Easy clean your plugs.

[mleadbeater]

In a few recent posts, there is the mention of plug’s becoming sooted, and even  the talk of plug’s being ruined by this and needing replacement.

So, I thought my own method of cleaning dirty plugs might be of interest.

It involves the use of a cheap and very safe and gentle blasting medium, sodium bicarbonate, in a coarse form, and the use of a spot- blasting gun which , for me I already owned, but cheap to buy .

Literally around 2 seconds of blasting using compressed air at around 60 psi gives good results, removing carbon and other deposits, leaving the electrodes and insulator undamaged as the bicarb will not damage most materials, including aluminium, brass, plastics, glass , and rubber.

I use the round rubber nozzle provided with the gun , escape of bicarb is minimal. 

A quick flush with water, or blast with an air gun removes the residues.

See photos below.

Bought the bicarb on ebay, 5 kg in granular form has lasted years, and also great to clean fiddly components such as carbs, electrical components etc.

Hope this is of interest, the though of dumping good plugs just because they are sooted, especially as a Yorkshireman, gives me the heebie-jeebies!
Mike

 

 

 

 

Edited November 4, 2023 by mleadbeater

[TR NIALL]

I could do with that as I’ve more Plugs than a Motor Factors.

[mleadbeater]

Niall

me too , 50 + cars over 45 years, plus a basic hoarding compulsion leads to boxes of junk.

 

[tr6tuga]

And I thought thats there was something wrong with me!

Can you send the link?

[mleadbeater]

sorry, what link?

[BlueTR3A-5EKT]

You could search for a Champion Spark Plug Service machine.

https://www.ebay.com/itm/185996740026?hash=item2b4e4505ba:g:tfAAAOSwWVpkuMl0

 

 

Here is a diy 12 volt jobbie on e bay.   https://www.ebay.co.uk/itm/204528468759?hash=item2f9ed8c317:g:meMAAOSwpNRlRoGT&amdata=enc%3AAQAIAAAA0AM62kK0Sl2wqZJADi83u7k%2FDmsfNMlZxhP%2F8YS1m%2FN3pxLGBJlI%2BnRHSk%2BzGhQO%2B230c7ALTXQZhIj%2BHrynezTZPQpFAYC4VPjz3YdsXrwJQnsW4wUl%2B2qj5hUIv0W1f7TMxF11%2B9xkt7yPechmX0mfhRLE3QnO%2BBmX4fE%2FztqSIv9TAaE1sWyRwcjvmO7kfP0h%2BEkd%2FENV0eFIRY%2BKzQMWYowy%2Bhq8rBxHQJe7X0Pu0cSUlZBN5k1uY%2BkDNZSX%2FFTRATU%2B98l66qFcst%2FU9iA%3D|tkp%3ABk9SR-qGxuzzYg
 

[RogerH]

Would they not damage the ceramic coating and make them porous to the petrol mixture?

 

Roger

[Waldi]

That was my thought too Roger, I did not have sooted plugs since my restoration, so simply replaced them after 3 years of service, given the relative low cost. 

Waldi

[RobH]

The problem isn't just sooty plugs and the topic of plug nose ceramic has been discussed before.

Back in the day the ceramic nose used to be glazed so there was only surface dirt which could be cleaned off - now it isn't glazed because modern precise engine management doesn't need it - so contaminants from over-fuelling of our less precise carburetted or PI engines will get into the pores of the ceramic.  Scouring cleaning methods will remove the surface stuff well but cannot touch contaminants deeper in the ceramic.    

Quote from here: https://www.gsparkplug.com/shop/fouling-shortingout-problem-modern-plugs-champion-vs-ngk/

"First let's define the problem with the new spark plugs. When the automobiles became controlled by computer, the spark plugs did not have to have the bottom of the insulator glazed. The cars have fuel injection and the computer will not put enough gasoline into the cylinder to flood it. It injects fuel into the cylinder and says I will not put any more fuel into the engine until it fires. Then it fires the cylinder with 4O,OOO volts, if something happens to this computer control and too much fuel is injected into the cylinder, and the engine floods, this vehicle will not run right until you have taken the old plugs out and replaced them with a new set. What has happened is the trash gasoline the Federal Government has forced on us has contaminated the spark plugs because they are not glazed on the bottom. However when was the last time you flooded a computer controlled vehicle? More than likely, never.

Now these old engines do not have computer control and if your carburetor is running rich or you flood the engine, the same thing happens. The bottom of the insulator where it fires the engine becomes contaminated and becomes junk. ......"

