Compression testing

[Old Dave]

I have a compression gauge, although I haven’t found which box it’s in yet. It is of the rubber cone type.

Please can someone tell me how I should use on the A7. Obviously I can disconnect the feed from the coil to distributor but should I stop the flow of fuel to the carb?

Advice gratefully received.

[AustinWood]

There is no need to stop the fuel flow.
The Austin Seven starter can be operated without having the ignition on so there is no need to disconnect the coil either.
You need the throttle fully open while doing the test so you might need a third hand (or foot) unless you can wedge the throttle fully open.
Provided your starter is accessible from under the bonnet you should be able to test the compressions, though a bit awkward. If it is inside the car two people are needed.
Screw in compression testers are mucg easier to use.

[Old Dave]

Thanks Jim. That sets me right nicely. I still haven’t found the gauge, but I notice a screw-in one with various adapters is only £10 to £15 so will probably make the purchase.
Thanks again
Dave

[John Mason]

It is a lot easier with a screw in gauge as it eliminates the possibility os leaks.

John Mason.

[Old Dave]

Definite going the screw in route - thanks

[dickie65]

I have just blagged an old thread in compression tester it has a tyre pressure type rod to register compression.

[falcott]

The other day I did a compression test on the old girl -- sorry, car. They were all about 60lbs, but after a few days I realised that I didn't open the throttle when I was cranking it over. It was just a rubber push-on compression tester that I borrowed, so I didn't have a free hand anyway. One solution would have been to slip a small piece of wood under the throttle on the carb.

[Greig Smith]

I needed to check the compressions of the supercharged race car last week while we were prepping it for the upcoming hill climb. As the ring gear is in the Colin Chapman weight saving bin & the little blower is driven off the nose of the crank, I pulled the 4 plugs out, then jacked up one rear wheel and wrapped a length of belting around it. The blower wasn't connected to the intake as yet, so no worry about throttle opening. 4 Good pulls and all 4 showed 60+ Psi

Aye
Greig

[Old Dave]

Thanks all for your help. I did find the box with the guage in today, but it is a Gunson with a rubber bung. I will invest in a screw-in one soon.

Cheers

Dave

[Tony Press]

A search for compression pressures gives:

Compression pressures (austinsevenfriends.co.uk)

Reminded me- did any New Zealand Friends find what happened to Bob Culver ? 

I didn't always agree with his often off topic comments but he was a regular poster some years back.

From memory quite a few Friends enjoyed Bob's comments.

Cheers, Tony.