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Spark plug tubes. Repairable?

Posted: Sat Feb 27, 2016 9:30 pm
by Sundowner
Hi,

Yesterday I found that 2 of my SPRINTS spark plugs were swimming in an oil bath. :(

I did a lot of looking around and found that in order to cure this common problem, the club, along with a couple of the vendors, sell alloy 'O' ringed replacements.
Now, bearing in mind that I haven't taken mine out to have a look at them yet, can somebody advise me as to why the originals cant be rebuilt? I see that Rimmer's sell the 'O' rings and going down this route would be much cheaper.

So why is it that nearly everybody has swapped over to the alloy's? Can't the steel originals be overhauled satisfactorily? What am I missing? :?

Thanks & Cheers,
Rob

Re: Spark plug tubes. Repairable?

Posted: Sat Feb 27, 2016 9:44 pm
by Galileo
The O rings listed on the rimmer site are replacements for their own (overpriced in comparison to the TDC ones) replacement tubes.

I've a small confession, I cleaned up my original alloy tubes that were covered in instant gasket, and then glued some off the shelf O rings on to them in the style of Bodget and Skarper Automotive Engineers...

Re: Spark plug tubes. Repairable?

Posted: Sat Feb 27, 2016 10:59 pm
by mahony
I have not needed to upgrade to the alloy tubes as of yet as the original ones have always been oil tight by using two of the 'o' rings on the bottom of the tube and one on the top and some rubber grease, the Rimmer ones should be ok as they will have to be the same size as the original tubes :D

Re: Spark plug tubes. Repairable?

Posted: Sun Feb 28, 2016 11:45 am
by Galileo
Are the originals supposed to be steel? Both my car and my spare engines ones are aluminium tubes.

Re: Spark plug tubes. Repairable?

Posted: Sun Feb 28, 2016 6:42 pm
by Sundowner
Galileo wrote:Are the originals supposed to be steel? Both my car and my spare engines ones are aluminium tubes.
The tubes in my car are steel and the 'O' rings are bonded to them.
Rob

Re: Spark plug tubes. Repairable?

Posted: Sun Feb 28, 2016 7:02 pm
by Mahesh
I'll be removing mine on Tuesday evening, being a late replacement engine, it may throw up another variant.

Re: Spark plug tubes. Repairable?

Posted: Mon Feb 29, 2016 6:11 am
by Sundowner
Here's an alternative from the USofA.
http://www.prothanesuspensionparts.com/2749043
Cheers,
Rob

Re: Spark plug tubes. Repairable?

Posted: Mon Feb 29, 2016 7:12 am
by tony g
Thats a neat solution, almost factory :), but clicking add to basket its not clear if the $37 is for one piece or one set

Tony

Re: Spark plug tubes. Repairable?

Posted: Mon Feb 29, 2016 9:45 am
by RJF_70
tony g wrote:Thats a neat solution, almost factory :), but clicking add to basket its not clear if the $37 is for one piece or one set

Tony
Tony, if you look in bottom right corner and click on in the box of 2749043 of that product it says 4- Triumph spark plug tube! So looks like it's a set?
Rich.. :D

Re: Spark plug tubes. Repairable?

Posted: Mon Feb 29, 2016 10:56 am
by xvivalve
It is astounding that there is sufficient demand stateside for 16v components; there must be a lot of Sprinted TR7 out there I suppose.

OE tubes were aluminium with hard rubber collars bonded to each end.

Re: Spark plug tubes. Repairable?

Posted: Mon Feb 29, 2016 12:04 pm
by tony g
Cheers Rich :thumbsup:
RJF_70 wrote:
tony g wrote:Thats a neat solution, almost factory :), but clicking add to basket its not clear if the $37 is for one piece or one set

Tony
Tony, if you look in bottom right corner and click on in the box of 2749043 of that product it says 4- Triumph spark plug tube! So looks like it's a set?
Rich.. :D

Re: Spark plug tubes. Repairable?

Posted: Mon Feb 29, 2016 1:56 pm
by GrahamFountain
Sundowner wrote:The tubes in my car are steel and the 'O' rings are bonded to them.
I've never seen steel ones, ever. All I've ever seen are the cast aluminium alloy tubes, with hard (often brittle) plastic oil seals bonded to the tubes. All I've ever done is use silicon goo to seal them, though I've chucked a couple over the years where the oil seals have broken up. I must admit, the alloy is very hard though. Nearly as hard as the aircraft spec stuff.

The extra trick I find is to smear a small amount of goo into the crack between the top of the tube and the rocker box cover, just before I tighten it down. Doing that, as well as liberally coating the bonded seals before assembly, seems to keep the oil out of the plug tubes.

Graham

Re: Spark plug tubes. Repairable?

Posted: Wed Mar 16, 2016 5:25 am
by Sundowner
GrahamFountain wrote:
Sundowner wrote:The tubes in my car are steel and the 'O' rings are bonded to them.
I've never seen steel ones, ever. All I've ever seen are the cast aluminium alloy tubes, with hard (often brittle) plastic oil seals bonded to the tubes. All I've ever done is use silicon goo to seal them, though I've chucked a couple over the years where the oil seals have broken up. I must admit, the alloy is very hard though. Nearly as hard as the aircraft spec stuff.

The extra trick I find is to smear a small amount of goo into the crack between the top of the tube and the rocker box cover, just before I tighten it down. Doing that, as well as liberally coating the bonded seals before assembly, seems to keep the oil out of the plug tubes.

Graham
Graham,
I've just R&R'd mine and I was both wrong and right.
Wrong in assuming that they were the original tubes with the O rings bonded to them, (even though I've had them out before) but right in that they are steel.
I guess someone made these up some time ago for a previous owner.
They're now back in the car with both new O rings and some sealant.
Cheers,
Rob

Re: Spark plug tubes. Repairable?

Posted: Wed Mar 16, 2016 11:14 am
by Jon Tilson
Indeed Rob...those are non OE and someone looks to have made a nice job of them.

I can testify to the general naff-ness of the OE ones, but my plugs dont seem to mind being in an oil bath too much.

Jonners