Joe,
What type of rpm sensor are you using and where did you mount it. I have an optical futaba that would work with my s bus.
Regards Hank
Latest and greatest timing and deck height?
Re: Latest and greatest timing and deck height?
Ray,
I have a stupid question. When you say Mothers polish, is there a specific kind or do just look for Mothers polish.
When you say 1500, is that paper or steel wool?
Hank D
I have a stupid question. When you say Mothers polish, is there a specific kind or do just look for Mothers polish.
When you say 1500, is that paper or steel wool?
Hank D
-
fizzwater2
- Super Contributor
- Posts: 513
- Joined: Wed Mar 09, 2011 11:44 am
- Location: Paola, KS
- Contact:
Re: Latest and greatest timing and deck height?
Out of all the places we could be, this is one of them.
Re: Latest and greatest timing and deck height?
Yep, that's the polish. The 1500 is sand paper. Wet/dry. 2000 is good too. don't polish it to a mirror, just clean off the carbon and cleanup the sides.
And I said, here am I send me.
Re: Latest and greatest timing and deck height?
28.500
after looking at joe's chart it would seem the 28.5 is accurate. question for joe d. what was your peak rpm otg.
after looking at joe's chart it would seem the 28.5 is accurate. question for joe d. what was your peak rpm otg.
And I said, here am I send me.
Re: Latest and greatest timing and deck height?
Judging by the graph I'd guess 24.5, shown right after start up.
Re: Latest and greatest timing and deck height?
I tend to not peak on the line, I am more of set based on last needle and lean out a little if plug looks I can and not sure what it peaked at last time I bench run.....so can't really say what peak on the ground.
That initial peak on startup is not me peaking. This engine has a tendency to want to jump on the pipe hard right at the start even a half or 3/4 of needle open from my set point. I use thumb partially over venturi to quickly get it a little rich until it warms up and then position set, so bottom line, wouldn't read much into anything before launch.
I am using the Spektrum backplate sensor which is a hall effect sensor that detects crank pin. Zap a dap goo'd into the backplate.
That initial peak on startup is not me peaking. This engine has a tendency to want to jump on the pipe hard right at the start even a half or 3/4 of needle open from my set point. I use thumb partially over venturi to quickly get it a little rich until it warms up and then position set, so bottom line, wouldn't read much into anything before launch.
I am using the Spektrum backplate sensor which is a hall effect sensor that detects crank pin. Zap a dap goo'd into the backplate.
Re: Latest and greatest timing and deck height?
Thanks joe. The jump on the pipe is the result of no tank pressure at start up.
Based on the 3000 unload theory if it's correct your ground peak rpm around 25.3. The needle setting or rpm you left at obviously lower. More food for thought, the gray area of needling a motor. Been playing with the cold start. Preset needle, motor choked at startup until a couple seconds before the flag. The reason being if you start and let it run on the pipe for the 45 seconds your letting the motor heat up. Then your needling a motor at operating temp. This will cause a rich needle setting. To qualify that, after you have flown while needling and letting the motor heat up, now, with the needle in the same position, start it choked, keep it choked for 30 or 40 seconds pull your finger off the venturi and push it. It will fly rich all 10 laps. Now, finding the rite needle setting for this type of start. After you have done the two flights mentioned above, your next start, with the needle the same, choke it, let it run 30 or 40 seconds to simulate a heat. When you pull your finger off it should be running rich. Turn the needle in until it hits the pipe and shut it off. After it cools fly it again. go through the start sequence again. This time when you pull your finger off it should hit the pipe hard. its important that only a couple seconds are left on the clock before you pull your finger off and push. Don't let it sit there and run. Now your first lap is on the pipe and running. the motor never gets a chance to heat up and if everything is good it should run all 10 laps hard. All of this is just another option of finding more speed. It will work for some but not all.
Based on the 3000 unload theory if it's correct your ground peak rpm around 25.3. The needle setting or rpm you left at obviously lower. More food for thought, the gray area of needling a motor. Been playing with the cold start. Preset needle, motor choked at startup until a couple seconds before the flag. The reason being if you start and let it run on the pipe for the 45 seconds your letting the motor heat up. Then your needling a motor at operating temp. This will cause a rich needle setting. To qualify that, after you have flown while needling and letting the motor heat up, now, with the needle in the same position, start it choked, keep it choked for 30 or 40 seconds pull your finger off the venturi and push it. It will fly rich all 10 laps. Now, finding the rite needle setting for this type of start. After you have done the two flights mentioned above, your next start, with the needle the same, choke it, let it run 30 or 40 seconds to simulate a heat. When you pull your finger off it should be running rich. Turn the needle in until it hits the pipe and shut it off. After it cools fly it again. go through the start sequence again. This time when you pull your finger off it should hit the pipe hard. its important that only a couple seconds are left on the clock before you pull your finger off and push. Don't let it sit there and run. Now your first lap is on the pipe and running. the motor never gets a chance to heat up and if everything is good it should run all 10 laps hard. All of this is just another option of finding more speed. It will work for some but not all.
And I said, here am I send me.
Re: Latest and greatest timing and deck height?
Here's a link to a YouTube video using the choke. Check out the first lap.
https://youtu.be/dcdwkEdJ9o8
https://youtu.be/dcdwkEdJ9o8
And I said, here am I send me.
Re: Latest and greatest timing and deck height?
Do any of you self proclaimed experts own a degree wheel?
Re: Latest and greatest timing and deck height?
Dont see any self proclaimed experts. That was the next thread.
Maybe you could educate them.
Maybe you could educate them.
And I said, here am I send me.
Re: Latest and greatest timing and deck height?
Well, lee, we're waiting. Dazzle us with your brilliance.
And I said, here am I send me.
Re: Latest and greatest timing and deck height?
Well let me start with an apology for the sarcastic classification of all of you that are trying to figure out how to find that optimum set up for the Nelson Q-40 engine. I have to admit that the term "Scientist" would have been a little better. Never the less a degree wheel can give documentation on the "seal to fit" relationship. Ultimately it should seal and hold that seal with very little friction induced between the piston and the sleeve. This information that the degree wheel can give you is just one of over a hundred things that can help with the refinement of finding the right set up. Also an additional note: Telemetry can be a bit deceiving, If an airframe has more drag or is not as rigid the numbers could be off. An airframe with more drag or is less rigid can show that the engine might not unload as much or as quick as it should. However it is a good way to determine which airframe the engine likes more. Von Der Hey.
Re: Latest and greatest timing and deck height?
Hey Kurt, see what happens when you ask a question?
Re: Latest and greatest timing and deck height?
This info is directed towards Kurt but would work for all. You can call up Mike @ APM and order the set-up that I use. .192 & .019 . Ask for no glue in the crank and the piston fit @ .280 to .290 Break it in just like Ray says and race it with a 7.4 X 7.5 After a few runs you should be leaving the ground around 25K to 25.5K Ray is right when it comes to the piston / sleeve fit. As accurate as Mike makes all of the engine parts the chroming and fitting is the biggest variable with these engines. However Mike makes them as good as they will ever get so just about every engine that leaves his shop is a sub-minute engine. Along with all of this information I must stress that a .58 engine will only go 1.04 or slower in a bad airframe. Having the front of the airframe rigid is as important as having a sub-minute engine. Von Der Hey.