Distributor cap corrosion

BlueSkye
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Distributor cap corrosion

Post by BlueSkye »

I replaced my original (1972) points distributors with Pertronix Flamethrowers on the Chrysler 318s. Very nice to not be servicing the points at inconvenient moments, but now I am servicing the distributor caps at inconvenient moments. Corrosion builds up on the brass posts so that after 100 hours I have to change the caps. It is bad enough that I keep a dremmel ready and a collection of spare caps. Tech support has not been much help. One guy told me it was moisture and I should use dielectric grease on the posts and rotor. This didn't help. I don't think it is condensation of moisture because it doesn't get better when I am underway every day. I did talk to one old hand who said it sounds like high voltage. When I switched to the electronic ignition, I eliminated the ballast resistor. Wondering if I should put one back in. Any thoughts or experience would be welcome.
1971 32ft Express 2x318
Seneca Lake, Erie Canal, Lake Ontario, Rideau
Fastjeff
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Re: Distributor cap corrosion

Post by Fastjeff »

I doubt if that would help.

Sounds like the venting system is letting in moisture. How about putting a hose on the vent and run it to a warmer, drier area? Mercury outboards did that on their old magneto engines.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
jmonday
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Re: Distributor cap corrosion

Post by jmonday »

I am also a test guy for pertronix I have the newest system to go in this year.( I will post and update) As for the Ballast My boat does not have it. I also had a friend that purchased a complete system (Old system)last year and I did leave the resistor in. (He had the same cap problem in less time than mine.)
When I say new and old system I'm speaking about the distributor having vent vs no vent and rotor and cap design and material change. ( Dave has posted Photo's of the new cap and rotor. )
Jeff Monday (Blue Mondays)
1973 28 ft Express single 318 1976 StarCraft Islander 1961 Sea Nymph
Lower River rd
Rabbit Hash KY
BlueSkye
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Re: Distributor cap corrosion

Post by BlueSkye »

Jeff, can to point to Dave's post? search on Pertronix does not locate it.

The caps on mine are not vented. The vent is in the body of the distributor.
1971 32ft Express 2x318
Seneca Lake, Erie Canal, Lake Ontario, Rideau
jmonday
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Re: Distributor cap corrosion

Post by jmonday »

Correct the vent is in Distributor on the old OEM and Old style Pertronix. Barkleydave has alot of good reading in (Pertronix Distributor Test) If you read all you can on this site about the OEM point sytem you will get a good handle on the way you need to go. The only reason I'm with Pertronix is that they sent one free to test. Again Like Dave I'm not paid a Dime to give the information out about what I have tested and like you will see many people go with Mallory, custom built, Junk yard H.E.I. style and still the people cleaning the old style point systems. At the end of the day if Pertronix keeps working at it I think you will see a safe dependable system that is a plug and play as good as any. They have been really good with helping and my boat does run well until the cap fails. (lets hope this next Distributor this year takes care of that.)
Good luck
Jeff
Jeff Monday (Blue Mondays)
1973 28 ft Express single 318 1976 StarCraft Islander 1961 Sea Nymph
Lower River rd
Rabbit Hash KY
BlueSkye
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Re: Distributor cap corrosion

Post by BlueSkye »

I talked to Pertronix again today. They assured me that this is very rare. However they have a new cap design because they discovered the old cap material (Bakelite) was absorbing moisture. Tech support didn't think the high voltage thought was possible, as the system works on engines other than Chrysler that never had ballast resistors. Recommended that I makeshift a gasket for the cap and check that the vent is clear. Seems a contradiction to me.

Still scratching my head.
1971 32ft Express 2x318
Seneca Lake, Erie Canal, Lake Ontario, Rideau
barkleydave
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Re: Distributor cap corrosion

Post by barkleydave »

Moisture has been a concern with all the Dist. in the Big M's. My STB dist even the old Prestolite had moisture issue more so than the port.

Interesting that they have discovered the caps were holding moisture. I now have the New and Improved and will be interesting to see if there is an improvement. I agrree no ballast resistor for the Ignitor required. Now one thing to keep in mind. Once you have converted to the Flame Thrower and Ignitor your spark is VERY VERY HOT compared to the OEM. If you have any breakdown in the old plug wires... you will have issues with missing and St Elmo's Fire jumping around. With my coil wire pulled from the coil if I turn it over it will arch from the coil to the block! ZAPPO!
1987 Marinette 29 FB Sedan
Retired Boat Accident UL and USCG trained investigator
Retired USCG Captain
jmonday
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Re: Distributor cap corrosion

Post by jmonday »

Bluesky Maybe now they have new material for the cap I hope it is rare but I find it hard to believe that I have seen two fail in the same year and Barkleydave had the same. They did send us new distributors one to replace my test one with new coatings and new design and they also sent one to replace the one my friend bought. If you do buy make sure you are talking with someone that knows what they are sending you. In the past I had a hard time getting the correct length and you for sure want the non vented with the new cap material.
Jeff Monday (Blue Mondays)
1973 28 ft Express single 318 1976 StarCraft Islander 1961 Sea Nymph
Lower River rd
Rabbit Hash KY
BlueSkye
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Re: Distributor cap corrosion

Post by BlueSkye »

Jeff,

Interesting you mention correct length. I had to take the one for my port engine to a machine shop to get the drive gear to engage. I thought it was an engine variant. Pertronix offered to machine it but I was about to go on a cruise and the redhead was getting impatient.

When you say new design, does this involve anything beyond the distributor cap?
1971 32ft Express 2x318
Seneca Lake, Erie Canal, Lake Ontario, Rideau
jmonday
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Posts: 154
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Re: Distributor cap corrosion

Post by jmonday »

Yes I will check and make sure but I think they spent the money for testing and the housing itself is a non vented housing. BUt like Fastjeff was talking about if you pipe the vent out to a place that will never see moisture this maybe all that is needed with the new cap material. At one point I ask about a gasket and because of safety testing they did not agree with using one. (Now that we know the material itself holds moisture not sure any of this would help.)
Jeff Monday (Blue Mondays)
1973 28 ft Express single 318 1976 StarCraft Islander 1961 Sea Nymph
Lower River rd
Rabbit Hash KY
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