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Technical engine paint

Discussion in 'The Hokey Ass Message Board' started by 46poncho, Feb 12, 2020.

  1. 46poncho
    Joined: May 24, 2009
    Posts: 236

    46poncho
    Member
    from Indiana

    i am sure this topic has been covered many times, but I am bringing it up again. I have tried to do some research on high temp paints and temps of engine blocks and exhaust. I have some Pontiacs and it seems the paint on the exhaust ports on the heads always burn off. I have heard a bunch of different paints and tried some heat paints with no luck. what is everybody using? Primers, Paint, process, without issues and decent paint life???
    thanks
    scott
     
  2. KoolKat-57
    Joined: Feb 22, 2010
    Posts: 2,960

    KoolKat-57
    Member
    from Dublin, OH

    Having owned a couple of Pontiacs for many years, I have not found a way to keep the paint on the cylinder heads exhaust ports from burning.
    Years ago I saw a very, very high dollar OT Pontiac GTO that was only started to get the car off the trailer and to the show field and then back on the trailer.
    The cylinder head exhaust areas were discolored and slightly burned!
    The owner had tried nearly everything and did not find anything that worked.
    KK
     
  3. Bugguts
    Joined: Aug 13, 2011
    Posts: 647

    Bugguts
    Member

    It shows its not a trailer queen! Good for you.
     
    270ci likes this.
  4. 270ci
    Joined: May 17, 2010
    Posts: 366

    270ci
    Member

    Those long Pontiac exhaust runners get pretty hot and everyone I've seen had the paint burned or discolored.
    Too bad Eastwood Stainless Steel paint only comes in one color. It holds fine up on headers and cast iron exhaust manifolds, so it would probably not burn off Pontiac heads, but it won't be Pontiac blue.
     
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  5. wvenfield
    Joined: Nov 23, 2006
    Posts: 5,077

    wvenfield
    Member

    Leave that spot unpainted. Presto, no burnt paint.
     
    firstinsteele likes this.
  6. Gman0046
    Joined: Jul 24, 2005
    Posts: 6,262

    Gman0046
    Member

    Used Jegs header paint on the 400 in my 60 Pontiac. Seems to be holding up well. gkz4KZrsQg6RQf%PzkX6Sw.jpg
     
    Last edited: Feb 13, 2020
  7. wvenfield
    Joined: Nov 23, 2006
    Posts: 5,077

    wvenfield
    Member

    Looks to me like the area that burns off isn't painted.
     
    jimgoetz likes this.
  8. Almostdone
    Joined: Dec 19, 2019
    Posts: 278

    Almostdone
    Member

    Have you tried the POR15 engine enamel? It comes in your color and has very high solid content. I haven’t tried it in your application tough. Just a thought. I have it on a 348 Chevy.
     
  9. squirrel
    Joined: Sep 23, 2004
    Posts: 46,362

    squirrel
    Member

    The manifolds are indeed holding up well. Too bad the heads aren't painted with the same stuff, the paint has burned off of them.
     
  10. hirschauto.com the best.
     
  11. 46poncho
    Joined: May 24, 2009
    Posts: 236

    46poncho
    Member
    from Indiana

    I am hoping to find a product that I can use on any engine that will hold up, not flake or burn off, not just pontiacs. I used some stuff that was like por 15 for engines but it flaked off too.
    Again thanks for the response!

    Sent from my SM-S367VL using The H.A.M.B. mobile app
     
  12. anthony myrick
    Joined: Sep 4, 2009
    Posts: 5,923

    anthony myrick
    Member

    Curious also.
    Never seen any paint that didn’t.
    The best I have used is normal automotive paints.
    I have wondered how a powder coat would hold up.
    I think issue with painting a fresh engine is the higher than normal temps on the exhaust. I friend of mine never breaks in an engine with the headers he is using for the build. He used a cheap set.
    I cooked a set of headers on my last break in.
    Wonder how it holds up if you touch it up after the break in period.
    Just a goofy thought.
    https://centuryperformance.freshdes...7000029628-new-engine-break-in-coated-headers
    If a fresh engine will damage coated headers, it’s gonna kill any paint on exhaust side of heads like the Pontiac and similar designs.
     
