Timing

Post by **David53** » Wed Oct 14, 2009 5:53 am

Just tried to adjust the timing as per Mike Perry's technique of turning dizzie body for smoothest idle. Unfortunately i stupidly didn't tippex the body before i started so lost my original point of refence. The plan was to advance until it "pinked" then retard it slightly.

What I found was that turning clockwise gave a faster idle but the car ran worse under load. After a dozen or so road tests the best setting was turning back anti-clockwise a little (ie: Retarded). By advancing it I could not get it to "pink", it just ran lumpy under load. Retarding it again made for a smoother run...Does this sound right?

Post by **mike.perry** » Wed Oct 14, 2009 9:42 am

Check the points gap and set the dizzy where the car runs best. You only have 30 horses so you don't want any having a rest

Post by **David53** » Wed Oct 14, 2009 1:35 pm

Points gap is spot on (Dwell angle of 60). i was just curious why advancing the timing made it run worse...I thought advancing would give more power and you just had to watch out for pinking?

Post by **bmcecosse** » Wed Oct 14, 2009 3:58 pm

Have you checked if the vacuum advance is working correctly yet ?

Post by **David53** » Wed Oct 14, 2009 10:53 pm

Good point will have a suck and see

Post by **mike.perry** » Thu Oct 15, 2009 12:44 am

If the advance is too early it can try to push the piston back down the bore before it has reached the top especially on a low powered engine and you might not hear any pinking.
I found that my side valve engine would run over a wide range of timings but there seemed to be a critical point where it went best so the easiest way to set it up was to go for fastest tickover then road test it up the nearby hill with small adjustments until I was happy with it. It was imporant to mark the starting point as a reference particularly as the s/v dizzy tends to wind itself out of the head when the clamp is slackened

Post by **David53** » Thu Oct 15, 2009 2:24 am

Yes will have to have another tinker this weekend.

Initially turned slightly to the right and idle speed increased substantially. "Brilliant" I thought and took it for a short run but the accleration was lumpy she ran badly - power greatly diminsihed under load. So I am wondering about the vacuum advance as BMC says.

For now have turned it back anticlockwise and it is running better, but idle still a little lumpy. Kicking myself for not marking the original position!

Post by **David53** » Thu Oct 15, 2009 8:37 am

Actually, I'm REALLY kicking myself for fiddling about with it when she was running quite well

When will I learn.......?

Post by **alanworland** » Thu Oct 15, 2009 8:41 am

Surely you can reset the timing to its 'correct' position as you must have done when you rebuilt it - then mark it up and start again?

Post by **David53** » Thu Oct 15, 2009 8:45 am

Well, yes I guess I could by doing static timing but my engine has no timing marks so would need to pull rocker cover off, watch the valves, hook up a light bulb etc. Was trying to go for the "twist it and see" method

What I meant was I should have marked it before I moved it as it was actually running very well

Post by **mike.perry** » Thu Oct 15, 2009 9:32 am

You should have a notch in the crankshaft pulley and an arrow on the timing chain cover at 12 o'clock. Later engines had the 3 pointers below the timing cover. I guess it is important not to mix up pulleys and covers or you could be 180 deg out!

Post by **David53** » Thu Oct 15, 2009 10:29 pm

Actually no arrow which is strange....not that you could see the thing if it was there anyway!! Just about to replace the timing cover with a Mini one so I can have the better seal.

Post by **mike.perry** » Thu Oct 15, 2009 10:37 pm

The Mini cover will probably have the 3 pointers at the bottom which could be confusing. Could you mark the crankshaft pulley 180 deg out? Possibly with a notch on the back rim of of the pulley if the original is on the front rim. It would need to be accurate.

Post by **cormorant** » Thu Oct 15, 2009 11:02 pm

I must admit I couldn't get my engine to pink either no matter how much I advanced the ignition - it just ran worse eventually and I ended up setting to 3 degrees btdc static (1098) was a bit miffed as I liked the idea of trying this method

Post by **David53** » Thu Oct 15, 2009 11:40 pm

Ahh so I'm not alone then

I think I'll start from scratch - fit the new timing cover, find TDC and then mark the cover and pulley, set the timing using the static method, mark the dizzie body and go from there.

But first I will check the vacuum advance - I have a feeling this might not be working...

Post by **bmcecosse** » Fri Oct 16, 2009 9:00 am

If very low/poor compression I suppose it may not be possible to induce pinking!

Post by **mike.perry** » Fri Oct 16, 2009 10:18 am

If the vacuum unit diaphram is damaged it can allow petrol vapour to be sucked into the distributor, ignited by the points and shatter the dizzy. Unlikely but it happened to me.