dblades

My Feedback: (28)

Need help with measurements. ZDZ 80 appears to have same vertical mount spacing as the ZENOAH GT-80 (59 mm). Seems that if you draw horizontal lines thru the exiting holes in firewall you just need to position the standoffs some measurement on those lines. If so, what is measurement or how did you position? Thanks in advance. Dennis

Forgues Research

My Feedback: (7)

Dennis,
I have been making a lot of standoff's for this very combination.
2 7/16" is the lenght that everyone seems to favor. I don't own this combination but with over two dozen orders for that combination should prove to be the right one.

dblades

My Feedback: (28)

Hi Roger,

Got the measurement of the length of standoffs from you and ordered a set from you yesterday. What I am trying to determine is the correct mounting position on the firewall.

Thanks
Dennis

Forgues Research

My Feedback: (7)

Sorry about that Dennis, didn't recognize you.
Your standoff's and fuel caps will be shipped tomorow.

bpryor

My Feedback: (45)

Hi Dennis,

As long as you're using the original engine mount position, which you are, all you should have to do it measure from the existing centerpoint of the original mounting holes for the GT-80 and then center the ZDZ mounting holes on that center point. It should come out perfectly. I just made a template of my ZDZ80 mounting holes, centered it on the center point and marked the holes. Done.

augiep38

My Feedback: (3)

The ZDZ mounting holes ar 5/8" narrower than the holes in the existing motorbox. Move 5/16" in on each side and it will line up perfectly.

Todd

bpryor

My Feedback: (45)

Todd's right if you're mounting the engine inverted, which I'm not, so that wouldn't have worked for me, but his way is the easiest if you're mounting inverted.

augiep38

My Feedback: (3)

Bill is right. I forgot to mention that my engine is mounted inverted. I am using the Supersonic pitts muffler. I had the 80mm can and header setup from RCS.

I bought this before I realized that the wing tube was in the way of mounting the can internally. I ended up returning the can and getting the pitts muffler as I did not want to mess with that large can hanging under the fuse.

Todd

Mike Wiz

My Feedback: (2)

I used Roger's standoffs on mine too. For the alignment I did the following;

Filled in the holes on the firewall with JB Weld

Stood the plane up on it's tail and strapped it to my workbench.

Bolted the standoffs to the engine.

Went in the kitchen and got a chair to stand on.

Set the engine on the firewall in it's approximate location.

Mounted the cowl.

Put the spinner on.

Slid the engine around untill the spinner lined up with the cowl.

Put a little CA on the standoffs so they wouldn't slide while I removed the spinner and cowl.

Marked the standoff position with a pencil.

Removed the engine and drilled the holes

Removed the silly aluminum "L" brackets and pinned the cowl with 1/8" dowel. This was necessary because I wanted to use fender washers on the inside of the firewall and they hit the brackets.

Bolted it all back up and Viola! Everything fits like nicely.

BTW, I mounted the 80mm can inside the fuse and made a pipe tunnel. I had to bend the header a little and use a flexible coupling. The whole thing was a giant hassle. If I had it to do over I'd get the wrap around pitts muffler for inverted engine installation.

Wiz

bpryor

My Feedback: (45)

Hi Wiz,

That sounds like a great way to get the engine mounting perfect, but I'm going to do the old measure and drill as I don't have the time or patience to do all you did.

Good info on the fender washers and the aluminum brackets. I bought fender washers to put on too but hadn't tried the fit yet. I'll probably do the same thing you did.

Man, I never would have thought there was room for the can ( especially the big one) and fuel tank inside the fuse, though I was going to take a shot at it.

Thanks for the good info.

Mike Wiz

My Feedback: (2)

Bill,

The whole opperation of locating the engine on the firewall took maybe a half hour. Of course the JB weld took a day to harden, but you'll probably be filling in those holes anyway.....that is unless you don't mind having holes that are way too big for their screws.

I'll have to take some photos of the Cap and post them here for people to see. It's tight, but not as tight as things are in my Sp 400 pylon racer.

Wiz

bpryor

My Feedback: (45)

Wiz,

I just can't visualize fitting the engine the way you did it... You did all that while standing on a chair....I can't imagine. Did you take video of it by any chance? Maybe "Viola" helped you?

