Timing & Pinking on a B18b

[A Sherratt]

Whilst the weather 's been fine I decided to do some tinkering on my P1800s (1968). She's only been on the road two months after a lay-up of ten years or more.

She was suffering from pinking on the hills and so after reading the 'haynes' manual i decided to retard the ignition timing as detailed in the manual.

Anyways, the pinking has now gone but my timing gun now says the ignition is set at 1 degree. She starts up first time every time and runs lovely, however, I am concerned that by altering the timing so much I may suffer further problems in the future!!!

Any thoughts????

I know the timing gun is spot on as I have used it on other cars. The only other answer may be that the marks are out on the flywheel!!!

Adrian

[Pigeon]

I don't know what procedure the HBOL gives for setting the timing that might end up leaving you with it set to 1 degree, but I always do it like this:

Drive far enough to get the engine thoroughly warmed up, then find a hill of sufficient gradient to be able to floor it in top at around 30-40mph without anything much happening in the way of acceleration. If it pinks under these conditions, I retard it a tincy wincy bit; if it doesn't, I advance it. After a few runs I get it to the point where you maybe get a little rattle for half a second at one point but nothing else. I call that "correctly set".

With a B18B I'd reckon it's worth using the highest octane fuel you can find, as well - Shell 99 octane or Tesco do a 99 I believe - or adding 10% cellulose thinners to the tank.

Or you could run it on pure cellulose thinners and raise the compression to 12:1 odd and make it go a bit quicker...

[A Sherratt]

Pigeon, thats exactly how Ive set it but using standard unleaded fuel as I did'nt want to mess around with octane booster all the time.

Once it was set up using this tried and tested method I thought I would check it with the timing gun and thats the result!!!

Adrian

[Pigeon]

Well standard unleaded is only 95 octane which is decidedly on the low side... try filling up with V-Power and see if that makes any difference.

[AidanC]

You haven't got a vacuum retard distributor by any chance have you? What speed was the engine running at when you checked the timing?

[A Sherratt]

AidanC, the engine was running at 1500rpm and there isn't a vacuum retard.

I know my rev counter is wildly in-accurate so I use the one on the timing gun.

Next time I fill up I will try the V power fuel.

[devilishdesigner]

definitely go with the high end fuel. when i got my 'zon (has high comp engine) the previos owner (who was also the car's first owner) told me only to run it on the top stuff, never to even attempt regular. well i have chucked regular in once by accident and it didnt have too much of a negative effect, but just going ftom 95/96 octane premium to 98 octane top shelf fuel i have found that there has been a 5-10% improvement in fuel economy, which makes me very happy

[austingipsy]

Has anyone tried this stuff yet ?
http://www.bp.com/sectiongenericarti...tentId=7016848

saves you mixing your own batch with thinners and since cellulose thinner is about 5 quid a litre I'm too mean to even consider it.

[Pigeon]

I am given to understand that it is considerably more expensive than normal petrol, whereas thinners is about the same price as petrol.

If I can I always fill up with LRP simply to save the hassle of mixing in valve seat protection additive (put additive in spare fuel can, add half a litre of petrol, stick nozzle in tank, fill up, attach spout to fuel can, swirl it around, pour into tank, put equipment back in boot, drive off with stench of petrol emanating from boot). Fortunately one of the local Sainsbury's still sells LRP, and the engine behaves as if its octane rating is a bit higher than the nominal 97.

[Gordon Hunter]

Originally Posted by austingipsy

Has anyone tried this stuff yet ?

Unfortunately it only seems to be available in the South of England or in Edinburgh.
Celly thinners it is then.

Gordon