Morris Minor Owners Club

It’s not a burnt valve given that the engine has never run since rebuild. Piston and rings are brand new too

Are you sure that you did not break one or more rings again?

Do the compression test again with oil down the bores - if no different it is either a valve stuck open or broken rings.

You must resolve the compression issue before anything else.

Who rebuilt the head?

Reading back through this thread is bewildering.

You say this is the first A series engine you have built/overhauled. Have you ever built/overhauled any other engines? Reading the thread, it appears as though this may be your first.

This engine seems to be a collection of parts, bought in from other parties, and has never been run previously (as an entity)?

You should get some compression pressure reading, even if a valve was very slightly open. I am thinking that one valve on that pot is not seated. Possibly new valve guides and the seats not recut? Who knows!

Are the plugs wet after trying to start the engine? If not, there is likely no fuel delivery.

An engine only needs four requirements to at least fire. Air, fuel (those two in the approx correct ratios), compression and a good spark (at the correct time). One or more of these requirements is clearly missing. But with only four things to check, a diagnosis should not be too difficult.

Compression on number 4 looks like another strip-down is going to be necessary.

Kittyhawk,

Where do you live? There might well be someone who lives close(ish) by who could offer a new look to help you.

Thank you Richard. I am in Malvern

Regards
Roger

I'm just down in Ledbury and have experience of both burning out valves and rebuilding engines if you need a hand.

The car is back on the road after the upgrade and going well. The improvement in performance is certainly noticeable, but then the engine was in a very poor state before. I am running a K&N cone type Air filter at the moment, with an AAU needle and red spring in the HS4. This runs well, but I have a round Mini filter, which I have drilled a number of holes around and with that on, she is running weak. What would be the suggested needle to go for? I have a yellow spring on order to see what difference that makes.

The only other problem is a slight leak of oil from the oil pump primer blanking plug. The plug is new and so is the crush washer. Any thoughts?

Do you mean a chrome pancake type filter?

I ended up using an AAA needle and it runs well, nice biscuit colour to the plugs after a run. That was after I fitted the Midget exhaust manifold, previously I had an AAU fitted.
It's a compromise really as it isn't a standard set up with all the different components that have been fitted the only way to really get it sorted properly and accurately is with a rolling road session with someone who knows SU's and how to modify them.

Sorry, I meant the 'round mini filter'...

rolling road go to south mini and metro center in southam i have used them for rolling road and part engine rebuild they are very very good