Front cowl mount on J3 with C90

[a3holerman]

Hi,
I am having a problem with the left front cowl mount when changing my 46 J3 from a A65 to a C90. I have posted on the J3 forum with considerable help but still am not clear on what to do.

Basically the front left cowl mount bracket mounts on standoffs that act also as the nuts for the front bearing case through bolts. The problem is that the C90 case flat area where the nuts sit is at a different location from the crankshaft c/l than is the 65. Actually the 90 is narrower so the mounting bracket will be closer to c/l than on the 65. What all this means is that the pin on the bracket will not match up with the holes on the cowling. It looks like I need to fabricate a wider nut/standoff or use a cylinder base nut type bracket. Wagaero shows, for the front mounting brackets, two cly base nut types, one for each side. The problem is they how no idea when asked if it will work on a C90.

There are a lot of C90/0200 powered cubs around so the issue has been addressed. Does anyone have any idea way is the accepted way to accomplish this?

Thanks for any help in advance.

 

[Snert]

Tom
I am going to the hanger late tonight and will try to remember to bring my camera. Maybe a couple snap shots will help.

 

[a3holerman]

Snert,

Thanks....that will probably help. I am hoping its a cylinder mount as that will be easier to get I think.

Tom

 

[Snert]

Tom
Is this what you are looking for?

 

[Longwinglover]

Tom,

For the J3 cowling bracket you speak of to mount on any Continental engine, the two normal nuts on the case through bolts get replaced with "nuts" that are approximately 1 inch long (give or take .25"). One end of this "nut" has female threads for the through bolts and the other end has a threaded protrusion that accepts the cowling bracket and a regular nut. This "nut" spaces the cowling bracket a) off the case and b) equidistant from the engine center-line to match the other cowling bracket.

I can understand these "nuts" not being present on your C-90, but they must be present on the A-65. Take the normal nuts off the C-90 and exchange them with the special "nuts" on the A-65.

EDIT: Snert posted pictures while I was writing. What his pictures show is different from every J3 I've seen (he's experimental) but it gets the same thing done. I'll try to get pictures within a few days.

John Scott

 

[behindpropellers]

The one here was cut and rewelded to fit. Took about 1/2 hour.

 

[Longwinglover]

Tom,

I posted pictures of what I'm talking about on the J3 website.

John Scott

 

[a3holerman]

John,

Then spacing from the case flat where the nut sits is different on the C90 than the A65. The A65 nuts that I have will not work on the C90 as they will be too short putting the bracket too close to the prop C/L and not matching up with the cowling holes.

 

[a3holerman]

Snert,

Thank you for the pics. It does help. I am not sure how what you have was fabricated but can probably come up with something. Could you possibly measure the distance from the case flat to the center of the pin that goes through the cowling. That would help a great deal.

Thanks again to all

 

[JimC]

http://www.pupco.com/products/pg45.html

What you need are a couple of threaded rod couplers. I don't know if the ones at the attached url are the correct size -- I just include this url so you can see what I'm talking about. The rod couplers are near the bottom of the page. If you do a google search for "threaded rod couplers", multiple sources will turn up. you will probably need to cross drill them for safety wire and may need to cut them to length. You can then install the short mount to them with bolts (also cross drilled for safety wire).
JimC