6 replies to this topic

[zero_wlv]

'Flaky paint' appearance on spark plug electrodes

 

Hi everyone,

 

First of all apologies for posting yet another question on spark plug colour,  I know the forum gets quite a few of them.

 

Basically I've just replaced a shed load of stuff on my engine and took it for a 45 mile run this morning and it's actually running very well,  it looks as though I've also managed to cure an 18 month old overheating problem,  the car is now running cool as a cucumber  (although I'm not sure which replaced part 'fixed' it).

 

Some items replaced include the head gasket, manifold gasket, carb gaskets, and valve clearances have been set to 0.40.    I've also installed new BPR6ES spark plugs   (rather than the BPR7ES I've always used previously because the engine builder recommended them).

I HAVEN'T however adjusted either the timing or the mixture.

 

Could anyone tell me what the 'flaky paint' effect is on the electrodes below?

Remember these were brand new plugs this morning,   they have just done 45 miles,   about half on the motorway and half around town.

If anything I'm sort of pleased with the results because the previous plugs used to tend towards being quite sooty.

 

Now I've finally cured the chronic overheating problem,  I'm inclined to get the car rolling roaded again (last time it was done was 5 years ago) but my local rolling road has a 3 month wait time,   so I want to make sure I'm not gonna do any damage to the engine by driving it around ridiculously out of tune for the next 3 months.

For what it's worth,   the last emissions test 3 months ago came back as 0.02% CO,  18ppm   (to me, both sound implausibly low for a carb car).

 

Engine is a lightly tuned 998cc with large bore head and Stage 1 kit,  also a Kent 266 clone cam and Hif38 carb.

Fuel is Shell 99 VPower.

 

 Cylinder 1.jpg   24.5K   2 downloads

 Cylinder 1 (b).jpg   24.74K   1 downloads

 Cylinder 2.jpg   38.8K   1 downloads

 Cylinder 3.jpg   18.5K   1 downloads

 Cylinder 4.jpg   42.01K   1 downloads

 

Thanks everyone,

Liam

Edited by zero_wlv, 07 July 2022 - 01:17 PM.

[Maccmike8]

Hi, running too lean or timing slightly off.

[croc7]

Surely you meant spark plug gap to .040" and not valve clearance.

[cal844]

Get an AC Dodd tune up (he will come to you) and get the car running bang on how it should

[zero_wlv]

Surely you meant spark plug gap to .040" and not valve clearance.

 

The spark plugs were already gapped correctly (0.80mm as per Haynes) when I took them out the packet,  I gave them a quick check.

 

I set the valve clearance at 0.40 as this is what the camshaft supplier specified on their data  (they've gone out of business but I wrote it down a few years ago).

I notice Haynes recommends 0.30 for all engines but I assume this only applies to the stock BL/Austin/Rover camshafts.

Edited by zero_wlv, 07 July 2022 - 06:28 PM.

[Maccmike8]

Get an AC Dodd tune up (he will come to you) and get the car running bang on how it should

 

Thats very good to know 

[croc7]

 

Surely you meant spark plug gap to .040" and not valve clearance.

 

The spark plugs were already gapped correctly (0.80mm as per Haynes) when I took them out the packet,  I gave them a quick check.

 

I set the valve clearance at 0.40 as this is what the camshaft supplier specified on their data  (they've gone out of business but I wrote it down a few years ago).

I notice Haynes recommends 0.30 for all engines but I assume this only applies to the stock BL/Austin/Rover camshafts.

 

My mistake, I thought that you meant inches rather than mm.