Engine Temps

[Norm Doerr]

Iv got such a animal, one that measures pipe temps and adjust mixture to hold a preset pipe temp, never broken a K type probe, but I can write a few new lines of code to adjust back to start center if the probe fails.

opto sensors are not accurate in our boats, oil and trash can effect they way they "see" the flying white dot, I'm still a big fan of the hall effect sensor, they hold there tune well enough?

I'm working with a atmel 8051 microproc right now, so internal memory is all I have to work with, need to pick up a micro SD adapter board for external cache.

If Marty gets time to work with me on numbers and ideal tunes, we might be able to produce some of these little guys. as it stands they wont add enough weight to bother your boat, I run mine off a single 600mah li-po cell.

The one I use was Marty's idea, only real difference I got to see was in the corner, my red pig roadrunner (rest it's wooden soul) used to be a dog in the corner, after Marty pointed me to the pipe temps, we got that issue resolved.

Amazing!!! Now you are taking fun.

We use a Mote Opto with an aluminum wheel with a bunch of holes drilled in it, I think it is the same set up he used to get the data he posted above.

 

[Norm Doerr]

I have been thinking that I would really like to have a place that Nitro topics could be discussed on a very technical basis. I know that there are many people who are good thinkers and technically oriented.

Would some of you be interested in starting a small group of people to discuss technical issues about nitro engines and outriggers? Would be a great way to advance our segment of the hobby.

Yes Sir. That is a super excellent idea. A lot could be accomplished

 

[John Knight]

I have been thinking that I would really like to have a place that Nitro topics could be discussed on a very technical basis. I know that there are many people who are good thinkers and technically oriented.

Would some of you be interested in starting a small group of people to discuss technical issues about nitro engines and outriggers? Would be a great way to advance our segment of the hobby.

Yes Sir. That is a super excellent idea. A lot could be accomplished

Just try and keep in simple terms for us non-technical folks. Very few of us are engineers and do not talk that gibberish. I worked among them for over 25 years and have profound respect for them but that does not mean I understand any of it. And I am not alone in than aspect either!

 

[Scott Norris]

I have been thinking that I would really like to have a place that Nitro topics could be discussed on a very technical basis. I know that there are many people who are good thinkers and technically oriented.

Would some of you be interested in starting a small group of people to discuss technical issues about nitro engines and outriggers? Would be a great way to advance our segment of the hobby.

Yes Sir. That is a super excellent idea. A lot could be accomplished

Just try and keep in simple terms for us non-technical folks. Very few of us are engineers and do not talk that gibberish. I worked among them for over 25 years and have profound respect for them but that does not mean I understand any of it. And I am not alone in than aspect either!

Don't worry about it John. Your boats race fine and so do mine. That's all that matters!!

 

[Charles Perdue]

That sounds like a great idea. I like all RC boats but I really love fast riggers. My time is limited also (some of us still have to work for a living)

but I will be glad to dive in sometimes.

Charles

 

[Marty Davis]

OK, here is the link to sign up.

http://rcboat.com/forums/

Be SURE to use your full name.

Pass this around to those that you think would enjoy this Technical Discussion Forum.

 

[Marty Davis]

Hold off on this registration until I get a little glitch fixed.

 

[Jim Caldwell]

Just a couple of notes for your consideration;

All from GAS GP bike motors and Dyno.

1. probe at fatest part of pipe - as exaust gas expands it cools down. Probes were placed about 1" before the pipe started to expand, the same fixed distance from the center of the cly. You can change pipes that way and see the effect they have by having the same constant location for the probe.

2. Steel pipes make more power, they keep the heat in the pipe to enhance the return pressure wave. Pipe wrap is even better on a Steel pipe.

3. More nitro slows down the Flame front or the rate of burn and limits the RPM's you can turn. Nitro will keep burning down the pipe in large %. Thats why the dragsters look so good at night. But it can limit the return pressure wave if it burns in the pipe too long.

4. We had by far the best results using a 180 degree F Thermostat to stablize the cly. temp giving us a stable base to work from.

Keep up the good work Marty, big gobs of power to come.

 

[Marty Davis]

OK, the glitch is fixed. A little different registration link:

http://rcboat.com/forums/

Anyone that previously registered, please do so again.

 

[Tim_Duggan]

May I be so bold as to ask;

What was the effect of TCR on EGT with all other variables fixed?

TD

 

[dwilfong]

Pressure waves change speed when the air density changes.Air density changes with temp. So when you load the eng the temp rises. this changes the tune length of the pipe. The pipe can not push the charge in the cyl as much.

