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Seized spark plug in Ford Popular sidevalve cylinder head
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Classicars



Joined: 07 Feb 2011
Posts: 58

PostPosted: Tue Nov 18, 2014 9:24 pm    Post subject: Seized spark plug in Ford Popular sidevalve cylinder head Reply with quote

Hi,
The spark plug from the front of the cylinder head of my Ford Popular 103E is really stuck. Any tips how to remove without breaking please?
Thanks to all.
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Old Wrench



Joined: 23 Dec 2013
Posts: 226
Location: Essex and France

PostPosted: Tue Nov 18, 2014 9:41 pm    Post subject: Reply with quote

Sadly you have two choices:

1. Remove the head. Not too onerous since this is a side valve engine and therefore the only replacement parts needed will be the cylinder head gasket: or,

2. Loads of heat applied to the sparking plug (propane lamp would be OK: Oxy-Acetylene allows much greater localised heat). This however will damage the porcelain insulator and its seal with the steel plug body.

If it were me, then I would firstly, remove the cylinder head to make life much easier.
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Classicars



Joined: 07 Feb 2011
Posts: 58

PostPosted: Tue Nov 18, 2014 9:53 pm    Post subject: Reply with quote

Hi,
1) If I were to take the first option, how should I proceed to remove the plug?
2) If I were to take the second option, can the plug be heated in place without removing the head? I think that replacing a plug after removal is less expensive than replacing the cylinder head gasket. However, thanks for your interest
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goneps



Joined: 18 Jun 2013
Posts: 601
Location: Auckland, New Zealand

PostPosted: Tue Nov 18, 2014 10:46 pm    Post subject: Reply with quote

Presumably you've already tried the obvious first step of soaking with penetrating oil or similar for a few days? Removing the head would allow you to attack it thus from both sides, and might also offer a clue as to why it's resisting removal.

If a good quality copper/asbestos head gasket has been used it will not necessarily need to be replaced. When I was a lad such items were renewed only when necessary. Replacing gaskets every time regardless of condition is a (relatively) modern fad.
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colwyn500



Joined: 21 Oct 2012
Posts: 1745
Location: Nairn, Scotland

PostPosted: Tue Nov 18, 2014 11:00 pm    Post subject: Reply with quote

If the hexagon of the plug is undamaged and presuming the head is cast-iron, I would use a top quality deep plug socket on a half inch drive bar in situ, This obviously gives the benefit of being able to put a fair bit of torque on it.
You probably don't have acetylene or you would have thought of that, but the propane torch for a good length of time...several minutes, should work wonders. Stay with it and have an extinguisher ready. It shouldn't damage the gasket. If the plug doesn't immediately start moving as you put the strain on, have a heavy hammer handy and give some sharp taps on the bar about 30cm out from the plug.
All this needs great care to keep the socket in the axis of the spark plug so as not to snap it.

If this fails you could take the head off but I think the job is likely to be made harder even though access might be better. The head would still need to be steadied and I'm not sure you would find a vice wide enough in which to clamp the head. A long shot, which is likely to be logistically impossible, would be too clamp the plug or external hexagon of the socket in a large vice and then grip the head and turn it against the immobile plug.

That would work but there are likely to be bits in the way of this even on a sidevalve head.

Keep us posted.
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Peter_L



Joined: 10 Apr 2008
Posts: 2680
Location: New Brunswick. Canada.

PostPosted: Tue Nov 18, 2014 11:35 pm    Post subject: Reply with quote

I would take off the head. Turn in upside down and soak it on a regular basis with a penetrating oil of your choice.

Take the opportunity to build a jig on a work bench that will take the cylinder head, using existing holes to accept bolts from the jig.

Carefully warm the head at an inch or so away from the plug, the head needs to expand more than the plug.

Beg borrow or otherwise acquire an impact wrench to attack the plug, sometimes a slight tightening jolt before untightening can cause some rotation, once some rotation has begun, add as much lubrication as possible from the underside and if it is still tight, work it forward and backwards all the way out.

Patience is a virtue and if takes a few days it is still better than the alternatives.
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Penman



Joined: 23 Nov 2007
Posts: 4750
Location: Swindon, Wilts.

PostPosted: Tue Nov 18, 2014 11:55 pm    Post subject: Reply with quote

Hi
Pardon the query, but won't heating the plug make it expand and thus make it tighter in the threads?
Or is there some secondary effect which I have missed?
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Peter_L



Joined: 10 Apr 2008
Posts: 2680
Location: New Brunswick. Canada.

