Jabiru repairs

[BrendAn]

A friend repaired my exhaust and I refitted it today. Looks good, sounds better.

[BrendAn]

Then I thought I would pull the plugs and do a compression check.

First plug I turned snapped off. 

After cursing my stupidity I put the leads back on and ran the engine to warm it up. Got the rest of the plugs out with a bit of finesse and CRC.

I removed the head with the damaged plug and ran it over to southern aviation services at sale.

We are so lucky to have this business in our area. Dave the owner is always ready to help. 

He got the plug out after a battle with it. He found something baked on the thread which glued the plugs in.  

Wrong anti seize is a possibility .

 

[Blueadventures]

I believe they want spark plug threads cleaned using a plastic / nylon brush and a solvent and installed with an application of Copper-max anti-seize compound to the threads.  

 

Maybe yours spark plug was cleaned with a wire or brass brush that has resulted in a corrosive binding reaction? (Just a guess)

 

Nice its sorted and your operational in quick time.

[BrendAn]

9 minutes ago, Blueadventures said:

I believe they want spark plug threads cleaned using a plastic / nylon brush and a solvent and installed with an application of Copper-max anti-seize compound to the threads.  

 

Maybe yours spark plug was cleaned with a wire or brass brush that has resulted in a corrosive binding reaction? (Just a guess)

 

Nice its sorted and your operational in quick time.

thanks mike.  i got told to use hi temp nickel antiseize.  the manual says to coat the head bolts with copper antiseize . i guess that is what you are talking about.  is copper max a brand or a specification. would repco sell it.  i would prefer to just buy the copper stuff for both jobs.

Edited Friday at 10:13 AM by BrendAn

[Blueadventures]

11 minutes ago, BrendAn said:

thanks mike.  i got told to use hi temp nickel antiseize.  the manual says to coat the head bolts with copper antiseize . i guess that is what you are talking about.  is copper max a brand or a specification. would repco sell it.  i would prefer to just buy the copper stuff for both jobs.

Download their maintenance and service manual (JEM0004) it'll list the coating types and the anti seize for the spark plugs - they do want what I posted on the spark plug threads now.

Edited Friday at 10:22 AM by Blueadventures

[BrendAn]

8 minutes ago, Blueadventures said:

Download their maintenance and service manual (JEM0004) it'll list the coating types and the anti seize for the spark plugs - they do want what I posted on the spark plug threads now.

just realised i am reading jem0002. earlier version.

hows this for confusing. the list of sealants and lubricants recommends nickel for the head bolts then you go to the maintenance section and they recommend copper for the head bolts.🙂

 

loctite Nickel Anti-Seize is copper free. Recommended for stainless steel and other metal fittings. For preventing corrosion, seizing, and galling in harsh, chemical environments, and temperatures to 2400 °F (1315 °C). Used on cylinder head screws.

 

If the engine has been operating in a corrosive environment (such as coastal areas) it is possible for the cylinder head screws to rust in place. In this scenario it may be necessary to periodically removed screw one at a time (do not remove all at once), check for rust (substantially corroded screws must be replaced), and apply copper anti-seize before reinstalling to the torque setting.

Edited Friday at 10:32 AM by BrendAn

[BrendAn]

14 minutes ago, Blueadventures said:

Download their maintenance and service manual (JEM0004) it'll list the coating types and the anti seize for the spark plugs - they do want what I posted on the spark plug threads now.

no argument here. i will buy it in the morning.  

[BrendAn]

loctite C5-A • Copper based anti-seize lubricant • Used on threaded connections prone to corrosion seizure such as spark plugs, cylinder head bolts and pipe retaining capscrews • Production Manual reference – ‘Copper-max’ or ‘Anti Seize Lubricant’

 

found it. repco should have it

Edited Friday at 10:44 AM by BrendAn

[Blueadventures]

6 minutes ago, BrendAn said:

no argument here. i will buy it in the morning.  

All good, many stuff will work, only passing on what I know.  Cheers.

[turboplanner]

10 hours ago, BrendAn said:

loctite C5-A • Copper based anti-seize lubricant • Used on threaded connections prone to corrosion seizure such as spark plugs, cylinder head bolts and pipe retaining capscrews • Production Manual reference – ‘Copper-max’ or ‘Anti Seize Lubricant’

 

found it. repco should have it

Every engine I have now, except the old Fergy and B275 tractors has an aluminium head.

I learnt three things.

