Morris Minor Owners Club

Hi folks, my 1275 A-plus makes a clattering noise during tickover (see video). I have removed the rocker and timing cover for clarity. The clattering noise dissapears when I rev the engine. The first 4 photographs show the valve gear as removed from the engine, the second 4 photos show the valve gear which I am planning to use to quieten down the noise. Any thoughts and suggestions on what may be causing the clatter at tickover would be greatly appreciated. The timing chain and tensioner appear fine, oil is being supplied to all 4 pedestals.

Many thanks and kind regards
Will



VIDEO



PHOTOGRAPHS A





PHOTOGRAPHS B

is your air filter cover on tight?
I had a clatter, and tightening the screw on my air filter cover fixed it.

I don't think the 'clattering' is anything to do with the rockers........ But certainly the pressed steel rockers are generally recognised as being stronger - although the sintered items are plenty strong enough for a standard engine. If you use the pressed steel set - you will need to re-align them on the shaft so they act directly over the tips of each valve. The sintered rockers get round this by being so wide! The carb on that engine is far too small for a 1275........ It will run - but the performance will be strangled.

I dont suppose the rocker shaft is badly worn by chance.

There is no real perceptible play in either rocker shaft but I have not stripped them yet. How much (if any) wear is acceptable?

Sounds more like big ends bearings to me whats you oil pressure like? Its too noisy to be just tappets surely.

Pretty much NO wear is acceptable on the rocker shaft.

The video makes it sounds like an air leak. The tickover seems a bit erratic too. I see you have a servo. Is the takeoff secure?
Any sign of soot staining on the manifold gasket?

The tickover is erratic and the mixture seems to be all over the place. The servo pipe was damaged and leaking at both ends but I have repaired this. I would have thought that big end bearing noise would stay audible or get noisier as the revs increase, mine seems to get quieter / smoother as the revs increase?
I dont have an oil pressure guage but the light goes out and stays out.
I am informed the camshaft has been changed, should the followers have been replaced to suit? could this be the problem?
I really dont like noisy engines - unless they are supposed to be. I will do a full strip down and check this week end.
Cheers,Will .

Big ends usually rattle when accelerating - not so much at idle. Why was the cam changed? For performance reasons - or because there was a problem with it ? And yes - the followers should at least have been carefully examined to see if they were fit - or renewed. Be aware if you loosen the head nuts - you should change the head gasket. It is possible to change the rocker shaft and the rockers without loosening the head nuts........

Cheers Roy, I have not had the car long, it was an ebay buy. The owners informed me that the cam had been changed for one from an Ital - dont know why? They called it a half race cam ?? Anyway, something is noisy as I have had some very sweet sounding A series engines.
I will take your advice on the head gasket as it will give me a chance to grind the valves in, change stem oil seals etc.
I dont have a Vizard book can you advise on improving flow on the cylinder head whils it is off and what sort of tools are required?
This engine has double valve springs, is that standard on all 1275 heads? What benefit does it give?
A lot of questions I know but worth asking while you are reading anyway.
Cheers,Will .

Double valve springs will increase wear on your rockers & push rods. Only necessary on a race engine that rev's very high, not a "standard" road going engine..

That makes sense and I dont remember my Marina having double valve springs. I wonder if this is an A+ Ital engine??

I believe the A+ had a ribbed block but still did not have double valve springs....

Can we identify it if i post the engine number?

worth a try although pics of the block may be more helpful to those in the know

Pics and engine number tomorrow then.
Cheers,Will.

Only the MG Mutro and the 'Cooper ' Mini had double springs as standard on the 940 head. An 'Ital' camshaft would make no difference - any variations were tiny - and I'm not sure there were any at all! It's possible the engine has both cam and head from an MG Mutro - and that would be worth having. But unless you plan to use high revs - remove the inner 'double' springs.They are just wasting energy. Plenty of Vizard books on ebay - and cheap!

You have got me thinking now , If it transpires I have an MG Metro head - I may as well utilise it. I am taking the engine out shortly to do the clutch anyway so it might be a good time to inspect and upgrade the internals too. I have a LCB manifold and MG Metro inlet manifold coupled to a Hif 44. The car has discs up front and telescopic conversion all round so it should be able to take a step up in power .
I was going to run it as is but the thought of a peppy Traveller sounds like fun - oil cooler, electronic ignition, balanced and nitrided crank, sodium filled valves, 1 3/4 exhaust, K&N filter, stage 2 head - have I missed anything ?? Oh yes - the cost .

Errr -where will you get the 'nitrided' crank ??? And - sodium filled valves are only for super/turbo charged engines.......