Antique

My Feedback: (4)

AV8TOR,,, Aero nut has the right idea, make some and sell em. A suggestion, for what it's worth, make them from the small bore ZAMA's that we all have lying around. We'll send you a small bore ZAMA, you mod it and charge us for your magic.

mikenlapaz

Congradulations!
Been wondering how it went. Looking at the success post date, I figure your testing has created all the local cloud cover locally! Viewing the sat pictures loops indicate source to be your part of AZ.
Agree with idea of recycling the small bore carbs into smoke pumps. As an alternative to putting fitting in engine case / port, how about just putting a fitting on the carb and share the pulse it gets thru the adapter plate pulse hole?

av8tor1977

My Feedback: (6)

Well, if I made all the cloud cover, what made all this damn wind??!! YUUCKK!! Third day of 30+ mph winds; no good for motor testing!!

Anyway, thanks for the interest and comments, and I'll give some thought to making some pumps. I have another idea I want to check out first that might be even better. I'll let you guys know...

Meanwhile, I'm trying to get some more testing in on the 30cc "hot rod". I think I may have gone a little to far with the port timing, and it doesn't want to perform up to expectations without a tuned pipe. More testing will tell, if the wind will ever stop blowing!

Take care,
AV8TOR

Orvie6

Hey guys, I have an external pump that was on one of my weedeaters that I picked up from my local dealer/repair shop. It is just the thing for the smoke systems. The only problem is... I can't remember the brand of weedeater it came off of!! I do remember it had a case very similar to a chainsaw and was a lime green color. I took it off when I stripped all my weedies down and just remembered it while reading this post. I took some pictures of it, althought I don't think they turned out very good. I will try and post them anyway. The pump mounted to the case with 2 screws and the pulse line went in the hole in the metal case. The intake is on the side of the pump and the output is on the rear/bottom of the pump between the other holes which mount the pump to the case. Not sure if your local dealer will have a listing for this or not since Im not sure of the brand name that uses it... sorry.

w8ye

My Feedback: (16)

Wayne,

It appears to be a chain oiler pump from a Poulan chain saw?

Jim

av8tor1977

My Feedback: (6)

This is the "idea" that I wrote about in my last post. If you look in post number 5 I mentioned it also. Go to the Walbro website and type in "WIP". Cute little pumps from Walbro for around $25.00. I live a hundred miles from a dealer, but when I get to town I'm going to order one to try out.

Have fun!
AV8TOR

mikenlapaz

AV8TOR
Wonder what application they are used for. Someone mention the oiler pump on chain saw did not supply enough volume. Would you expect the flow to be greater on 4 cycle version if installed on 2 cycle engine?

av8tor1977

My Feedback: (6)

HI,

I don't know about the oiler pump. On the Walbro site, it says some of the "WIP" pumps are fuel pumps for racing go karts. There are a number of these pumps listed. What I need to do is find out if the distributor knows which ones are which, what size inlets and outlets, etc. Then I'll order one and try it. If anyone is able to do so before I get around to it, please let us know!

AV8TOR

Antique

My Feedback: (4)

If you're in Ashfork there are a couple of these about 20 miles away
They're 1.9 inches square,1.3 inches thick, have 3 molded fittings that are .300 diameter..Cost $24.77 retail from Walbro....Assembled in Mexico...

Orvie6

I have modified the pump I have by drilling out the intake and output fittings. Actually, I took the small brass tube that was in the output and installed an 8-32 pressure fitting, like for the muffler pressure. The input side as a very small hole in it, but I drilled it to 1/16 inch and soldered a small brass tube to the metal cover for a pulse line. The chamber of the pump seems to be of enough size to work well with smoke.

