Cylinder head retorquing

Discussion of the Aerovee kit engine.

Re: Cylinder head retorquing

Postby karmarepair » Mon Jan 30, 2023 7:09 pm

A tool I didn't even imagine, and now I need http://www.motionpro.com/a/adjustable-t ... r-08-0380/
I started to make the Torque Adapters Bryan highlights in an earlier thread but I am ot set up to weld to do If have to pay someone for it. This adapter maybe the cheaper way, and it is certainly more versatile.
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Re: Cylinder head retorquing

Postby Bryan Cotton » Sun Jan 21, 2024 8:38 pm

I'm doing my annual because the weather sucks. It's not actually due until June but June weather is generally nice compared to January and February in northern Illinois. I had a fair amount of motion when I torqued my heads, especially nut 1 and 3 in the manual. I've never had no motion. I'm trying to decide if this is an issue or not. Also considering torquing every other valve adjustment, or 100 hours. We have been flying at a rate of about 200 hours per year. Any Aerovee guys who have thoughts would be great if you shared them.
Bryan Cotton
Poplar Grove, IL C77
Waiex 191 N191YX
Taildragger, Aerovee, acro ailerons
dual sticks with sport trainer controls
Prebuilt spars and machined angle kit
Year 2 flying and approaching 200 hours December 23
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Re: Cylinder head retorquing

Postby Murray Parr » Mon Jan 22, 2024 2:38 am

Proper method of torquing almost anything is to follow the recommended torque sequence (usually starting in the center and working outwards in a circular pattern) starting at a fairly low torque setting and complete the sequence a few times increasing torque each time you go around, working up to the proper torque in stages.

I would imagine the manual shows this somewhere. What it might not show is final torque should be held for a few seconds on each nut during this sequence (the click off type of torque wrench isn't good for this) and once done go around again and keep going around until no nuts turn any further holding the torque value for a few seconds. Each time one nut torques down a bit further it effects the other nuts a bit (especially those nearest to it) and that is why you usually find yourself going around the sequence and seemingly getting nowhere. I am not a VW expert but most likely these best practices would still apply. If the nuts keep needing torquing after a few runs around the sequence and don't seem to be improving then something could be amiss, most likely the stud pulling through the casing or stripping out somewhere, but this shouldn't be a problem if everything is designed and installed correctly.

If the studs are installed so that they are unable to move, you will find that after a few heat cycles and torquing a couple of times the torquing should become only minor or no changes once everything has settled in.
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Re: Cylinder head retorquing

Postby Bryan Cotton » Mon Jan 22, 2024 9:14 am

Thanks Murray. What you described is what is in the Aerovee manual, and what I have been doing. My one thought is I wish I had loctited in the studs, but that was not in the manual. I do use a click type wrench though.
Bryan Cotton
Poplar Grove, IL C77
Waiex 191 N191YX
Taildragger, Aerovee, acro ailerons
dual sticks with sport trainer controls
Prebuilt spars and machined angle kit
Year 2 flying and approaching 200 hours December 23
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Joined: Mon Jul 01, 2013 9:54 pm
Location: C77

Re: Cylinder head retorquing

Postby Area 51% » Mon Jan 22, 2024 10:10 am

You might try a dab of torque seal at the junction of the case and stud before torquing to make sure the stud isn't turning or pulling.
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Re: Cylinder head retorquing

Postby Murray Parr » Mon Jan 22, 2024 4:12 pm

Bryan Cotton wrote:Thanks Murray. What you described is what is in the Aerovee manual, and what I have been doing. My one thought is I wish I had loctited in the studs, but that was not in the manual. I do use a click type wrench though.


If you use a click type, just add the pressure real slow and smooth. You will likely have to go around the sequence an extra lap or 2.

Area 51"s advice is good with the torque seal paint. Hopefully the studs aren't pulling through.
Murray Parr
WXB0015
Rotax 912ULS
MGL Explorer Lite
First flight May 6/23
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