Questions on 73S Engine

[rmfent]

2 questions for the experts for 9/72 build 73S

1. Is the alternator strap for a 9/72 build single bolt with gold cad finish?
2. Are at the lower valve covers magnesium or aluminum?

Thank so much.

[rmfent]

bump to the top..
Anyone please

[Chuck Miller]

1. Is the alternator strap for a 9/72 build single bolt with gold cad finish?

- As far as I can figure, 'single bolts' started somewhere between late Jan. and early March '73, so would assume your's would be black double bolt...

- Not sure about the lower valve covers ...

Hope this helps,
cm

[911MRP]

Thread discussion here may have some relevant information

http://www.early911sregistry.org/for...ight=Fan+strap

Hth

[smedley]

Valve covers still magnesium but black...generally thought to be early powder coating or some other baked/cured coating. The coating was masked off the gasket mating surfaces inside.

[frankc]

If this helps, the fan strap on my '73 TV engine #6530905 was the black with two bolts type.

[VintageExcellen]

There are 3 different fan ring straps in 1973, my very early 73 911 had a black painted strap with 2 bolts. There is a later yellow cad double bolt and finally a single allen yellow cad strap.

Mag lower valve covers - originals were covering in black goo that is terrible to get off. Black paint or powdercoat will work however.

[edmayo]

Mark, I'm pretty sure the black goo (for noise reduction) was around 75, 76 .

[RSTarga]

From my memory, and I have to dig my original lower valve covers to verify, the top covers had a black powder coat finish, but the lowers were bare magnesium chrome finish with tectyl wax coating.
For such an early build two bolt black strap.
Keeping the lower mag covers leak free, is an impossible task. There is a very good reason, most have switched to turbo lower valve covers.

[edmayo]

I can get them fairly leak free. I flat sand the gasket surface and end mill the sealing washer surface.