Cotton AeroVee 0795

[Area 51%]

If you drilled through the nut, you just guaranteed yourself an oil leak. The whole idea of the acorn nut is to stop any oil that gets past the sump threads. Enter the copper gaskets under (or on top of) the acorn nuts.

[Bryan Cotton]

If you drilled through the nut, you just guaranteed yourself an oil leak. The whole idea of the acorn nut is to stop any oil that gets past the sump threads. Enter the copper gaskets under (or on top of) the acorn nuts.

I drilled through the corner, not through the threaded hole in the middle.

Edit: had I drilled through the center, how could I have gotten the safety wire through?

[Area 51%]

Presumably, the stud doesn't go all the way to the bottom of the nut. If it does, the sump plate will leak due to lack of tension.
Good job with the corner engineering.

[Bryan Cotton]

Presumably, the stud doesn't go all the way to the bottom of the nut. If it does, the sump plate will leak due to lack of tension.

I don't think it does. The copper is squished a little bit not destroyed from following torque specs like last time. I used a nutdriver and did it by feel.

[Bryan Cotton]

Update - no more oil puddle under the engine. Looks like success!

[Bryan Cotton]

I'd edit that last post, but that would be dishonest. There is plenty of oil on the ground. Not from static sitting, but from when I run it. Those updates go in the "quest for the elusive dry aerovee" thread.

I think I might be running lean. I have high EGTs and little difference when I go lean and rich on the mixture. Unfortunately my nifty reversing linkages are in the way, so I have to pull my aerocarb out to make the adjustment. The manual says 1/8 to 1/2 turn. I'm thinking of shooting for 1/4 turn but would like to hear opinions from those with experience.

[Area 51%]

You've just entered one of the most frustrating aspects of phase 1 testing. A little can go a long way.......or make no difference at all. If you don't yet have to lean to get full throttle, I'd start with 1/4 turn richer. It's not likely you're going to hit it right on the first try anyway, so go for an overshoot, then come back.

The frustration comes from turning the needle carrier 1/4 turn, only to have the setscrew muck-up your adjustment leaving you with a random setting.

If you don't have one already, put a 3/16 ball bearing between the carrier and setscrew. It keeps the setscrew from turning the carrier.

You have my sympathy.

[Bryan Cotton]

I finally understand the ball bearing thing. I'll try that - someday. I did my 1/4 turn richer and it seems to run great, and the EGTs are now reasonable.

I think for now I'm not going to mess with it.

[Bryan Cotton]

[Bryan Cotton]

We have had a few findings and I'll try and get some pictures later. Here is a short list though:
1) One of the pushrod ends fell out when I removed it from the engine. The end of the tube looked beat up - there was a big burr on it.
2) Our thrust shimming was bad. Looked like about 0.020" of clearance. Besides a lot of play, the crank web has polished into the case web a little.
3) I think I posted pics in the other thread, but the #3 exhaust valve looked deformed where it contacts the seat. And, the #3 intake seat fell out of the head.