spark plug spacers ?

Post by **grainger** » Fri Jun 25, 2004 1:05 pm

hi

my (main) problem is number 2 cylinder is leaking oil, which clogs the plug and causes a misfire. the old man at the post office says they used to use plug spacers to lift the plug out of the cylinder to stop it getting oiled up. anyone have any idea where i can get one to try it out, it could save an engine rebuild for a while longer

cheers
grainger

Post by **Kevin** » Fri Jun 25, 2004 4:54 pm

the old man at the post office says they used to use plug spacers to lift the plug out of the cylinder to stop it getting oiled up

Well thats a new one especially as the plug only sits in the head a small amount and does not reach into the bore.
Have you tried using a copper cored plug as it might last longer between cleaning.

Post by **grainger** » Sat Jun 26, 2004 12:17 am

hi kev

yes i might try a copper plug, sounds like it could be worth a go, im also thinking of using a hotter plug maybe just for that cylinder (a bp5es instead of bp6es ?) would that help ?

i notice the others have a white deposit on them which i now find out also indicates oil leakage (i always thought it meant it was just running too lean), so maybe all the rings are going ?

anythings worth a try to avoid a rebuild, ive got to spend a bit getting it through an mot as it is, is it likely to fail on emmissions if its not burning efficiently ?

cheers
grainger

Post by **rayofleamington** » Sat Jun 26, 2004 12:30 am

emmissions test for Morris Minor:
Start car, leave it running for a little while.
Rev car up - look in rear view mirror to see if garage has dissapeared in a cloud of smoke.
If no cloud of smoke, car has passed.

Post by **57traveller** » Sat Jun 26, 2004 9:58 am

Never heard of these! The plug tip (electrode) is just about level with the underside of the head, sufficient for the spark to ignite the mixture.
If it was situated further away from the piston crown then the combustion process will be altered and the compression ratio will be changed quite considerably I'd think.
He may have been thinking of something else.

Post by **grainger** » Sat Jun 26, 2004 1:54 pm

yeah that sounds about right ray

possibly this guy was confused as you point out,57 , it would change the compression if you moved the plug out of the head. he was also talking about how old spark plugs used to come in 2 halves ? possibly it was different then.

never mind ive got to find some way of doing it, i cant keep running it round with this misfire, it could damage the whole engine. at the moment im carrying 2 or 3 spare plugs on each journey, ready cleaned and gapped and when it starts i have to change the plug

real hands on motoring !!

cheers
grainger

Post by **Willie** » Mon Jun 28, 2004 9:09 pm

Your informant was correct. In the days of the Austin 7's(1930's)
it was common for the plugs to oil up within 20 miles of having
cleaned them! extensions were available which held the plugs
further out of the chambers to delay the 'oiling up' episodes. I
seem to remember that it was common to insert a Bone button
between each plug lead(bone,not plastic) which had the effect,
allegedly, of increasing the spark intensity which also delayed the
oiling up period.

Post by **grainger** » Mon Jun 28, 2004 9:59 pm

ah ah thanks willie, he is a very old guy. probably drove austin 7s in his youth !! ... he did talk of oil consumption only being a problem if it was getting through a pint a day !!! its nothing like that, maybe a half pint every 100 miles

but anyway i can see its not the sort of thing we should do with the moggy, i understand it would affect the compression.

ta
grainger

Post by **Willie** » Tue Jun 29, 2004 6:41 pm

The effect on the compression would be completely unnoticeable.
Have you tried a compression test? If the 'oiling up cylinder' is
a lower pressure than the others then yes,you have a bore wear/
rebuild coming up. If the compressions all read within a few lbs then
it is more likely that you need a cylinder head overhaul.

Post by **57traveller** » Wed Jun 30, 2004 11:41 am

Compression ratio Willie, not just compression. With the small clearance volume at t.d.c. this increase if the plug were higher in the head could be quite a high percentage of the original. Thus lowering the compression ratio. That's what I was trying to indicate.

Post by **Willie** » Wed Jun 30, 2004 6:43 pm

You are undoubtedly correct '57 but I doubt it would be at all
noticeable when driving the car.