What's the point of wrinkle finish

[albatcha]

I tried looking this up but could only find people talking about how to do a wrinkle finish on a valve cover, no actual experts talking about why it is done.

 

Does anyone here know? Why did we start putting wrinkle finishes on valve/rocker covers? Is there an actual benefit? Or at some point did we think there was a benefit?

 

I'm guessing it might be like gold painted wheels. Something we copied from race cars, where the look was related to the purpose. If you didn't know, all those magnesium racing wheels are gold because they dipped the bare magnesium in a chemical to protect it from corrosion, and that process gives it the gold color.

[02Pilot]

+5 horsepower. +10 if it's red.

 

Prove me wrong.

[tech71]

There is no point, people do it because they can and they think it looks cool.

Kinda like choosing to paint your house burnt orange.

[conkitchen]

I'm starting to ask this question of my wife.

If anything, it certainly does not make her go faster. 

AaayOooh! 

Edited August 12, 2020 by conkitchen

[zinz]

1 hour ago, Andrej said:

+5 horsepower. +10 if it's red.

 

[NYNick]

Ridiculous. Like too much chrome.

[theNomad]

It's because

[AustrianVespaGuy]

Actually, on a nice aluminum cover like the 2002s not much.  But on *some* other high end cars, the OEMs like to try to save a tiny bit more weight by using magnesium for the valve covers.  And magnesium flows like SHIT when you cast it, AND it's a royal pain in the ass to machine, so the outer surface finish is then generally super crappy. So I think wrinkle paint or similar wrinkly/bumpy powder coating is often used to 'hide' the natural crappy finish that would otherwise be noticeable with regular paint.  Both the old 911 and more modern E39 M62/S62 engines had such covers.  Both were really horrible surface finishes when I had them off and stripped, and got wrinkly coatings accordingly.  My 2002 cover on the other hand, is nice shiny, smooth gloss black!  Aluminum valve covers are certainly NOT the first place I'd go to shave some weight in vehicle design, but OEMs will be OEMs. . .

[jp5Touring]

Because we can

 

[calw]

Wrinkle finish is much better at trapping oily crud than a smooth finish.  Keeps the engine bay detailers in work

[albatcha]

Lol thanks everyone, now I'm thinking I should paint my valve cover again, since the old wrinkle paint came off. Sounds like there's a lot of good reasons.

 

AustrianVespaGuy that sounds very possibly the real explanation. A little bit of googling and I see it looks like a lot of ferrari engines like the 250 gto were using magnesium valve covers too. Then maybe we were just copying the fancier cars.

[jp5Touring]

Do as you like,its your car.  I always build my cars for me, not for other people.

[albatcha]

Yes I agree, but to clarify I still want to know who started the trend of wrinkle valve/rocker/cam cover finish, and why did they choose to do it, just out of curiosity. If you who knows the answer come across this thread even in five years or more I give you permission to revive it. I'll take the blame.

Edited August 13, 2020 by albatcha
typo

[TobyB]

I think AVG nailed it-  "It covers a multytood of sins".

 

And anyway, if you sprayed undercoat on a valve cover,

EVERYONE would know something was up!

 

t

getting more wrinkly as he ages.

 

Edited August 14, 2020 by TobyB

[halboyles]

On 8/12/2020 at 6:27 PM, AustrianVespaGuy said:

used to 'hide' the natural crappy finish that would otherwise be noticeable

Yep, for the same reason home builders use popcorn spray on the ceilings and even on walls.