Monday, November 30, 2015

240z su carb gaskets

I cleaned the SU carbs on the 240Z since there were pretty gross and I assumed the grime was the cause of the motor to not be able to idle properly. Since I had ruined the carb to manifold gaskets, I knew I would have to make some new gaskets to be able to run the car this weekend. I've seen my Dad make some makeshift gaskets over the years out of old cereal boxes and gasket material so I figured I could whip up some gaskets. I ran to Rural King and picked up some gasket material (ya know... since my hometown Datsun dealership was closed).

This is the gasket material that I purchased from Rural King. The thickness matched the gaskets i took off.

I grabbed some oil from my Dad's South Bend lathe shelf.

Put a few drops on the gasket/manifold mating surface...

and rubbed the oil around the surface to insure an even coating.

Then I pressed the gasket material against the carb making sure not to let the gasket material shift or slip.

The result is a sort of "print" of what the gasket should look like. Note: these carbs have an area where antifreeze runs into a passage in the carb to warm the carbs slightly. This area needs to be sealed well for certain.

I took a "used" brass shell casing that matched the diameter of the holes I wanted to cut. I believe a 9mm was too small so I used something Dad had lying around.

I ground a slight bevel on the shell casing.

I rough cut the gasket with scissors.

I then used the soft end grain of an old board and punched some holes into the gasket; making sure to line up my holes properly.

Then I used a piece of synthetic deck material as a cutting surface and used the x-acto to accurately cut the gasket center out and trimmed the edges.

I only needed two gaskets, but cut an extra to keep with my supplies.

Perfect match!

I polished up the Su carb dashpots and filled them with damper oil after reinstalling the gaskets with a little gasket sealer.

I cleaned up the distinctive 240Z air cleaner housing and then tuned the carbs. Everything works great now and the car starts very easily with the choke and idles down nicely once the engine is warm and the choke is closed. It would have been nice to make these gaskets with a laser cutter, but my old technique gets the job done. I know Eric and I have discussed this before when working on VW's out at his parents place, but there's something really great about making due with what you have and using as little as possible to accomplish a job. It was fun to do this little project in my Dad's garage over the weekend.


Chris P said...

this worked great, thanks for this easy super fix!!!

Frankie Flood said...

Glad to help Chris!