The sectret of great comedy is... - TIMING!

alfesti

alfesti

Member
I know the old V8 has a reputation for the timing slipping out, but 3 times over 500 miles in a weekend (4 if you include setting it before leaving) seems a tad excesive.

Anyone had this before and would electronic ignition suffer the same as the whole dizzy is rotating?

Thanks chaps

Matt
 
If the distributor is moving it will be the same with points or electronic. If this is the case the answer would appear to be stop the distributor moving.
 
Are you setting your points with a dwell meter, or feeler guages? The points gap can seriously affect the timing. I always set mine with a dwell meter, then run the car around the block, then reset with the dwell meter, then adjust the timing. I normally find that the timing stays pretty good after this.

With the problems you are experiencing, I would check that the mechanical advance weights are operating correctly, and not sticking, and also check that the vacumn advance unit is operating correctly. It is not beyond the realms of possibility that the rotor arm is moving a little on the end of the distributor shaft either. They are not always an exact fit. Distributor shaft wear will cause problems getting the points gap right, and may cause the timing to fluctuate a little, but wouldn't cause the timing to go out.
One last suggestion, check that the distributor clamp is tight. I know this may sound silly, but several times I have found the clamp is loose, because the bolt feels tight, but it is actually tight in it's thread, and not fully tightened down onto the clamp.

I'm starting to have problems getting hold of decent quality points these days, so I would say that electronic ignition is definately the way to go. I'm tempted at the moment to fit the Aldon Ignitor system.

Hope this helps
 
Get the dizzy off and check the drive cog.

I had a friend who had exactly the same symptoms you describe.
The cog on the end of the cam and dizzy both stripped a tooth as the wrong woodruff key was fitted meaning no oil was actually getting in to lubricate the dizzy.

Take the dizzy out and make sure theres oil on the end!

What was happening, is he set the timing, turned the engine over and the drive cog would skip one tooth as the broken one came around. The engine ran like a dog.
New cog on the cam and a mallory dizzy and the engine will tick over easily at 400rpm and will rev smoothly to 6000rpm.

It is the standard MGB block with stage 2 heads and a typhoon camshaft.
 
Thanks guys,

I'll have to have it out and have a poke. I'm definately going to get electronic on its ass, bu its interesting that it only seems to go out when its been turned off, then after starting well does further and further out after a minute or so. Last time it went I reset it in Peterborough and didnt switch off till Maidstone an hour or so later, well an hour and a half maybe, and its still fine. That vac advance sounds like a culprit...
 
If nothing amiss is found with the dist. and its drive, it may be worth checking the timing chain and gears.
If the chain is excessively slack it would throw the timing out, especially when stopping and restarting the engine.
 
PeterB76 said:
If nothing amiss is found with the dist. and its drive, it may be worth checking the timing chain and gears.
If the chain is excessively slack it would throw the timing out, especially when stopping and restarting the engine.
Click to expand...
Agreed.
Would be worth changing it anyway for a pre-streched duplex chain and solid gearset. Those plastic gears are a waste of time.
 
Thanks for all the ideas, Im sure it will be expensive! However, I havnt touched it since last slip, its abit advanced but runs well, even squeaking its tyres for the first time (ahh, bless) so maybe just needed the extra anger in the tourquing up to grip it better. Maybe I was being too wussy and worrying about stripping yet another ally thread!
 
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