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vegas paul
05-08-2007, 09:55 PM
I've searched older topics but haven't quite figured out the answer to this:

1951 Champion flat head 6.

I am installing one of Dave Thibault's electronic ignition systems, after finishing my 12V conversion. Prior to doing anything about taking out my old distributor, I aligned the engine to UDC (which is either #1 or #6) and noted where the rotor was pointing (to ensure the timing would be correct upon reinstalling the new distributor). It was pointing (almost) forward, which tells me I got cylinder #1 at UDC.

Problem: This forward pointing ignition post is connected to #6 cylinder spark plug. All the cylinders are wired in the proper order from ther, but 180 degrees out from what I would have expected. Does this matter?

The car was running OK (but not great) prior to my starting this conversion. I can't do the "bump" test yet to determine which cylinder is actually compressing since I haven't yet hooked up a 12V battery. I guess that might be next, but any ideas what's going on?

I thought (from reading previous posts) that cylinder #1 was supposed to be the forward-pointing distributor post, but maybe it doesn't matter as long as the order is correct. Maybe the PO installed the oil pump strangely which misaligned everything.

All suggestions, advice, insults, opinions or anecdotal stories will be appreciated...

Las Vegas, NV
'51 Champion Business Coupe G899965 10G-Q4-1434
http://i151.photobucket.com/albums/s144/vegas_paul/graciestude.jpghttp://i151.photobucket.com/albums/s144/vegas_paul/1462673_2_350.jpg

Dick Steinkamp
05-08-2007, 10:34 PM
quote:Originally posted by vegas paul

I thought (from reading previous posts) that cylinder #1 was supposed to be the forward-pointing distributor post, but maybe it doesn't matter as long as the order is correct.



It really doesn't matter as long as the order is correct.

Keep in mind that a cylinder will fire on every SECOND revolution of the crankshaft. With the firing order of your engine being 1-5-3-6-2-4 that means that half the time when the pointer is at the UDC mark the #1 cylinder will be in the firing position, and half the time the #6 cylinder will be in the firing position. It looks like you just happened to have the #6 cylinder at UDC. If you want #1 at UDC, turn the engine one more revolution.

http://thenobot.org/images/s2d/s2d_01.jpg

vegas paul
05-08-2007, 10:39 PM
Thanks Dick, I understand. I was just surprised that when #6 cylinder was firing, the rotor was pointed forward. This seems to be contrary to what the other posts said was originally designed. Is there any other way (besides "bumping" the engine) to tell when the #1 cylinder is at UDC?

Las Vegas, NV
'51 Champion Business Coupe G899965 10G-Q4-1434
http://i151.photobucket.com/albums/s144/vegas_paul/graciestude.jpghttp://i151.photobucket.com/albums/s144/vegas_paul/1462673_2_350.jpg

Dick Steinkamp
05-08-2007, 10:49 PM
quote:Originally posted by vegas paul
Is there any other way (besides "bumping" the engine) to tell when the #1 cylinder is at UDC?


If it is an engine capable of running, then when the dist rotor is pointing to the spark plug lead going to #1, then #1 will be at UDC (or close to it depending upon what the initial advance was set at).

http://thenobot.org/images/s2d/s2d_01.jpg