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-   -   TO WRAP OR NOT TO WRAP ????????? (https://www.rctech.net/forum/nitro-off-road/283603-wrap-not-wrap.html)

RadioCircus 03-19-2009 11:57 PM

TO WRAP OR NOT TO WRAP ?????????
 
I am guessing this question has been brought up before i am wondering if there is power to be gained by wrapping the header on a nitro engine im new to rc but have built countless open modified kart engines with good success in karts it pulls heat out of the head and pushes it through the exhuast creating more exhuast pressure faster exhaust speed lower engie temps and usually a better low end power band we were running 4 stroke engines not sure if the same principles apply with a 2 stroke any ideas:D

gotspeed_2000 03-20-2009 01:24 AM

It really depends on what material you are using to wrap the header. By wrapping an exhaust header with a heat isulator type wrap, I thought you isolate the heat in the exhaust from the rest of the motor. The result is a lower engine temp in the head area due to a lower surrounding temp. I'm pretty sure that the wrap itself does not draw much heat by itself from the motor or the block, but it's main benefit is to keep the heat from the exhaust in the pipe with minimal impact to the rest of the motor. If you have some sort of material that increases heat dissipation or surface area, then it could have a side affect that could draw some heat away from the motor. But that impact would be minimal as would the exhaust wrap.
Air circulation and aftermarket heads available are able to control heat within reason and allow a good amount of power while running in hot conditions.

RadioCircus 03-20-2009 02:13 AM

again i have to fall back on 4 stroke kart knowledge at racing speed there basically is no header heat accumulating around the head the wrap builds the heat inside the pipe which speeds up gas flow the hotter a gas becomes the more pressure and speed you can get out of the flow this being said the hotter the gas the faster the flow the quicker it moves out of the engine the smother the powerband basically by wrapping a header you move heat away from the head faster reducing overall temps my 2 stroke knowledge is basically crap so any thoughts or ideas are welcome

gotspeed_2000 03-20-2009 02:22 AM

The idea sounds correct, but I'm not sure what kind of gain you could get out of a small motor and whether it would be noticeable or worth the trouble. I'd be more concerned about keeping head temps within a good operating temp range. You can't overly lean a motor even if the head temps are low because you'd also be starving the engine for oil because they are two strokes. Without adding something to the fuel to add oil, running overly lean will starve the engine of vital oil, especially in the bearings which would lead to engine failure.

RadioCircus 03-20-2009 03:12 AM

good point i am going to sound like an idiot with this but i was thinking about 4 strokes so much i forgot 2 strokes oil is in the fuel

butch man 03-20-2009 08:01 PM

Somebody within the last few weeks had a thread on ceramic coating exaust.Something like jethot or another & was gonna try it but I didnt follow & dont know if it ever happened.Theory is good but practice may be different,these motors spin alot more than any full sized motors that I have ever seen it tried on.I do know that thin pipes are the hot ticket just like in full sized 2 stroke motors, learned that in my on road days but after making several thin walled RB 1/10 onroad pipes flatter than a piece of paper & can do without the extra power wasnt worth it even on super high traction asphalt.In off road with much less traction I think the cost of coating or the weight of wrap would be out weighed unless it does something awsome for fuel milage.Let us know what happens if you try.


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