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EFV-8 Club Forum / General Ford Discussion / '36 ignition problems?

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Posted By Discussion Topic: '36 ignition problems? -- page: 1 2 3     TomO 07-15-2012 @ 6:26 PM reply profile send p.m. Senior Posts: 7385 Joined: Oct 2009 Bob, I am glad that you solved your problem. Only the "Shadow knows" why the new parts that we get do not work as intended. Tom Flatbob 07-13-2012 @ 9:08 PM reply profile send p.m. Member Posts: 437 Joined: Oct 2009 TomO, after Skip rebuilding coil & checking dizzy on machine and new inner caps am getting spark like I never had before; I can hold plug wire a good 1/2" away from plug and get a mini lightning bolt between wire end and plug. However, 6,7 & 8 plug won't ignite. Very hot in the garage could only pull the plugs, tomorrow will do compression test on failed cylinders. Maybe compression is too low for charge to ignite? This was the my first flathead rebuild and I have low compression on all cylinders 70-90 lbs. I put adjustable lifters in & am wondering if I adjusted them without the valves completely on the seats. The car previously ran & idled very well despite the low compression. Did a compression check this morning, cylinders 1-5 stayed the same or were slightly up over the last time I checked with 97 miles on the car. Cylinders 6,7 & 8 (non firing cylinders) have dropped 9, 5 and 15 lbs. respectively, the lowest cylinder reading 75 lbs.; I have other cylinders on the other side with reading this low but they fire. Am going to put new plugs in 6,7 & 8 and see what happens; if this doesn't work am going to pull engine and replace with another I have.........am too old for this much aggravation! Replaced plugs with new old Champion plug made in the USA, runs better than it ever did! I don't understand how 3 plugs next to each other could all fail at the same time. Anyway, am a happy man. Thanks everyone for the help. This message was edited by Flatbob on 7-14-12 @ 1:59 PM TomO 07-13-2012 @ 7:18 AM reply profile send p.m. Senior Posts: 7385 Joined: Oct 2009 Bob, you stated earlier that you had no spark to cyl 5,6,7. Is this still the situation with the new caps? Did you check the rotor to cap clearance when you had the distributor out? Did you check the seating of the caps by examining the rotor to cap clearance with the distributor on the car? Tom Flatbob 07-12-2012 @ 3:37 PM reply profile send p.m. Member Posts: 437 Joined: Oct 2009 Got new inner caps (origin unknown) from C&G and sanded inner caps so they would fit in the outer caps and replaced dizzy. Fired up immediately but then started backfiring out the exhaust,amazing how well it runs on 5 cylinders but will not idle. Don offered some advice to check compression; wish I would have done that earlier. Right now it's too hot in the garage temps. have been 110+ degrees here in Vegas. Maybe tonight after sun goes down will do compression test. Thanks everyone for the help. This message was edited by Flatbob on 7-12-12 @ 3:40 PM TomO 07-07-2012 @ 8:24 AM reply profile send p.m. Senior Posts: 7385 Joined: Oct 2009 Bob, if the caps from C&G are made in Argentina, you may have to file down the terminals as well. Some of the terminal are so long that the rotor will be damaged. The ones that I have seen like this have aluminum terminals that die out after a few hundred miles. Drake makes new inner caps, but I do not know how they fit or last. Tom Flatbob 07-06-2012 @ 11:10 AM reply profile send p.m. Member Posts: 437 Joined: Oct 2009 Checked the inner caps & they have no Ford PN as TomO suggested an original would have so they must be replacements but fit very well. Ordered two new caps from C&G; Kyle was upfront & told me I would have to "sand to fit." I checked inner cap for passenger side gap to rotor blades and it's much tighter than the side with the problems; hopefully this will solve the problem. Will post the outcome; again thanks everyone for the help. Bob TomO 07-06-2012 @ 8:16 AM reply profile send p.m. Senior Posts: 7385 Joined: Oct 2009 The Ford caps have the P/N cast into them. The aftermarket ones do not. Some manufacturers are proud enough of their product to put their name on the product. Now that you know that the gap is too big, you need to determine if it is because the cap cannot be seated fully or it is just worn out. 40 Coupe has good advice in checking any that you purchase, on the distributor before you put the wires in it. Beware of the used caps that are sold as new. The contacts should be smooth with no signs of arcing. Tom 40 Coupe 07-06-2012 @ 4:20 AM reply profile send p.m. Senior Posts: 1801 Joined: Oct 2009 The Max. gap between the rotor and the inner cap terminals is 0.0105, Min. gap is 0.0035. This is for the 48-12201 rotor. As per Subject 12000 page 4 April 18, 1948. The plug gap for the #7 plug is 0.025-0.028 The spark gaps add up and increase the demand on the coil to jump these gaps. The rebuilt coil has limits as to it's voltage output. As the spark gap widens the coil can fail to deliver spark at the plugs. As a note the largest spark gap in any part of the spark circuit should be the plugs. If you decide to change the inner caps do it with the distributor removed this way you can see if either of the TWO rotor terminals are touching the eight new inner cap terminals (as well as the proper gap), and make sure the new caps fit properly into the distributor (sometimes the plastic body needs to be sanded to fit properly) This message was edited by 40 Coupe on 7-6-12 @ 4:23 AM Don 07-05-2012 @ 7:32 PM reply profile send p.m. Member Posts: 24 Joined: Nov 2009 You need to do a compression check, since everything else checks out OK. Perhaps valves are hanging up. Don Flatbob 07-05-2012 @ 2:19 PM reply profile send p.m. Member Posts: 437 Joined: Oct 2009 Update: Skip says the dizzy checked out fine on the machine and there was no sign of rotor arcing. He told me to check continuity from center brass band of rotor to 4 end contacts on the rotor. I see 2 contact points being the rotor blades where the other two are I don't know. The two I checked had good continuity. The gap between the rotor blades and the inner cap contacts is approx. .046"; even with this big of a gap # 5 still fires. I believe the inner cap is original, there is is no origin of manufacture on the cap. So, is it the rotor blades or the inner cap that is bad. Would like to post picture of gap but picture size is too big; haven't figured out how to take smaller images with my camera. However, if I email I can reduce the picture size if anyone is interested. The brush is making contact with rotor ring through 360 degrees. Bob This message was edited by Flatbob on 7-5-12 @ 2:21 PM

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