Changing the pipe lenght in the turns would help with this problem.

I think it would be much easer to change pipe length than fuel mixture.

I had a cagiva 125 and thy used a knife valve on the ex port to change the port size. It was governed by RPM made for a more liner power band. Don't think that would help much with this type of eng. Don't do that much throttling.

David

 

[Tim_Duggan]

Changing the pipe lenght in the turns would help with this problem.

I think it would be much easer to change pipe length than fuel mixture.

It's very possible, in fact some people already do this, but it does have some drawbacks. Those being it is mechanically more complicated (and therefore less K.I.S.S) as it has to account for expansion etc. and it also adds more weight.

 

[dwilfong]

Yes I have seen some of the setups on hear. But if you hook it to the rudder servo with a linkage I don't think it would add that much.

A lot more KISS than soft wear and programing.

And you could find a happy medium with the pipe.

You could also slide the fat section and not the throat.

David

 

[Tim_Duggan]

Yes I have seen some of the setups on hear. But if you hook it to the rudder servo with a linkage I don't think it would add that much.

A lot more KISS than soft wear and programing.

And you could find a happy medium with the pipe.

You could also slide the fat section and not the throat.

David

It would be nice if it was as simple as attaching a linkage to the rudder, but I can't see it being that simple. There Has to be provisions in the mount of the pipe and not compromising the rigidity of the mount if the boat should happen to come unstuck and roll. In a word - weight. In the larger classes, not such a big deal, but in the smaller classes - vital.

From an electronics perspective, the programming aspect may be tricky, but once it is set it would be more reliable than more moving parts - no question. Unless it gets wet! Ideally, the function would happen with little to no input at all once set up.

Therefore, "fooling" the pipe into acting longer rather than physically making it longer has real merit in my opinion.

 

[dwilfong]

If changing the fat section could be done in the can of the muffler the pipe could be welded to the header and the back of the pipe solid mounted.

Got this out of the kitchen could make a rear cone that would slide in to the front to change pipe shape front and rear size and length.

Gust a thought that I had.

Yuo could use the shift sw on the raido to move the 3rd chanel when you go in to the coner if you want to make it real KISS.

David

 

[camaroboy383]

is this not what you guys are trying to accomplish here??????????????? with a adjustable pipe on the fly that is...

http://bukupower.com/

 

[Marty Davis]

I have been thinking that I would really like to have a place that Nitro topics could be discussed on a very technical basis. I know that there are many people who are good thinkers and technically oriented.

Would some of you be interested in starting a small group of people to discuss technical issues about nitro engines and outriggers? Would be a great way to advance our segment of the hobby.

Yes Sir. That is a super excellent idea. A lot could be accomplished

Just try and keep in simple terms for us non-technical folks. Very few of us are engineers and do not talk that gibberish. I worked among them for over 25 years and have profound respect for them but that does not mean I understand any of it. And I am not alone in than aspect either!

John:

I understand exactly what you are saying. I had to have Brian Callahan simplify most everything that we talked about. He would have to tell me in several ways so that I could understand. Some of us are technical training challenged. :blink:

 

[Marty Davis]

May I be so bold as to ask;

What was the effect of TCR on EGT with all other variables fixed?

TD

TCR???

 

[Marty Davis]

Yes I have seen some of the setups on hear. But if you hook it to the rudder servo with a linkage I don't think it would add that much.

A lot more KISS than soft wear and programing.

And you could find a happy medium with the pipe.

You could also slide the fat section and not the throat.

David

It would be nice if it was as simple as attaching a linkage to the rudder, but I can't see it being that simple. There Has to be provisions in the mount of the pipe and not compromising the rigidity of the mount if the boat should happen to come unstuck and roll. In a word - weight. In the larger classes, not such a big deal, but in the smaller classes - vital.

From an electronics perspective, the programming aspect may be tricky, but once it is set it would be more reliable than more moving parts - no question. Unless it gets wet! Ideally, the function would happen with little to no input at all once set up.

Therefore, "fooling" the pipe into acting longer rather than physically making it longer has real merit in my opinion.

Why mechanically change the pipe length? Why not use water injection to do the same thing?

 

[Charles Perdue]

I was curious as to how long it would take someone to think of this. Marty gets the jelly beans.

Water injection in the pipe?

Spray the pipe with water?

Wrap the pipe with tubing and flow water thru the tubing in the turns and on launch?

Thats KISS!!!

Charles