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how to Check total Advance on Dist

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hondo402000

hondo402000

Darth Vader
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How do you check total advance on a TR6 Dist with out reving the car up to 4000 rpm in the drive way,, Is it possible?

Hondo
 
"Total" is taken as initial plus centrifugal, and on a Lucas dizzy the max centrifugal is set by a positive stop. So one way is to measure initial advance and then add the max centrifugal (which is usually marked on the stop).

But if your stop has been modified or you just don't trust it, then you'll have to spin the dizzy up. If not on the engine, then on a distributor machine. Old machines sometimes sell for cheap:
https://www.ebay.com/itm/GAS-STATION-VTG-...=item1e6768f262

Another approach that might be amusing (if your talents lie in that direction) is to install a crank sensor and build a circuit to measure and display the advance in the cockpit. But of course if you are going that far, might as well have it control the timing as well (making it adjustable from the cockpit).
 
Is 4000 where your total advance peaks?
Actually that isn't that much of a spin up. And it don't have to be there very long
 
Jeff at advance recurved my dist, and I talked to him on the phone, he said he had my file but on paper not on a computer, so he couldnt go back and tell me the total advance he set, but he did say if I increased the CR that it might need to be recurved again. but the good news is I centered the thumb wheel, set the timing at 14 BTDC, changed the choke tubes, jets in my webers back to the best setting I had and now its almost perfect, AF is in the 12.5 at idle to 13.5 range from Idle to WOT. the Miss at 3000 is gone!. I think I had the thumb wheel adjustment all the way to one side and the timing could not get to full advance. So now I am going to put some miles on it, watch the AF meter for a while and just do some tweeking.

Hondo
 
Glad to see that 90% of all carb problems are electrical, once again........
 
Sounds like you've gotten past the frustratin' part, Hondo and now into the fun part of the process.
Basically with the mods on your engine you have a 'one of a kind' and you won't find the answer in any book or manual as to what's your engine's sweet spot, but rather (in the absence of a "rollin road") by the ever so much fun test drive after test drive.
After nearly one year and 7000 miles on my moded engine.I find myself pretty darn close. but not so close that I want to stop tweaking.
Heck, even if I did, Winter will be here soon and I might have to make a few adjustments to be in harmony with the cold air that my carbs will soon be digesting,
 
they have cold air in Mississippi,,,, and do you mean from 100 degrees to 75

lol. well charlotte we can get down to the teens in the winter but then I dont drive when its that cold, now in the 30's yes

I only have 375 miles on mine and going to check cylinder pressures and send them to Jeff and see what he says



Hondo
 
I saw where you mentioned the cylinder pressure. I'm guessing that would be doing a compression test, right ?
I don't get the relationship to the advance curve though.

I did 3 compression test so far on my engine
The first was at 500 miles which averaged 152
The next was at 1500 miles which averaged 166
The last was at 6700 miles which averaged 176

And, cold ? Hondo when you spend 3 months sweating at 100, 70's do actually feel cold.
 
yes compression test, I dont get the relationship either but Jeff at advance said if the pressures are higher than when I sent the distributor out a few years ago it would need to be recurved,

Hondo
 
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