ignition timing

[nashy4]

can anyone tell me what the static timing setting is for a 1850 running on unleaded fuel also do i need hardened valve seats in the head cheers andy

[JPB]

You already have suitable valve seat metallurgy for unleaded, the OHC cars were built that way, try the factory figure (11 degrees before, static). Mine runs fine at closer to 16, has had one skim and doesn't pink. Ever. Retard it slightly if yours does pink though. Chances are it won't unless it's in dire need of a decoke.

That said, and nothing to do with those valve seats; Super unleaded can give you better fuel economy than Premium, so maybe fork out the extra 3p per litre for that and see which suits you better.

[nashy4]

cheers for tht info john i have recently replaced the cylinder head so decoke has been done it has a tr7 head on a 1850 block starts well on standard points needs the carbs set up and a quieter exhaust as someone has put a loud bore on it cheers andy

[sprint95m]

To add to John's post,
I reckon the factory figure of 11 degrees BTDC is not far enough advanced for normal unleaded.
The old "advance it as far as possible without pinking" is sound advice for an 1850.

I think mine is set to something like 15 degrees BTDC and I run it on normal unleaded as that is the only choice
(we have a Tesco here now, therefore Super unleaded in not available, given the filling station closures).

[Sprint East]

What John and Ian said.

Apparently today's fuels burn more slowly than 70s four star so need more of an advance, otherwise still burning fuel mix is expelled into the exhaust - which is why many people say modern fuels burn hotter (if they really burned hotter one would expect more expansion in the cylinder and hence more power). I seem to remember the MG club doing some 'proper' scientific research into this.

My Sprint is about 16 deg running on Shell VPower, it runs like a dog at book settings.

[Toledo Man]

Brown's on factory settings and running on bog standard supermarket 95 RON. I'll be having a play with the timing later on tonight after I've done a couple of errands. I need an excuse to take Brown out for a run.

[Toledo Man]

With my electronic ignition (I recommend this. Well worth every penny) and the timing on 16 deg BTDC Brown was pinking on normal 95 RON supermarket unleaded.

[Toledo Man]

Having gone back to points and condensor I set the static timing by the book figure with the use of a test lamp. Once the car was running and up to operating temperature I then advanced the timing gradually until the hesitation under acceleration had gone.

[Edin Dundee]

Having gone back to points and condensor I set the static timing by the book figure with the use of a test lamp. Once the car was running and up to operating temperature I then advanced the timing gradually until the hesitation under acceleration had gone.

May I ask why you've gone back to points?

[Toledo Man]

The Newtronic unit seems to have died (no spark at the coil) so I'm back on points and condensor. I fitted new ones just before the MoT with little use since so I knew they were working fine. I'll be looking at a brand new unit once I've re-taxed Becky II.

[Toledo Man]

I think I've now worked out the best method which is to set the static timing by the book settings with a test lamp to get the engine running. Once up to operating temperature advance the timing until the revs go up. If it pinks then retard the timing until it stops pinking. This will be trial and error and adjustments will have to be made a little at a time with road testing until you get it right.

[G-Ray]

This is good to know, as I just adjusted the timng after buying my 1850, it was at about 10deg, now set at about 11, near 12. Runs ok, but tempted to try advancing it a couple of degrees now.

[Toledo Man]

To add to this you should adjust the timing until you get the fastest smooth idle. If it pinks then retard it until it stops pinking. I'm back on electronic ignition (Britpart in a Sprint dizzy) for those that don't already know.