Series 3 Ignition timing 2.25 petrol

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if you're running points and not 'upgraded' to electronic ignition timing then a dodgy condenser can give some very weird running problems, can you turn the rotor arm back and forth with your fingers?
 
Hi back to basics. Check the tdc mark is really tdc. Check you're actually getting a spark on #1 at the set point. Have you got a timing light? Have you got the right plugs in and what do they look like? Are the plug leads in good order? What about the coil?
Sorry if I'm repeating anything
 
Checking TDC is correct, is well worthwhile. When I was getting my engine running after swapping the distributor, I was struggling to get the engine to run much faster than idle, even with the throttle wide open. Engine was getting very warm but wasn't going to have enough power to pull the skin off a rice pudding. Turns out the pulley mark was completely wrong, and I was sparking at something like 45 degrees ATDC, if not more. Doh!

Checked the real TDC with a thin stick in number 1 cylinder plug hole and remarked the pulley. Ran much better after that! :D

However, if it's still pinking when you're retarding the ignition enough to notice such a significant drop in engine power, then I think something else is definitely wrong. I assume it's known-good fuel, and not been in your tank too long? Might be worth running at 3 degrees ATDC, and see how much it's pinking vs the engine power at that setting.

How are you checking your timing?
 
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I was thinking about this some more. This might be a bit farfetched on a Landy engine, but do check the compression.

On 'performance' engines, if the head is skimmed, it can increase the compression too far and you get pinking if the fuel octane rating isn't high enough. You mentioned this started when the head gasket was changed. Was the head skimmed at the same time?

I know the Landy engine isn't normally what you'd call a high compression engine, so unless *a lot* of metal was removed, it's unlikely this would be the cause, but might be worth checking to be sure.
 
I was thinking about this some more. This might be a bit farfetched on a Landy engine, but do check the compression.

On 'performance' engines, if the head is skimmed, it can increase the compression too far and you get pinking if the fuel octane rating isn't high enough. You mentioned this started when the head gasket was changed. Was the head skimmed at the same time?

I know the Landy engine isn't normally what you'd call a high compression engine, so unless *a lot* of metal was removed, it's unlikely this would be the cause, but might be worth checking to be sure.
I've heard folks skim to get extra compression and more power, never heard of any problems as a result. Always a first time i guess
 
I've heard folks skim to get extra compression and more power, never heard of any problems as a result. Always a first time i guess
There's a limit. Otherwise, you'd just keep skimming and skimming and getting more and more power...
The Landy engine is deliberately lower compression so it can run on almost any fuel without problems and less fussy about having the timing spot-on.
 
Or you bend a valve :rolleyes:
True, although a less-aggressive cam profile can avoid that. I'm assuming Landy cams aren't particularly 'hot', in which case the valves might be firmly closed towards the top of the stroke.

Was the replacement head gasket thinner than the one it replaced? That's another reason the CR may have risen...
 
Checking TDC is correct, is well worthwhile. When I was getting my engine running after swapping the distributor, I was struggling to get the engine to run much faster than idle, even with the throttle wide open. Engine was getting very warm but wasn't going to have enough power to pull the skin off a rice pudding. Turns out the pulley mark was completely wrong, and I was sparking at something like 45 degrees ATDC, if not more. Doh!

Checked the real TDC with a thin stick in number 1 cylinder plug hole and remarked the pulley. Ran much better after that! :D

However, if it's still pinking when you're retarding the ignition enough to notice such a significant drop in engine power, then I think something else is definitely wrong. I assume it's known-good fuel, and not been in your tank too long? Might be worth running at 3 degrees ATDC, and see how much it's pinking vs the engine power at that setting.

How are you checking your timing?
True, although a less-aggressive cam profile can avoid that. I'm assuming Landy cams aren't particularly 'hot', in which case the valves might be firmly closed towards the top of the stroke.

Was the replacement head gasket thinner than the one it replaced? That's another reason the CR may have risen...
No that head gasket wasn't I don't think but I know it has been skimmed 2-3 times, the valves are all fine I'm guessing because it's very smooth on the flat it's only under full acceleration or uphill that it happens
 
Checking TDC is correct, is well worthwhile. When I was getting my engine running after swapping the distributor, I was struggling to get the engine to run much faster than idle, even with the throttle wide open. Engine was getting very warm but wasn't going to have enough power to pull the skin off a rice pudding. Turns out the pulley mark was completely wrong, and I was sparking at something like 45 degrees ATDC, if not more. Doh!

Checked the real TDC with a thin stick in number 1 cylinder plug hole and remarked the pulley. Ran much better after that! :D

However, if it's still pinking when you're retarding the ignition enough to notice such a significant drop in engine power, then I think something else is definitely wrong. I assume it's known-good fuel, and not been in your tank too long? Might be worth running at 3 degrees ATDC, and see how much it's pinking vs the engine power at that setting.

How are you checking your timing?
Okay could it be 180 degrees out or would the symptoms be way worse, also I was reading on series123 and that the emission controlled engines stock were timed to 6atdc? I'm using a timing light and the original knotch in the pulley
 
The engine probably started as 8:1 compression. I read somewhere that the highest you can go is just slightly above 9:1. I don't know what that is 1000ths of an inch of skimming but skimmed 3 times sounds too much to me.

Col
 
The engine probably started as 8:1 compression. I read somewhere that the highest you can go is just slightly above 9:1. I don't know what that is 1000ths of an inch of skimming but skimmed 3 times sounds too much to me.

Col
Oh okay so you think it may need a new head, I'll buy and do a compression test to see if it has increased to much
 
Okay could it be 180 degrees out or would the symptoms be way worse, also I was reading on series123 and that the emission controlled engines stock were timed to 6atdc? I'm using a timing light and the original knotch in the pulley
It wouldn't run at all if it was 180 degrees out...you'd be firing at the bottom of the stroke, when the mixture isn't compressed, so won't really do anything. You might get a backfire if the mixture ignites as the exhaust valve starts to open.
You could check the accuracy of the pulley notch by using a very clean, think stick in the plug hole and rocking the engine back and forwards to get it spot on TDC, but I think the fact that it's mostly OK and you're detecting the loss in power at 6 degrees ATDC, you're probably about right and you've not got a pulley with it's notch way out like mine was, so I would guess you are about right with how you've set it.
 
Oh okay so you think it may need a new head, I'll buy and do a compression test to see if it has increased to much
You might be able to get away with finding a thick head gasket from somewhere. I think they can be cut from copper sheet, but never tried it or know anyone that has. Might not be terribly cheap, either....but hopefully cheaper than a replacement head.
 
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