Stage 1 V8

My mates Range rover did the same a few years ago. The garage found a bent valve and said it had been like it for years. Good luck let us know how you get on

i remember i had this before, but i had allready su carbs fitted.
it would run o.k. but it would not pull. topspeed was 40 km per hour at full throttle.
it turned out in one carb the piston was not lifting.
in a su it could be stuck (just free it) and with the stromberg either the diafragm is leaking or the hole that gives the pressure of the atmosphere on the top of the diafragm is stuck (no difference of pressure under and over the diafragm results in no lift of the needle). i believe the hole is in the top of the damper on top of thre carb.

Darren, do you have a temperature gauge which works? Assuming the vehicle was running fine before and has only just started to run rough, I am wondering whether it has overheated and warped the cylinder heads. Those compression readings are shockingly bad.

If there were sticking valves, I would expect the engine to spit back through the carburettors or exhaust.

Richard

It may be worth checking your camshaft mate, they are prone to wear and this would stop the valves opening properly.
I have taken them out and there has been barely a lobe left and they where still running.

Basil

Just done a compression test on mine. Cylinders 1 & 7 are 20psi down on the others and go back with a squirt of oil. Looks like my bores are worn. Also found my dwell angle was at 43 degrees which wont help.

What does black plugs mean?

Jon

the haynes manual does a good info section on plug colours and what it all means.....

Hi all,

Firstly cheers for all the advice. I have found the problem.

One of the exhaust valves has a couple of splits in it (see pic) the others where quite badly carboned up on the seats. Re-gound in all the valves and ordering a new exhaust valve.

I will let you all know if this cures the prob (I suspect it will).

Does anybody know what would have caused the valve to do this.

Cheers

Darren