4 stroken ron

My Feedback: (29)

Ralph, I think I am detecting an underlying message here. Is it possible that these pumps don't work well, are heavy, or has some other problem for our smoke pumps?
Ron

Antique

My Feedback: (4)

Not at all, they work very well and are not very heavy, they're plastic... we have used these on our racing engines to pressurize the carbs..FWIW, the fitting in the homemade pulse pumps goes in the cast cover, not the steel one...the diaphragm with the metal center and the inlet needle, along with the other needles, can be cut off and thrown away, they have no function in the pump part of the carb..all you need is enough of the carb body for the cast cover and the diaphragm with the two flappers on it...You plug up the hole that came from the pulse hole in the base and put a pressure fitting in the cast cover....If you're testing your homemade pump and you can blow any air at all through the pulse fitting it won't work right..
The pulse goes to a closed chamber above the diaphragm..It pushes the diaphragm up and down enough to work the two little flapper valves that do the pumping...If you have a pressure test pump it should hold whatever pressure you can put on it without leaking down..You can trace the in and out from the flappers and put muffler pressure fittings in the holes, as has been done....I'll mill an old Zama to see what it takes.....

av8tor1977

My Feedback: (6)

YEP!!

And if you blow into a inlet/outlet tube or fitting and you can't, it's the outlet. If you blow into an inlet/outlet tube or fitting and you can, it's the inlet!

AV8TOR

av8tor1977

My Feedback: (6)

Ok, I am quite a bit happier with my Homey "hot rod 30" now. It's a little embarrassing but I'll share so everyone can learn.

The rings were junk!!!! The piston and cylinder looked so nice with no noticeable wear, so I hopped that little guy up and neglected to actually measure the ring gap! Never forget the basics! (And I don't know how many times I've preached this to other people over the years... oh well.)

Anyway, now it's turning an APC 16 x 8 prop at 9400 rpms, and that's without much run time on the new rings, nor any re-optimizing of the timing, etc. now that the engine is actually sealing and making some pressure! Not bad for my density altitude I think. I used Frank Bowman's rings, and I can't say enough good things about him and his product. He answers questions and e-mails immediately, and I received my rings two days after ordering them. The rings are a notched design that fit over the locating pins and allow for a tighter gap and better sealing. They seem to have seated in with just slightly more than a tank of gas, though I think it will get even better over the next hour or so.

So, here's some numbers:

Homelite 30cc - older design with small transfer ports.
Weight with muffler - 2 lbs. 14 oz. (More cutting/grinding on this one than my Homey 25cc)
Muffler - Stock, square, gutted, with two brass 1/2" i.d. outlets added.
Carb - 11mm Walbro, manifold ported to match, external pulse line.
Ignition - CH Ignitions electronic set at about 26 degrees presently.
Cylinder - Quench or Squish band removed, cylinder to head clearance set at .020"
Port timing - Exhaust 165 degrees, Intake 148 degrees, Transfers 120 degrees (22 degrees blowdown)
Rings - FRANK BOWMAN'S NOW!
RPM - APC 16 x 8 = 9400 (Possibly more with tuning and more run time. Also, with this port timing, a tuned pipe would probably give 800 to 1000 more.)
Test conditions - 4200 feet altitude, temperature 78 degrees, barometric pressure 29.75"

Please also note that while I did modify the transfer port timing, I did not alter the size and I think this would also help. I'll do that on the next one for sure.

Ralph, I know this isn't too much more performance than a G-26, but including the new rings I only have $38.00 in this motor!! (Also a lot of satisfaction in doing it.)

So there you have it....

AV8TOR

av8tor1977

My Feedback: (6)

Hi,

Just had a strange one. My Homelite 30cc started running ratty. Misfiring at all rpms, then running ok, then misfiring again and sometimes quitting completely. I was sure it was ignition by the sound of it. Started the trouble-shooting routine. Different plug, different battery, different switch assembly... no change. Then I thought it must be the ignition unit so I went after that. Let me tell you, if you do an electronic ignition Ultra Lite Stick 120, do yourself a favor and put a hatch on the front. It's a bear doing maintenance through the former below the wing leading edge. So I had to tear out my fuel tank, smoke tank, smoke pump, and everything to get to the ignition unit to change it. I didn't have a spare, so I also had to take apart another plane to steal the ignition. Then, (drum roll here...) NO CHANGE. !!@##%$#@%$##

I really didn't think it could be the Hall effect pick-up sensor, because I figured that would either work or not; not be intermittent in failure. Anyway, now you've guessed it. That's what it was. Now, with a different sensor, it runs better than ever. How strange, and what a bunch of work and hassle to find it. The darn sensor doesn't have two hours running time on it, but it's bad. At this point, still frustrated but glad the plane is fixed!!

