Dist. A/R adjustment

[tahoe healey]

Would anyone know the relationship between each click of the advance/retard adjustment knob and the amount of engine advance/retard? I run advanced up here at high altitude (6400 ft) retard when I am down at lower levels getting out the timing light. This not always convienent at the side of the road due to sun light. I guess this would also be valuable to those who attend "Open Roads" in June. (Hey Tracy, a plug for GGAHC).

 

[John Loftus]

Hi TH,

I don't have an answer for you but it would be fairly easy to test x number of clicks it takes to advance/retard x number of degrees in the comfort of your garage. This way you know what works for your particular motor/ignition setup when you are out on the road. Of course if someone comes along with conversion it will be even easier! /bcforum/images/%%GRAEMLIN_URL%%/grin.gif

Cheers,
John

 

[Keoke]

Here is another suggestion TH, because that control provides minor changes in the timing. Set the knurled knob all the way advanced, then set the advance timing You use on the mountain by rotating the Dizzy body. Mark that location on the Dizzy flange and the clamping bracket. Now back off the advance knob until you get 15 Deg BTDC, if you can get there and make another mark on the clamping bracket. Many of these knurled adjusters are so worn and the closeness of the detentes makes counting a bit difficult. A bit of colored paint on the marks might aid locating them by eye. Oh an don't forget "U" Specks. ---Keoke

 

[tahoe healey]

Thanks John.
Keoke, I was thinking about setting the timing while at the all the way advanced postion cause I don't get enough movement form the A/R knob some times. I don't know what "U" Specks are.
TH

 

[John Loftus]

I don't know what "U" Specks are.
TH

/bcforum/images/%%GRAEMLIN_URL%%/cool.gif

 

[Keoke]

/bcforum/images/%%GRAEMLIN_URL%%/shocked.gif The wrap around kind TH.

I better splain John. TH some folks call em "Eye Glasses" but after you get em ifin you can see out of em it's a spectacle .So we just shorten the name to;"Specks". If they "U" specks they belong to YOU!



OH! John, you so trickey wid the computer!!---Keoke- /bcforum/images/%%GRAEMLIN_URL%%/grin.gif

 

[BobHorvath]

Hi all I am new to this form.
I too live @ high altitude and will be faced with these adjustments. I just went through my BJ8 distributor and I agree with the chap who states that the A/R adjustment is not very precise. Here is an idea which may have been stated earlier. What might be more precise is to bottom out the A/R control in the full advanced position. If you mostly operate @ high altidude, set your your healey up for max advance (with the hold down bolt) @ 4500 RPM (35deg BTDC)PLUS what you want to use as a high altitude differential. Here is where altidude experienced Healey drivers like the author of this thread (I'm thinking an extra 5 degrees might be ok up here). As you all know detonation is the danger when you drop in altitude. Detonation comes from many factors, gas quality, density altitude, lean mixture, heat and timing. If you set the timing for your high altitude max there is little danger and better performance at higher altitudes. Now is where you use the suggested method. Turn the knob as much as you want, it might take more turns than you think, and then Come up with the amount of adjustment to take you back to 35deg BTDC. The next thing to think about is point wear, that is if you still have points, here is where the electronic ignitions shine. The points wear and the timing changes as a result, so keep them tuned. The pointless designs will hold their timing for a long time. WHEN you drop in altitude then give her the amount of twists that your test said brought you back to 35. When you go back up the hill, twist it to the A stop and you will be right back to 40deg BTDC.
If you normally run in the flat land set the R against the stop @ 35deg BTDC and dial in the 5deg by twisting per your initial test number of twists. If you forget to retard on the way back down the hill you can always stop and twist to the R stop and be assured you are safe. Sorry to be so long winded. I will shorten my response in the future. Having a light that takes a dial in preset of so many degrees 35, then line up the TDC marks, has its advantages. Has anybody tried the weak metering for the SU's @ altitude? How do they work?

 

[bighly]

Bob,

Good to see you found us here. Nice speaking on the phone the other evening.

Tracy

 

[Michael Oritt]

TH--

I believe it is five clicks to the degree.

 

[johnea]

Hi TH,
11 clicks on the A/R fine adjustment is one crankshaft degree, providing there is no slak in the linkage.