RV-12 Spinner -v- Coweling Clearance

[Geico266]

I just finished fitting my cowling after fitting the spinner and finishing up other FF projects. There seems to be a clearance issue. While not touching it is VERY close.

The clearance / gap should be approximately 3/32" (.094)? There is nothing in the plans. Standing in front of the spinner I have clearances of;

1. .010 @ 1200
2. .050 @ 0300
3. .080 @ 0600
4. .065 @ 0900

The spinner is centered perfectly. There is a drop in the cowling -v- spinner on the top line of about 3/32".

Any ideas?

For those of you building other RV's the cowling on a -12 is fitted before you install the engine. Any ideas you have would be greatly appreciated.

 

[vernhendershott]

Hi Larry,

Sorry to hear that you are having this problem, on RV-8's the engine tends to sag a little after it has been hung for a while and in that case we were able to help it with washers under the lower engine mount rubbers, also the pattern of tightening the engine mount bolts can have an effect.

I like the others here at Spruce Creek decided to wait until we had the engine in place to do the cowling for just this issue as it is much simpler to adjust before you install the hinges.

Good luck with it and have a good day.

Best regards,
Vern

 

[Peterk]

Engine mounts

Vern,

When you say the pattern of the engine mount bolt tightening are you referring to mounts-to-engine or mounts-to-firewall? I'm not there yet either but am anticipating. Thx.

 

[vernhendershott]

Hi Pete,

I was talking about the four number 6 bolts that have the rubber donuts on them that connect the part of the engine mount that bolts on to the engine hard with bolts to the firewall on the bottom and the other part of the engine mount at the top. It will not create a large shift but a very small shift in the firewall area causes a noticeable shift at the prop end of the engine.

Best regards,
Vern

 

[Geico266]

Hi Pete,

I was talking about the four number 6 bolts that have the rubber donuts on them that connect the part of the engine mount that bolts on to the engine hard with bolts to the firewall on the bottom and the other part of the engine mount at the top. It will not create a large shift but a very small shift in the firewall area causes a noticeable shift at the prop end of the engine.

Best regards,
Vern

Thanks Vern, I'll try re-touquing in a different sequence.

 

[vernhendershott]

Hi Larry,

You might try tightening the one that is nearest to the largest gap first and the next largest gap second and so on. I would only just loosen the nuts about three threads each and then use the prop hub and move the engine up and down then left to right, let it settle and then start the process.

Best regards,
Vern

 

[Peterk]

Spinner

Vern,

Sounds like a good plan to me too. I also like you idea about leaving the cowling hinges tiill the end...wish I had had the foresight.

Thanks again,

 

[vernhendershott]

Hi Pete,

As we say here at Spruce Creek, "It takes a village to build a RV", and the other people here were the ones who told me I should wait until the engine is on. They are a lot of help, gut they set a high standard for quality, I can here one now "that looks good but your not going to leave it like that are you?".

Best regards,
Vern

 

[Peterk]

Fly-In Communities

Vern,

I've heard of Spruce Creek. I live in Pecan Plantation in Texas and have similar "funny" comments about my building. When I had my engine all over the table (for the shroud) several walked in and said, "oh my God, what have done? You don't take the engine apart, you just bolt it on!" They have been lots of help though as you say, "too much slop in your elevator control, etc" . Unlike your place though I am the only one building a 12, they all have 7's and 8's and 10's. Many have said however that they look foward to letting me work through all the "beta" problems before they get interested. Its been fun. Thanks again for the input.