Thanks for the info.
In your experience, can an higher performance engine like yours tolerate more
or less total advance compared to a "stock" engine like mine. ?
Right now I am at about 7 degrees advance at 1000 rpm idle with the vacuum
attached.
I agree that the advance alone is probably not the entire answer, but it made
an enormous improvement to un-retard it!
Now it is quite "normal" feeling and no longer idles with dropping down over
30-60 seconds to near-stall conditions.
Also, now I can hear the response to idle mixture adjustments when using the
lifting pins on the SU's. Previously it had to be enormously rich or lean to
hear the engine note change.
So, it is running much better and pulls very well. Still no ping at 7 degrees
advance, so I will go to 8 degrees this weekend.
The remaining issue is the quality of the idle. It seems to have a random miss
that becomes "worse" (maybe just more noticeable) at lower idle RPM. It will
idle at 600, but it is noticeably rough. Idle of 800 is adequate, but not
smooth. Idle of 1000 is pretty smooth.
I have found no air leaks yet. The carbs are just rebuilt and SEEM to be OK.
I will be pursuing this over the next several weeks, I am sure.
-Tony
_____ORIGINAL MESSAGE_____
>Hi Tony,
>
>I have a TR4A also, just recently gotten running. I've found my idle timing
>to >be happiest around 10 degrees advance. However, my engine is highly
>>modified. Way too much to go into, let's just say I studied the art of
>timing >quite a bit trying to figure out where to be. There is the rule of
>thumb in the >Moss catalog, which says advance the timing to the highest RPM
>and then >back it down until the revs drop by 100, but that seems a little
>hazy to me. >The best rule I found was to work out what the engine needed at
>full >advance (32 degrees) and then working backwards with the distributor
>>advance I arrived at 10 degrees for the idle (Mallory dual point with an
>>adjustable advance curve, just to make it more complicated).
>
>Based on what you are describing, I don't know if ign advance is your
>>problem, though...
>
>Dave Rupert
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