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
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
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.
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.
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.
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
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.
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.
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.
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.
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.
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
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
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
i too just use regular automotive epoxy primer & paint. never had an issue with heat bothering it, and its for sure gas proof
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
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
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.
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.
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..
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.