compression test results

[sg1]

Help... can anybody interperate my compression test results?

1 - cold 110 Psi, hot 108, plug black
2 - Cold 110 Psi, hot 108, plug black
3 - Cold 115 Psi, hot 115, plug black
4 - Cold 115 Psi, hot 125, plug brown

Best regards,
SG1

[bmcecosse]

Utterly knackered engine.......... ! What engine is it ? may be 'just about' ok for a side-valve.

[sg1]

Alas it is a 1098, 1968 1000.
SG1

[MarkyB]

Probably cream crackered.
Any better hot, or with a little oil down the bores?
Does a lot of smoke come out when it is running? If so what colour, Black or Blue?

[bmcecosse]

It's well gone....... Decent 1098 would be 160/170 psi.

[sg1]

Thanks for your help. RIP
SG1

[sgray]

Couldn't it just be the head?

My 948 was giving 80,30,80,80 before I changed the head and now it's 150 across the board. And the head just cost me £50

[mike.perry]

Utterly knackered engine.......... ! What engine is it ? may be 'just about' ok for a side-valve.

Not even any good for a S/V, mine are 130psi. The book says 150psi for a 1098. Maybe you are better off with the 948.

[millerman]

Forget the doom and gloom merchants!

Are you 1).satisfied with your car's performance and 2) does it use very much oil

If the answer to 1. is yes and 2. no, then keep driving and service regularly

[bmcecosse]

I suppose it is entirely possible that the valves and seats in the head are all knackered. Usually just one or two fail before the hopeless performance forces the owner to do something about it! So, yes - there is no harm in lifting the head and checking it for any problems.