compression testing nc30

[stefan]

hi can anyone help me out i am trying to find a 8mm adapter so i can check the compression of my engine but it seems that no one in the UK sells one can anybody help thanks.

[alexwitham]

I am also finding it difficult to obtain an adapter so am having to make one using an old plug.

[arsey30]

I use one with no thread, just a rubber bung type seal, Gunson

Sealey ct 954 similar, but unsure of length.

[stefan]

thanks for the replies i have tried to make an adapter from a spark plug but not having much luck on getting a air tight seal, also struggling to get a good enough seal with the push on tester. i have heard that an adapter can be made i just don't have the tools to make one has anyone been able to make one.

[Lane]

I made one out of an old spark plug with the porcelain removed and a pipe brazed on with a female thread at the top to screw the 10mm compression tester adaptor into.

I also have a rubber push fit one which works just as well, however it takes a couple of attempts to get the seal right.

[stefan]

What psi readings were you getting with the push on type tester

[Neosophist]

I use one with no thread, just a rubber bung type seal, Gunson

Sealey ct 954 similar, but unsure of length.

That looks just like my old gunson from the 80s!

[krisztian_andre]

A machinist made an adaptor for me, I'll post photo and details when it arrives.

[Lane]

What psi readings were you getting with the push on type tester

It's a freshly rebuilt engine that had 0.5mm skimmed from the heads and has 220 psi on all four pots, rings and cylinder walls aren't bedded in yet.