Friends of mine have used clear (PPG) to paint a new intake and it yellowed. From that point on , they never use clear on intakes. I want to clear it a two piece aluminum timing cover (Rocket Racing). I polished it but the material is soft and scratches easily. Does anyone have a known clear that will not yellow in this situation? I may end up powder coating it but trying to save some cash. Is there is a good clear that will also do the job? I have hi-temp engine clear and also some wheel clear (all spray cans), but don't want to get into a two month ok, and then it yellows.

 

I use the VHT engine clear; it works well. However, clear over polished might not work so good if the surface doesn't have enough "tooth".

 

Have you considered using aluminum or steel colored paint? Whatever you use as long as it's engine enamel or designed to resist heat I think you'll be ok.

 

X2
The substrate / surface has to have a tooth and be 100 percent free of contamination for the top coat to have proper adhesion.

 

I sanded it with 600, but that may not be enough grit for it to adhere.

 

I wanted to keep the polished look and protect with the clear. I have used that aluminum paint in the past for alternators with good success

 

I used BASF (Glasurit and/or Diamont) over the years. Did it yellow? Unfortunately I’m not sure because it was usually over gold basecoat. I can say that in the relatively few that retained exhaust crossover heat, it held up pretty well. Not perfect, but well. I saw no apparent yellowing over BBO blue but can’t say that it didn’t. Sorry, not that helpful, but figured I’d throw it in here.

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I would definitely go with powder coat. It may cloud up a touch, but definitely won't yellow.

 

The March Pulleys are all clear powder coated, and I also recall that I had an aluminum underdrive pully powder coated and it wasn't really clouded.