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I just picked up my intake from having it powder coated, to my surprise it looks like they did the inside of the intake. Even though they provided pictures of it being taped it sure looks like to me they powder coated it... Not real sure what to do next, if this is not a problem for me later on down the road and it holds up.. Or if I take it back to them and tell them they owe me a new intake?? (This is a Victor Jr. off my 73)
Did they coat the underside and mounting surfaces too? I would only want the top (visible) surface coated if it were mine. Then nothing has a chance to come loose and go through the engine, and I would want machined mating surfaces for the heads and carb.
H-m-m-m-m-m. Don't like that idea of doing the interior or the carb base. No expert on air / fuel mixture but I bet someone will mention that the inside should be fairly rough for turbulence. Otherwise the gas droplets will settle to the floor.
I think somebody screwed up and should have taped off gasket mating surfaces and the plenum. That's poor project communication on behalf of the shop, the applier or you.
Last edited by HeadsU.P.; Feb 1, 2019 at 07:09 PM.
Guess I'm screwed then, I will be taking it back to the shop that did it.... There is no way that they can undo what they did to make it right as the entire interior of the intake is coated.. as well as all the mating surfaces... This shop told me that they had been doing intakes for 17 years....
If the shop had the tools to coat the inside, maybe they have the tools to media blast the inside and remove that coating. I suppose a disk grinder could clean up the carb pad, but I would be leery of any deep scratches.
Ask the shop of what they did is normal procedure. Maybe it was a new guy, but still . . . . .
Guess I'm screwed then, I will be taking it back to the shop that did it.... There is no way that they can undo what they did to make it right as the entire interior of the intake is coated.. as well as all the mating surfaces... This shop told me that they had been doing intakes for 17 years....
Powder is temp sensitive. Don't know what an intake temp but powder is baked on at 350 plus degrees. If they did it right is will take sand blasting to remove the powder. It's not like paint. The powder is plastic so the sand just bonces off the powder. The sand blasting will need to kind of wear off the powder.
Did not specify in writing, but did relay to him in person what I wanted coated and what needed to be taped off even had my wife with me and even she said that she thought they understood what I said... Also they provided me pictures with the intake taped off that's why I was surprised to find what I did...
They would also have had to tape off the runners. That stuff is attracted to all 'available' metal when it is sprayed. Also, once baked, that stuff is dang hard to remove. Lacquer thinner won't touch it...so I doubt that air/fuel mixture will. It can take 400-500*F with no problem, so I don't think temperature is any issue--except with the heat riser passage, and that's connected to the exhaust system which should not be an issue.
I'd stick it on and run it.
P.S. If they put a thick coating on your part, you may have to use a tap to chase out threads and/or open up some bolt holes, if they prove to be tight.
My concern would not be about the coating coming off. My concern would be how the fuel / air mixture blends, mixes or atomizes, in the plenum. Its my understanding that one should NEVER polish the internals of an intake. You can port it, but not polish. I believe you have to have a rough surface inside to get a get swirl of the vapors or the gas molecules will drop out causing a lean cylinder and a flooded plenum. So, in laymans terms, the plenum has had the pores or roughness smoothed out by the application of the coating.
The carb pad may have been ok as far as sealing against vacuum leaks. But I would prefer bare metal at that location.
I would want some compensation or a full refund or a replacement from the shop. That application is not acceptable.
Last edited by HeadsU.P.; Feb 2, 2019 at 02:53 PM.
They would also have had to tape off the runners. That stuff is attracted to all 'available' metal when it is sprayed. Also, once baked, that stuff is dang hard to remove. Lacquer thinner won't touch it...so I doubt that air/fuel mixture will. It can take 400-500*F with no problem, so I don't think temperature is any issue--except with the heat riser passage, and that's connected to the exhaust system which should not be an issue.
I'd stick it on and run it.
P.S. If they put a thick coating on your part, you may have to use a tap to chase out threads and/or open up some bolt holes, if they prove to be tight.
Maybe, if you are lucky, they used a "heat insulating" coating, that will keep the runners cooler. Does the coating look the same, both inside and outside the manifold? The picture doesn't show the contrast clearly, but the outside looks shiny silver, while the inside doesn't....
leadfoot4, the inside of the intake has a rough finish to it, its not smooth or shiny as the outside and is a slightly darker shade of gray. The other thing that I am concerned about is there is PC on all the mating services, which again surprised me as they sent pictures to me showing that they all were taped up.
Why take the chance of damaging your engine by putting it on? Powder coater probably had Gomer the parts chaser paint it. They need to make it right. Who would want that paint flaking off and getting into the engine, absolutely no reason to do that.
Last edited by Cooter Tech; Feb 2, 2019 at 03:43 PM.
On the intake to head surface flange, I would apply a dab of Permatex Black. Let it cure overnite. Next morning, see if that RTV wants to adhere to the coating or not. That will determine if your gaskets will ever seal or not. It bet it won't stick very well. Isn't that part of the reason for powder coating the intake is to seal out oil stains, gas stains, RTV, etc?
As far as porosity and texture to the plenum: It is not as shiny as the exterior but that could be the camera lighting. But it still looks way too smooth to me.
You can mount the intake if you want, but I truly believe you will have fuel mixture issues, vacuum leaks and oil leaks. They likely sprayed coating where the China wall has to seal also. And once the intake is installed, you are telling the shop you think its acceptable and are not as likely to get any compensation.
Communication is everything in a business offering a service. Because you left the shop without questions, they think everything is just biffy. You need to take the intake back and have a calm and informative discussion with them and that you question wither the mating surfaces will ever seal a gasket. And that you are not happy about the outcome. The ball will be in their court. Lets see how they play it.
Your move, your money, your car.
Last edited by HeadsU.P.; Feb 2, 2019 at 04:23 PM.
Thanks guys I will be taking it back to the shop on Monday, you would think that them telling me they have been doing this for 17 years they would have known better.... As far as I am concerned they owe me a new intake...
Powder Coated Intake Problem?
