Spark plugs

[Classiccars]

As not having any luck with fitting rocker gaskets as usual.Too loose too tight I noticed as oil went in to the spark plug there appeared to be an air leak at the plug.Have I got the wrong plugs

[les]

It depends on the spark plug number, you need to check what it is. Champion N9Y or N5 would be ok. Not sure what you mean about an air leak involving plugs, any leaking there would involve the sealing washer, assuming the plug is not cross threaded !

[svenedin]

So if I understand it, oil leaked from the rocker cover gasket and ran down into the spark plug recess? Then what happened?

If you had the engine running and there was a pool of oil around where the spark plug threads in and a leak you would alternately get air coming out and air going in to the engine.

Champion N9YC or NGK BP6ES are suitable plugs for A-series. They are the same thread but require a different sized spanner between the Champion and NGK.

Always thread a spark plug in by hand to start with to ensure it is not cross-threaded. They should not be loose but neither should they be over-tightened. Manufacturers do give a torque setting which I will try to find for you.......https://www.championautoparts.com/Techn ... tions.html

With your rocket gasket, clean the surface of the cylinder head then smear the gasket with grease with your fingers. Then put the gasket in place. Fit the rocker cover and tighten to the specified torque 4 lb ft.

Stephen

[Classiccars]

Great info as usual thanks all.

[philthehill]

Make sure that the sealing ring seat in the head is clean and free of crud.
Scrape around the seat and then turn the engine over to blow away any crud.
As regards the rocker cover gasket - clean the rocker cover gasket seat apply general purpose glue to the rocker cover gasket seat and fit the gasket to the rocker cover. When the glue is dry grease the gasket face that goes against the head and fit the rocker cover to the head.

[svenedin]

Make sure that the sealing ring seat in the head is clean and free of crud.
Scrape around the seat and then turn the engine over to blow away any crud.
As regards the rocker cover gasket - clean the rocker cover gasket seat apply general purpose glue to the rocker cover gasket seat and fit the gasket to the rocker cover. When the glue is dry grease the gasket face that goes against the head and fit the rocker cover to the head.

I know a lot of people glue the gasket to the rocker cover but I have never understood why this is necessary. I have always found that providing it is fitted correctly the first time, the gasket sticks itself to the cylinder head.

Stephen

[philthehill]

In many cases the gasket moves out of position when the rocker cover is fitted. Gluing the gasket to the rocker cover helps reduce that happening.
Greasing the face of the gasket against the head also helps keep the gasket supple and stops the gasket sticking to the head when the rocker cover is removed.

[geoberni]

I noticed as oil went in to the spark plug there appeared to be an air leak at the plug.Have I got the wrong plugs

I was running my car's engine after an oil change, having spilt a dribble of oil that went around one of the plugs.
I noticed a miniscule little bubble appearing, presumably on every compression stroke, I tweaked the plug an extra 'smidgin' and it stopped.

Simple as that....

[myoldjalopy]

In many cases the gasket moves out of position when the rocker cover is fitted. Gluing the gasket to the rocker cover helps reduce that happening.
Greasing the face of the gasket against the head also helps keep the gasket supple and stops the gasket sticking to the head when the rocker cover is removed.

Completely correct - it allows you to remove the rocker cover time and again to check the valve clearances, for example, without issue. I use contact adhesive. The only thing is to be sure not to over-tighten on subsequent re-fittings, otherwise the gasket can get squished - and start leaking.....

[Classiccars]

Thanks very much all.

[svenedin]

Incidentally, there is a silicone rubber rocker cover gasket available (Mini Spares GUG705009EVO) but it is a lot more expensive than a cork gasket (£9.84 versus £1.56 for cork)

IMG_9957.jpeg (2.3 MiB) Viewed 157 times

[philthehill]

If fitted correctly the cork gasket is just as good as the silicon rubber gasket.
The silicon rubber gasket is overkill IMHO.

[svenedin]

If fitted correctly the cork gasket is just as good as the silicon rubber gasket.
The silicon rubber gasket is overkill IMHO.

I agree but just saying that there is an alternative

[Classiccars]

Good to know thanks.