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V8-250 Saloon: Spark Plug Tubes - Thread Size

Posted: Sat Jul 13, 2019 3:54 pm
by classiclife
Hello,

Does anyone know the thread size of the spark plug tubes, please ??

I'm guessing the thread size and pitch is the same top and bottom ??

I would like to try and create a tool for removing them out of the cylinder head and then reseating them.

Many thanks.

Richard.

Re: V8-250 Saloon: Spark Plug Tubes - Thread Size

Posted: Sat Jul 13, 2019 5:11 pm
by John-B
There already is a spanner for V8 plug tubes. Laurence Jones got a lot made but I don't know if he has any left. Tel. 0770 226337 or 01245 226337.
It's a large ring spanner with a small cut out to pass the plug lead.

Edit: Read the last post by laurie1js http://archive.dloc.co.uk/forum/topic.a ... ug,spanner Apparently Barry Thorne is marketing them tel. 01306 711789 or 07885 882416

Re: V8-250 Saloon: Spark Plug Tubes - Thread Size

Posted: Sat Jul 13, 2019 5:29 pm
by classiclife
Thanks John - that's excellent news.

All the best.

Richard.

Re: V8-250 Saloon: Spark Plug Tubes - Thread Size

Posted: Sat Jul 13, 2019 6:01 pm
by Vortex O'Plinth
John-B wrote: Sat Jul 13, 2019 5:11 pm There already is a spanner for V8 plug tubes. Laurence Jones got a lot made but I don't know if he has any left. Tel. 0770 226337 or 01245 226337.
It's a large ring spanner with a small cut out to pass the plug lead.
The spanner you refer to John is for the rocker cover nuts. I read the OP's post as referring to the plug tubes?

Re: V8-250 Saloon: Spark Plug Tubes - Thread Size

Posted: Sat Jul 13, 2019 7:07 pm
by Alpine Daimler
Not sure of the actual thread size but I am pretty sure the oil filler tube lock nut, 1 5/8" AF, is the same so perhaps "borrow" that one, get another and use the two of them locked together and apply spanner to lower nut and out they come.....maybe!!

Regards
Rob C.

Re: V8-250 Saloon: Spark Plug Tubes - Thread Size

Posted: Sat Jul 13, 2019 7:24 pm
by Alpine Daimler

Re: V8-250 Saloon: Spark Plug Tubes - Thread Size

Posted: Sat Jul 13, 2019 9:31 pm
by daimlersteve
Yep ,Thats it , use two oil filler nuts . just need a large spanner. Doing it while they are hot makes it easier, either from running or from propane.
Steve

Re: V8-250 Saloon: Spark Plug Tubes - Thread Size

Posted: Sat Jul 13, 2019 10:32 pm
by classiclife
Vortex O'Plinth wrote: Sat Jul 13, 2019 6:01 pm The spanner you refer to John is for the rocker cover nuts. I read the OP's post as referring to the plug tubes?
Thanks Nick, that is correct. I can undo the securing rocker cover nuts with no issue using other tools.

The 1 5/8" dimension mentioned by Rob is a good start and will work on that.

Regards.

Richard.

Re: V8-250 Saloon: Spark Plug Tubes - Thread Size

Posted: Sun Jul 14, 2019 8:28 pm
by silverdart
Laurence showed me a tool for removing the plug tubes last year at the NEC, but, as has already been said, you should be able to remove them with 2 locknuts.

Dave.

Re: V8-250 Saloon: Spark Plug Tubes - Thread Size

Posted: Sun Jul 14, 2019 9:15 pm
by faeton
To remove tubes Screw a rocker cover nut upside down on the tubes thread as far as possible. ,screw another nut right way up tighten together with two stillsons or suitable grips as tight as possible.. Put stilson on bottom nut and unscrew , the stillsons will possibly damage the nuts so I have a couple of old spares , which I keep for this purpose .. I have seen tubes damaged by trying to remove directly with grips or stilsons. Apart from marking can collapse the tube

Dave Boon SP250 3662D