sure going to 30% without richening the engine.

Nitromethane provides more oxygen to the engine as it atomizes and the more oxygen you give going from 20% to 30%, the leaner (hotter) your engine will run unless you richen the needle. Higher nitro fuels also have a narrower tuning range. With 20% you may be good within 1/4 turn on the top end needle.... 30% you will need to be within 1/8 turn or less (numbers just for example- not exact).
Thank you for explaining to them.
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Old 08-14-2007, 09:34 AM   #10
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Thank you for explaining to them.
These off-road guy's need all the help they can get jk guy's
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Old 08-14-2007, 10:20 AM   #11
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yep. running 30% does require more refined tuning, but once tuned right, your motors should run cooler by ave of 10 or more degrees

i had a HB Lightning 26. broke it in and ran about 2/3rd gal of 20% thru it. ave temps were about 250ish *f. switched to 30%. added a headshim. did a quice brake in for the 30, and ave temps afterward were high 220s, low 230s. lost 20*f swapting to 30% on that motor.

run BO 30% in my Jammin JPX .21 after a 30 minute main im about 225*f.
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Old 08-14-2007, 10:25 AM   #12
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Originally Posted by cdelong View Post
higher nitro raises engine temps unless you take action on tuning the engine. to compensate for this you need to richen the needles. if you leave the needles alone and go from 20% to 30% let me know how long before your engines performance degrades. If you're already on the edge with 20%, you'll detonate the engine for sure going to 30% without richening the engine.

Nitromethane provides more oxygen to the engine as it atomizes and the more oxygen you give going from 20% to 30%, the leaner (hotter) your engine will run unless you richen the needle. Higher nitro fuels also have a narrower tuning range. With 20% you may be good within 1/4 turn on the top end needle.... 30% you will need to be within 1/8 turn or less (numbers just for example- not exact).
I live in central FL, one of the most humid places on the planet :\

To take into account the high heat and humidity, I should run a higher nitro percentage, correct? Since hot/wet air carries less oxygen?

I know in general high heat means you have to lean it a bit more, too, right?
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Old 08-14-2007, 01:42 PM   #13
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high heat (260ish* f or over) says Richen it up!!!! leaning will create more heat, richening will reduce heat.

it gets pretty humid here in Mi too. over the last weekend, it was 94*f with about 95% humidity. not sure where we are at with sea level, but the bay is only 1 mile east of the track and its flatlands.

the percentage of nitro used in a fuel is varried for many reasons. im not sure i ever heard of a high heat/humid climate should be useing higher %nitro. i think its much more of a comfort level and knowing how to tune and what to use for how your run more than anything. but ive been wrong b4. lol


i used 20% last yr. use 30% this yr and like it much better.
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Old 08-14-2007, 11:55 PM   #14
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Default Higher nitro does run cooler

Its the timing that is thrown off by going to a higher nitro %. A lot of people try to compensate by using the carb needles but that only goes so far. Head shims, Nitro % and plug heat range determine the timing. Change one and you have to change the others as well to keep the motor happy. The reason a motor will get hot with more nitro % leaving everything else alone is that more nitro advances the timing. Turning the needles to richen it up just puts more oil into the motor and cools if off a bit. The reason for this is that the nitro and the platinum in the glow plug wire cause a chemical reaction when put together under compression. Using the same plug the actual point of ignition will advance because you have more nitro to make the chemical reaction go. Get yourself a good loupe and learn to read the plug. That is the best way to make sure you aren't going to detonate a motor. A couple of things to look for in particular is if the coil is offset to one side after the plug has been run and the general condition of the wire. If the coil is offset you have too much compression, too low a deck height or its right on the verge of detonating. If the wire looks severely pitted then you are closer to detonating one than you want to be. The pits come from the platinum wire getting blown off by the higher than normal pressures developed in the cylinder. A couple of rules of thumb are

1. more shim retards the timing with the same plug and nitro%
2. less shim advances the timing with the same plug and nitro%
3. More nitro% advances the timing if the shims and plug stay the same
4. Less nitro% retards the timing if the shims and plug stay the same
5. Hotter plug advances the timing if the other two variables stay the same
6. Colder plug retards the timing if the other two variables stay the same

Start working with the plug shims and nitro% and you won't be messing with those needles near as much. A deck height gauge is a handy tool to have but you can measure the deck height with a piece of solder and a caliper as well. A motor will overheat if its too advanced or too retarded in timing. When its timed properly the exhaust will have a sharp cracking sound instead of a dull thud when it fires. And if you get out to the track one day and its super humid drop that nitro % and your motor will run better.

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Old 08-15-2007, 02:17 AM   #15
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Quote:
Originally Posted by Timmahh View Post
yep. running 30% does require more refined tuning, but once tuned right, your motors should run cooler by ave of 10 or more degrees

i had a HB Lightning 26. broke it in and ran about 2/3rd gal of 20% thru it. ave temps were about 250ish *f. switched to 30%. added a headshim. did a quice brake in for the 30, and ave temps afterward were high 220s, low 230s. lost 20*f swapting to 30% on that motor.

run BO 30% in my Jammin JPX .21 after a 30 minute main im about 225*f.
you changed two things at once.... fuel and shimming, so your conclusion that 30% alone lowered temps is invalid. The shimming helped with the temps being lower.

Plus your engine was still breaking in with only 2/3 of a gallon on it.... of course temps will get lower as it breaks in and loosens up. Try this on an engine with three gallons on it thats already loose.
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