Cooling head essay question

[killahbz]

Ok...let's say that your engine only runs good at 280 degrees which is a little hot. So you purchase an aftermarket cooling head that will reduce your temps by 60 degrees. Let's also say that it works and you are now running at a cool 220 or any other "made-up" temp...should you lean the high speed for more power or leave the needles alone and be happy with your new temp. Explain....

 

[militarymaxx]

Most data will tell you that you shouldn't tune based on temp alone. Sound, amount of smoke, glow plug condition and overall performance should also be considered. I don't know how realistic a 60 degree temp drop is just by replacing the head but I do recall seeing a buggy at a race a few weeks ago and the head on this thing was huge. Not your normal aftermarket larger head, this thing was huge. He said is was called a "summer head". We didn't get into specifics regarding tuning. You make a good point. Can we extract more power by simply providing better/more cooling ? I think the important to remember, and this was mentioned by another member (sorry I can't recall who), but the amount of fuel that is allowed into the engine plays a big role in the cooling process as well. The chemical properties of nitromethane serve many purposes and cooling is one of them. Leaning it out might compromise other things. There's got to be a cut-off otherwise we could cool these things to the point that they're so lean, a tank of gas would last a 30 minute main.

 

[robriguez]

you also have to take into consideration that our fuel and lubrication is all part ofthe same liquid. If you lean the fuel you are also lessening the amount of lubrication the engine is getting as well. Rubbing metal parts at high temps and high rpm with no lube = blowed up engine.

The only reason I would entertain getting a super cooling head is if I ran in very hot temps to begin with. Like Florida or desert type weather.

 

[SavageRockS]

I agree with MilMaxx, and that's why it is important to know how to deal with fine tuning a nitro engine. Let me also say that each engine is different from the other in terms of power and output based on how you fine tune them. That's why I treat each bashing day one day at a time, making sure all parts are in good running condition. If something breaks, that's fine, replace the parts if you can the same day, otherwise, come back the next day.
:ahh:

 

[militarymaxx]

robriguez probably mentioned the most important reason not to lean these things out too much. LUBRICATION. I completely forgot the fact that these engines use it's fuel for engine lubrication. Good point robriguez, can't loose sight of that.

 

[bkunar5356]

my associated used to run about 260 at stock needle settings. i made my own cooling head that is just under double the size and now i run about 220 or 230 with about 1/2 of a turn leaner on the hsn. i got an increase in power and have not noticed any unwanted results. the pipe still spews smoke and i have not had any problems with my glow plug.

 

[Rolex]

I just dealt with this a few weeks ago when I installed an ACNCM monster cooling head on my 2.5. I started to tune it for temps, when Christian added in the post that running too lean without overheating would cut back on lubricating oil also.
I make a point of seeing smoke, preferring to run at a 'happy' point, but keep the engine safe. It's running great at 235.

 

[Hypedonrc]

Just put a Golden Horizon head on my 2.5 yesterday. Temps went from 280-300= in the grass to 245-270 in the grass. It may be a little lean by the sound of that, but for the first two full tanks of gas that thing has ever run with out flamming out, it had lots of smoke, ran great, and I have new found interest in my Maxx. So to give my $0.02 I say leave the needle alone. richer equals more oil, and longer life.

 

[Digital Liquid]

By switching out cooling heads, you are actually creating a sliding scale. Look at this pic below:

You stated that you run normal @ 280. So imagine on that chart that where it says "racing", it represents 280 degrees for you. If you go any higher than that you are in the danger zone.

Now by changing out heads, all you are really doing is dropping the temp scale. For example, you run 280 & change heads & drop down to 240. Well, now when you look at the chart, where it says "racing", it represents 240 for you (instead of your previous 280). If you try to lean it out more, you will just be getting into the danger zone. You will be getting into the danger zone not b/c of temps, but b/c of the other factors that everybody else has mentioned above.

There is a benefit to dropping your temp down by switching out cooling heads. It is to help with the longetivity of your engine, not to allow you to lean it out for more power. A engine constantly running @ 280 will not last as long as one that runs constantly @ 240.

Hopefully, that made some sense. Another thing to look at is what fuel you are using. Is it fresh? Oil percent? Do you pour fuel from your tank back into your quart bottle? etc....

Later...:mex:

 

[dmckie]

cooling

TUNNING W/ A AFTERMARKET COOLING HEAd

1) Tune the engine w/ the reagular stock head first. Get on the track and run at least one full tank, tuning the engine to maximize preformance while retaining plenty of smoke ,a soild idle,and a clean sounding exhaust note. Note the engine's temp at this point and bring the car in.

2) Remove the stock head, and install the aftermarket head without touching the carb settings .

3)Take the car back out on the track and note any preformance changes.there sould be no preformace change's,but your engine's head temp's should drop. Use the head temps at this point as your reference temp range in the future.

Leaning the engine more at this point will only damage the engine. Assuming you tuned the engine for max preformance in step 1. In theory ,the tuning you placed on the engine with the stock head provides the maximum power possiable while retaining adequate lubrication. Although an aftermarket head will drop head temps ,it will not compensate for overly lean tuning or provide the engine with adequate lub when tuned lean . Leaning the engine with the aftermarket head installed in attempt to match the initial temp with the stock head will starve the engine of fuel and lubrication and will accelerate wear on the piston ,sleeve, and bearings even though the head temp's may seem OK.

this is from a artical in jun issue of Xtreme rc car . check it out

 

[NooP]

With all this talk, I'm wondering if there is any kind of lube that can stick to the internals of our engines. Something like what duralube claims to do for 1:1 cars. If there was some type of lube that we could use before a race or bash that would stick to the moving metals in our cars, we could lean it out for more power.

sounds good, just dont know if it exist or is possible.

--NooP

 

[Hypedonrc]

I would say the possibilities exist. Just that with 1:1 cars you have a 4 strock engine with a crank case full of oil that VERY slightly gets burt in the combustion chamber, so you have options such as Royal Purple or any synthetic to lube the moving parts. Someone will probably know if the oil content in nitro is synthetic, or not, but they are a totally differant concept.