13/60 pinking in third or top when going up hill

[CarlM]

Hello some advice on next thing to do!
13/60 is run on Momentum or Vpower. As not unleaded head I use an additive.

Valve clearances set. New points, plugs and condenser.

Cold or when engine warm and on flat no pinking. When engine warmed up and driving on road if going up hill in top or third and accelerator pressed I get pinking.

static timing set to 10 deg btdc and get this, tried retarding timing (running about 5 deg btdc) and same problem.

any suggestions on where next to try would be appreciated.

thanks

Carl 

Edited July 21 by CarlM

[johny]

Pinking is acceptable up to a limit which is, engine up to temperature and accelerating hard in 4th on the flat the pinking must stop by the time you get to 2000rpm (if no tacho youll have to calculate this from speed). Pinking is usually made worse by running excessively lean or hot so hows your mixture and cooling?

[Pete Lewis]

what addative are you using and what are the sparkplugs   what the suffix marked on them 

Pete

[CarlM]

Mixture is more rich than lean. I had a leak on radiator fixed and part of this was to put rad on rig and do overnight treatment and flush. I was told at time that it was about 85% efficient. I am likely to get it recored later in year.

but will try the acceleration in 4th on the flat….

[CarlM]

I run NGK BP6ES and the additive is Castrol valvemaster.

 

[CarlM]

Just wondered if centrifugal weights or vac advance retard on distributor might be at ‘fault’?

[johny]

Yes its just possible that the distributor springs that control the fly out weights (and subsequently advance) have gone weak or broken so timing is excessively advancing on acceleration. This can be checked with the car stationary using a strobe to measure the advance at different revs (vac disconnected) and compare with the manual figures...

[Pete Lewis]

good thats the correct plug spec.   

are you running points or electronic dizzy ???

i dont see the need for any addative there is years of lead memory in the head casting , 

addatives can cause odd problems i would save you money  just buy fuel in the 97+ region 

most dizzy testing data in the manuals will show as done decelerating ...there is a difference here .

bob weights and springs can go wildly out of spec.   the vac unit only gets its vacuum from the carbs at light throttle cruise conditions   there is a spring inside which if failed can allow the base plate to shift around with no control

a good hard suck on the thing will show if it basically works and returns fully 

note it  wont taste very nice  !!!!

Pete

Edited July 22 by Pete Lewis

[CarlM]

On points.

I’ve tried the suck test from the carb end, with the spring disconnected from base plate and I detect some movement of the spring, not a lot but some.

used to play in a brass band some years ago, so hopefully can apply the right vac!, but you are right there are nicer tasting things out there….