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Subject: 8N front mount distributor timing

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Brian    Posted 09-27-2021 at 17:11:13 [URL] [DELETE]        [Reply] [Email]  
  • 8N front mount distributor timing
  • How does the timing advance with the counterweights? I know to set the initial timing with a rule coming off the tang on the drive of the distributor but when you tighten down the bolt how does the timing advance? Am I missing something somewhere? With the bolt loose the plate is free to move and as the RPM's increase I can see how the plate would rotate to advance the timing, but then how does the plate return back to its original position? And, how would this even be possible with the bolt tight?

    Carl    Posted 09-28-2021 at 09:56:52 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 8N front mount distributor timing
  • Brian-
    Maybe it will help to fully understand the front mount distributor and the cam and weights aren't the issue you seek. The FORD Front Mount Distributor is the 2nd most misunderstood faction of these old Fords. #1 is the 6V/POS GRN Electrical System. Take note of my post below from Tony in TX about the front mount and setting the points. You must first have a GOOD set of new points to work with. The STANDARD IGNTION/BLUE STREAK p/n FD-6769X, set is the best. ECHLIN, p/n CS-35 used to be as good as but now are made in the land of the Chi-Coms and are junk –they cannot be set and timed correctly. Both use the original phenolic rubbing block whereas all others made today use a plastic rubbing block. You can get them at NAPA but avoid the ECHLIN. Be sure you have all the required manuals to use as a reference. The manuals have the original timing method with the ¼” offset rule but there was a guy that made a handy setting gage which made it quicker and easier. Don’t’ know if he still sells them though. Also, get a copy of “75 Tips for N-Owners” by Bruce(VA) as he has a method of setting the timing and testing before you mount the unit. The biggest mistake folks make when mounting the front mount unit is to get it 180° off location. You will observe the male cam tangs on the unit are offset. Likewise, the cam shaft on the engine has female offset slots which mate into the tangs when unit is mounted correctly. If one forces the unit down off location when bolting to the engine, the second power is applied the unit will attempt to orientate itself but it’s too late and the aluminum base will break and bust up –see pictures below. The base is junk then and many do not notice this. You need to get a new base and just swap out all the guts. Remove your unit from the engine and see if it was ruined from incorrect mounting.

    FORD FRONT MOUNT DISTRIBUTOR:





    AFTERMARKET FORD FRONT MOUNT DISTRIBUTOR TIMING GAGE:

    FORD FRONT MOUNT DISTRIBUTOR – RESULTS WHEN UNIT MOUNTED 180° OFF:




    Steve Dabrowski    Posted 09-28-2021 at 18:41:28 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 8N front mount distributor timing
  • I have noted a number of comments re the ECHLIN, p/n CS-35 point set. I just bought and installed a set in my early 9N distributor and really saw no big issues with setting the gap or timing them properly. The set differs from the earlier product mostly in that there is no bronze bushing used for the pivot point, but rather the material is just drilled to fit the pin. If properly lubed on assembly this may not be an issue, I'm sure it saved some pretty good money in manufacture as it reduces a part and a couple of steps in the assembly process. I did have to tweek the point plate slightly with a set of pliers to get a good square mating of the points, but other then that I saw no issues.

    Now I will have to wait until I finish my s/n 292 to try them out-then I might have to eat my words. But I have a couple of slightly used older ones I might have to use if I'm wrong here.

    carl    Posted 09-29-2021 at 04:56:36 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 8N front mount distributor timing
  • You may have gotten an older NOS set Steve. Some places will probably still stock old sets that were made before the cave to the Chi-Coms. It's not like front mount points are just jumping off the shelves like the paniced fools idiot libs stocking up on toilet paper...

    Bruce(OR)    Posted 09-27-2021 at 17:51:37 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 8N front mount distributor timing
  • How does the timing advance with the counterweights?
    Centrifugal force with an increase in engine RPM.
    As the dist spins, the weights move out while the breaker plate that the points are mounted on rotates on the center shaft increasing the timing.
    When the engine slows down the weights return to a retracted position and timing reduces also.
    Setting base timing should be down at a slow RPM to ensure the weights are not advancing and creating a false setting.
    Counter weights inside the dist might also have springs to assist the return to the base setting at a slower RPM.
    All of this is inside the distributor and the outer distributor housing does not need to move to get this done.