 

 

[RogerH]

I found that NGK were worse than Champion for this problem.

I got about 1000 miles out of NGK and about 5000 miles on Champion ( L87 )

 

Roger

 

 

[stuart]

I have found when starting fresh rebuilds use an old set of plugs until the engine is tuned something like it and then fit a new set, this avoids any possible over wetting as the original carbon build up on an old plug stops it.

Stuart.

[mleadbeater]

glazed lower ceramic insulation?….new one on me , don’t recall having ever seen these, but I only go back to the late 1960’s.

You live and learn.

Is this glazing obvious and glossy as per the outer insulators?

 Come to think of it, I can only ever remember having one plug failure, and that was a new one.

Mike

ps just read the article as per the link, plug threads were always 14 mm. 

Edited November 5, 2023 by mleadbeater

[BlueTR3A-5EKT]

2 hours ago, RogerH said:

I found that NGK were worse than Champion for this problem.

I got about 1000 miles out of NGK and about 5000 miles on Champion ( L87 )

 

Roger

 

 

What made you decide to change the plugs Roger.   Can’t have been wear/erosion after 1000 miles, or was it?    I get carbon whispering that wire brushes off 

[RogerH]

Hi Pete,

Imagine running down a decent hill with a tight bend at the bottom. and a climb out the other side.

As you start to exit the bend you put your foot down in 2nd and it struggles to go.

Fit new plugs and when you start to exit the bend the engine picks up immediately and you climb out of the bend

 

Champion L87 have apprx 5000 miles in them  NGK where quite useless

 

Roger

[RobH]

10 minutes ago, mleadbeater said:

ps just read the article as per the link, plug threads were always 14 mm.

No-far from it.  The SAE standards cover 10, 12, 14 and 18mm.  My 1930 car has 18mm.  

[mleadbeater]

Peter, I used a wire brush to  clean plug tips for years, without problems, but read that the ceramic could become coated in the brush bristle’s  material, ie iron, obviously not good, so now use bicarbonate as my post.

 

Mike

[North London Mike]

LNK is a TR4 on twin 45 webers and a hot cam. During a recent trip to Italy (39 degs in Monza) and stuck in traffic I had to change plugs four times over a three day period due to Italian traffic management in and out of the circuit. Only option I had was a good go with the wire brush and then a final emery cloth polish. the original set went through the car three times, never lost a plug........but to be fair, both sets were less than 2000/3000 miles (NGK) after a mid year service

[Tim D.]

I've found a butane torch on the plug until the electrode starts to glow tends to burn off all the carbon. 

Tim

[Malcolm Tatton]

It was the green spark plug company who advised oven cleaner and a water wash. I've tried it following a spate of plug problems but haven't tried the washed sets yet

[Tom Fremont]

I've been lucky with NGKBP7ES on my Webered '250s since back in the 1900s. My driver's get changed every 30,000 miles whether they need it or not ( they don't seem to ).

They have been through some tuning exercises which exposed them to rich mixtures but never let me down. I have heard tell of such however.

Baking soda is great for cleaning, won't scratch anything so if it comes clean there are no worries.

Unleaded fuel and decent mixture control make for long plug service life. This is possible with Weber DCOEs but many tuners are not lucky with them; it's part of the mystique I guess. On your side of the pond there is more expertise than here in the 'States. Having been lucky with mine I'll never go back 

[Andy Moltu]

I have to say that in over 37 years of TR ownership I have never needed to clean the plugs.

I tried it on the 7 when I had repeated failures, eventually traced to fake NGKs.

I remember they had a proper spark plug cleaner st the garage I worked at during my student days rarely got used back then. Modern fuels seem to burn cleaner. How often are cars de-coked these days?

[mleadbeater]

Better carb design and starting enrichment systems, during the 70’s, followed by injection with mixture and temperature feedback , also lambda sensors, seem to have mainly eliminated carbon buildup. 

Mike

ps Interesting that this topic has sparked off so many comments (sorry, couldn’t resist).

Edited November 8, 2023 by mleadbeater

[Steve-B]

Here’s a possible simpler solution. I grabbed a NGK plug and a measure. A Battery Terminal cleaner with a fine brush as it too is same diameter. Shove plug into cleaner receptacle and twist the plug several times and voila, clean plug. 

[Barry Bell]

Correct - never ever use a wire brush for reasons stated. And the firing end of ceramic was never glazed. - I was 32 years working for Champion

[john.r.davies]

How should you clean them, then?