Do most guys check the temp on the purple ring? I have a motor that reads 230 sometimes - but only 150 on the actual silver ridges. Can a ring the rotates real less than one that is tight? Just curious where everyone checks theirs - and what the average temps are. Granted we are racing outside with track temps at 140 and air temp at 95...

i have been told to check it on the sticker?

Mike-
We take the ring off, and that kills a lot of the heat. But from what I have seen with the ring on it always reads way higher than on the "fins" of the motor. I would think if the ring is tight it would cool better just because it can pull the heat out of the motor.

If you check on the fins it'll always read 50+ low, at least with the cheapo temp guns. If you temp on the sticker that is on the ring that is the best. If you check it on just the ring it'll be maybe 10 degree higher than on the sticker, with my gun at least

230 is way too hot. I've raced on 135 degree asphalt before and wasn't even remotely close to that. 180 or so would be more reasonable for 10.5 in those conditions.

The difference in temp. readings using and IR temp. gun may be due to the emissivity of the surface. The "purple" color of the surface will give a different temp reading then the shiny surface of bare aluminum.

From http://www.raytek.com/Raytek/en-r0/IREducation/Emissivity.htm

Emissivity is the measure of an object's ability to emit infrared energy. Emitted energy indicates the temperature of the object. Emissivity can have a value from 0 (shiny mirror) to 1.0 (blackbody). Most organic, painted, or oxidized surfaces have emissivity values close to 0.95. Majority of Raytek sensors have adjustable emissivity feature to ensure accuracy when measuring other materials such as shiny metals.

If you are using a thermometer with a fixed, preset emissivity of 0.95, and need to measure a shiny object you can compensate by covering the surface to be measured with spray oil, flat black paint or masking tape. Measure the temperature of the taped or painted surface. That is the true temperature.

check on the sticker is was i hear

I think it is actually the shape of the rings mainly. Maybe the light doesn't reflect back properly because of the ribs? Anyway if you check on the silver part on an old style non-ribbed it'll give you a better number.

Just to note:

For R/C use, there are 3 commonly used
emissivity settings:
1) Aluminum: Sandblasted (standard car and airplane engines, not anodized) set the
emissivity at 21E.
2) Aluminum: Anodized (for colored car and airplane engines, may be powder coated) set
the emissivity at 77E.
3) Batteries Packs (with or without covering) and Airplane Covering: Leave at default 95E.

I was told that you can't get a reading on the laminations without the ring, the temp gun won't read on the laminations, just put any type of sticker on the laminations, battery tape works great!

Last month I was at Easley, they run without the rings there, we took our rings off and where able to run on the lam's. temp numbers where much lower.

I always heard the sticker was the place to check it. I have a Nomadio with a temp probe I am going to use on my 21.5 car. You can get real time temp readings on your radio while your car is on the track and under way. Plus you can set the radio to vibrate or alarm if the motor exceeds a pre set maximum temperature. Does anyone know where you can buy that heat transfer paste novak uses for the motor heat sinks?

Cliff for awhile I was using a little venom temp probe made for gas engines. Probably similar to the nomadio probe? It is just a probe on a loop of wire and you sinch it up around the motor. Anyway it gave pretty accurate (similar to temp gun) results without using thermal paste. Only reason I don't use it now is I always forget to turn it off and the batteries are perpetually dead.

If you do want thermal paste though you can go to any computer store and get it. They use it for putting heatsinks on CPUs, etc.

cool, the nomadio probe is not the loop wire type, more of a little square sensor that will have to be attached with glue around the edges or something then it plugs into the rcvr and sends the data back to the radio. I just figured the paste would help with accuracy

http://www.radioshack.com/product/index.jsp?productId=2526910&cp=&sr=1&origkw=heat+transfer+paste&kw=heat+transfer+paste&parentPage=search

has anybody tried to use the temp prime from a muchmore charger to check the motor.

so i have an o'donnell tgx-1 temp gun, and a duratrax mini gun, and they both are set at 95e (emissivity) which i read everywhere that...that is the standard for most items.

when i check temps against things, the duratrax always reads almost 8 ~ 10 degrees lower than the o'donnell.

i noticed at the track, my readings were always lower than other guns which were set at 95e which was dangerous because i didn't temp my motors right.

is my gun off.. or is the emissivity diff on these two guns?

hmm....

Be sure to check the "lens" of the temp gun. If it is dirty it will read incorrectly. Use a q-tip and some alcohol.

How much of a difference is there when temping a motor with ring vs no ring? I've run my 17.5 both ways. Something else I wondered, When everyone cranks up the timing on these motors, how much does that effect the efficiency? Someone with a dyno should be able to answer that.

I think it is actually the shape of the rings mainly. Maybe the light doesn't reflect back properly because of the ribs? Anyway if you check on the silver part on an old style non-ribbed it'll give you a better number.

The temp gun doesn't read any reflected light. The laser light is just for aiming the gun. The gun reads the infrared light radiated by the heat source.

just for kicks ill point both guns at my skin, or wall, or my cat.... and they both read like 5-8 degrees off with a 95e setting.. :| one gun is wrong.. hmm..