I just stuck my 65mm can into the fuse and I can't easily see how it will work. Where did you put the fuel tank, under the can? Did you have to extend the exhaust stack to exit the fuse? Obviously pictures would be nice.

You're right on the mounting holes. There's no way to center it in the inverted position without overlapping the holes, so they need to be filled. I was going to plug them with wood, but the JB weld sounds easier to me.

Mike Wiz

My Feedback: (2)

The only video I have is in my mind. Actually, it was someone here on RCU....or it might have been the SA mailing list that described the process to me. It's really easy. Just set it (the engine w/standoffs) up there on the firewall, mount the cowl and spinner and slide it around till you like the alignment. Then fix the position with a tack joint or two of ca. After that, remove the cowl and spinner and mark the location on the firewall with a pencil. After that you can take the whole mess down and drill it. It was really easy once I got Viola to hold the chair so I ddn't fall off.

BTW, I strapped the fuse to the side of my bench with a bungee so my hands were free to work.

My digital camera just went to the Buick Open with my father, so it'll be a day or two before I can snap some pictures of the pipe installation and fuel tank. The tank is mounted on it's side on the right hand side of the pipe tunnel. It's not ideal, but it's not bad.

Wiz

bpryor

My Feedback: (45)

Wiz,

>>BTW, I strapped the fuse to the side of my bench with a bungee so my hands were free to work.

That was the part I was missing. I really thought Viola must have been holding the plane while you worked on it.

If you could get pictures that would be great. I doubt I'll be getting around to this for a few days anyway.

Thanks again for the info.

Diablo-RCU

My Feedback: (1)

Geez, you guys make it sound so hard.
I just drew pencil lines (horizontal and vertical through the stock holes. Measured the distance between lines and wrote the number down. Measured the distance between the holes on the engine backplate. Did the math and divided by 2. Drew another set of vertical and horizontal lines exactly parallel with the originals and offset by the distance calculated above. Where they intersect is where you drill the new holes.

To make it more interesting, I hung the tail of the plane from the ceiling and laid on the floor on my back to do all the measurements........otherwise it would have been too easy.

bpryor

My Feedback: (45)

Hi Diablo,

Yep that's how I suggested doing it and that's exactly how I did it last night...and it worked out perfectly.....I didn't do the tail hanging thing either.

FYI, I finally made up my mind and mounted the engine sideways. It worked out perfectly, though the plug cap will stick out about 3/8", but that is a much smaller hole than mounting it any other way....but of course, the only way you can mount it in this direction is if you have a muffler to match, so this mounting commits me to the canister setup with custom header. I looked at it carefully last night and there is room to mount the can in the fuse as Wiz did, but for simplicity's sake I'm going to mount mine like Dick Hanson did, under the plane in a channel. I'll take pictures as I get stuff done on it. I removed the aluminum angle pieces too, and I'm going to pin the firewall and also add Kevlar cloth and resin on the corners as per the DP Extra firewall I redid. I also plan to put many screws in the top cover of the engine box to use it as a structual member as mounting the engine the way I did placed the top mounting holes within a 1/4" of the top of the firewall, and along with enlarging the hole in the firewall for airflow to the carb, the firewall flexes easily at the top now.

BTW, I think someone mentioned that one of the distances between the stock mounting holes was the same as the ZDZ and it is not. The stock holes are 59mm, but the ZDZ is 60mm, though this is moot since no matter which way you mount the engine, the holes won't line up anyway.

Mike Wiz

My Feedback: (2)

I've mounted many an engine using that method and also just using the stock firewall hole location. Ya know what.....the spinner never fit the cowl very well. Sure it worked, but it was always off more than I liked from a cosmetic stand point.....maybe it was just me???

Wiz

P.S. My digital camera is back, so I can get some pictures tonight.

bpryor

My Feedback: (45)

Hi Wiz,

You're absolutey right that your method is more accurate, as I think I mentioned before, I'm just too lazy. Your method eliminates any errors from variations in cowl fit and stock hole alignment, which I guarantee there is sure to be, even in the best ARF. In fact my cowl doesn't fit very well on mine, but my aligment ended up close enough for me, though not perfect like it would have been with your method.

