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FE Power Forums => FE Technical Forum => Topic started by: alf1960 on July 30, 2015, 06:50:06 AM

Title: 428 CJ valve covers
Post by: alf1960 on July 30, 2015, 06:50:06 AM
  My neighbor just started restoring his 70 Mach1 428 CJ car. The valve covers are  finned aluminum. They almost look like they have been painted aluminum color at some time though. He was wondering what would be correct as he is keeping the car as original as possible. He doesn`t do computers.
Title: Re: 428 CJ valve covers
Post by: ScotiaFE on July 30, 2015, 07:04:11 AM
They would have been as cast aluminum.
Title: Re: 428 CJ valve covers
Post by: machoneman on July 30, 2015, 07:06:39 AM
Yep, natural unpainted cast aluminum. Your pal should look here: https://www.428cobrajet.org/
Title: Re: 428 CJ valve covers
Post by: alf1960 on July 30, 2015, 07:10:33 AM
 Thanks for the help. He is old school. No satellite, cable or internet.  Just cars.
Title: Re: 428 CJ valve covers
Post by: TomP on July 30, 2015, 04:13:35 PM
They are die cast though so glass beading makes the wrong finish.
Title: Re: 428 CJ valve covers
Post by: alf1960 on August 01, 2015, 06:18:54 PM
 My buddy thanks you all for the info. Thanks for the not bead blasting tip.
Title: Re: 428 CJ valve covers
Post by: cjshaker on August 01, 2015, 09:03:15 PM
Not trying to be a technical Nancy here, but I believe the original finish was actually a belt sanded finish of about 1000 grit or finer. The type of belt they use on huge machines with long belts on soft backings, typically used to clean up cast finishes and polish parts on a production level. I say this because I have an NOS set still in the box. They are most definitely not as-cast, but have a very very fine finish to them. The finish does not go into the valve cover bolt recesses or inside the fins because the huge belts would only ride on the surface and not penetrate recessed areas. The oval air cleaners were also finished this way, but with a much coarser grit of about 40-60. The aftermarket covers are just cast. They look very nice, but that fine sanded finish looks much nicer. It's also hard to keep that way.

I've used 40 grit on a long sanding board taking full length one-way strokes to get that "just finished" look on the air cleaners, but the valve covers are much harder to do and make look right.