Correct finishes for engine components on 1978 308GTB ? | FerrariChat

Correct finishes for engine components on 1978 308GTB ?

Discussion in '308/328' started by Motob, Feb 9, 2019.

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  1. Motob

    Motob Formula 3
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    #1 Motob, Feb 9, 2019
    I am putting an engine together that came to me in boxes that was dismantled years ago. It is from a 1978 USA spec 308GTB (carbureted engine, twin distributors with single air injection pump and two catalytic converters). Although I am not building a show winner, but since everything needs to be refinished (all parts are corroded), I would like it to be as correct as is possible.

    It appears that the the cam covers were bare aluminum with no paint finish at all (although the casting of the rear cam cover is very rough, almost like it is wrinkle finish, and the front is very smooth). Am I correct in assuming that they were bare aluminum originally?
    The timing belt covers appear to have been painted silver in the past, but not wrinkle. From period photos it looks as they should be bare aluminum as well, is this correct?
    What about the intake manifolds, bare aluminum?

    Aside from the cam cover acorn nuts, I would assume that all of the steel fasteners and brackets (alternator and air pump adjuster, etc.) were originally yellow cad. plated (to be replated yellow zinc chromate).

    It's funny, that there is so much information and period photos of the engines of the high dollar V-12 out there, but next to nothing on the 308 V8 engines that Ferrari made so many of. I went through all of my Ferrari books, and there are usually only 3 or 4 photos of the 308, and they will all be of the outside of the car, virtually no engine shots.

    Thanks for your help!
    Brian Brown
     
  2. kiwiokie

    kiwiokie Formula 3

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    #2 kiwiokie, Feb 9, 2019
     
  3. Nuvolari

    Nuvolari F1 Veteran
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    #3 Nuvolari, Feb 9, 2019
    The different textures on the front and rear cam covers is correct for US spec cars and the factory finish is raw aluminum. This also goes for all cast metal parts

    Cam cover nuts are bright nickel (looks like chrome) closed end acorn nuts while most other engine bolts and nuts are yellow zinc.
     
  4. Dave rocks

    Dave rocks F1 World Champ
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    #4 Dave rocks, Feb 9, 2019
    Rob - Yellow Zinc or Yellow Cadmium?
     
  5. BigTex

    BigTex Seven Time F1 World Champ
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    #5 BigTex, Feb 9, 2019
    Its odd, but as above, the rear casting (to add the air pump!) makes cam cover sand cast compared to the front one, smooth.

    My mechanic shot silver paint the cam covers because they do get stained, but raw aluminum is correct there too.
    High polish looks really nice, but just "casual" is the way they came!!

    Thanks for checking in, that's flattering.
    :D :D :D
     
  6. lm2504me

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    #6 lm2504me, Feb 9, 2019
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  7. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #7 Rifledriver, Feb 9, 2019
    Never cad.
     
  8. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #8 Rifledriver, Feb 9, 2019
    Brian, Pat has my email. Send me an email, I have good pictures for you.
     
  9. miked

    miked Formula Junior

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    #9 miked, Feb 9, 2019
    Everyone has pretty well summed it up, bare aluminum finishes. The original 1973 Paris Auto Show GT4 was displayed in "not yet assembled" form with the engine on a stand. It was the only engine with painted cam covers (black crinkle) from the factory. It is fairly common for owners to paint their cam covers in black or red crinkle at some point. I think that the earlier cam covers with a separate reaction arm bracket (not part of the cover casting) can pull it off better. My car's cam covers were painted black crinkle by a former owner but I prefer (have) a driver rather than a show car.
     
  10. Dave rocks

    Dave rocks F1 World Champ
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    #10 Dave rocks, Feb 9, 2019
    On a 308 / 328? Other are CAD, correct?
     
  11. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #11 Rifledriver, Feb 9, 2019
    Yellow zinc.
     
  12. Dave rocks

    Dave rocks F1 World Champ
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    #12 Dave rocks, Feb 9, 2019
    Are you saying no Ferrari parts have ever been yellow CAD? I'm Told they have been which is why I'm asking. I did a bunch of my 355 parts in yellow zinc and was planning to redo them.
     
  13. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #13 Rifledriver, Feb 9, 2019
    Go back far enough and they probably were but not on the 355. The finish looks the same and any difference only reflects the technique used. Even people in the industry tell me they cant tell the difference. The shade, rainbowing, high sheen vs dull can be done with either.. Zinc became common in the 50s and Cad was phased out for the most part in the 70's. Cad is expensive and an environmental nightmare.

    Early zinc was a zinc cyanide process and was dull. In the 70's a zinc acid process was adopted and produces a shiny finish provided the surface is smooth.
     
  14. Motob

    Motob Formula 3
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    #14 Motob, Feb 10, 2019
    Thanks to everyone for all of the information! It's great when there is so much knowledge out there that people are willing to share.

    I guess that since Ferrari had to come up with a different cam cover for the cars with air injection, they just used a mold or casting process (sand casting?) that caused the part to have a much different surface finish than that of the front cover.

    Well it looks like it's time for a trip to the local vapor blaster to get all of the raw aluminum parts to look original . The carburetor bodies and the distributor housings are all corroded as well. I think that vapor blasting gives the nicest finish on raw aluminum parts.

    lm2504me, the photos of your car/engine are great! I noticed that the steel adjuster bracket for the air injection pump is plated silver, not yellow zinc as all of the other steel parts. Have you confirmed that this is the original plating/color for this part?

    Regards,
    Brian Brown
     
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  15. Dave rocks

    Dave rocks F1 World Champ
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    #15 Dave rocks, Feb 10, 2019
    Well that's good to know as it saves me replating a lot of parts. In speaking with players that still do yellow Cad, they tell me it offers better corrosion protection.


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  16. Nuvolari

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    #16 Nuvolari, Feb 10, 2019
    Exactly correct. Could not have said it better
     
  17. lm2504me

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    #17 lm2504me, Feb 10, 2019
    Contact me for any photos when you want to verify plating colors or anything else.
    T    he air pump adjustment bracket and the alternator adjustment bracket are not yellow plated.​
    Most yellow plating can be found on some clamps, vacuum actuators, carb hardware, some bolts and some lock nuts.
    I have photos of all areas of my 308 while getting it ready for Platinum level and I started with a 16k mile car.
    I spent a lot of time researching and looked at many 308 carb car photos.

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  18. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #18 Rifledriver, Feb 10, 2019

    Correct, all smog equipped cars had a sand cast 1/4 VC and a die cast 5/8 VC. All alloy castings are bare. I do believe the adj bracket was clear zinc but be careful. Yellow zinc is a 2 stage process and was very inconsistently done so can vary from quite yellow to very near silver. V12 Suspension pieces ( Daytona, C4 etc) are a good example. Some look silver and some look yellow on the same car.
     
  19. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #19 Rifledriver, Feb 10, 2019
    Those look great. You have a good plater. Who is it?
    Cad does have a greater resistance to salt and is still used in marine and things like that but nickel is better still. Cad really only makes sense anymore where they want to put a paint finish over it. Cad will accept paint, the others will not.
     
  20. Dave rocks

    Dave rocks F1 World Champ
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    #20 Dave rocks, Feb 10, 2019
    Thanks. So, part of the results are the prep I did. First, glass bead blast. Second, vibratory tumble.

    The plating shop is a friend, Buffalo Metal Finishing.

    Here are some in process photos.


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  21. Nuvolari

    Nuvolari F1 Veteran
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    #21 Nuvolari, Feb 10, 2019
    Good prep is incredibly important in determining the quality and final look of a plating finish. Dave certainly has his process right and the results speak for themselves
     
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