Water Proofing the Motor...

[87manche]

the new dist I put on the comanche has a vent already. It's a little black cap on the top. You might want to take off the black cap and run a tube to the top of your firewall.

 

[bajacalal]

COOL, so im all set. But i still dont understand the purpose of venting the cap when its already sealed on! What happens if i dont drill a hole and run a tube??

I believe most distributor caps (aftermarket and stock) you see for this motor have the vent (little rubber piece on top). This is necessary, especially, if you are planning on sealing the distributor. As your motor heats up to the usual 210 degree operating temp, the air inside does the same. Because air expands when it heats up, it creats pressure. Unless vented, the pressure could crack the cap. This is pretty unlikely, but the pressure would more easily blow out the gasket or sealeant you put on the cap, rendering the seal useless and allowing water in, which is what you are trying to prevent in the first place.