    Last edited: Feb 12, 2020
  13. harpo1313
    Joined: Jan 4, 2008
    Posts: 1,887

    harpo1313
    Member
    from wareham,ma

    Too hot for paint in those spots, 50 miles its bubbling 150 smoked gone.,draw a line across and leave those areas bare metal if you want to keep it pretty.
     
  14. bill gruendeman
    Joined: Jun 18, 2019
    Posts: 329

    bill gruendeman
    Member

    For the Pontiac motors with the metallic blue paint (late 60s) I found that if you paint it first with silver engine paint that the blue, the silver holds up better and looks better than just burned blue paint.
     
    Beanscoot likes this.
  15. Ziggster
    Joined: Aug 27, 2018
    Posts: 584

    Ziggster
    Member

    I just purchased some Dupli-Color engine enamel for my flathead. Sure hope is holds up. Seems like a quality paint from the build-up.
    image.jpeg
     
  16. How about VHT engine paint?
     
  17. anthony myrick
    Joined: Sep 4, 2009
    Posts: 5,923

    anthony myrick
    Member

  18. Gman0046
    Joined: Jul 24, 2005
    Posts: 6,262

    Gman0046
    Member

    Squirrel is right. The Jegs header paint is holding up better then the paint used on the engine. There's a couple of spots where the exhaust manifolds attach to the heads some paint has burned off. Not so sure it won't happen again after repainting. I'll probably repaint it and see what happens. Then again I might just leave it alone.
     
    Last edited: Feb 13, 2020
  19. justpassinthru
    Joined: Jul 23, 2010
    Posts: 271

    justpassinthru
    Member

    We have tried probably every engine paint there is over the years, from bomb can to spray gun and have never really been happy until I used Eastwood 2K engine paint.

    The best bomb can results we have had, were with VHT, using multiple coats for a good finish.
    For a complete engine paint of the block, heads, intake, oil pan, water pump and valve covers, you will end up using at least 4 cans or more, for real good coverage, at around $10.00 per can or so.

    We have gotten the best results from Eastwood 2K engine paint. This is all we use now.
    I have seen engines I painted, a few years later and the paint has not burned off of high temp areas. It is slightly discolored though.
    The paint seems to be much more durable and does not scratch or chip easily and is very glossy.
    We are very happy with the finished product now.

    I use the quarts, and spray out of a gun, mixed 4 parts paint, 1 part their hardener and 1 part mid temp. urethane reducer.
    Depending on the engine, I will prime first with quality 2K urethane sealer, for better coverage. As soon as the sealer flashes off, we spray the topcoat with a light tack coat and then with a finish coat.
    On high temp areas, I will not seal first, and only use the paint.

    Eastwood also sells the 2K engine paint in a bomb can, but we have not tried it, so I don't know how well that works.

    We can paint two engines with 1 quart of paint, 1/2 pint hardener, 1/2 pint of reducer at a cost of around $60.00. Seems more expensive than bomb cans, but is really not, cut that in 1/2 and its around $30.00 per engine, not including sealer if used.

    In our experiences, the Hirsch paint is really good for proper colors, but is not very durable in our experiences. It is 1K, lacquer based material.
    It will scratch and chip easily and also burn off the crossover in the intake and around the exhaust ports on Pontiac and Buick type engines. It also cures too quickly, and is hard to not get dry areas in the paint job.

    Hopes this helps, and no I don't work for Eastwood.

    Bill
     
    lurker mick likes this.
  20. Budget36
    Joined: Nov 29, 2014
    Posts: 3,591

    Budget36
    Member


    Hey Bill, good info.

    What is your prep procedure?

    Have my heads bagged right now and getting my block back in a few weeks.

    Thanks
     
  21. anthony myrick
    Joined: Sep 4, 2009
    Posts: 5,923

    anthony myrick
    Member

    I will clean and epoxy blocks and heads right from the machine shop
    then paint after assembly.
    the epoxy seals off the cast iron from all the oil during assembly and makes clean up easier.
    I use automotive or industrial 2k single stage
    I have about 30k miles on an sbc done this way and still looks great
     
    rusty valley likes this.
  22. rusty valley
    Joined: Oct 25, 2014
    Posts: 1,653

    rusty valley
    Member

    i too just use regular automotive epoxy primer & paint. never had an issue with heat bothering it, and its for sure gas proof
     
    anthony myrick likes this.
  23. Budget36
    Joined: Nov 29, 2014
    Posts: 3,591

    Budget36
    Member


    Do you just scrub a cleaner on it, or wire wheel it...etc?
     
