GTMUSTANGCS

can material be filed or sanded off the engines mounting beams to reduce the width of the beam. If so, how close to the mounting holes could you go

Live Wire

What is the purpose of grinding them off They can de ground off but why[:@]

GTMUSTANGCS

i can't open the engine mount any wider. i need just a little narrower width on the beam mounts or i could trim the engine mount but that would require me to cut down the sides of the engine mount

SeamusG

Weaken the crankcase by grinding away material so that it will "fit"? Seems to rank in there with tuggin' on Superman's cape, spitting into the wind, and messin' around with Jim.

How about sharing the plane and the engine in question?

GTMUSTANGCS

it's an old como 40 from the 80's. i've hardly ran it. it's going in and old Pilot QB40S that i just recovered. the motor beams are alot wider that the ones on my OS46. the mounting holes are about a 1/4 of an inch from the sides of the motor beams. i noticed that the holes on the 46 are close to the edge of the motor beams. thats what gave me the idea

Lnewqban

I see no problem in doing what you explain.

File it rather than sanding it.

Common practice is keeping minimum the diameter of the hole from the edge to the center of the hole; but if there is room for the head of the bolt or the nut and some washer, just go ahead with your idea.

Best !

Gray Beard

My Feedback: (-1)

Yes, you can remove material on the flanges. Pretty much everyone also drills the holes bigger so they can use bigger screws then 4-40 or whatever size the holes are when new.
Me thinks seamusG is just fooling around with Jim?? Whatever he is doing it busted me up!!!!!

SeamusG

What was Jim Croce's song?  Em ... Forgot "ya don't pull the mask off the old lone ranger ..."

Gray Beard

My Feedback: (-1)

OK Jim, some of us get you!!!

GTMUSTANGCS

i sanded some off each side and it worked perfect. plenty of material left for the mounting bolts. it helped center up the engine bolt holes to the motor mount to boot. i'm pleased with the results. thanks

SeamusG

GT - can ya take a pic or two and post them?

Luftwaffe Oberst 13

Good song bad, bad Leroy Brown!


And to GTMustangCS, I'm with Grey Beard- you should be OK, I've done it in the past and it worked.


Pete

Lone Star Charles

The "rule of thumb" for edge distance is one and one-half times the diameter of the hole. In other words,the center of a1/4" hole should be at least 3/8" from the edge of the material.

Gray Beard

My Feedback: (-1)

Sounds like a good ROT to me!! I have seen a flange or two break but it is always from a crash.. I have been given some engines with new screw holes drilled in them that were way more then the ROT. They still worked but it does make you wonder what the person with that drill as thinking.

DGrant

My Feedback: (4)

I'm sure it was only the top/inside edges of the mount that needed a little "bevel" to allow the engine to seat, with the engine lugs squarely/flatly on the surface. What some people don't think about is, the engine's lower case is ROUND.. thereby there should be plenty of "meat" left to drill/tap the holes...

If its a plastic mount, do yourself a favor, and be sure to use machine screws(allen-head preferably).. 4/40 for .40 size and smaller, 6/32 for .60 and larger is a rule of thumb.. the plastic mounts tap very nicely, and you can use a nut on the backside if you want.. other then that..a lock-washer works very well too. In my experience, the self-tapping, sheet-metal variety screws don't go well with plastic mounts.. they tend to stretch the plastic.. and the mounts usually fail on the inside hole(closest to firewall), as thats the weakest point once they're drilled.. just an FYI there.. Good luck.

AmishWarlord

My Feedback: (5)

Might want to try and charge engine mounts. rather than doing a hack job to an engine.

Also instead of drilling out the bolt holes to fit the 1/4" coarse thread wood screws you happen to have how about just going down to the hardware store and buying the right size ones?

balsa brain

Now I've got " song stuck in head syndrome ". Thanks, LOL.

Bill