Tappets

[Ruairidh Dunford]

   

[Bruce Nicholls]

I flatted mine on an oil stone used for sharpening chisels etc.

[Dave Mann]

I'll upset the apple cart, since getting my first Seven in 1962 and a copy of LM Williams Specials book I have always set the tappets at 0.004" cold. After an article on tappet clearances in the PWA7club magazine last year I took one of the Sevens out on a blistering hot day up a long steep hill grinding away in bottom, at the top I quickly stopped and dropped (literally) the tappet cover off and checked the exhaust valve tappet clearances. All were an easy 0.002". Any engine rebuild includes grinding out the wear dimple in the tappet screw. I had to wait a while before I could refit the tappet cover.

[Steve Jones]

And I've always gone for 0.006" cold for inlet and exhaust. However, Paul Bonewell said 0.008" cold for the cam he supplied for my new competition engine so I've followed his instruction.

Steve

[John Mason]

Does anybody know if the tappet settings I.e. the gap. is the same on big sevens as other sevens such as the Ruby etc. As this will help Hobbo with his car.

John Mason

[Bob Culver]

The 1957 Austin publication 843/c gives the same .004 hot setting for all 1936-39 models small Seven to Twenty. (.006 for low grade fuels, whatever these are. I do not know why the difference)

[Jeff Taylor]

John Mason said:

"Does anybody know if the tappet settings I.e. the gap. is the same on big sevens as other sevens such as the Ruby etc. As this will help Hobbo with his car."

John, if you look back at my earlier reply (post no. 4) on page 1 you'll find that I do indeed quote the tappet clearance for the BIG SEVEN and AUSTIN EIGHT given in Pitman's 'The Book of the Austin Seven and Eight' fourth edition 1953 as 0.008" to 0.009".

Jeff.  

[David Stepney]

Having had difficulty with tight tappets when I first bought my car (rough running hot with the occasional popping back through the carburettor when pulling hard), I set mine to 6 thou for both inlet and exhaust. I note that Woodrow recommends 6 thou inlet and 7 thou exhaust whilst Williams says 4 thou for both. The handbook that came with the car (edition 972) is silent on the gap, merely exhorting the owner to use the tappet clearance gauge! I tend to the view that 4 thou is a bit tight and tight tappets can do more damage than loose ones.

[John Mason]

Sorry Geoff I missed that one.

John Mason

[Roland Alcock]

There must be many others like me, who have arthritic wrists which no longer articulate well.
Therefore checking gap when hot is a definite no no.
Checking gap accurately with manifold on is also an impracticable no no.
However if I can discern a discernible movement by feel on the tappet to be measured I am content.
This is not ideal or recommended , but better than not knowing about a tight tappet clearance.
4, 6, 8 thou measurement with the engine in the car would be in my dreams!

Roly