Anyway, keep it in mind and I hope it helps someone someday.

P.S. The other day I wrote a new post about my Ultra Lite Stick 120 that is probably interesting to a some of you, but the powers that be moved it to first to "Multi Engine Aircraft" and then to "Tips and Hints" and won't move it back.

AV8TOR

Antique

My Feedback: (4)

Must be something in the air..I have had 2 new sensors go bad in the last two days, same symptoms as yours....Looked at everything else, finally put in a new sensor, problem went away.....

tkg

My Feedback: (1)

Top 10 reasons for hall sensor failure....well 3 or 4 anyway
1. It touched the prop hub/ the magnet rubbed it.
2. Broken wire at sensor.
3. The ignition was triggered with out a proper ground.
4. The sensor failed, normally they either work or not. BUT about 5% of the time they get weird just before they fail

av8tor1977

My Feedback: (6)

Hi,

I guess the problem with mine, and probably Ralph's, must be number 4. I can't see any marks where the magnet might have touched it, the wires look good, etc. Last flight it ran great. Took it out to fly today, and it wouldn't run right. I guess it's one of those "infant mortality" things they talk about in electronics. The one I put on that works fine now has lots of time on it.

How often to you have failures with these tkg?

AV8TOR

tkg

My Feedback: (1)

I have sensors that are 10 years old and still in use. I usually do a #3 to kill one.

Antique

My Feedback: (4)

I took an OLD 4.2 A&M Sachs apart once to convert it..The owner had attached the ground wire to the carb mounting bolt...The spark made a track about 1.8" deep through the phenolic to get to ground...I'd like to buy about 500 of those sensors, it wasn't one of the ones from Digi-Key.....
Same guy said he could see the spark in the gap between the sensor and the magnet when the engine was running....

av8tor1977

My Feedback: (6)

Wow, I can't beat that story. Closest I can come is the GM rotors I've found on car engines that have burned through and gone to ground. I have seen a lot of plugs so carboned up that I couldn't see how the engine could run, and I've seen plugs that looked fine that wouldn't run right, though I imagine we've all seen that.

Take care,
AV8TOR

captinjohn

AV8TOR...where is RCIGN....have not see any of his posts ? Thanks Capt,n

Antique

My Feedback: (4)

read the post just before AV.....Merry Christmas....

tatolazo

Hello Everyone:
I have just receive 10 minutes ago a package...inside.....one of Avtor 1977 pumps...........The only thing is that $99.90 is a little pricey!!!!!.............


Just kidding....he sent me this one for free, I´m sure we will find something interesting for him so i could send him something useful for his Homies or R/C in general.

The Pump looks very solid, just seing it tells you it will work great over the muffler pressure.
I can´t wait to finish my 80" extra, bolt on the Gas engine and smoke all over the sky.

Once I put it on duty will keep you posted.

Thanks a lot AVTOR, you did a great job...(Slimline and TME will be worried by now.)

That is my best Xmas gift, ever!!!


Tato Lazo.

APLANEGUY

Man, seems like the oldest threads are the most interesting. I'm gonna start searching strictly by date of the post I think :-)...

av8tor,
I love the concept of your homespun smoke pump. Seems like a brilliant idea and I have several carbs that will never be carbs again so I'm thinking of hacking one of them up. I'm setting up a Ryobi conversion and I may very well put a homemade smoke system on this one. I'll be using an aluminum muffler from wackerengines.com and never having set an engine up for smoke before I was wondering... First, did your pump work out as well as it seems this very old discussion suggests? Also, did you have to use a tubing coil of any kind inside the muffler or does it work ok with just a straight shot into the muffler once it's hot? My muffler is a welded unit so I won't be able to get inside it to do much fancy work.Just looking for a little input if you have a couple minutes sometime...

Thanks,
Pete