PostPosted: Wed Nov 19, 2014 12:02 am    Post subject: Reply with quote

Penman wrote:
Hi
Pardon the query, but won't heating the plug make it expand and thus make it tighter in the threads?
Or is there some secondary effect which I have missed?


Coefficient says yes.
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Peter_L



Joined: 10 Apr 2008
Posts: 2680
Location: New Brunswick. Canada.

PostPosted: Wed Nov 19, 2014 12:26 am    Post subject: Reply with quote

In days (years) gone by, decoke was a regular event with our assortment of Minis, Anglias and Cortinas. One little task was to take suitable thread size spark plug and cut slots at an angle along the length of the thread.

This modified plug could then be used as a low cost reamer to clean the plug hole threads. Used from top side and underside with lubricant, then washed out.
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ka



Joined: 03 Dec 2007
Posts: 600
Location: Orkney.

PostPosted: Wed Nov 19, 2014 7:03 am    Post subject: Reply with quote

All good advice, I too have come across plugs that have been in heads for years. With the head in situ, at least you can get some force from a strong bar behind it, where head off, you will need a good vice. As all have said, penetrating oil, heat are good options, but a long bar and plenty of grunt works well, I have never sheared one off in situ, but I bet someone else has!
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colwyn500



Joined: 21 Oct 2012
Posts: 1745
Location: Nairn, Scotland

PostPosted: Wed Nov 19, 2014 8:57 am    Post subject: Reply with quote

Heating to cherty red does work. We used that technique all the time often on really rusty bolts and nuts and it was often possible to remove fasteners which would otherwise have snapped.. I presume it will make the metal more malleable and if hot enough it can vaporise small flakes of rust which might be adding friction.
My car came complete with a broken, seized plug in an alloy head which had resulted in the car being off the road for over 40 years and with perseverance it came out.
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kevin2306



Joined: 01 Jul 2013
Posts: 1359
Location: nr Llangollen, north wales

PostPosted: Wed Nov 19, 2014 9:23 am    Post subject: Reply with quote

I would be using heat and plus gas over a week or so (unless you are in an obvious hurry)
I would heat it up, let it cool a bit and soak in plus gas (or diesel), next night give it a tweek with a decent socket and breaker bar (very little pressure applied though and probably give it a tighten first). if it is still stuck, repeat the above for as long as you have..as others have said, with a little careand time it should come out.
if that doest work, hit it with the largest hammer you have..wont help the stuck plug but it will make you feel a lot better :0)

Kev
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Old Wrench



Joined: 23 Dec 2013
Posts: 226
Location: Essex and France

PostPosted: Wed Nov 19, 2014 10:02 am    Post subject: Reply with quote

Penman wrote:
Hi
Pardon the query, but won't heating the plug make it expand and thus make it tighter in the threads?
Or is there some secondary effect which I have missed?


Heating (usually rust) seized parts breaks the bond. By local expansion.

This was reinforced back in the early 1970s, when I purchased a rather rusty E Type Jaguar drophead, series 1 1/2.

One of the first jobs was to rebuilt the bulkhead and in order to achieve this, I had to free off the caged nuts, which secured the front space frame to said bulkhead. Careful heating to cherry red of all bolts, broke the rust seal and once cool, off they came with a socket.

The idea of heating the plug, rather than the head is indeed to seek expansion in the plug, to assist in breaking this bond.

When faced with such a problem, I always, as well try to tighten the seized part, firstly; before undoing.

If you have a compressor, a 1/2" air impact driver sometimes works; since the repeated shock can free the part.
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Bitumen Boy



Joined: 26 Jan 2012
Posts: 1733
Location: Above the snow line in old Monmouthshire

PostPosted: Wed Nov 19, 2014 10:15 am    Post subject: Reply with quote

Lots of good advice here, but one point seems to have been missed. Is it currently a runner or not? If it does start and run after a fashion, simply running the engine until it's good and hot may make all the difference, and would be a logical and easy first step.
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Classicars



Joined: 07 Feb 2011
Posts: 58

PostPosted: Wed Nov 19, 2014 10:07 pm    Post subject: Reply with quote

Hi,
Thanks to all for your advice and interest in this topic. The car in the photo is my Ford and as you can see is in very good condition. The car had a full nut and bolt restoration about 25 years ago and has only 5000 miles on the clock. Sparking plugs fitted are Champion L86. With patience I will keep on trying on your advice and hope to have a positive result. If I don't succeed I am sure that Champion plugs will give me another 5000 miles for the coming years, surely not 25!
Thanks again.
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