Sonex-A purchase - What to look for

[BRS]

Using my Dyna-Vibe balancer with a wood Sensenich prop on my CAMit 3300, was able to bring it nicely in balance by just adding some large washers under the nuts of the prop bolts. That was about 3 or 4 years ago, time to do it again.

David A.

I've the same balancer. I should at least give it a try and see how far out of balance I am (the plane not me). Really though, in flight it feels smooth, it's just that if there is something to be tweaked (in a good way) why spend my time flying when I can find a reason to be wrenching. Ha.

Today I dusted off the DyaVibe installed two new 9v batteries. I really didn't 'feel' like doing a balance job since it all felt ok to me. I'm glad I did. The prop bolts have a diameter of only 4-3/8" so I was skeptical. The work started with the prop at 0.27 IPS (Inches Per Second) which is not awful. But by the time it balanced to 0.01 IPS the difference was noticeable. This should keep various parts happy longer. It just feels good to know how well balanced the prop now is instead of guessing.

[Kai]

Brock,

You´re a better man than me! With a prop bolt DIAMETER of only 4-3/8 in, I´m surprised you managed to balance anything at all :-)

[BRS]

Brock,

...With a prop bolt DIAMETER of only 4-3/8 in, I´m surprised you managed to balance anything at all :-)

Exactly! I didn't think it would work but in the end it was quite simple and worth the effort.

[Hambone]

So with lots of advice from Bryan Cotton, and my local VW engine specialist, and an A&P, I think she's almost ready to fly!

A few questions. The engine hasn't been run in almost 5 months, and only flew 7 hours after the previous oil change. It now has shiny new heads, which hopefully won't suffer the rear cylinder exhaust valve damage like the previous engine. Should I change the oil again? What about cleaning the oil screen? Also, the Penn oil is a lot more expensive than the Valvoline. Is there a problem swapping over from Penn to Valvoline?

Thanks in anticipation!

[daleandee]

A few questions. The engine hasn't been run in almost 5 months, and only flew 7 hours after the previous oil change. It now has shiny new heads, which hopefully won't suffer the rear cylinder exhaust valve damage like the previous engine. Should I change the oil again? What about cleaning the oil screen? Also, the Penn oil is a lot more expensive than the Valvoline. Is there a problem swapping over from Penn to Valvoline?

Yes ... change the oil.

I use & highly recommend Rotella 15W40 conventional oil. Recommended for my Corvair (flat tappet engine) but I also use it in my 74 VW Beetle & my Honda VTX 1800 V-twin motorcycle.

Dale
3.0 Corvair/Tailwheel

[Bryan Cotton]

We went further than changing the heads on our engine, as I documented, so I ended up changing the oil. Had I not messed with the oil I would probably have let it go the 25 hours - but then again oil is cheap in the great scheme of things.

I've been using the Valvoline oil as recommended by Sonex and I'd say go for it. I only remove and clean the screen at annual. So it's up to you if you want to reset the clock on that screen now or next year. Did you pull the screen when you were out in PA?

We did not bother with the new engine oil change schedule. All the bearings, cylinders, and that stuff was already broken in. But of course you do have to follow the schedule for the new engine valve adjustment and head torquing.

Glad to see you getting it back together!

[Hambone]

Thanks!

We didn't clean the screen in PA, and we're doing the annual, so I'll clean it. I realize it's a messy job, but I want to learn how to do it, and it's only once a year.

My question regarding the oil is if it's OK to swap from Penn to Valvoline. I've read that some engines 'get used' to having a particular brand of oil, and don't like change.

[Bryan Cotton]

The service bulletin lists them both as approved:
http://www.aeroconversions.com/support/aerovee_sb.html

If it was me, I'd just change. But as the SB says, if you have a question on oil then email tech support.

Approved Post-Break-in Oils Are:
Valvoline VR-1, 20w50, non-synthetic
Brad Penn Penn-Grade 1 Racing 20w50 (Partially Synthetic: Recommended for AeroVee Turbo)

[Hambone]

Any tips or tricks on checking the oil screen? I have a bottom-mounted oil cooler.

Also, one spring that connects the two sections of the exhaust on one side is stretched nice and tight, and the other one is much less tight. Is this an issue? Also, the previous owner ran safety wire down the middle of the exhaust pipe connector springs. Is this necessary?

Thanks!

[Bryan Cotton]

You will need new gaskets and copper washers. I put the screen in a clear cup with mineral spirits in it. You are looking for unexpected big chunks of stuff. If the prior owner was crazy with sealant you may find some there.

I don't have safety wire on my springs. I'd be concerned if there was any possibility of it coming loose. They really just hold the pipes on.