Compression testing a flathead 4 cyl?

[Mogul]

I have a 1933 Flathead 4 cyl, which I wish to test the compression on. The engine runs, but I am merely curious to see that condition of the beast...

The plugs are 18mm, thus my dilema, my compression tester doesn't have an adapter that large. Does anyone know whether one even exists, or any other thoughts on getting it to work?

Finally, what compression range would I be shooting/wishing for...Obviously main concern is that all 4 cyls are near equal, but what would be ideal?

[46fordtruck]

Not sure on the optimal compression, but the adaptor should not be a prob, some small block Fords used an 18mm plug.

[56f600]

My comp. tester has a rubber tapered end on it that you just push into the plug hole. Of course it is a two man job, one to crank the enging and one to lean on the tester to keep it from blowing out. Check your local auto parts store, they should be able to set you up.

[Mogul]

Thanks for the suggestions, I have found both of the options you speak of...thank again