heli coil

[docjeffry]

I need to replace my upper (thank God) in cylinder #3 of a Lycoming o-235-C2C. In reviewing the FAA's maintenance manual, vol. 1, CH 5, I noted an absence of and type of adhesive such as locktite, etc. Any comments on that? Note: All of my owner assist MX is performed with a certified A&P/AI. 

 

I'll let you know how I do.

[Pinecone]

On 3/24/2021 at 5:57 PM, M20Doc said:

If you’ve ever seen this stuff, you must be older than you let on.

Clarence

The USAF still used it into the 80s.  They even ran the O-2A/Bs (Cessna Skymaster) on it.  I am sure they had lead fouling issues.

You cannot have an "octane rating" higher than 100, as by definition, pure iso-octane is 100 octane.   So above that it is technically a performance number.

To get those higher ratings, you go to aromatic compounds.  I know that at one point, Formula 1 cars were running almost pure toluene.  Xylene is used in G100UL to boost the rating.  And metallic additives, such as tetraethyl lead.

Even today, you can get leaded race fuels.  VP Racing fuels makes an MON 120+ fuel.  MON is similar to the 115 of the 115/145 fuel.

IIRC G100UL is something like 98/140+

 

 

 

[PT20J]

7 hours ago, docjeffry said:

I need to replace my upper (thank God) in cylinder #3 of a Lycoming o-235-C2C. In reviewing the FAA's maintenance manual, vol. 1, CH 5, I noted an absence of and type of adhesive such as locktite, etc. Any comments on that? Note: All of my owner assist MX is performed with a certified A&P/AI. 

 

I'll let you know how I do.

If you are talking about the spark plug, Lycoming uses a special serrated helicoil to make sure it stays in place. There is a special tool to do it correctly.

https://www.aircraft-tool.com/shop/detail.aspx?id=4260-18

[docjeffry]

On 12/5/2022 at 4:11 PM, PT20J said:

If you are talking about the spark plug, Lycoming uses a special serrated helicoil to make sure it stays in place. There is a special tool to do it correctly.

https://www.aircraft-tool.com/shop/detail.aspx?id=4260-18

Fast forward a little more than 2 years. I ended up replacing my cylinder last month and currently breaking it in (1,910.00). I would take all the advice given above to not tackle this job (Heli-Coil replacement) on your own. If you're in Texas, go to Sal's Aircraft Cylinders Inc. If the head is serviceable, he can do it.

Y'all be good. Happy flying. 

 

JCF

[M20F]

I just use JB Weld.  

[MikeOH]

57 minutes ago, M20F said:

I just use JB Weld.  

Yeah, Silly Putty just didn't cut it.

[cliffy]

RTV seals anything and everything :-)

[N201MKTurbo]

When I was in high school my buddies and I were into Corvairs. They had airplane like engines after all.

We had one junk engine we would pass around to put in our cars when we were working on our good engines. It had one cylinder with a stripped out spark plug hole. I was the one who discovered that if you whacked the spark plug with a hammer so the threads were a bit oval shaped, you could screw it in and it wouldn't randomly blow out of the cylinder. Oh the good old days when you could buy a spare engine for $50.

The three of us could swap an engine in 30 min flat. Add 15 minutes if we had to swap transmissions.

[M20F]

20 minutes ago, cliffy said:

RTV seals anything and everything :-)

Room temperature vulcanizing??? Vulcanizing versus WELDING??

You need to do your research sir!

[MikeOH]

1 hour ago, M20F said:

Room temperature vulcanizing??? Vulcanizing versus WELDING??

You need to do your research sir!

Hmm, I think I'll pick Vulcans over Welders.

[Hank]

3 hours ago, M20F said:

Room temperature vulcanizing??? Vulcanizing versus WELDING??

You need to do your research sir!

 

2 hours ago, MikeOH said:

Hmm, I think I'll pick Vulcans over Welders.

Live long and prosper, both of you!

[cliffy]

6 hours ago, M20F said:

Room temperature vulcanizing??? Vulcanizing versus WELDING??

You need to do your research sir!

Not quite sure what you mean

Lots of "mechanics" use RTV for all kinds of sealing even if it doesn't work.  I've even seen it used to seal mufflers!  (it didn't work)

I guess the comedy of the quip was lost in translation?

[cliffy]

6 hours ago, N201MKTurbo said:

When I was in high school my buddies and I were into Corvairs. They had airplane like engines after all.

We had one junk engine we would pass around to put in our cars when we were working on our good engines. It had one cylinder with a stripped out spark plug hole. I was the one who discovered that if you whacked the spark plug with a hammer so the threads were a bit oval shaped, you could screw it in and it wouldn't randomly blow out of the cylinder. Oh the good old days when you could buy a spare engine for $50.

The three of us could swap an engine in 30 min flat. Add 15 minutes if we had to swap transmissions.

I had a mid 60s VW that I could have the engine on the ground, by my self, in 7 mins!!  

In high school my buddy and I changed many transmissions (Powerglides) in a 55 Chevy in a weekend laying on the floor. 

We blew them up right and left. 

[N201MKTurbo]

7 hours ago, cliffy said:

I had a mid 60s VW that I could have the engine on the ground, by my self, in 7 mins!!  

In high school my buddy and I changed many transmissions (Powerglides) in a 55 Chevy in a weekend laying on the floor. 

We blew them up right and left. 

Yep, the Corvair engine was designed by VW. Same process for both.

[Fly Boomer]

2 hours ago, N201MKTurbo said:

Yep, the Corvair engine was designed by VW. Same process for both.

 

I'm not a fan of AI, but this was the first thing that came up.

 

[N201MKTurbo]

39 minutes ago, Fly Boomer said:

 

I'm not a fan of AI, but this was the first thing that came up.

 

My Corvair days were a long time ago. And I haven't thought about them in quite a while. That was the general consensus back in the day. I even had books about Corvairs that perpetuated that myth.

Now that there is the internet, information is easier to come by. It seems that the design was all GM and inspired by a Continental aircraft engine.

https://en.wikipedia.org/wiki/Chevrolet_Turbo-Air_6_engine

We sure had a lot of fun with those cars. We could hot rod them so they would kick ass on most of the pony cars. And the late models would out handle almost anything on the road. No matter what Ralph Nader said!

[Fly Boomer]

2 hours ago, N201MKTurbo said:

No matter what Ralph Nader said!

  He was a funny boy.

[EricJ]

6 hours ago, N201MKTurbo said:

We sure had a lot of fun with those cars. We could hot rod them so they would kick ass on most of the pony cars. And the late models would out handle almost anything on the road. No matter what Ralph Nader said!

The early Corvairs with the swing-axle rear suspension were genuinely dangerous and were the subject of Nader's book.   The later ones, after the redesign, were amazingly good.    The Spiders were popular race cars for a long, long time.

There's a pretty healthy community that still uses Corvair engines for experimental airplanes.   There's at least one FB group dedicated to that with some active rebuild and installation shops.

[N201MKTurbo]

2 hours ago, EricJ said:

The early Corvairs with the swing-axle rear suspension were genuinely dangerous and were the subject of Nader's book.   The later ones, after the redesign, were amazingly good.    The Spiders were popular race cars for a long, long time.

There's a pretty healthy community that still uses Corvair engines for experimental airplanes.   There's at least one FB group dedicated to that with some active rebuild and installation shops.

In 64 they added a leaf spring to the rear end. That mitigated the roll over, then in 65 they gave it the Corvette suspension.

[N201MKTurbo]

BTW, we had a 63 junker for a while. We tried like hell to roll it over. We were obviously not as talented as Ralph.