  24. justpassinthru
    Joined: Jul 23, 2010
    Posts: 271

    justpassinthru
    Member

    If the engine is being rebuilt from a engine shop, tell them not to paint it. If it is painted, it is probably is not done very well and will have to strip the paint.

    If it is an old engine that has been painted previously and the paint is pretty sound, on the cast stuff, we will degrease, scrape, wire brush by hand or with a rotary wire wheel to get any loose stuff off.

    Generally tin stuff, like valve covers, pan etc usually need to be stripped or media blasted, to end up with a nice finish. Stuff can be scuffed up with a Scotch Brite type pad also.

    Everything needs to be free of grease/dirt/loose paint/oil etc. Clean-Clean-Clean!
    Wash with a grease and oil cutting type soap and water and blow dry quickly to minimize surface rust.
    Stuff can also be final washed of with prep-sol sprayed out of a spray gun and quickly blow dried, although most time,s this is not necessary if cleaned right the first time. Do not dry with cloth or paper towels, as this will cause a lot of lint stuck to rough cast surfaces and will be forever in your paint job. If you do have to use towels, make sure they are lint free type.

    The best finishes are with a light coat of primer/sealer first, then paint.

    Bill
     
    Budget36 likes this.
  25. anthony myrick
    Joined: Sep 4, 2009
    Posts: 5,923

    anthony myrick
    Member

    if its fresh from the machine shop. I use red scuffpads and a squirt bottle with automotive wax and grease remover
    if not a fresh build I clean it with oven cleaner. a lot. that stuff usually eats off cheap paint
    cast iron is porous and the epoxy seems to like that

    always allow plenty of flash time when using wax and grease removers on cast iron before spraying
    that stuff has to evap out of the pours
     
    Budget36 likes this.
  26. Ports on Pontiacs, Ford FEs, etc., being outside the water jacket are essentially exhaust manifolds. There isn't any paint that will hold up under that +1,000F temperature. Specialty coatings like stainless,zinc, etc. will hold up ok but aren't sexy colors. That being said, burned FE ports have a sex appeal of their own. For the rest of the engine I really like catalyzed urethane base coat/clear coat that is used on bodies. Dries rock hard, Looks like ceramic coating, is resistant to just about everything but nuclear attack, and obviously available in infinite color selection. I have found it resistant to all engine heat except the direct exhaust temps.

    I also like powder coating for everything but exhaust manifolds. It is essentially the same plastic resin as in urethane paint. I have coated entire engines, clear coated polished tranny cases, valve covers etc., and even exhaust systems downstream of headers with great results. Ceramic coat the headers, urethane paint or powder coat all the rest.

    As justpassinthru says, prep is the same as painting a body. The powder coating guys will sand blast unpolished finishes so they take care of the prep for you.

    The engines, trannys, and chassis on these projects were all powder coated. Even PC'd the fender wells on the pickup.
    In progress frame front.JPG pontiac_4.jpg pontiac_3..JPG
     
  27. 67drake
    Joined: Aug 8, 2008
    Posts: 73

    67drake
    ALLIANCE MEMBER
    from Avoca WI

    On my GTO I painted first with a high temperature exhaust paint as a base, I then applied my Pontiac blue over that. It seems the paint burns in those hot areas regardless, so I figured if the blue burns away at least I’ll have a base coat of header paint that won’t rust.
     
    Gman0046 likes this.
  28. Elcohaulic
    Joined: Dec 27, 2017
    Posts: 1,030

    Elcohaulic
    Member

    On the 389s you just need to hammer a freeze plug into the exhaust crossover port. The paint will stay nice and the car will run better on todays gas with ethanol..
     
  29. streetrodder71
    Joined: Jan 15, 2015
    Posts: 709

    streetrodder71

    I have used PPG Concept Auto paint over etch primer. YOU can get in any color & I have
    had good success on the SBC engines in my cars. Works better than any rattle can engine
    paint I have tried.
     

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