Okay, so I'm going to be painting my Duke with MG Maroon POR-15 enamel (just to make maintenance easy, so I can just rinse it off quick, and be done, rather than taking forever, getting the embedded grease out), but I was wondering since the block and head were already coated with a black paint by the shops that did the work, would I have to go through all the steps, or could I just put the Metal Ready/Prep&Ready on there, and continue from there? Both have been bagged since they've been worked on, so it's highly unlikely for there to be any rust/gunk left (unlike the intake manifold. I have to clean that more, since there's a lot of black flake chunks left on it, similar to brittle paint peeling).

If I understand, your wanting to use POR to paint your engine and the engine shop has already cleaned and painted it. If they cleaned it first, I see no reason you cant just put the POR right on over it. You do need to use the prep on any unpainted or dirty parts. On the already painted parts, paint a small area in an out of sight place to make sure they are compatible. You dont want the POR to crayze or bubble their paint or you will have to strip it all first.

I think the metal ready says on it only to use it on metal. But they also recommend not using POR over another paint. I tend to think the POR would stick well. But if tehre were no paint under it it would be best. How did you get a custom color POR paint?

quote Originally posted by 2.5: I think the metal ready says on it only to use it on metal. But they also recommend not using POR over another paint. I tend to think the POR would stick well. But if tehre were no paint under it it would be best. How did you get a custom color POR paint?

por 15 bonds to the etched metal.. not paint. it will fail..

quote Originally posted by E.Furgal: por 15 bonds to the etched metal.. not paint. it will fail..

The Metal-Ready says to apply itself to the block, so the POR-15 will chemically bond. I guess I will just have to try this on a small part of the block, or the tappet/rocker cover

quote Originally posted by 2.5: I think the metal ready says on it only to use it on metal.But they also recommend not using POR over another paint. I tend to think the POR would stick well. But if tehre were no paint under it it would be best. How did you get a custom color POR paint?

My bet is that they say that because of the risk that the paint might not have been applied right, so they just say that to keep everyone happy.

It's an engine painting kit.
http://www.por15.com/ENGINE...IT/productinfo/EPKA/

quote Originally posted by rogergarrison: If I understand, your wanting to use POR to paint your engine and the engine shop has already cleaned and painted it. If they cleaned it first, I see no reason you cant just put the POR right on over it. You do need to use the prep on any unpainted or dirty parts. On the already painted parts, paint a small area in an out of sight place to make sure they are compatible. You dont want the POR to crayze or bubble their paint or you will have to strip it all first.

Correct. It has been hot tanked and a protective paint applied to it, to prevent rust.

[This message has been edited by Bstrickler934 (edited 05-22-2012).]

POR-15 will peel and flake off if put on a painted surface, been there found out first hand.

I guess the others input answers your question. Personally, I paint my engines on my showcars with regular auto body paint. Sometimes single stage acrylic enamel and sometimes basecoat/clearcoat. On my new cars with alloy engines, i wash them good on delivery and spray them with a good coat of urathane clear. Those engines look brand new 5 years later. It totally eliminates the powdery corrosion I see on others engines.

quote Originally posted by rogergarrison: I guess the others input answers your question. Personally, I paint my engines on my showcars with regular auto body paint. Sometimes single stage acrylic enamel and sometimes basecoat/clearcoat. On my new cars with alloy engines, i wash them good on delivery and spray them with a good coat of urathane clear. Those engines look brand new 5 years later. It totally eliminates the powdery corrosion I see on others engines.

it's all in the prep..
por 15 says right on the can(have one here) not over old or new paint..
it also doesn't like clean metal.. and what I mean by clean is rust free.. the metal has to be clean, but it bonds to the rust that no matter what you do is still there..
if you wanna use it on a block. they make a high heat por15..
I'd use engine paint, but I 'm not into show cars.. did that once, the upkeep and sweeting over driving it was not worth it..
when I build my 496 I'm gonna try autobody paint, so the block matches the truck,
did you use etch primer under the base on the iron blocks?

I call them show cars but I drive them all all year round, usually about 7,000 miles each per year. I just hose them off every few months. I dont use primer because you have to scuff primer to paint over it. I just use non sanding sealer and paint. If Its just the clear like on my Magnum or Bullet, I just clean it, blow it dry and spray the urathane clear right on bare alloy. I havent had any peel off in years. For those that use PPG primer, Driver says you can spray it and spray color directly over it without sanding if you do it right away. I dont know, because Ive never done it.

Ive only used POR on bare car frames on ground up restorations, so it was always bare sandblasted metal. Im thinking maybe they just say over bare metal to protect themselves from it peeling off a bad previous paint job and it being blamed. One of these days im going to have to do a couple of test pieces to leave outside for a year or so to see what happens.

I use light colors on the block (so I can see any leaks)
Makes it easier to track down where the leak is coming from

I've used POR on 1972 brake drums, and on an oil pan, it lasted. It says the regular POR is good to 300 degrees, but my guess is higher.

POR20 is the high heat one, its good too. I've had it on some headers for 4 years.