Frank M Klenk

Hi Fellas:
I have a 1/2A Dallaire that I will fly in some contests this summer and I was wondering what setups are other guys using. So, I did some bench tests today (it's still not nice enough to fly here yet) and was pretty pleased with run times. I got almost 4 minutes with 5cc, swinging a 8x5 woody. Fuel was 15%. So what are you guys using for props, fuel and glow heads, and how do your times compare?? Let's hear from you's. Thanks.

Frank

Strat2003

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Hand carved undercambered (like a rubber prop) 8X6, 8 head gaskets, 15% castor/synthetic fuel.
4500 rpm for an average of 6:45, times vary from 6:00 to as much as 8:20. REALY, lol.
Six minutes on this setup will get you uncomfortably high. 8:20 will have you trimming the plane down for at least the last two minutes and it's not fun anymore.
There's an article somewhere in this forum (do a search) that tells you how to blueprint a Texaco, basically stuff to make sure the sealing surfaces seal and everything runs freely. It's well worth the time it takes.

Strat2003

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Here's a pic of one of the props.

And yes, 8 gaskets is a lot, it's just about all you can use and still have the head screw in....but it works for me!

BMatthews

Geez, I was going to say that 4 minutes is great but I'm astounded at the 6:45 and more. I've been using about 3 or 4 head gaskets and 5% fuel with a 9x6 cut down to 8x6 to get the wider blades and then thinned and undercambered much like Strat is saying. With this setup I've been getting from 4 to 4:30 pretty consistently with the odd run of 5:00 when the air density is thinner on hot days.

I'm going to have to get me some more gaskets and some 15% and try that.

Frank M Klenk

Thanks for the replies guys. That's pretty amazing Strat, 6 to 8 minutes! Let's see that puts me in ... last place LOL! Do you carve the props yourself? That's something I've never tried. I got looking at the APC props I use on my aerobatic planes and they have quite a unique shape to them. Thin at the tips and thicker towards the center with an undercamber. I wonder how they would work?? I'll have to go the hobby shop and see what he has in stock. I use the 4 fin glow head for extra cooling. My fuel is 15% cool power heli blend, straight synthetic, the heli blend has more oil, 20% total I believe. I'll see if I can find the blueprint info too. Thanks guys.

Frank

Jim Thomerson

Out of curiosity, would it be legal to run diesel fuel under the Texaco rules? I'm not talking running a diesel conversion head, but rather just running diesel fuel in your glow engine. I think if you kept the glow plug connected (and played with shims) until the engine warmed up, it would probably keep running. If not, maybe you could carry a flight pack to keep the plug hot.

Reason I wonder about this, the 1951 Aeromodeller Annual has a bunch of fuel efficiency tests of various 15 size engines. The most efficient were two glow engines running on diesel fuel, one needed the glow plug kept hot. I've run a K&B 4011 on Davis 1/2A diesel fuel with good results, same RPM as glow on an 11 x 5 APC, but with the Super Tigre needle turned in 1 1/2 turns. Actually tried two different engines. One ran fine after about 20 seconds on the glowplug. The other needed the glow plug heated up to run well.

Jim

BMatthews

If it's NOT illegal it soon would be if you entered one of those arrangements. The SAM guys already went from the larger 8cc tank back to the 5cc tank to reduce the engine run and also put the restriction on the prop diameter at 8 inches max. Prior to that folks were using up to 10 inch props and getting about a 10 minute run on the engines so the 15 minute max was pretty much a done deal as long as you could keep it out of any bad sink. I suspect that anything that would further bump up the engine run would be legislated out pretty durn quickly.

Strat2003

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I'm pretty sure the rulebook requires methanol-based fuels. I know gasoline is prohibited as an additive. My ruleook is in the bedroom with my sleeping wife, so confirmation on that will have to wait, lol.
Yes, I carve the props myself. If you're interested I can post the dimensions to lay out the block....it's really kinda fun, takes about an evening to do one. Some guys have had success with the APCs, and others like the old white Tornados, and I've heard that some are experimenting with electric props, too. They load the engine down enough that the prop can take it.

I usually use the tall head, but sometimes the regular head works well in cooler conditions. If the engine slows down when you remove the starting batterey, or the setting gets weird when you remove the heater, try the regular head. Also, if you're brave, you can use a straight pin and pull the coil down into the combustion chamber a little bit (about one coil's worth) to make the plug hotter under those conditions.

