Early Ford V-8 Club Forum

EFV-8 Club Forum / General Ford Discussion / Points bounce on 46 Ford V-8

Reply to Discussion | New Discussion << previous || next >>

Posted By Discussion Topic: Points bounce on 46 Ford V-8 -- page: 1 2     supereal 02-20-2013 @ 12:23 PM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 We detect point bounce on the Sun machine strobe. It appears as an extraneous "blip" on the strobe disk, and increases as the distributor rotation speed is increased. Almost always, it is due to weak point set springs. If you see a pronounced variation in dwell, it is usually due to worn bushings and/or shaft that causes varience in point gap as the shaft turns. The dwell reading is dependent upon the gap in both point sets. On the machine, we block one set, then the other, and the resultant dwell is a combination of the two, as one makes the connection to the coil, and the other breaks it. The "dwell" is the entire period between when one set makes and the other set breaks the circuit, and determines the charging of the coil. Any interruption, such as bounce, results in weak spark. If you wish to test the spring tension with a scale, it should read between 20 to 24 ozs. Hook the scale in the back side of the point contacts. If the tension is too low, the engine will miss at higher speeds. If too high, the arm rubbing block will wear quickly, reducing point gap. The Ford distributor is a marvel of endurance, but must be set up properly. TomO 02-20-2013 @ 8:20 AM reply profile send p.m. Senior Posts: 7264 Joined: Oct 2009 I agree with 37ragtopman that further diagnosis should be done before replacing parts. Point bounce can happen at 35mph, but is unlikely. A good mechanic would not just think that the points are bouncing, he would perform tests to determine the cause of the miss. You should hook up a dwell meter and check the dwell at idle,1,000 rpm and 1,500 rpm. If you have point bounce it will show up in the change in dwell. The points without the brass sleeve in the pivot tend to bind and fail to make. This also shows up when checking dwell. Check your spark output at the above rpms also. You could have a weak condenser or coil. Check compression to make sure that it is equal on all cylinders. you may have a valve sticking. A vacuum gauge will help determine this. Tom 37RAGTOPMAN 02-19-2013 @ 4:42 PM reply profile send p.m. Senior Posts: 1969 Joined: Oct 2009 HI I would check for a loose connection in the primary circut,you might have a loose connection, how many miles on engine since rebuilt ? did you use top oil, to keep the valves from sticking, point bounce is possible but I doubt it, maybe at 80 miles an hour,but at 30-40 clean the plugs or atleast check them, I was wondering if you could hook up a dwell meter and take for a ride, if that changed when you hit 30-40 and get the miss that might show up in the different reading, let us know how you make out, just my 32 cents 37 RAGTOPMAN Rob F 02-12-2013 @ 10:00 AM reply profile send p.m. Member Posts: 6 Joined: Jan 2013 Thanks a lot for all of your help. I just love old car Forums. What a great bunch of people and so much help! I was able to find a set of NOS Ford Script points from Dick Spadaro by sending him an email. I got the tip about Dick Spadaro from Alan above in this post. Thanks again. Rob supereal 02-12-2013 @ 7:01 AM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 I can't disagree with that, but with most old car parts now being made in foreign, often third world countries, it isn't surprising, old car parts are a limited "niche" market that can't support large manufacturers in this or other places. This doesn't excuse making defective parts, but shouldn't seem surprising. My main complaint is that many vendors do a poor job of weeding out these sources even when many of us complain. The usual response is. "no one else is having your problem". Large amounts of parts being made for current vehicles come from "off shore" now, and at our shop we find increasing problems with many new ones still in the box. deuce_roadster 02-11-2013 @ 9:55 PM reply profile send p.m. Member Posts: 284 Joined: Oct 2009 Rob, I have always wonderd why if someone went to all the trouble to reproduce a part, any part, why not do it correctly? There is a long list of repro parts that don't quite fit, don't quite work like they are supposed to etc. It hasn't ever made any sense to me, that parts aren't manufactured correctly. It would cost the same to make the part within specs as to make it wrong. My $0.02 supereal 02-11-2013 @ 8:28 PM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 We haven't had problems with point sets from C&G, but other suppliers, including Mac's, seem to be having problems with poor quality points. We are finding weak springs and connectors with poor or missing threads. The springs showed up on our Sun machine when the distributor was strobed. Unless you have a sensitive scale or a machine, you probably won't know the difference in spring tension. A machine will also show problems with a worn distributor shaft or bushings. Find a shop with the proper equipment, or send out yours to Skip Haney or other pro. Rob F 02-11-2013 @ 8:09 PM reply profile send p.m. Member Posts: 6 Joined: Jan 2013 I have to wonder why some company hasn't started making good points for these cars, if the only ones that will work correctly are the originals. How hard could it be to duplicate the originals? If the originals are getting very hard to find it would seem to me there would be plenty of market for quality replacements. Rob deuce_roadster 02-11-2013 @ 3:56 PM reply profile send p.m. Member Posts: 284 Joined: Oct 2009 NOS points are getting harder to find but still are available. They will have the Ford script printed on the points on the red micarta part in an orange ink. If you find some for sale look closely at the spring and metal conductor where the connecting hole is to make sure they haven't been installed. Make sure you get a pair, there is a right and left of the non pivoting contact that is scr*w*d down. I usually find them at Hershey but they show up on ebay occasionally. I agree that NOS points are the only way to go. For some reason the new versions just aren't as good. If you find some new replacement points from the 40s or 50s that look like the originals (micarta with a brass bushing, not plastic) I would try them as a second best solution if you can't find gennie ones. Get the distributor set up on a machine like a Sun or Allen. Good luck. ford38v8 02-11-2013 @ 3:25 PM reply profile send p.m. Senior Posts: 2780 Joined: Oct 2009 Rob, yes, manufactured by Ford. You won't find them at any Big Box supplier, or in any catalogue. Try the smaller suppliers that handle NOS parts like Baxter Ford, Little Dearborn, C&G, Spadaro, and although not that small, even Carpenter has lots of NOS Ford parts, and is also likely to have your points. By the way, I just reread yor original post and got a laugh! You actually talked to a "Tech Support" guy at Macs? I bet that really made your day! Alan

<< previous || next >>

PAGE: 1 2

NOTE: YOU MUST BE A REGISTERED USER AND BE LOGGED IN TO POST (and reply to) messages in this forum. If you are a first time user, please click the CREATE A NEW ACCOUNT in the masthead above to register and Log In. After that, all you do is LOG IN to enjoy using this site.

DISCLAIMER: The V-8 Club does no independent testing of any of the opinions, thoughts or suggestions presented in the website on the Forum, in the Tech Tips section, or any section. A reader should consider the website to be a forum wherein differing solutions to a particular set of circumstances may be discussed. Ultimately, the selection of an item for an individual's vehicle must be based upon the independent study of the vehicle owner in consultation with people in the hobby and restoration experts.

EFV-8 Club Forum Home | Back to Home Page | Contact the Webmaster

Copyright © 2009 - EFV-8.org
Powered by < CF FORUM > v.2.1