Engine Mount Washers

[Tom]

Pressing on with my Clipper rebuild and there are large area fiber washers between the engine mount and firewall on both the front and back sides of the firewall. Have checked all the parts manuals and blueprint CD but can't seem to locate. Any suggestions?

Tom

[Steve Pierce]

Tom, I have always wondered what those washers were for and what they were made of. I thought of using phenolic but it seems softer than phenolic. I also was never sure where Piper put them. I will have to look at my pictures to see if I had them on both sides of the firewall. Could they have been to seal the holes, isolate vibration, any other ideas?

[Jim]

Hi,

......Could they have been to seal the holes, isolate vibration, any other ideas?

I'd guess they work like the nylon washers we put under the screws on the exterior of our planes, anti-chafe for the firewall.

[Hillbilly]

Tom, I have always wondered what those washers were for and what they were made of. I thought of using phenolic but it seems softer than phenolic. I also was never sure where Piper put them. I will have to look at my pictures to see if I had them on both sides of the firewall. Could they have been to seal the holes, isolate vibration, any other ideas?

Steve, I had the very same idea and came close to offering to make him some from phenolic, but I agree, I think its too brittle. Since then I have had another off the shelf Idea... When I was a young man I ran a small engine shop for our local hardware dealer...Many of the lawnmower blade adapters used to have two fibre washers on either side of the blade to provide some grip with a little forgiveness...these washers were about 1/8" (or slightly less) thick, about 2" in diameter with a 3/8" hole...
Could it be that is what Piper used, given his propensity to use off the shelf hardware? What do you think?

[Steve Pierce]

Could be. I will have to see if Clyde Smith has any ideas.

[Tom]

Steve, yes I think phenolic would be a little too brittle. I would reuse the ones that I have but they are curled and somewhat hardened after sitting in a box for 43 years. If I had to say, I think they were for vibration isolation mainly. Do you know if all the short wings had the fiber washers installed? Seems odd the parts books and blueprints do not show them. Maybe I'm just not looking at the right drawings?

Tom

[Steve Pierce]

Tom, I found them. 80122-43. Univair has them for $2.68. I was looking in my Super Cub parts manual and found the number. Haven't looked in a Short wing manual yet.

http://univairparts.com/shopping_291765 ... mit=Search

[andya]

steve

since you found them, have you seen them on Super Cubs? If any one gets one, let us know what they appear to be made from (old ones sound like they are unrecognizable material?)

[Steve Pierce]

I have seen them on Super Cubs. I found another one in the J3 parts manual 81342-22 but no reference in the PA16 parts list nor the PA20 nor PA22 parts manual.

From the drawings for washers:

80122-43 1 1/2" OD 437/447 or 417/447 ID drawing isn't very clear .062 thick Fibre is the material with a note "Purch. was J2-885"

81342-22 1 1/4" OD .448 ID .062 thick Fibre for material.

[Hillbilly]

Other than the OD I wonder how they compare to the blade washers I mentioned earlier, I'll try to round one up for comparison.