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Re: No compression on 2 cylinders 1938 Ruby

A bodge might free the sticking valves but for peace of mind I would take the head off and strip the valves out, first of all to determine why they had stuck and secondly to regrind the seats.

I had a stuck exhaust valve after doing my mega run to the top of the Col de la Bonnette and whilst the engine was still running OK it was a bit short on power on the way home. Even that little hiccup had enabled the exhaust gases to burn the seat.

Old adage - do it once, do it right. (I think it was Jack Reacher wot said it)

Re: No compression on 2 cylinders 1938 Ruby

Not as simple as a blown head gasket

Location: Oakley, hants

Re: No compression on 2 cylinders 1938 Ruby

To answer the original query: the two valves are both exhaust valves, so they have that in common, also they are to the rear of the engine which usually means they run a little hotter than the other two.

So maybe the deposits on the stem are a bit harder, so they are more likely to stick.

Simon

Location: On a hill in Wiltshire

Re: No compression on 2 cylinders 1938 Ruby

Thank you everyone for your advice. Sounds like the valves could coked up a bit. I have decided to take the head off etc and check nothing is bent or damaged and hopefully all it will require is a bit of a clean.
Will let you know when 'Ivy' is back running around my local lanes.

Re: No compression on 2 cylinders 1938 Ruby

Dave Wheatley
Ian, can you explain how poking a bent screwdriver through the plug hole to try to free a stuck valve will bend the valve head?
I'm not suggesting sticking a crow bar down you know. And if appreciable resistance is felt, stop and 'fix it properly'.

It's worth a shot.


I takes very little to tweak a seven valve head out of truth which may not be immediately apparent, and Reckers has given you the other part of my answer.....short cuts invariably cause more problems than they solve.

Location: NZ

Re: No compression on 2 cylinders 1938 Ruby

Hi,
Check that the cam followers drop away from the valves if you think you have stuck valves.
I have seen a few instances of split cam followers caused by overtightening the adjusters. the cam followers jam in the guides holding the valves open.
when you have a look at the followers, if split it will just look like a small vertical scratch. you need to pull the followers out and tighten the adjusters to see if a split opens up. or use a dye test kit.

you could try to loosen the tappet adjustment lock nut on the offending valves and see if it makes thing move.

Austin valves rarely jam in the guides unless they get bent.

Please report back on your findings.

Location: Cornwall