ahicks

My Feedback: (2)

That brings back some memories from when I had the Quadra on mine. There were very definite harmonics coming from that plane at some speeds while in the air! I would hear them and then adjust the throttle a little to avoid them! Mine flew great on either an 18x8 or a 20x6. FWIW

Brian Smith

My Feedback: (117)

I have 4 G38s. Love those Zenoah motors. They are easy to start, run good, last forever... I'm not a 3D guy so it is a perfect match for the Sportster. I use 18x8s and 18x10 props. 20x6 is a good choice as well. Brian

azalner

My Feedback: (8)

Brian

Any balancing issues with the G38? Where did you put your batteries & tank?

Al

Muttdog

Al, Why would you be worried about where to put the tank? Why should that matter for balance. From my very limited experience all of my models are balanced with an empty tank. I would think that the ideal placement would be over the CG or as close to it as possible so as not to change the balance in flight. I realize there is some weight in the empty tank but what reason would you have to place the tank anywhere but closest to the CGas possible? I always thought that was one of the big advantages of the gassers in that they can pump the fuel out of the tank from anywhere instead of the glow engines that must have as short a run as possible.

Brian Smith

My Feedback: (117)

The tank is over the CG. The radio equipment is "all" behind the tank. I have Hi-Tec MG servos in the tail. I did not take an exact measurement on the CG. It will spin nicely so I know it is not extremely nose heavy.. I can send picture to an email address. I don't know how to load them here. my email is. ivabrian _at_ gmail.com Brian

ahicks

My Feedback: (2)

Keep the engine as close to the firewall as you can, batteries go in the tail, everything else as far back as you can for a mag G38/Q42. I had some lead under the horizontal stabilizer even with that.

Muttdog

Does anyone have balance info with the DLE30? I think the Zenoah installations are not the same due to the weight. The DLE is much closer in weight to the OS FX 1.60 Glow engine. The zenoahs are carrying the flywheel and coil right there in the front so that adds a lot of weight. My DLE setup will actually be lighter as Isaved almost 3 ounces in the motor mount setup over the stock glow engine/mount configuration. I sure would hate to have to add that back in lead. I was test fitting the engine in the firewall yesterday and I see what others have said about the pitts muffler being extremely close to the cowl. Is it OK to shift the engine away from the centerline of the firewall to make clearance for this. If not how close will it actually be? I have not drilled the holes yet but it sure does look close. The drive washer is exactly 7 1/4" away from the firewall and I am using a bisson pitts muffler. If there is a little air gap then Ican use some stick on heat shield that I use in the motorcycle industry but it does require at least a small air gap plus the blanket is about 1/8" thick. Ihope to post my LGpics tomorrow

azalner

My Feedback: (8)

Muttdog

I am also using a DLE30. See my previous post regarding battery placement. Since the DLE is roughly 1 lb. lighter than the g38 we should not have to worry about moving the batteries and weight to the tail. At least I hope so. I believe that someone else has used a SAP180 on this plane so the weight distribution should be roughly the same. Maybe someone else can chime in on this.

I'm not sure what you mean about the Pitts muffler being too close to the cowl. Are you refering to the barrel of the muffler touching the sides of the cowl? I'm on the road for the next couple of days, but I'll check it when I get back.

Al

Muttdog

Yes Al I am referring to the side of the muffler and it is VERY close to the side of the cowl. I remember seeing a post where someone said there were some burn marks on the cowl. This thread is sooooo long that it is impossible to find anything but I remember seeing it somewhere.

bhorton

My Feedback: (26)

Muttdog, I would not shift the engine away from the centerline of the firewall. Doing that may cause the plane to turn to the left or right. That would require rudder trim to correct and the amount of trim might vary depending on the throttle setting. Years ago I shifted the engine over on a .40 size plane because of the muffler or needle valve and it looked like it was crabbing slightly to one side all the time. I am building a Super Sportster with a DLE 30 but I am using a J'Tec muffler. I have not mounted the cowl yet but I don't think there will be a problem with the muffler being too close to the cowl on my plane. I remember the pic of the scorched paint on the cowl. I think someone glued a piece of thin aluminum on the inside of the cowl to prevent scorching the cowl. That is what I will try if the muffler is too close to the cowl on my plane.

Muttdog

Bhorton, I looked at the J-tec and they both look close. I have some foil backed heat lining that is self adhesive. We use it in the Motorcycle industry to keep mufflers from melting plastic fenders and it does a great job. If anyone is interested in it, I can sell it to you direct or I can provide you with a part number to take to your local dealer as it's not very expensive. Your post is exactly what I was looking for and what I was expecting to hear. I was very nervous about shifting the engine over and your experience confirms that. I will definitely center the engine and deal with the muffler as it comes up. Right now it is too hard to tell but it looks very close

Joystick TX

I'm using the SAP-180 on my plane which should be pretty close to the weight of the DLE-30.. When I first gotmy SAPI thought I would need to add nose weight because it was so light. My battery packsare right on the CG, 6" behind the wing. They fit perfectly between the rear of the 16 oz fuel tank and in front of the fuselage bulkhead.

ahicks

My Feedback: (2)

I found there was over 2lbs difference Quadra vs. Syssa 30 (16.5 vs. just over 14). My battereies went from in the tail to against the firewall. It may have something to do with the fact I'm running the standard gear though? Also, I prefer to run the CG back a bit further than many do. I'm an inch or more to the rear of suggested. Been there so long I've forgotten exactly where I ended up. It's back far enough where the plane slows down VERY quickly when you remove the power!

