1963 L76 340 HP Engine - Thermostat Cover

[Collin MacDonald]

The JM states the Thermostat Cover on the 340HP 1963 is painted silver, and does NOT use SS studs and nuts... My question is are the studs and nuts painted or left natural.... Sounds kinda like a stupid question, but it would seem to me if they had it already assembled on the intake and the Thermostat Cover was painted the same cover...then why would the studs and nuts be painted too... Or was the cover installed after the manifold was painted on the block???

Thanks in advance...Restro coming along SLOW but SURE should be at Carlisle..

[Michael H.]

Re: 1963 L76 340 HP Engine - Thermostat Cover

Collin,

The nuts and the exposed portion of the studs on a 63 L76 would have a coating of silver paint, along with the rest of the thermostat housing. This silver coating was applied after the moly orange engine color was applied to the completed engine assy so you may find traces of silver overspray on the ends of the cyl heads and top sides of the exhaust manifolds.

BTW, lock washers seem to be "optional" in this location for some strange reason. If we look at 20 factory photos of brand new 340 or 360 HP engines, we see that some have the washers and some don't. ????

Michael

[Collin MacDonald]

Re: 1963 L76 340 HP Engine - Thermostat Cover

Thanks Michael for your quick response. I think I got the overspray on the rest of the engine correct...so you provided the missing information I will spray the hardware (exposed) as well as the housing....let me know what you think of the rebuild so far....

[Michael H.]

Re: 1963 L76 340 HP Engine - Thermostat Cover

The silver looks good Collin. Now just attach the thermo housing and mist a little silver on it and the silver will be complete. The open end of the thermo housing was masked to prevent paint from entering the cooling system.

If you're restoring back to correct/original, you will have to paint most, or all, of the water pump bypass hose and it's clamps, orange. It was installed on the engine before paint and not masked at all. The very rear most end of the hose and part of the clamp can/should show a bit of silver overspray as the silver was done after the orange.

Your bypass hose fitting in the intake manifold is incorrect. It should be without the hex wrench flats. I believe the correct fitting is available from a few different Corvette parts vendors. The bypass hose clamps look close but not exactly like original but I know of no source for dead on correct originals.

The idler pulley stud was installed at the St. Louis plant so it would have had no orange paint on it.

On the right side valve cover, the temp sender wire clips that are mounted under two valve cover bolts, were in place when the engine was painted so at least the top side of each clip would have the silver paint.

Difficult to tell in the pic but, do you have washers under the intake manifold mounting bolts? Should be installed without washers.

Spark plugs would have been in the heads during the engine paint operation. The porclin and part of the metal shell was cupped to mask it but the majority of the shell would have a coating of orange paint. (if you place a spark plug socket over each plug during your paint operation, this will nearly exactly duplicate the mask that was used in production)

The exhaust manifolds would have been in place during the paint operation so the top and outer surfaces would be completely covered in moly orange.

Michael

[Collin MacDonald]

Re: 1963 L76 340 HP Engine - Thermostat Cover

Thanks Michael, this is my first attempt, so any source you have for better parts would be appreciated....the bypass hose fitting where can I get that Paragon or LIC? I do NOT use washer for the valve covers have the phillips screw that holds them on....Again thanks.

[Tracy C.]

Re: 1963 L76 340 HP Engine - Thermostat Cover

Collin,

The intake manifold should be raw aluminum except for overspray as previously mentioned. It may be the flash from the camera, but it looks like the entire intake has been painted aluminum?

tc

[Michael H.]

Pic Of Painted Bypass Hose/Fitting

Collin,

This pic of a completely unrestored low mileage 63 340 HP engine was taken about 25 or 30 years ago. Note the paint on the water pump bypass hose and fitting. Obviously, there was no attempt made to mask any part of it. Also visible is a mist of silver paint on the rear of the hose and clamp. The small gap between the rear of the bypass hose and the manifold would indicate that the fitting does not have the hex, or wrench flats that you're has. I would guess that Paragon probably has the proper fitting for you.

[Michael H.]

Another Shot Of a Brand New Engine...

This is a pic of a brand new 63 340 HP engine during assembly. As can be seen, the mist of silver paint was everywhere. The intended targets were the areas on the cyl head between the intake manifold and valve cover, and the front, including the thermostat housing etc. The original color of the thermostat housing was black so that tells us how much silver went on these engines as it's now completely covered in silver, along with the studs and nuts.