It's possible to run on low-oil fuel, too, to get more burnable fuel in the tank. I've run 10%nitro/10% synthetic oil without any aparent damage but it makes me nervous to do it and I haven't noticed a huge increase in runtimes anyway.

1/2 A Texaco is one of the most challenging and frustrating events in SAM, but one of the most enjoyable when you get it right. Good luck!

BMatthews

In my case I started with Zinger props. I keep the lower edges as pitch references and then add undercamber (almost 1/32 at the widest point), thin and reshape the hub and thin the blades so the thickness is about 1/16 at the widest part and 1/32 at the tips. I kept the blades about 1/8 thick near the hub.

Frank M Klenk

So my goal tonight was to increase my run times, as I stated before I was getting 4 minutes. I tried several different props from my trusty bucket, no luck. Then I pulled the prop off my indoor electric and gave it a try. It's an APC electric slow fly. With it I had 4 runs averaging 6 min 10 sec, 4000 RPM and 6 head shims. Will probably need more shims on a hot day. Has anyone measured head temp to establish what is ideal? Now, I wonder if it will have enough thrust to pull the little runt up. I guess a test flight will tell. What are the all up weights of your planes? Mine is a 52 inch wing. Weight is 17.3 oz (I think it's heavy).

Strat2003

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Now yer talkin' !
Regarding head temps...one of the guys in our club did some work on that and thought he'd figured it out, but like everything else in Texaco, you only figure it out for a little while, lol. It seems that temperatures change with altitude, and not always at the same rate, so what was OK on the ground wasn't always right in the air.

The wing loading rule for 1/2A Texaco is 8 oz./sq ft. 288 sq in. is a prety common size, so that wing loading comes out to 16 oz. If your plane is at the minimum loading that setup will take it up fine. Wing loading matters a lot. If you're under, maxes are pretty easy and if you're over they're very tough. It's pretty easy to build underweight if you use small servos and batteries, so don't be decieved if you're flying real well and underweight. I'm not sure, but 17.3 might be a little heavy for a Dallaire. You might be able to go to a smaller batterey to save an ounce or so.

Good Luck!

Frank M Klenk

My Dallaire is a 52" wing. That works out to 341 sq in. At an 8 ounce min loading that's a minimum weight of 18.9 oz. I think I figured that out right? So, actually I'm underweight? Is there a penalty for underweight or do I have to add lead (ughh!)? Just a question on head temps ... is it fair to say if the plug burns out it's too hot, and if it lasts it's ok?
The 049 in my glider runs a small prop and it's screamin! When it shuts off it's HOT! can't touch it. When my Texaco engine shuts off why I can handle the engine without getting burned. Just a thought.

Frank

Strat2003

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Yep, you're underweight, so to be legal you need to add ugly lead!
I syould point out that I'm talking about SAM rules...if you're flying in a club contest they may be different. Something I've done with new airplanes is to fly them light the first couple of times to see if the balance is right and then add my ballast in a location that moves the CG to where I want it.

If your engine is cool enough to grab the head you can probably go a little leaner on your setting, but that will vary from day to day. In my experience, the "right" setting is pretty hard on glow heads. After a few flights the element gets a sort of bumpy, frosty appearance (but it still works) and then it starts to distort. The prudent thing would be to go just a tad richer, but, as I've said before, getting the setting right is tricky and often you don't know it was right or wrong until about 5 minutes into the flight, lol!

Strat2003

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Frank, have you had a chance to fly that Dallaire with the electric prop and the extra shims?

Frank M Klenk

Hi Strat
I flew it a couple weekends ago. It was pretty windy but I was anxious to find out. When I launched I realized it was tail heavy ... Not like I can shut it off and land right. So the wind played with the plane and I ended up with a 8 minute flight. This weekend is supposed to be nice so I'll be at the field. I've got some different pitch props to try. The prop I used was an APC 8x6 electric slow fly. Did I mention that already? I can see a lot of tuning will be required. The extra couple of ounces the Dallaire weighs over your setup sure means a lot to the 049. Wish me luck and I'll let you know how the weekend goes.