1. Plugs have a habit of seizing up in aluminium, and plenty of people have just wrenched the entire thread out of the head.

2. I use a tube of Herschell Copper grease anti-seize for all bolts into aluminium; tube has lasted for 10 years -         problem solved.

3. I torque the spark plugs and all other bolts to the recommented figure. (I used to tear a lot of threads out).

Edited Friday at 09:41 PM by turboplanner

[skippydiesel]

15 hours ago, BrendAn said:

 

 

Hi BrendAn,

 

Are the exhaust springs standard Jab - they look quite light weight?

The location/angle of some of the exhaust springs, does not look to be optimal?

What is function of the hose clamp on one muffler flange?

 

😈

[facthunter]

Using a toothbrush with solvent could well have been the Problem. It would leave a coating of dissolved plastic that would form carbon. Air cooled motors in particular, need a good antiseize when they have alloy heads especially with aircraft which run hard. Copper is just ONE of  them, originally made by AMPOL a LONG time ago. I'm sure there are as good (or Better) types available since then. I use a very expensive and Heavy silvery  product these days. Excess amounts can short the Plug out if it gets on the Insulator. Tension the Plugs correctly. Too loose and the body of them can run hot and cause detonation.  Nev

[onetrack]

You know, high temperature RTV is just as effective at sealing bolt threads against corrosion and thread galling (thread "pick up"), than any anti-seize compound. But I'm not saying go against manufacturers recommendations.

 

But Permatex Ultra Copper can withstand 371°C and that is way above the generally recommended maximum cylinder head temperature of 230°C. Plus, RTV is more effective at preventing loosening of threads than any anti-seize compound.

 

Permatex Ultra Copper can be used on manifold studs and is therefore just as suitable to use on spark plug threads.

 

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[BrendAn]

5 hours ago, skippydiesel said:

Hi BrendAn,

 

Are the exhaust springs standard Jab - they look quite light weight?

The location/angle of some of the exhaust springs, does not look to be optimal?

What is function of the hose clamp on one muffler flange?

 

😈

Sorry. I thought I answered earlier. 

Didn't go through.

The springs I put on are slightly heavier than the ones that were on there. The anchor points must be ok. I haven't heard of a jab exhaust falling off.

The clamp is holding the O2 sensor.

[BrendAn]

The clamp is holding the O2 sensor.

 

that was a joke. the collar the pipe goes into has crack we missed. i put the clamp on to squeeze it up

until i take it off to weld .

[BrendAn]

Jab is back together now.

[skippydiesel]

Why does the Jab's exhaust system require so much repair/welding??😈

[BrendAn]

19 minutes ago, skippydiesel said:

Why does the Jab's exhaust system require so much repair/welding??😈

probably because it is 22 years old.

[facthunter]

It's a very neat exhaust system as I recall it. Vibration in 4's is worse than sixes.  IF it's Stainless it cracks faster than mild steel but it's available in thinner wall thicknesses than MS and corrodes less. Nev

[BrendAn]

2 minutes ago, facthunter said:

It's a very neat exhaust system as I recall it. Vibration in 4's is worse than sixes.  IF it's Stainless it cracks faster than mild steel but it's available in thinner wall thicknesses than MS and corrodes less. Nev

they are ms but quite thin . they would be saving weight i guess. they need to save every ounce possible. only 430 kg mtow and empty 266 kg

[facthunter]

I've never been able to get thin walled MS tube.   Nev

[BrendAn]

6 minutes ago, facthunter said:

I've never been able to get thin walled MS tube.   Nev

I don't know what the thickness is but it is pretty thin 

[onetrack]

I have never seen MS exhaust tubing thinner than 1.6mm. You can buy 1.2mm thickness exhaust tubing, but it's only available in 304 stainless. I guess Jabiru could have always put out a special order for 1.2mm tubing in MS.

However, there is a rust and flake factor with MS tubing. As it ages, it becomes thinner simply due to rust and metal flaking off it.

[facthunter]

So is the stuff originally used on Veteran American motorcycles. Over lander always made his exhaust systems in SS.   SS systems tend to crack rather than Corrode. Nev

Edited Saturday at 08:06 AM by facthunter
more content.

[BrendAn]

35 minutes ago, facthunter said:

So is the stuff originally used on Veteran American motorcycles. Over lander always made his exhaust systems in SS.   SS systems tend to crack rather than Corrode. Nev

jab exhaust is cracked not rusty so maybe it is stainless under the brown colouring.