1965 vauxhall victor low compression

[garagejunkie]

Hi guys, I have recently been recommissioning a 1965 victor fb. The car had been starting and running fine after renewing ignition components. After getting it out onto the road for the first time ( first time under load) there was an instant problem with shuddering, no power unless the clutch was in . Almost like fuel starvation( it's not) . White grey smoke from exhaust .

I managed to get the car home labouring in 4th . A compression test shows 25psi in all cylinders ( compression ratio should be 120psi when new) I then squirted some oil in the bores and tested again which raised the compression to around 50 psi . So there is leakage past the rings but I'm more concerned about where the other 60psi is going . I was also puzzled to why it was even wear.

Could this be a cylinder head / valve problem ?

I think it should be a leaded cylinder head an my thoughts are the valves and seats are nackered with wrong fuel possibly? I've no history for the car. But I do know the mileage is genuine at 63,000 .

any thoughts or procedures to try would be welcome . But I'm sure the head needs to come off ....

Any my help out there?

Thanks m

[garagejunkie]

crossy67 said:

Easy diy leak down test. Find a way of plumbing a compressor hose into your spark plug hole. Make sure both valves are closed and pressurise your cylinder. You will hear where the pressure is escaping.

Thanks crossy
If never done this before but sounds like something I need to do before diving in and stripping, what sort of pressure will I put into the head ? Would a foot pump do the job and use the gauge ?


Mileage is low as it was stored for a while and I have the original dealer service book / receipts / mots etc

[garagejunkie]

I feel a it stupid , before I went to strip things to investigate I nipped up to screw fix and bought another compression tester , it now has 120psi ! It turned out to be a problem with the ignition . It was firing on all cylinders at idle and under load only 2 and 4 were continuing to spark . The points seem to have been sticking or welding them selfs . It's now re timed AND new points and it seems to be running well on the road except from a flat spot when pulling away from junctions . Thanks for all the help and sorry to waste people's time , but I will remember all the above info many thanks

[garagejunkie]

kev b said:

A common problem on Vauxhalls of old was poor quality distributors where the four lobes which open the points for firing each cylinder were not the same height.

This results in wildly different points gaps between cylinders either wide or narrow, depending on which lobe was used to set the gap, causing misfiring due to a weak spark.

The way around this is to measure the gap for all four cylinders and set the gap so all cylinders are somewhere near.

Thanks for that info ! I have fitted a spare distributer that I had all set up ready to use (hands were to cold to fiddle with the one that was in it ) I suspect there was something faulty with the one I took out so I will do your described check tomorrow. I'd like to get to the bottom of what happened. I just thought it being strange how 4 and 2 were firing fine and 1 and 3 weren't under load . . . .

All i have really done is change the distributer / points and problem solved.

(Just glad it wasn't a compression problem)

Thanks again guys I'll remember the advice !