308 Distributor Cap Question

Look inside the cap and you will see 4 screws. You need to unscrew them and the wires will pull out. Next you need to pull out the carbon center brush for the coil. Under it you will find the screw for the coil wire. When you replace the wires make sure that the screws pierse the wires and there is continuity. You are done.

 

Yeah, but dont drop any of those screws and lose them, or youll really be *&#%)ed.

 

Doc, use a fine QUALITY SCREWDRIVER to get them out.

do not use a cheap one and bugger the slot in the heads. it is very easy to strip the slot because the brass is old, soft and usually corroded a bit in place.

i use Di-electric grease on the screws when i reinstall them, and put a lite coat on the plug wire ends as i slide in the new wires.

best,

Michael

 

Don't forget about the spring under the center carbon. You don't want to misplace that little bugger!

 

You should buy a new carbon piece and spring for the coil wire. Ricambi has them for $15. Well worth it.

Gene

 

Well, now you know how to do it.

If you're replacing the caps due to a problem, fine.

If you're replacing the wires due to a problem, check the caps for arcing while you have them off.

 

Doc
You might want to check the ohms resistance with a multi-meter on each old wire prior to removal from the cap and write it down. The new wires should be an improvement. Check the search function for recommended resistence for each wire. Also check each new wire for continuity as you can miss contact with the screw and the wire. Just a thought.

Checked my notes and another member said his new Cavis OEM were: (not including the plug extension)

Wires ohms
1/8 1272
2/7 1167
3/6 900
4/5 720
Coil 500

 

One last trick I read about, is to strip a bit of the wire so you can then fold the inner lead wire over the outside of the insulating rubber, then insert into the cap and look in the hole where the set screw goes in to make sure the exposed lead wire is lined up in the hole, then screw it down , this insures that you have positive contact with the screw/ cap, and now will have two points of contact.

 

Doctor....I can't over emphasize the need to make contact as prescribed. I didn't on my 308 2V and I fried the caps & rotors. Seems that the resistance was increased (from coils) and the increased current had the net effect of pulling the brass off the posts in the caps (or "cutting" a notch in them, the reverse of arc welder). Dave Helms still remembers fixing this goof up for me...and in the process ohmed each wire when he put them back in the new cap$$$.... This was a few yrs ago and the 2v rotors were almost unobtainuim..found two but had to do alot of searching.. Yes I am one of those who really tries to be a DIY person but end up providing job security for the true professionals!!.. Still learning. lol..lol

 

I don't understand. I also admit my ignorance in this area . I know Dave Helms chimes in from time to time -- maybe he can elaborate?

My "original" wires had not been installed with any stripping to expose a lead wire and I followed suit with my replacements. That stripped exposed wire I found on the "standard" setup where the metal sleeves are crimped on. Makes sense to do it there but it shouldn't be necessary for the cap.

My understanding is we are dealing with low current high voltage. I was told on this forum my car won't run with the high resistance wires I have yet it does. I am curious about exactly how your cap was fried.

Seamus

 

About the best I can describe is that that posts inside the cap had a "groove" cut into them as though someone used a lathe. The metal from the posts was "pulled" off the posts and the rotors were melted right down to the middle where they mount. It wasn't a matter of stripping the wire but rather, "piercing" the wire with the distributor cap screws (something I dind't do very well). Another F-chatter saw them also and remarked that the resistance was so high that the rotor acted as a "arc welder" but only in reverse. Instead of "throwing metal" (ie arc welder) it was pulling metal off the posts inside the distributor cap. Dave Helms called me and asked how the car was running... since I drove it to him and said fine...he replied "no how is this car running?".. We then discussed what I did. Not believing what he told me I went to the shop to see for myself (since about a month earlier I replaced the wires & everything was fine). We were both scratching our heads and the resistance is what we came up with.

Hey Finnerty, care to chime in maybe you can describe this better than me!