[dhcarguy]

Should there be a gasket under the base of the dizzy at the block. I didn't put one there. Will oil leak out there?

Thanks, Dave

[dpoltzer]

Yes on the distributor to block gasket.

[25stevem]

It sure will leak and you may not now have enough play between the cam gear and the distributor drive gear when the motor is up to temp.

[242177P]

Originally Posted by 25stevem

... and you may not now have enough play between the cam gear and the distributor drive gear ...

Hmm? It's a helical gear, not beveled. Raised or lowered
by .020 shouldn't affect engagement.

[tom s]

I have run them with out gaskets on a lot of engines with no issues.Tom

[Sun Tuned]

FelPro #11497

[Half-Inch Stud]

Originally Posted by dpoltzer

Yes on the distributor to block gasket.

and THAT is why you best ought run a dedicated GND wire from dizzy cup to Head.

[Schurkey]

Originally Posted by Half-Inch Stud

and THAT is why you best ought run a dedicated GND wire from dizzy cup to Head.

I'd expect adequate ground via the distributor clamp and clamp bolt. Clearly, GM didn't think there was a grounding problem on points- or electronic-ignition distributors.

[Cliff R]

Some distributors use an "O" ring on the main hsg to seal them up, Pontiac uses a gasket under the flange and if you leave it out it's likely to leak some oil back there.....

[Schurkey]

Originally Posted by Cliff R

Some distributors use an "O" ring on the main hsg to seal them up, Pontiac uses a gasket under the flange and if you leave it out it's likely to leak some oil back there.

Olds and Buick use O-rings. Chevy, Pontiac, Cadillac "Big Block" 472/500/425/368 use gaskets. Caddy "HT"4100, etc. have an O-ring.

[Quad]

Years ago a friend with a 1973 Bird had heaps of intermittent problems with his ignition. The car would stall with no spark. Rarely re-started straight away. Then eventually it would start but sometimes it would take between 15mins to 60mins before firing up. Every time the distributor was tested out of the car it was fine. After he grounded distributor from the block to under a vacuum advance screw as per the Jim Hand book problem solved.

[Half-Inch Stud]

Originally Posted by Schurkey

I'd expect adequate ground via the distributor clamp and clamp bolt. Clearly, GM didn't think there was a grounding problem on points- or electronic-ignition distributors.

I've done such a good primer and paint job that....the dizzy would walk off time. Oh reminds me to tell all "Don't powdercoat your dizzy clamp" even with a GND wire.

The GND path may chatter in vibration, while trying to make power, will loose TQ.

[Bill Meyer]

Also, the gasket is needed to isolate the different metals found in the block and dist. If dissimilar metals carry any current, they tend to bond.

[25stevem]

Especially Aluminum and cast iron long term!

I wish they never stopped making the sturdy cast iron Dizzy’s!

[grivera]

Do all distributors need ground wire? Including HEIs, Hall effect, MSD?

[25stevem]

Only a points type does since none of the electronic types need a reference to ground to perform there function other then the grounding of there control box for its power feed and of course the grounding of each spark plug to the head, assuming the whole motor has a good ground on that end of the system.

PS, let me amend what I just posted , the HEI type or any like it that has a capacitor in it does need a good ground.
The motor will run without it, but not too well.

[track73]

I grounded the distributor on my stock car back to the battery.

[72projectbird]

Should there be a gasket? Yes. Do you need one? It doesn't hurt to have it, but I've had setups without them that never leaked. Also had some that leaked to the point where you thought the rear main was gone.

I guess it depends on the surface finish on the mounting pads on the block and distributor.

[Cliff R]

GM points distributors used a separate ground wire from the plate where the points/condenser mount to the housing. You can see it in the pic below of one I just finished up. The housing grounds via the distributor hold down clamp and bolt so make sure you don't powder coat all those part or you may run into some issue with distibutor function.

[SRR]

I usually seal the gasket to the distributor and lightly grease the other side so it stays put.