I'm going to have the outside of a few intake manifolds done with powder coating.Since the coating is so smooth I have been thinking about doing the inside also,at least as much as can be seen when looking inside the intake itself.Both of these manifolds are injected,so gasoline would not be a problem because of it's ability to act as a solvent.One is a TPI from an 88 305 out of a Camaro,one is a Lingenfelter Superram(Turbocharged).Does anyone have any experience in having the inside done?I have done some research and found that temperatures would have to exceed far more than the engine is capable of taking in order for the coating to melt and hurt the engine.Even if the coating should somehow come off it seems to me it would not be hard enough to damage the engine.Any thoughts?

I wouldn't do it mainly because if it fails it will get sucked into the engine. Also, since the intake air is dry until it gets to the injectors there wouldn't be any real benefit to smoothing it out. If anything, the existing texture helps promote laminar boundry air flow.

JazzMan

The issue here is that you would not know if the inside surface is clean enough to ensure proper adhesion of the powder. If not clean, it will not adhere. The rough surface, as JazzMan indicated, is not an issue, but I would comment that it would promote turbulent flow at the surface, not laminar.

If you really want to have them coated, why not get them ceramic coated? I've only seen steel items ceramic coated, but I don't see really why you woudln't be able to do it with aluminum as well? Can't hurt. Ceramic coating is also pretty smooth as well, more or less like powder coating.

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Todd,
2006 Pontiac Solstice
2004 Volkswagen Beetle Convertible (Wife's Car)
2002 Ford Crown Victoria LX
1987 Pontiac Fiero SE / V6 (3.2) 5-Speed
1984 Porsche 944 5-Speed
1981 Pontiac TransAm (Olds 455BB)
1973 Volkswagen Type-2 Transporter

It sounds like an underlying assumption in your inquiry, hugh, is that "smooth is good" even inside an intake manifold.

However, until that's been shown to be true, I'd avoid this "smoothing" that was mentioned --- for the reasons that Jazzman and olejoedad volunteered earlier in this thread.

I also learned this morning that even my interest in chrome-plating the exterior of a Trueleo intake manifold could be complicated in part by the plater's (pre-chroming) smoothing copper substrate possibly getting inside the manifold's runners, and then flaking off into the underlying engine.

Regardless of its supposed performance merits (which seem unproven), maybe doing what you've mentioned won't flake off into the cylinders; I don't know. What I'm learning rather quickly however, is that plating metal engine components seems noticeably more complicated than just painting metal engine components.

My thinking was if time was spent polishing the intake system as is the practice in racecars,it could be easier and more cost effective to have the inside of the intake system powder coated.I already know about port matching and gasket trimming.

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#1112
Question my ability,question my intelligence,never question my integrity!
87drivetrain http://fieroaddiction.com/SBCTa.html

The ONLY thing I would be afraid of is that since aluminum oxidizes if not prepped well, you could lose a piece of powdercoat that could...if you are really unlucky.....get stuck on the flat seal portion of a valve. You would then burn the valve and have to repair it.

The only real issue that could cause a problem is adheasion. If you properly cleaned and blasted the manifold it can be coated and it will stick. Even if it did fall off, the engine could easily eat it. Powder is basicly just plastic. I have seen much worse go through engines.

The big issue though is it likely will hurt preformance. As was stated earlier, you do not fully smooth out the intake when porting, you do that in the exaust. If I remember correct (I could be off) you use about 60 grit and no smoother on the intake side. The small amount of turbulance is considered a positive thing.

If you want it coated I will coat it for you insid eand out, then it will look pretty.

Aaron