Distributor Vents

[Scooterwrench]

I was just reading another post about the rust and corrosion found inside a T400 distributor.

When bought Smoky one of the first things that got replaced were the secondary ignition components and when I removed the cap I discovered the reluctor and pickup coil were seriously rusted up and the contacts in the cap were pretty crusted too,I was surprised I made it home with the thing.
Yeah,it got a new dist. too.

I worked on marine engines with HEI's for 20yrs and never saw corrosion like I'm seeing in these T400 distributors and the only difference I can see in the T400's is the presence of that vent in the base plate. I'm guessing that vent is there to vent off ionized air but is the ionization worse than the corrosive effects of the vent?

 

[Supercharged111]

@L31MaxExpress has mentioned adding a vacuum port to the distributor to forcibly move air through the housing. It's one of those things I've never gotten around to, but GM did it with the 95+ LT1s to make the opti suck less so there is merit to the idea.

 

[HotWheelsBurban]

I was just reading another post about the rust and corrosion found inside a T400 distributor.

When bought Smoky one of the first things that got replaced were the secondary ignition components and when I removed the cap I discovered the reluctor and pickup coil were seriously rusted up and the contacts in the cap were pretty crusted too,I was surprised I made it home with the thing.
Yeah,it got a new dist. too.

I worked on marine engines with HEI's for 20yrs and never saw corrosion like I'm seeing in these T400 distributors and the only difference I can see in the T400's is the presence of that vent in the base plate. I'm guessing that vent is there to vent off ionized air but is the ionization worse than the corrosive effects of the vent?

Probably depends on the location and climate. I'm honestly not sure if the dizzy on either of my trucks has the vent holes in the base housing (cause ya kinda gotta stand on yer head to see in there) but I do know that once I installed the UMP vented cap and the better quality rotor, they performed better than before. And in Houston, Texas area it's frequently pretty humid, most of the year.

 

[Supercharged111]

Probably depends on the location and climate. I'm honestly not sure if the dizzy on either of my trucks has the vent holes in the base housing (cause ya kinda gotta stand on yer head to see in there) but I do know that once I installed the UMP vented cap and the better quality rotor, they performed better than before. And in Houston, Texas area it's frequently pretty humid, most of the year.

They should have a hole drilled in them with a screen occupying it.

 

[Scooterwrench]

Probably depends on the location and climate. I'm honestly not sure if the dizzy on either of my trucks has the vent holes in the base housing (cause ya kinda gotta stand on yer head to see in there) but I do know that once I installed the UMP vented cap and the better quality rotor, they performed better than before. And in Houston, Texas area it's frequently pretty humid, most of the year.

If it has it you should be able to see a little screen in the baseplate once you remove the cap.
Fl. is rarely below 50% humidity.

 

[Scooterwrench]

They should have a hole drilled in them with a screen occupying it.

Quick Draw!!!

 

[Supercharged111]

Quick Draw!!!

Good to finally be on the winning end!