    Steve Dabrowski    Posted 09-27-2021 at 18:28:05 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 8N front mount distributor timing
  • The plate holding the points does not advance or even move except to determine the point separation when the tang is set as indicated. The plate is manually moved to the point where the points just begin to open.

    What the weights do is move the distributor points cam in relation to the rotor by acting on two slotted parts of the driven rotor that moves the points cam around the driven rotor. Disassembly of the distributor will reveal what I am indicating. The plate holding the points is static, held in place by a large circlip.

    When rebuilding the distributor removal of the weights and separation of the two rotor parts is needed to clean and grease them as well as removal of the rear screw plug in the center of the rotor and the clean-out of that passage and the oil weep hole that serves the front bushing. Put in a new felt wick and re-install the plug after filling the rotor with oil and stake the plug so it doesn't come out from the rotor rotation.

    The flyweights should have a pair of matched springs on each weight to function properly-grease the poles they turn on so they move freely before putting it all back together.

    Brian    Posted 10-08-2021 at 20:44:26 [URL] [DELETE]        [Reply] [Email]  
  • Re: 8N front mount distributor timing
  • Thanks for the explanation. This is making more sense now.
    I see the two holes in the back of the distributor that go to the bushing but do not go thru the bushing . There is no plug on the end of the shaft and there was no wick inside when I removed the distributor, there is not a small hole that is at the front bushing area but it doesn't lead anywhere.
    There is .004" clearance in the rear bushing and .006" in the front bushing so I guess its time to rebuild the distributor, probably from lack of oil.
    How does the distributor hold oil? From what I see, there is an opening on the bottom and Carl had shared a picture of the front part of the engine where it looks like a drain hole underneath the camshaft.
    Seems to have a lot of movement on the pins for the counterweights as well but the weights seem to move freely.
    What type of grease do you recommend for the counterweight pins?
    I haven't had time to look for the "75 tips" yet. I thought I had them but it might be at my fathers cabin.
    Once again, thanks for your input.

    Steve Dabrowski    Posted 10-09-2021 at 17:02:01 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 8N front mount distributor timing
  • The two holes feed a channel outside the bushing which absorbs the engine oil thus supplied. When you push out the bushing (can use a socket in conjunction with a bench vise)you will see the channel and can clean it. The plug is located at the rear center of the shaft between the tangs that engage the camshaft. Should be a slotted screw head, but sometimes the slot is broken or smoothed off. Without this plug and a clean center felt wick inside the distributor shaft no oil will reach the front bushing and it will wear pretty quickly even if greased.
    I just used some wheel bearing grease on mine. The clearances you note seem large to me and probably will make point gap unreliable when running. I think 0.0005-0.001" probably right, these bushings are normally reamed to fit although I have done mine just inserting them and if they turn reasonably easily leaving it to wear in with oil passages unobstructed of course.

    Brian    Posted 10-04-2021 at 11:35:41 [URL] [DELETE]        [Reply] [Email]  
  • Re: 8N front mount distributor timing
  • Thanks to all for your reply and explanation on how this works. I made a tool to help with setting the timing but I need to go back to the drawing board as I when I made my print I forgot about the offset of the tang and it was off. So I will make another one.

    TheOldHokie    Posted 10-05-2021 at 19:02:52 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 8N front mount distributor timing
  • The offset should not matter. You just need 1/4" from the side of the tang.

    TOH

    TheOkldHokie    Posted 10-05-2021 at 19:06:30 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 8N front mount distributor timing
  • Brian    Posted 10-08-2021 at 20:11:33 [URL] [DELETE]        [Reply] [Email]  
  • Re: 8N front mount distributor timing
  • The one I made doesn't look at good as this one but its functional. I got it to work but I need to replace the bushings.
    Thanks again for the advice.

    JMOR    Posted 09-27-2021 at 19:51:25 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 8N front mount distributor timing

  • Brian    Posted 10-04-2021 at 07:41:38 [URL] [DELETE]        [Reply] [Email]  
  • Re: 8N front mount distributor timing
  • Thanks fr all of your input. I now have a better understanding of how this all works.

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