Blew a Plug

[Wally]

Blew a plug out the right cylinder last week.
So time to fit my 750 engine thats been on the bench
But Its beer O'clock now so completing it will have to wait till Tomorrow

 

[cros36]

what kind of ignition is that? ive only seen points and pamco. sorry about the random ass question.

 

[Wally]

Mine is a Boyer
http://www.boyerbransden.com/

There also probe ignitions & am shore a few others

 

[tonyc]

Wally where is your box for your Boyer mounted? Do you have picture of it? Thanks Tony C. P.S. I am trying to re-lpcate my Boyer from the front reflecter mount.

 

[Wally]

My boyer box is wrapped in rubber & then stuck up in the space at the top of the frame were the top & bottom tube meet the neck
there is a sace that you can stick it in from the back

 

[gggGary]

Yeah pooched threads aren't unusual. But it sucks when that spark plug won't tighten up. Anti seize EVERY TIME I reinstall a plug. An insert works too and better than a helicoil I think.

 

[TeeCat]

I just put my hand on the actual ratchet part of the wrench and tighten - NOT on the grip of the lever - so I use less torque. How 'bout you all... any other good methods to keep from overtorqueing? Anyone actually use a torque wrench on plugs?

TC

 

[gggGary]

"Anyone actually use a torque wrench on plugs?"
Not I! LOL
When new it's tighten to snug then a half turn to crush the washer to seal.

3. Tighten the spark plug finger tight until the gasket reaches the cylinder head, then tighten about 1/2-2/3 turn more with a spark plug wrench.


Here's NGK's full say on it. http://www.ngksparkplugs.com/techinfo/spark_plugs/installation.asp

 

[tonyc]

I put a rubber hose on the plug and screw the plug until hand tight and then I put a wrench on the plug to snug up. I always use never-sieze on the threads but make sure you do not get any on the elctrode because it is conductive.

 

[cmattina1]

finger until snug and then a half turn seems to work. though my new '75 is already a bit loose. and yes i am talking about spark plugs

 

[retiredgentleman]

Nothing worse than a stripped spark plug thread. Say, isn't this a thread about another thread.

There's no reason to have this happen. To much torque will do it for sure. I suspect another reason is cross threading. If someone first starts the plug using a socket or spark plug wrench, there is no "feel" whether its cross threaded. When it gets stuck, they may then put the beef to it and really strip the thread.

I like to use my fingers to turn the plug in. I used to use a little "Never sieze", but found that it makes it difficult to "feel" if the thread is turning freely. Now, I never use "Never sieze" (no pun intended). I make sure the threads are clean, and turn the plug almost fully in using my fingers. No chance of cross threading that way. I use 14 ft-lbs torque, and yes I use a torque wrench every time.

 

[XSLeo]

I don't use anti-sieze on spark plugs. The anti-sieze acts as an insulator. The heat from the plugs can't transfer to the head as well and makes the plug run hot.
Leo

 

[TeeCat]

I start the plug by hand til it seats on the washer, and then snug it up with a ratchet, holding it at the 90-degree. No anti-seize.

TC

 

[gggGary]

It appears there is room on both sides of this argument.....

From piston aircraft maintenance;
Champion recommends using 2602 spark plug anti-seize. Use sparingly

Start at second or third thread from end. Any time you use a lubricant consider reducing tightening torque from the "dry" spec.

 

[Robhall]

I have also heard of anti-seize increasing the heat on a plug. Sometimes I use it, sometimes i don't, depends on how it's been running lately I suppose. And gggGary is correct for aircraft plugs, however the same rule applies for turbine engine igniter plugs. I heard it came from long ago when some non-mechanically adept crew chiefs were just dipping the whole bottom of the plugs in the can of anti-seize and installing them and wondering why their plane wouldn't run

 

[littlebill31]

Nothing to do with this, but when I drank beer I loved Victoria Bitter. Man is it good. I only got it when I went to Australia though.

 

[xjwmx]

Not using anti-seize is risking a real problem in order to prevent imaginary problems.

 

[gggGary]

I'm with xjwmx on this that anti seize makes sense. It is getting to be real problem on late model cars trucks and diesels. With aluminum heads and 100K maintenance intervals a lot of injectors and spark plugs are breaking off at first change. Usually means pulling the head to repair or some god awful drill/extraction routine leaving who knows what in the engine.

XSLeo any data on the heat conduction issue? I would think anti seize is no worse than rust and aluminum oxide at moving heat. Since the plug tightens to the flange the threads should be metal on metal on one surface of the thread with a gap on the other, air or anti seize which is better?

 

[xjwmx]

^Anti-seize would improve plug cooling actually, if it had any effect at all, by eliminating air space between the two threaded surfaces. That's how heat sink compound for transistors, etc., works. Nothing insulates like air...

 

[Wally]

Nothing to do with this, but when I drank beer I loved Victoria Bitter. Man is it good. I only got it when I went to Australia though.

Fosters /Carlton United Brewers (CUB ) Is no longer Australian owned & there talk of dropping some beer lines.

http://en.wikipedia.org/wiki/Victoria_Bitter