Engine Temps

[Tim_Duggan]

Hmmmm - direct injection into the cyl. That could potentially change the way we look at port config and combustion chamber design entirely.

 

[Tim_Duggan]

Going to a constant fuel pressure system would most likely make low end needle carbs more vital, as the current style spraybars with no low end rely on the drop of fuel pressure to prevent severe flooding at partial throttle.

Our current archaic fuel systems also indirectly affect pipe stinger size by altering the fuel pressure. By going to a fixed fuel pressure system, it allows fine tuning of the stinger with the fuel aspect removed from the equasion......

 

[Marty Davis]

May I be so bold as to ask;

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

TD

Tim:

I have arrived at the TCR that I find works best for me on my .21's. That is 10.25:1. So, I have not split tested TCR in this regard. What effect do you think that would have?

Marty,

I have seen examples where the temp of the pipe goes up as the engine gets older / loses the ability to burn the mixture as effectively in the engine, and as a result burns it in the pipe. I was curious to know if Compression ratio gave a similar result from a controlled test, rather than theorising or assuming.

If lower TCR = Higher EGT at a stoichiometric mixture(not lean), it would go some ways to explaining those cases often heard of the "freak" engines that run the best they ever have with a poor seal or fit of the piston and sleeve...... possibly due to the pipe length or shape was not compatible with the lower EGT when the motor had a good seal.

Engine was completely fresh with great seal.

 

[Charles Perdue]

Hmmmm - direct injection into the cyl. That could potentially change the way we look at port config and combustion chamber design entirely.

In the 80's an Australian company named Orbital Engines developed a direct injection fuel injection system for 2 stroke engines. It uses a combination of compressed air and fuel injected directly into the combustion chamber. It is being used in some full size outboard engines and on daily transportation vehicles in the Asian countries.

According to their figures, they spent over 100 MILLION dollars in this developement process.

Charles

 

[Charles Perdue]

In Europe using a float chamber are common in the FSR V and also the O class - never seen it used in the H class.

Also keeping the low speed needle intact gives you more driveability.

With a noise rule - max 82 DB - a extra muffled pipe is required. Performance and heat problems are easily affected by this.

Many years ago, I made another simple fuel system that was not sensitive to the changing fuel levels in our toy boats.

I mounted a small fuel tank (1 oz) above the main fuel tank and fed it with a pulse operated pump. The fuel level in the auxilary tank was kept constant by allowing the excess fuel to overflow back into the main tank by a fuel outlet placed in the auxilary tank at about 3/4 level. A separate pickup was used to feed the carb. This system worked very well.

The main requirement was that the overflow level in the auxilary tank must be above the full fuel level in the main tank.

This system was used on an outboard but it would work well on other classes of boats also.

Charles

 

[Marty Davis]

For your information, Tom Morehouse has agreed to place a new Board on his IW Forum fo us to discuss Technical issues about Nitro Engines and Outrigger Hydros.

Not sure when this will be up, but this will simplify things and we will not need another place for this.

Stay tuned.....

 

[Charles Perdue]

Hmmmm - direct injection into the cyl. That could potentially change the way we look at port config and combustion chamber design entirely.

In the 80's an Australian company named Orbital Engines developed a direct injection fuel injection system for 2 stroke engines. It uses a combination of compressed air and fuel injected directly into the combustion chamber. It is being used in some full size outboard engines and on daily transportation vehicles in the Asian countries.

According to their figures, they spent over 100 MILLION dollars in this developement process.

Charles

There is maybe one way that we could go on the direct injection for our engines. Orbital Engines is producing by the millions, a retro fit kit for the small 2 cycle engines that are used in personal transportation, bicycles,3 wheeled carts,ect in most of the Asian countries. This would have to be a VERY simple kit for it to be used in this application. If you could get your hands on one of these kits, it may be possible to adapt some of its technology to our use. Just a thought.......

Charles

 

[tnrcboatracer]

Orbital also developed a small 2 cycle for the automotive market. THe issue was that the hydrocarbon emissions were unacceptable, as I recall. The auto engine used a supercharger to fill the cylinders without running air through the crank case. This all but eliminated the oil in the combustion process. They still had an issue with unburned fuel in the exhaust gas stream.

 

[Marty Davis]

Hang tight on the new forum. Tommy Dodd is installing a much better forum so that we can eliminate the current problems. We are also working on something on IW to take care of us.

 

[dwilfong]

Detroit diesel supercharged 2 stroke with ex valves in head. the superchargers are already available and R/C eng with valves in the head. think some of you guys could make a hybrid with parts already out there.

David

 

[Marty Davis]

OK, Tommy Dodd has installed a new Forum on my server and it is much better than the one I installed. Should operate without problems. Here is the link: http://rcboat.com/forums/

Those of you that signed up for the other install will need to re-signup.

REMEMBER: Sign up using your real name or you will be automatically bumped out.

Let me know if you see anything that needs attention.

 

[BB Mods's]

YOU HAVE TO REGISTER WITH YOUR REAL NAME

Ron, register again.

 

[Norm Doerr]

I must have checked the wrong box. I messed up the code thing and put in a "O" instead of a "0" and when it sent me back I forgot to redo the age box. Now I have to get a parent to sign some permission slip, Help

 

[BB Mods's]

I must have checked the wrong box. I messed up the code thing and put in a "O" instead of a "0" and when it sent me back I forgot to redo the age box. Now I have to get a parent to sign some permission slip, Help

No problem, Ill get your account activated in 30 sec.

done.

 

[carlnoki]

Might want to give Mike Z at his place of business a shout and see if he can't find the tech. literature on teh discontinued (if memory serves) O.S. 160 or was it the 140 front intake rear exhaust FAI F3A

R/C pattern motor.

These motors were ACUTALLY fuel injected, used EGT, RPM,ect.

Carl

 

[Marty Davis]

OK, everything is set up on a new forum for Technical Discussion. Go here to sign up. Be SURE to use your real name or it will boot you off.

I have started a few new topics that should be very interesting to anyone interested in the technical aspects of our hobby.

http://rcboat.com/forums

 

[Charles Perdue]

OK, everything is set up on a new forum for Technical Discussion. Go here to sign up. Be SURE to use your real name or it will boot you off.

I have started a few new topics that should be very interesting to anyone interested in the technical aspects of our hobby.

http://rcboat.com/forums

Marty, your new site doesn't like me already. I will not approve me and it will not let me sign up again.

Signed: Frusterrrrated

 

[Marty Davis]

OK, everything is set up on a new forum for Technical Discussion. Go here to sign up. Be SURE to use your real name or it will boot you off.

I have started a few new topics that should be very interesting to anyone interested in the technical aspects of our hobby.

http://rcboat.com/forums

Marty, your new site doesn't like me already. I will not approve me and it will not let me sign up again.

Signed: Frusterrrrated

You are all set....

 

[tnrcboatracer]

Some of the graphics don't show up for me. But I'm in per the message, just waiting for administator approval.......

 

[scootertrash]

alot of the car guys use engine temp to tune