Frank

Frank M Klenk

I flew on saturday and my best times were 10 minutes. The weather was cool so I had 4 head shims. Wind was about 12 mph. The plane has the glide of a Mack truck and I don't like the way it launches or lands, it's a hand full. Looking to make improvements, I spent saturday night going over my setup. First I checked my building plans. I had the wing back too far. It's in the right spot now. The plane weighed 20.3 ounces (fatso). I opened up an access hole to get at the space behind the firewall and installed a square battery pack in, it fits perfect. I rebalanced and it comes in at 19.1 oz. Contest weight will be 18.9. Just a tad nose heavy now. The plans show the wing with the leading edge raised 2 degrees (negative incidence) and 2 degrees of engine downthrust. Would you guys say this setup is right? I would like to leave the wing as is and set the engine at 0 incidence. Maybe this will help my launches. Any thoughts appreciated. Have you guys been out practising?

Frank

Strat2003

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Ten minutes is a pretty good time under those conditions. 1/2As don't fly very fast, so you were probably spending most of your time just keeping it in the area rather than hunting for lift, which was probably somewhat scarce on a cool day anyway. Also, in my experience, these little guys don't ever glide as well as larger old timers or gliders, so if that's what you've been flying you may be expecting too much.
I like to set up the glide by fiddling with balance/incidence, then trim the climb with downthrust. Get the glide right with the elevator in neutral, then adjust the thrust to get a good climb without retrimming the elevator. It's a lot easier if you can count on the airplane gliding right when the engine quits at altitude where you can't really see what it's doing. You may also want to mess with some side thrust so you don't need to re trim the rudder, although it's easier to see if it's turning than to judge the glide angle when it's real high.

Good Luck!

Frank M Klenk

Since we have been discussing plane / engine setups I thought I would give you guys an update as to our Canadian Nationals SAM event which ran August 10th. First off we all had a lot of fun (very important). Secondly there was a pretty good turn out of pilots. Weather was inclement, thermals were scarce, had a couple showers and it was windy. The event was quite competetive. So, as soon as it quit raining we immediately flew 1/2A before the wind got back up. Some good times were logged. For everyone's perusal here is the link from our South West Zone with names and times etc ... http://www.swzone-maac.com/index.htm ... then click on Nationals.
So, how about you guys, what events did you go to and how did you fair??

Frank Klenk

Strat2003

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Frank,
Congratulations on doing so well in your Texaco events!

I've flown in two 1/2A contests so far this summer, got a first with a 23 minute total in one (a max and an 8 minute flight) and a second in the other. The second came as a result of being one of the two guys stupid enough to try flying in 15 to 25 mph winds....we drove three hours to get to the contest and I wasn't about to go home without flying! I folded the wing diving the airplane back to the field. All the parts DID land on the runway, so it was an official flight, lol! The replacement airplane has a much stronger wing structure.

What kind of setups have you settled on? I've mostly used a Master Airscrew 8 X 4 with a bunch of head gaskets to give me runs in the 4:00 to 4:15 range. The real long runs with the wide blade undercambered props just make me nervous because you get so high under power. That prop gives a little higher airspeed and lets you fly in a little more wind, too. Sometimes it's more fun to keep it in sight, lol!

Frank M Klenk

Thanks Strat. I was pleased with my results too! Congrats on your results in 1/2A! By far 1/2A is the most challenging. Sorry to hear about the folded wing though. I settled on an APC slow fly electric prop with 7 head shims for 1/2A. But we all got our butt kicked by Richard Barlow. He was using what looked like a Mills repro, and it ran sweet. You see, Canadian rules differ from yours. In 1/2A we can use any engine up to .050. It surprised me when I saw the diesel, but I assumed it had to be glow ... Needless to say I am now researching a suitable diesel replacement. I have an original Mills 045. So, I ran it yesterday to break it in. Runs nice. Also considering a PAW. I believe Eric sells a competition Texaco 049 and 030. The Texaco setup for my big Dallaire ran mint. A 7 pound plane and the PAW 35 on 28 cc of fuel pulled it up to a spec. My A Texaco also has a PAW and it performed well, but I need to lighten the plane up a bit more. Going to try some mini servos. The Clipper in 90 second was a flying brick. Originally the plane had a 60 ignition on it. With my Torp 29 up front I had to add lead (embarassed to say how much), so I need to lighten up the tail group. That will be a winter project. I have in mind to use carbon fiber for the push rods, the elevator link that actuates both elevator halves and the rudder bell crank in the fuse. If I can save 1 ounce back there that's a lot up front. Bmatthews, did you make any events this summer? I'm not sure if the local old timers club called "SWOOT" is having any events this fall. I'm hoping so. Any other guys on here attend events this summer?? Let's hear from ya.