Note: the weights listed are with the plane balanced where I like to run it. There was a lot of lead removed from the tail in that conversion as well?

Muttdog

I finally got my landing gear about 95% finished and wanted to share some pics. Iwill try to attach the pics but I have never done that before so if it doesn't work, I will try again later. So far everything is coming together very well. The hole was cut to about 3/4 for the main block that the gear attaches to and then another 1/8" so that the gear would sit flush with the bottom of the fuse. I took ideas from others here and formulated some of my own. The parts were weighed when everything was cut and fitted. The total before cutting the holes was about 390 grams. I was able to trim about 60 grams or so after lightening. The stock gear is about 250 when all of the plastic clamps and screws that attach it are calculated in. It certainly could have been made lighter but we are talking 3-4 ounces here and Isaved a lot of weight in the engine mount so in the end Ithink it evens out. All that is left is to go over all the joints with Epoxy and then glue in the main block, add some monokote and Ican put this part to bed. I also drilled the holes for the motor mount and was very diappointed in the muffler as it sticks out the side so it looks like I will have to research a different one. I thought about spinning the cylinder and piston 180 degrees as there is more room on the other side but Iam not 100% sure it can be done with the dle (depends on how the transfer ports line up to the cases) but if I did that, I would have to cut and weld the muffler. That is a project I would rather avoid if possible so Iguess the J'tec may be the way to go. I hope the pics upload. MD

Brian Smith

My Feedback: (117)

Looks good MD.. Brian

JoeMamma

Nice job dog !

After going through this entire thread, it’s nice to see all of the different engineering and structural ideas being used.

Plus, it helps to keep the brain active.

Joe M.

Muttdog

Well it looks like I screwed up on the muffler purchase. My Bisson is 1" wide plus a 1/4" flange and I am about 1/4" too wide now. Kevin at J'Tec sent the specs for their pipe and it is 3/4" with no flange so I really need that 1/2" clearance to call it a day. I am going to post this in the engine forum but if anyone is interested in a trade let me know. The Bisson is constructed very well and it has a smoke port already built in. It is brand new never used.

Muttdog

Iwanted to post some pics of my engine mount setup. I have the individual pieces laid out in the first pic along with a complete assembly ready for installation. Starting from left to right, the first part is the stock mount that the GSScame with for the Fuji engine. I simply milled it down to 1" to get the proper spacing. The next part is a plastic bushing that came from a set of Robart wheels that I never used. It is only to keep the spacer centered on the shaft as the hole pre drilled through it is bigger then the 5mm thread size of the DLE mounts. The stud was nothing but a long 5mm screw that I had laying around. It was red loctited into the DLE mount and then I cut the head off and filed the threads smooth. Everything else is standard DLE stuff. The last pic is the engine mounted in the airframe. One advantage that I see to this method is the room behind the carb to run linkages, fuel lines etc. Also, I feel this is the lightest setup possible and certainly one of the easiest (and cheapest)

SkyPilot101

Muttdog, any way you could post some pic's of your Bission mounted, Currious as to the interfearance problem that you have with this exhaust

azalner

My Feedback: (8)

I am using a J'tec muffler and I have 1/4" clearance from the side of the barrel to the cowl. It looks as if the mounting bolts are hitting the cowl, but when I put the cowl on, there is enough flex in the cowl so the bolt heads dont touch.

Al

Muttdog

skypilot, I am at work and don't have the pics now but if you look at Al's pics where he is showing his J'tec setup you can understand my issue. In the pic where he is saying it looks like the bolt will stick out, my muffler body IS sticking out the side so in essence the side of the cowl would rub the side of the exhaust. The Bisson does not have the bolt issue as they actually go down into the body of the muffler but there is a 1/4" flange that pushes it out, plus the body is 1 inch wide whereas the J'tec is 3/4". Al, if you end up having issues with the bolts, you could switch to phillips head screws as that would provide about 1/8 inch more clearance

azalner

My Feedback: (8)

Thanks for the tip MD.

By the way your engine mount arrangement is pretty spiffy - lotsa room to work in. I had to rout huge holes in my wooden specer block to clear the linkages.

AZ

SkyPilot101

Muttdog, Thankyou for the heads-up on the Bisson, I allmost ordered one a few days ago for the GSS, I'm glad that I held off! Sorry to hear of your headach though, hope that you can recover the cost of the mistake.

Muttdog

It shouldn't be a big deal. I own a motorcycle parts and accessories shop and my hobby shop ownerrides so we exchange discounts back and forth. I have it up for sale on Ebay now for $65 and Iposted something in the RCU engine forums. My hobby shop guy also told me he will help me sell it ifI can't. Live and learn I guess. Ifinished covering the landing gear so that job is now 100% done. I am not very good at covering and this job definitely proves that. There were a few compound curves that gave mesome fits. This is also the first time I have worked with monokote and I have to say it seemed harder to use then some of the other brands Ihave tried in the past. It's close enough and Idoubt too many people will notice (although it still bothers me). There were a lot of wrinkles in the airframe that I worked out but not as easily as other planes with different covering on them. Now starts the standard build.......

Brian Smith

My Feedback: (117)

When I purchased my DLE 20s from Tower they offered a regular wrap around muffler and the same in a compact. I think they are J'tec. I bought both versions. I supposed you have checked on all J'tec? I did not read thru the postings you made about it and gotta run this morn. Brian