Morris Minor Owners Club

Hi, I have a lead free head fitted to a recently purchased moggy, it sounds to have a slight rattle like noisy tappets. I would think this is down to the harden valve seats as I have checked and adjusted all the tappets. My other original 4 star head is sound

“Has this been mentioned before or has anyone else found this???”

I would imagine you would get a little bit of a tappety sound..................how bad is it? As you could have worn push rod seats or rockers, thats a classic source of knocking on many old BSA engines, i rekkon it would apply to the A series as well.

Not a bad rattle just like a slightly annoying tappet rattle. The head is supposed to be fully reconditioned. However when I checked the tappets (cold) they were all over the place some too tight and others too loose. It also had a new head gasket fit and that blew on the way home. Every thing seemed to be loose don’t think they had a torque wrench

the ends of the rockers wear a groove (over the end of the valve stem)
Often if you use a normal feeler gauge you can't get the clearance correct as it sits against the original face of the rocker, not the worn part that contacts the valve.
Therefore if you slim down the feeler gauge to be a little less wide than the valve stem you can get better success (unless they are new rockers in which case ignore that!)

Another cause of 'head rattle' is a worn timing chain.

And finally - a badly worn rocker shaft will cause a bit more tappet rattle although that's usually quieter than a worn timing chain.

You can 'stone' the rocker faces to make them nice and smooth!
But maybe the noise you hear is 'pinking' - is it only there when you are struggling up a hill in high gear ? it's certainly nothing to do with 'hard' valve seats!

Cheers Ray, They look like new rockers fitted. I don’t know the condition of the timing chain I will change it anyway in the winter months for a duplex.

No it’s not pinking its only noticeable when stood at tick over and you listen for it. You wouldn’t stand at the side of the car and say it’s noisy. However, when I know its there I here it all the time when it’s ticking over.

Well - start by stoning up the rocker end faces and getting nice even gaps on the valves. And - form an opinion if it's really the timing chain you are hearing - but watch for that spinning fan!

if its got hardened seats for unleaded then chances are the seats are incorrectly fitted and are loose. hence the valve clearances will measure ok.used to work for engine remanufacturer and this was common on ford kent engines.

If you really think it's possible the seats are loose (and I think it's highly unlikely) - take the head off and check - right away!

dont mean to depress you but if the head gasket went and it did overheat then this could cause valve seats to loosen. when the engine is running is there oil at the rocker shaft?

scotb wrote: when the engine is running is there oil at the rocker shaft?

Errrr I didn't check but i removed the rocker to paint it a few days ago and i seem to remember the rockers were wet and i had to give the cover a good clean so id say yes I have been running it for a while now and its not siezed