Regards ... Frank Klenk

Strat2003

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Frank, I've used Sullivan Kevlar pull cables on the rudder a couple of times to save some weight in the tail and had good results with them. I've also used a carbon fiber rod to actuate the elevator with the linkage hidden in the sub-fin of a Bomber. I have a Kerswap that I fly in Foxacoy with pull cables actuating a hidden horn, but can't find room to conceal the elevator linkage in there, so I settled for a small brass horn soldered to the joiner wire. It's held up fine and is pretty inconspicuous.

I've fooled around with one of those slow-flyer props, too, but couldn't quite find the right setup. It losded the engine down more than my hand-carved ones, so it shows lots of potential if I can just get it dialed in.
I wish they'd allow any .049 here, I think more guys would try the event if they didn't have to deal with the frustration of Cox engines! I can see how it would quickly become an all-deisel event, though. I have a friend in New Zealand who's flying A Texaco with an old diesel and he seems to like it very well, but he's familliar with them since they've been flying lots of deisels there for years.

Good luck with any future contests!

DSLarkin

Frank,

We've had the freedom to use diesels in 1/2 A Texaco in Canada for a couple of years now. There are quite a few options but any Mills .75 should work under most conditions. An Irvine Mills Mk I or Mk II would probably be the best bet, they are more consistent than the original engines. I did tests a few years back on a whole bunch of 1/2A diesels, and Roy Bourke has also done some. McCoy 049s were thirsty. PAW has or has had a variety of different 049s. I didn't realise that Eric had a Texaco version, but I haven't been in touch with him lately. But there was a Classic 80 in the older style PAW which gave long engine runs (It is significantly de-tuned). Alternatively you can use the standard PAW 80 or 049 to get a fast climb and punch the model up in conditions where there is sink at low level. The best engine I found for 1/2A Texaco was one of my FROG 80s. But I have three of them and only one was really good.

Before diesels were allowed, I used the Cox Texaco with the multi-fin head and zero nitro fuel with about 10% Castrol 747 oil and a dash of castor. This gave long, consistent runs. But on occasions at Gananocque my Buzzard Bombshell would not punch up through the turbulence from the line of trees.

Burning out of Cox glow heads can be avoided by a simple precaution. Do not use a glow driver. Use a NiCad. I used a NiStarter with the Headlock 1/2A glow plug attachment.

Dave Larkin
MAAC 3577L

Frank Schwartz

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Odd to find this link. After not flying my Dallaire Texaco for two years. I put fresh batteries in it and flew it yesterday afternoon late (9/11/05) ..No thermals but I did notice I am going to have to put some serious down thrust in the engine as the plane tries to climb too steeply under power and I have to use down trim..then when the engine quits, I have to up trim things. Using the Cox 7 inch prop, but may try bigger, and used Cox fuel...I am assuming that although some of you are using other fuels you may have too much oil??
Getting ready for the second flight I got the underside of my right forearm too close to the prop and got a nice cut...8 stitches...I MUST be more careful. Incidentally, my Dallaire has Hitec mini servos..and a Hitec two channel glider receiver...and my plane is silked and doped...love that old stuff.
Still, I will fly the plane some more...maybe I should get some wood 8 inch props and thin them out??? Also I haven't timed the engine run, but will do so soon..using the many finned glo plug...and the standard, not smaller tank... I've had 45 minute flights on this plane when there is some lift..

Frank M Klenk

Hi Dave
When I talked to Roy at the NATS he mentioned he had done some testing years ago and the Mills was very frugal on fuel. I do have a new Mills, I've bench run it, and it runs sweet. That being said, I went and bought a PAW 03 from Eric. Actually it just arrived today. Nice looking with the red head and spinner nut. I'm just waiting for the back plate mount as he was out. I can't wait to try it!

Hi Frank
Glad to hear you got the Dallaire out and flying. Yep, they need engine down thrust. Alternative if you have a computer radio that has flight modes, is to use 1 mode for launch and 1 for landings, trims are always saved. For fuel I used Cool Power 10%. The engine runs cool and is well lubricated. Sorry to hear you got hurt, hope your arm heals well. I find with the bigger props, I have to set the engine leaner on the ground, because it goes rich as it climbs. Maybe cooler fall weather will change this too. What's your plane weigh?

Regards ... Frank Klenk

boberos

Hi All,

Looking for plans for a 1/2A Texaco Dallaire Sportster.
I understand it is a good design for 1/2A Texaco.

Thanks,
Bob