Sparkplug nipple in the cylinder

[john.p.clegg]

It's MOT time and after doing the usual checks,finding one plug top missing,cranked her over for the trip to the MOT shop,PINGING,stopped the engine,so that's where it is.....can't see it...no endoscope...how do I find/recover it?

Plasticine on the end of a stick?

Blow it out through the open plug/exhaust?

Any helpful comments ???

John

[richardcox_lotus]

Uh-oh, that sounds unlucky. I once lost a small piece of ceramic casing into the cylinder, but I saw it land just on top of the piston, in the centre.

As its non-metallic, I took a long cotton bud (used for cleaning keyboards), made it damp & was able to pick it up that way.

If you can't see it, do you think its stuck under a valve ?

If not, then use a Powerful hoover ?

Let us know how you get on.

Regards
Richard

[john.p.clegg]

Step1

Having difficulty seeing into the hole,so a bright 12v LED on a piece of wire made up and lowered into the plughole...something shiny...blob of grease on the end of the mini-inspection lamp pulls out a small piece of steel....OOOhh...looks like head off if not engine out...

John

[john.p.clegg]

Step2
Head off,found 6 pieces of flattened ali,probably not all,some must have been blown down the exhaust but the good news is no damage to piston crown,bore or head ( thank God the plug caps are made of soft aluminium or aluminum if you're in the U.S.) so might as well do a quick lap of the valves while its off re-set the clearances and refit...

N.B.
Just check out the head to block drain tube-swollen more than a swollen thing....cheap crappy rubber

John

[attachment=0]2005_0218head-plugcap0001.JPG[/attachment]

[john.p.clegg]

Step 3
While the head is off, I know some of you have replaced the exhaust studs for allen screws? etc.etc.,have you re-threaded the Ali (helicoiled) with UNC or UNF ?.Might as well do it now as it's a bit tight in the engine bay especially round the exhaust studs....

John

P.S. the pieces of "steel" in my last post were actually newly flattened Ali..

[MickG]

Sorry to read of you problem.
I am assuming that you are refering to the screw on top connector of the spark plug?
How did that manage to find it's way into the engine?

Mick G

[john.p.clegg]

Mick
Was doing my pre MOT service,pulled the plug leads to find three partly unscrewed and one missing-checked the plug wells,checked the plug caps...obviously didn't see it in the well...cleaned and checked the gaps...replaced the plugs..now I'm paying the price for my failing eyesight..

John

but on the bright side..I'm going clean up the head, re-shim and fit screws for the exhaust..

[Spyder fan]

Bad luck, pleased it wasn't serious but such a lot of work to get to the bottom of it.

Your post has me thinking of another topic I need to start to get heads scratching (no pun intended)

[MickG]

Glad you had the sense to shut down before too much/any damage was done.
Something to look out for (no pun intended), I have the same problem with failing eyesight along with all the other useful bits.
Just so long as it's not an excuse to get away from the one who must be obeyed and do something interesting carry on with my blessing.

Regards Mick G

[alexblack13]

Step 3
While the head is off, I know some of you have replaced the exhaust studs for allen screws? etc.etc.,have you re-threaded the Ali (helicoiled) with UNC or UNF ?.Might as well do it now as it's a bit tight in the engine bay especially round the exhaust studs....

John

P.S. the pieces of "steel" in my last post were actually newly flattened Ali..

Hi John,

I would certainly use helicoils or similar if you are going the route of using bolts to secure the manifold. I also think this is a good idea and also intended doing the mod when I put the 5 speed box in but I chickened out. Mistake I now realise. That small mod' I think would be very worthwhile and make life easier when removing and refitting the manifold parts.

5/16" UNC would be what I would use but the metric equiv' (M8) would be fine too. Remember that one can apply 1.25 x the normal torque to a properly fitted helicoil (or similar)... So a bit tighter too. Should help to keep those pesky gaskets safer.

Keep us posted john..

Alex..

[john.p.clegg]

Head cleaned up,valves cleaned up,studs out,helicoils in the post,picking up the hex head cap screws today,not too sure about the length so will get slightly larger and cut down to fit (there's only 7/8" depth in the head)will set about the lapping/tapping today...

John

[john.p.clegg]

Valves cleaned and lapped-in,re-shimmed to suite,helicoils fitted,new gaskets at the ready,head on later today after I pick up a 5/16 guide stud/s...

John

[alexblack13]

Looking good John.

let us know what you think of the helicoil mod when you have the manifolds re attached. Was it easier to fit? did the fasteners slot in easy enough? Etc..

That was the job I chickened out of doing some time ago and wish I had done two or three times since!!

Cluck cluck cluck....

Remember you should be able to apply 1.25 times the torque required for the nuts. An advantage of Helicoils. They won't wear as fast either but just be careful not to cross thread.
Alex...

[john.p.clegg]

Update...

Head back on,test run completed,engine seems quieter and smoother,the allen bolts make the fitting of the exhaust manifold an easy job (no need for the crowbar) and the provision of a quick-shift on the 5 speed box is a definite improvement...
John