Engine mount adaptor 60 size to 40

[Alex(biggles) Wilkins]

A friend at my club is kindly giving me his old Wot 4 for a Winter Hacker, it currently has an engine mount installed for a 60 size engine.  Im planning on installing a Jen 57, which is a 40 size engine.  Are there any adaptors out there that would enable me to install this onto the 60 size engine mount? As Ide like to avoid having to drill new holes for a smaller engine mount.

[Engine Doctor]

NO dont thik there is . Probably better to plug the holes with a slightly tapered plug epoxyed in and drill new holes for a proper mounting.

[Stephen Grigg]

Im building a Flair cub.To fit a smaller engine if it isnt wide enough for the engine bearers they supplyan sluminium plate that fits flat onto the engine bearers and you can cut it to the size you need.

[Ernie]

Hi Guys, There is a potential wee problem with Stephens solution...If the jen 57 is only slightly smaller than  the original 60 then the new mounting holes will foul the original mount..  I'd  plug, with epoxy, and redrill, for a top class job

ernie 

[Stephen Grigg]

I did Ernies suggestion using wooden chopsticks worked a treat.

[Alex(biggles) Wilkins]

Thanks for the advice, but i think im going to get an SC91FS for it now.  I think ide need to cut the top of the front of the fuz off to install new captive nuts i dont fancy that idea!

[Braddock, VC]

Sorting out new blind nuts is only slightly frustrating, mark out the holes, drill them for a slight interference fit then poke a long piece of 16 or 18 swg wire with a tiny L shaped end ( you did take the tank out, didn't you ) fit the first blind nut on  and pull it into the appropriate hole as tightly as you can. Remove the wire and gently place the fus firewall down on a very firm base. With a long drift (dowel or similar) and press firmly on the end of the blind nut and then tap it with a small hammer. Once it's in, put the bolt thru the engine mount and WITHOUT pushing, engage the thread and screw it in until the thing starts to tighten up then pull it home hard. Do the same for each of the blind nuts.
The next job is to fix them in place permanently, remove the mount, get 4 small blobs of blu tack and with the drift, plonk it over the thread of each blind nut on the tank side of the firewall.

Seal all the holes in the firewall (blu tack is handy for this too)  then mix up enough 30 min epoxy to flood the tank side of the firewall to a depth of 2 mm whilst the fus is firewall down. When about 1/2 hour has elapsed, the epoxy will probably be a little bit sticky, use a drill smaller than the threads of the blind nut to clear the blu tack and partially set epoxy then screw the mount to the firewall.

Provided you get all the materiele to hand the whole job will take less time to do than I've spent typing this. HTH.

[Norman Eyers]

Thanks John! Never thought to use blue tack in the threads of the blind nut before.

You have no idea how many times I got epoxy on the threads and swore. Brilliant move..

[Jimbo565]

Alex,

Another option,makeup a 1/4 ply plate  and drill to fit the existing mount fixing holes,get a 40 size mount and drill and counter bore the hole for blind nuts so they sit flush with the back of the new plate ,bolt the plate to the original holes,

 

I feel sure the Jen being a 40 size case will be a tad shorter  than the 60. 

Jimbo