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I've got a plane in which the spinner backplate sits just 1/16" in front from the cowl. It's a solid setup and I've flown without problems but a 1/16th of extra space wouldn't bother me. The holes in the fuse and cowl are already drilled so I was thinking of some sort of spacer that I could use between the drive washer and the spinner. Any ideas?

jetmech05

1/16th is kinda tight..you say you have flown it this way??? seems to me it's safer to fly it the way it is than to try and put a spacer behind the spinner backplate...you know the old saying if it aint broke don't fix it

Spitfire222

I would just leave it. Why do you feel the need for more clearance if it works fine?

carrellh

I would use washers between the engine mount and fiewall to move the engine forward a tiny bit.

plugin

I think that as the cowl is new, probably some 10 flights or so might give it enough play for it to come in contact with the spinner. This could have horrible results at 10k r.p.m. That's the reason why I want to perform a preemptive fix instead of waiting for the problem to arise. I thought about the washers on the firewall but I haven't decided yet on the definitive fix that I'll be performing. I was really hoping that there was a washer that had the crankshaft's diameter so I could space the spinner.

brett65

My Feedback: (18)

If you put a washer on the crank, it would have to be one that has some sort of texture to it so that it would have some grip. The best option IMO would be to space the mount out.

Gray Beard

My Feedback: (-1)

1/16th is what I set my cowl and spinner at when I'm setting up A plane so I would say don't bother. If the cowl slides A little it isn't as bad as some people think, the back plate just rubs A little, no real harm done. If you must move the engine forward then use A sheet of 1/16th ply behind the mount to move everything forward, washers work but with the ply you will have even mounting pressure.

Spitfire222

I asked because my Showtime also has very little clearance between the spinner and cowl, and I havent had a problem in dozens of flights. Its one of those personal experience things. Works for me, should work for you.

However, if you're really set on spacing it, the plywood spacer idea is probably the best bet.

Redback

I have made a spacer from the back plate of a spinner and used it without a problem. Mounted it in my drill press and used a file to get it properly round.

Terry

jrcaster

You can also go out and get a spinner from a different brand. Some recess more than others.

da Rock

It's a lot better to move the cowl. And that's easy. Simply fill the holes that exist in it with epoxy. And then drill new ones slightly ahead of where the others were. While you're at it, you can reinforce the area around each hole and you wind up with a lot more servicable cowl attachment.

However, 1/16" is more than enough clearance. If you've got the cowling securely attached, that clearance is on the big side of perfect.

If you are seeing some rubbing in flight, you need to add another cowl screw or two. That clearance shouldn't allow any rubbing at all, ever.

doubledee

My Feedback: (4)

1/16 inch is plenty of clearance. Don't mess with it.
Make sure the cowling screws have washers and are good and tight. If they screw into blind nuts add a little blue Locktite.

plugin

They have washers and o-rings made from fuel tubing to protect the paint of the cowl and reduce vibration a bit. I'll leave it as it is and check within a few flights.