Howdy Howard,
I'd be inclined to paint with the best two-pack available over any powder coat application, from both sides of the equation, prep and results. PC'rs like to bead blast which is just adding risk to a power unit already in service as opposed to one being resusitated from the crusty dead. No commercial establishment can afford to carefully mask off the mating faces and vary the surface depth where needed (recessed lands on covers held by tight fitting cheesehead screws) to provide adequate clearance.
Once stripped of paint (air craft stripper is sypathetic to alloy), Hot soda wash your parts (transmission rebuild shops or similar) which act as an astringent to boil the oils out of the more porous pieces. Don't worry about bearings left in situ, this process leaves a film that protects bare steel to a degree and you'll be cleaning it off prior to painting anyway. Hit your finished surfaces (primary, timing cover) with scotch brite pads then clean the lot with a fast flashing lacquer thinner of similar to remove any oil and film. Tape off mating surfaces. You've got your choice at this stage, brave? Shoot color straight on the alloy (I shot my carbs depicted below 10 years ago with Glasurit's base silver mixing metallic over bare metal and none has come off after repeating soakings in gasoline though now in need of being cleaned up a bit, admittedly). Otherwise, use a low build final color tinted etching primer. For color, I've had absolutely superb luck with Glasurit 21 and now 22 line high solids base black. I shot this engine in 1992 and it only needs a swipe of the cloth laden in Brake Clean to shine like new.
Be advized the same havoc being wreaked on tank lining concoctions by new fuel formulations will have no less dramatic effect on your painted surfaces. Just as no suppliers of the former can assure you without a doubt their product will hold up to these rather transient standards - in our case the EPA - over time, neither can automotive finish suppliers. That is why I recommend using the best you can obtain and letting the chips fall where they may.
Don't know how accurate you want to get it but attached is a pic of a 2,500 mile totally original Shadow for reference (displayed at the VOC NA rally on Saturday along with a portion of the crate it arrived in). You'll note the heads/cylinders look to be shot bare and have less gloss that the cases and covers. Note also the masked off (bare metal) lands for the valve covers. Glasurit sells deglossing agents to mix with their paints.
Good luck.
I'd be inclined to paint with the best two-pack available over any powder coat application, from both sides of the equation, prep and results. PC'rs like to bead blast which is just adding risk to a power unit already in service as opposed to one being resusitated from the crusty dead. No commercial establishment can afford to carefully mask off the mating faces and vary the surface depth where needed (recessed lands on covers held by tight fitting cheesehead screws) to provide adequate clearance.
Once stripped of paint (air craft stripper is sypathetic to alloy), Hot soda wash your parts (transmission rebuild shops or similar) which act as an astringent to boil the oils out of the more porous pieces. Don't worry about bearings left in situ, this process leaves a film that protects bare steel to a degree and you'll be cleaning it off prior to painting anyway. Hit your finished surfaces (primary, timing cover) with scotch brite pads then clean the lot with a fast flashing lacquer thinner of similar to remove any oil and film. Tape off mating surfaces. You've got your choice at this stage, brave? Shoot color straight on the alloy (I shot my carbs depicted below 10 years ago with Glasurit's base silver mixing metallic over bare metal and none has come off after repeating soakings in gasoline though now in need of being cleaned up a bit, admittedly). Otherwise, use a low build final color tinted etching primer. For color, I've had absolutely superb luck with Glasurit 21 and now 22 line high solids base black. I shot this engine in 1992 and it only needs a swipe of the cloth laden in Brake Clean to shine like new.
Be advized the same havoc being wreaked on tank lining concoctions by new fuel formulations will have no less dramatic effect on your painted surfaces. Just as no suppliers of the former can assure you without a doubt their product will hold up to these rather transient standards - in our case the EPA - over time, neither can automotive finish suppliers. That is why I recommend using the best you can obtain and letting the chips fall where they may.
Don't know how accurate you want to get it but attached is a pic of a 2,500 mile totally original Shadow for reference (displayed at the VOC NA rally on Saturday along with a portion of the crate it arrived in). You'll note the heads/cylinders look to be shot bare and have less gloss that the cases and covers. Note also the masked off (bare metal) lands for the valve covers. Glasurit sells deglossing agents to mix with their paints.
Good luck.
