Practically Classics Forum

Being in the market for a new compression tester, I want one that will do deep plug hole's ala the PT Cruiser etal and the XK series motor in the Jag / Daimler, but there seems to be a bit of negative feedback about the Am Tech kit, now I know it's a cheapy but it's not like it's going to get professional usage any one any views on it's usability. Any one want to suggest alternatives, looked at Draper but don't know about usablity of the long brass bit

Why not make your own long reach adapter then you can use any tester you like.

I have a gunson one, I've had it for about 25 years or so- it can easily be used on deep reach plug holes because although it's a flexible rubber tube it's quite stiff and relies on an o-ring for it's seal, hence it doesn't need to be screwed in particularly tightly. No tools required, you just aim and screw, so to speak......

mr rusty wrote:I have a gunson one, I've had it for about 25 years or so- it can easily be used on deep reach plug holes because although it's a flexible rubber tube it's quite stiff and relies on an o-ring for it's seal, hence it doesn't need to be screwed in particularly tightly. No tools required, you just aim and screw, so to speak......

^^^WHS^^^

Likewise I have one, works fine. Used it on some deep recesses over the years, no problem. I wouldn't bet my house on the accuracy of the actual reading, but the main thing with compression testing is to measure the differences between cylinders (look for <10%) and this it does admirably.

mr rusty wrote:I have a gunson one, I've had it for about 25 years or so- it can easily be used on deep reach plug holes because although it's a flexible rubber tube it's quite stiff and relies on an o-ring for it's seal, hence it doesn't need to be screwed in particularly tightly. No tools required, you just aim and screw, so to speak......

I've got one of those, and have had it for over 30 years (so there! ). Still works a treat. The other advantage with the screw in fitting over the push in ones is you can do the tests on your own without wedging the throttle open and hotwiring the starter.

I also have a Gunson one. I got the more expensive one, with a few long reach adaptors. The one bit of advice I'd say is to use the adaptor rather than screw the flexible pipe straight into the plug hole if it's deep. The first time I used it was on a Porsche 944 engine and it took me a long while with long nose pliers to get it out again. For some reason the fitting on the flexible tube doesn't have spanner flats on it like the extension tubes do.

Mike

I've yet to have an issue with a long reach tester, I think mines a Gunson too, and is suitable for both plug types with the aid of the included adaptor.