Plug Doctor

[stallie]

Upon removing the plugs to start the timing checks, I thought I'd take a couple of pics and seek comments from those more experienced than me.

 

Except the obvious that #1 and #6 are different brands any other comments about the condition? This is the first time I have had them out of the car. Can experienced eyes tell me anything about the tuning of the engine from these shots?

 

Needless to say I'll be replacing all the plugs.

 

Images are here (too large to post).

 

Thanks in advance

 

Dan

Edited February 18, 2009 by stallie

[stallie]

Furthermore - I just checked the timing.

 

All plugs out except #1 hooked up to a timing light.

 

Via a combination of turning a jacked rear wheel and a 15/16 ring spanner on the alternator and puling the fan belt for tension (the most force seemed to be by pulling out on the downwards side below the alternator) I saw the timing light flash on at 4 degrees AFTER.

 

Now the good brown bible says 11deg BTDC.... Could it be that far out (the engine ran OK) or have I done something wrong?

 

It's a CP 77052.

 

Timing pulley pic linked here

Edited February 18, 2009 by stallie

[Mike C]

Are you using a flashing discharge type timing light(about 40 years ago they were called a Xenon tube timing light)?I've never used a discharge timing light for static timing.I've used multimeters,test lamps and cigarette papers etc on the points for static timing but with a discharge timing light I always have the engine running as per the "Maintenance" section in the front of the Brown Book.If you want to check the timing statically use the method for the static distributor timing described under "Electrical" in the back of the Brown Book.The test lamp in this section is a humble 12V globe.After static timing I always recheck the timing with the engine running at low speed so that the centrifugal advance doesn't come in.This also ensures any backlash in the distributor drive system is accounted for.Note my PI engine has no vacuum advance connected to the distributor.I have known people in the past to retard the ignition to allow the engine to run on lower octane fuel -like when super was phased out in Australia.

[stallie]

Thanks Mike,

 

It's a very old "Neon Timing Light" made for Kmart Australia. Judging by the font on the box, it could well date back to the 70s.

 

I've revisted the Brown Bible and checked the contact gap and set up the circuit using the light globe method between the dizzy fly lead and +ve terminal.

 

I now get the light going out at 4 degrees Before TDC.

 

This still seems like a large gap - it should be 11? As mentioned the engine ran OK (but not 100% hence my fiddling).

Edited February 18, 2009 by stallie

[Richard Crawley]

Yes the engine will run with the timing that far out but it won’t be developing the power it should & acceleration will be down. Mile’s covered the timing issues, bearing in mind I’m only looking at photos; no 1 looks about right but looking at all of them, the general colouring looks like it’s generally running rich but this could be the result of prolonged idling & also dodgy injectors; 6, 2 & 4 also look a little oily especially no 4.

 

Get a decent set of new plugs, reset the timing & see what happens, take it for a good blow out & then check the colour again.

 

This might be usefull;

http://www.spark-plugs.co.uk/pages/technical/diagnosis.htm

[stallie]

Thanks for the advice again.

 

I put in new plugs, I reset the static timing to 11BTDC (found it at 4deg BTDC) and I reckon I have found an extra 30 horsepower!

 

The only issue is a little bit of pinging under load (foot to floor) so I'll back it off a degree or two and see.

[Richard Crawley]

I put in new plugs, I reset the static timing to 11BTDC (found it at 4deg BTDC) and I reckon I have found an extra 30 horsepower!

Cheapest form of tuning you can get.

 

The only issue is a little bit of pinging under load (foot to floor) so I'll back it off a degree or two and see.

If the timing has been set with the vernier adjusting screw on the dizzy at the centre of it’s adjustment, you can very often gain enough to stop it pinking just by adjusting the screw a little at a time; this way you can do it out on the road in between hard runs.

[Mike C]

Stallie.Good to hear of the power improvement.Before you back off the timing make sure that your fuel octane rating is correct.I run on 98 octane-its the highest I can get readily-Shell and Caltex service stations normally have it around Melbourne.