I'm looking forward to the pictures. Thanks.

Giant Scale

Mike Wiz,
Your method sounds like it will work very well for my situation. I need to mount an engine in my 50% CAP 232 and there are no reference lines on the plans. Assuming I get the cowl installed properly your method will ensure a properly aligned engine. When you mounted your engines was the right thrust built into the engine box or the standoffs? If the engine is not centered in the cowl opening will the plane fly properly?? Typically the models thrust line passes through the center of the cowl as you deviate from this line will the planes performance suffer? Does anyone have an answer to this.

JoeEagle

My Feedback: (26)

Hi Guys.

I'm just starting on my Cap, with ZDZ. I made a drawing in a cad program with the mounting holes, alignment crosshairs, and a area for the carb depicted. i then just printed it out on transparency media on my ink jet printer. then i just use the factory crosshairs to line up my template and mark where the mounting holes are thru the transparency into the wood and remove transparency and drill.

my question is, since i havent really looked at the firewall is, if i mount inverted and use a pitts muffler (or one of those cool greg jesco mufflers-hey, where did he go anyway?), is everyone saying that the stock firewall has holes in it for the gt-80?? and they are too close to utilize or drill outside of??

isnt there a firewall adaptor for the g-62 included that bolts to the main firewall that is not drilled? could you use that as the firewall to mount to? hmmm, maybe not cause the bolts still have to go thru the original.

my experience with jb weld was not great, i tried to use it to hold a pressure fitting into a saito 180 muffler (cleaned everything with alcohol and acetone) and it came loose after 2 flights.

if people are not mounting inverted, are they using a cannister for other mounting positions???

help!!

cheers

joe

bpryor

My Feedback: (45)

Hi Joe,

I'm glad you're doing a Cap/ZDZ too. If you mount the engine inverted the new holes you have to drill intersect the GT-80 holes(BTW, I think it is really presumptuous and absurd they pre-drill the firewall for a specific engine. I doubt 10% of the people that bought this plane use the GT-80...thanks H9 marketing! NOT, bad decision! ). Your idea on using the supplied G-62 mount will not work since it uses the GT-80 mounting holes to bolt onto. You really just need to either fill the existing holes(just drill out for closest wood dowel size and epoxy in plugs, if you're not happy with the JB Weld solution), or glue on a new plywood plate on back of the existing firewall...but if you do this you should still fill the holes, it just won't be as critical on how you do it. Some people are gluing the extra plate on anyway for strength.

On your question on engines not mounted inverted, such as mine, I don't see that you have any choice but to use a canister system, since to the best of my knowledge no one makes an in cowl muffler for the ZDZ for other than inverted installations.

Buzzard Dave

Hi all, i did the same thing that diablo did [except i did it suspended on a trapeze wearing nothing - above a pit of alligators - just to make it interesting].

just kidding (i was wearing clothes).


re: the holes. i epoxied an extra 1" strip of 1/4" ply the height of the firewall over the old and new holes. it gave something good to drill those holes into since some of them were so close to the existing holes.


David

hotdog

My Feedback: (14)

do you hav any pix of viola

JoeEagle

My Feedback: (26)

Bill P,

I decided to bite the bullet and buy a DA 100 for the cap. I always wanted a DA, so now, i'll have an engine that will work with a 35% a/c if i go that big.

i'm still waiting for my zdz 50 and da 50. oh well, cannot fly my dp extra until something comes in...maybe i should just mount my ys 140 and 3 # of lead and go fly!!

cheers

joe


and thanks for all of your input and thoughts

bpryor

My Feedback: (45)

Hi Joe,

>>I decided to bite the bullet and buy a DA 100 for the cap.

You won't be disappointed. I've only had a DA 150, but from everything I've heard and seen, the 100 is just as good...relatively. That will be a spectacular engine in the Cap, as has been reported by others that have used it.

>>...maybe i should just mount my ys 140 and 3 # of lead and go fly!!

Nooooo, wait for the gassers...or cancel your order on the ZDZ and DA and get a real motor...the Taurus TS-52.