Pinking

Post by **guystrungout** » Wed Mar 18, 2009 7:03 pm

Hi there, my Moggy has a 1098 in it which is timed and the mixture is fine, I've done the pin on the carb test so why is it pinking on hills and occasionally running on? I'm running it on unleaded with the Castrol additive while I wait for my unleaded head to come back from the engineers. Any advice would be welcome.

Post by **aupickup** » Wed Mar 18, 2009 7:12 pm

just retard the ignition a tad

Post by **PSL184** » Wed Mar 18, 2009 7:21 pm

Yes, as Dennis says - There is no "real" book figure for timing as each engine requires something slightly different. Just retard the timing to the point where the pinking just stops and it is then set right for your car.....

Post by **bmcecosse** » Wed Mar 18, 2009 10:43 pm

The best timing setting is where the engine is 'not quite pinking' - so just retard it slightly as Dennis suggests. However - you should check that the vacuum advance mechanism is working correctly - as this can cause excessive static advance to be required for good idling if it's not working. Also try without the Castrol additive, and perhaps also try a different brand of petrol. The only genuine 'lead' additive is Tetra-boost - which actually contains Lead Tetra-ethyl and converst unleaded fuel to leaded! All the other additives contain sodium/potassium mixtures along with a large pinch of hocus-pocus. They are of doubtful value. Minor engines will run for many thousands of miles on unleaded fuel without ANY additive. Problems only arise if they are thrashed regularly - and/or do high Mway mileages. Even then - all that happens is that the exhaust valve gaps close up - and just need resetting. Eventually a head change may be required if the valves become excessively pocketed. That's the time to fit another head!

Post by **superchargedfool** » Wed Mar 18, 2009 11:02 pm

as said try retarding till no pinking.

but the reason i am responding is that I want to say I agree totally with bmc about not worrying too much about leaded unleaded if the car is not worked too hard.

I have run many classics without unleaded heads for many miles without usually stopping to worry about unleaded. By the time it becomes a problem, which it usually never does all that is needed is to convert the head or replace it.

Which is no bigger or costlier job than you would have done in the first place.

Post by **Kevin** » Thu Mar 19, 2009 1:01 am

All the other additives contain sodium/potassium mixtures along with a large pinch of hocus-pocus. They are of doubtful value.

Sorry to disagree but that is a completly false statement and just your opinion.
As you well know the ones reccomended by the FBHVC were done in the correct test conditions.

Post by **bmcecosse** » Thu Mar 19, 2009 11:53 am

" Correct test conditions" - aye right! Did they compare with an engine running with NO additive ? Most A series engine s will happily run with no additive for a long long time.
I stick by my original view - that if you must add an additive - the only one worth considering is the one that actually contains Tetra-ethyl lead ie Tetraboost.

Post by **alex_holden** » Thu Mar 19, 2009 12:01 pm

I believe they did indeed use both leaded and unleaded (no additive) fuel as controls in their independently verified tests.

Post by **bmcecosse** » Thu Mar 19, 2009 2:22 pm

I seem to remember there was considerable controversy about the validity of the 'tests'.

Post by **guystrungout** » Thu Mar 19, 2009 7:04 pm

Thank you, I'll get on to it immediately!

Post by **MGFmad** » Thu Mar 19, 2009 7:38 pm

I would go with retarding the ignition as well. I had a Chevette many years ago that would pink when set up to the correct timing mark, retarding the ignition a tadd had it running perfectly.

Post by **bmcecosse** » Thu Mar 19, 2009 8:28 pm

Many of the 'additives' do contain an Octane Booster of some sort - and so in this sense they will allow the engine to run on lower octane 'unleaded' fuel without pinking and without the ignition timing being adjusted away from the previous 'leaded' fuel setting. To this extent only - they are effective for use with unleaded petrol. But as for long term exhaust valve seat protection, well .....

Post by **Kevin** » Fri Mar 20, 2009 9:01 am

Here is the link to the reccommended additives as fully tested by the FBHVC.
http://www.fbhvc.co.uk/fuel/index.htm#adds

I seem to remember there was considerable controversy about the validity of the 'tests'.

I don't remember that and the tests were fully independant, the only complaints I remember were from the so called unleaded inline products that refused to submit there products for testing.
If you think the tests were not valid why are you reccommending one of the test products.

All the other additives contain sodium/potassium mixtures, not completely true either have a look at the list.

Post by **PAULJ** » Fri Mar 20, 2009 9:37 pm

If the general feeling is that an additive is not required what does it matter which one you use!!

Post by **bmcecosse** » Fri Mar 20, 2009 11:00 pm

Thanks for the list! Ok - Manganese and Phosphorous too! I wasn't aware of them (or more likely had forgotten). Quite a selection!
I still believe that only the genuine Tetra Ethy Lead will do any real good for exhaust valve seats. That's what was in original 'leaded' fuel - and so if you are worried that 'unleaded' fuel may damage your precious engine, the only sensible way to protect it will be by using 'leaded' fuel - ie unleaded + Tetra Ethyl Lead - exactly as it used to be.

Post by **guystrungout** » Sun Mar 22, 2009 9:53 pm

It was the advance and retard unit, it was disfunctional, don't know why I didn't think to check it first off. Then I had to play about with the timing a tad but its all good now. Thanks for your help.