Throttle Body and Paint?

[Daniel_Mc]

The Powder Coating thread got me thinking and not to hijack that thread I wanted to ask a few questions. I was going to refinish the black motor in the ZR-1 and have heard the throttle body needs to be disassembled for this. I did a few searches but don’t see where anyone has done this themselves or at least I can’t find it. What all is involved in the disassembly? Also I was going to use DRM to redo the black (so that the engine would have the correct finish) but now the original paint that they were going to use is NLA and they want to use a local guy. That is fine by me but I have a friend that does automotive powder coating and we can really do it ourselves. Would anyone have a good high resolution picture of one of the black motor cars? I will go mostly off of mine now but someone along the way spilt something on one of the cam covers and it is not the correct finish the plenum and IH’s are sort of “OK” but where it was flaking off someone has used black spray paint

Thanks Guys

[rhipsher]

Hey Dan. How are you doing buddy? I've done it. If you'd like I can pm you pics and tell you what's involved and pm you my#.

[Daniel_Mc]

rhipsher

Sounds perfect I'll PM you my email address.

Thanks!

Daniel

[DaveK]

Rhipsher

Would you be willing to share the info more widely? I guess i will have to disassemble the TB as well when I send my stuff off.

Thanks

Dave

[rhipsher]

Originally Posted by DaveK

Rhipsher

Would you be willing to share the info more widely? I guess i will have to disassemble the TB as well when I send my stuff off.

Thanks

Dave

I'll explain the powder coating prep process the way it was explained to me by John of precision powder coating who did mine. First they chemically strip & clean the parts. Next they bake them in an oven at about 500 degrees for six hours to burn off any impurities like oil grease sealant ect. Next they mask off areas that are marked and agreed on by you and the powder coated. Next they media blast the parts with 1000psi course glass beads to insure perfect bonding bonding surface. Then they are coated and cured in and oven. So you have to remove any electrical or plastic parts (anything that could melt)
Even though the parts on the engine are made to handle the kind of heat an engine generates 500 degrees will cook them. For example I forgot to take out the plastic cam chain guids that mount inside the cam covers. They are usually a green color. But the heat turned them black. Although they are still fine that is proof that the heat generated by the ovens is far greater that any engine heat.
Now the early cars have two throttle cables that can be removed from the pullys. You just have to pay attention to how tightly the spring is wound. Count how many revolutions it makes as you slowly unwind the tension on the spring. That will help you know how tight to wind upon reassembly. Next you have to remove the throttle position sensor. After that you have to unscrew the secondary throttle plates. No need to remove the primary plate because that gets masked off for coating and there's nothing tied to it that sticks out. Now what I found is that the plate screws are sweged down inside and flush with the throttle rod I suspect for two reasons. #1 so the screws don't back out and get suck itk the intake. And #2 so there is smooth air flow. When I backed mine out the sweged tip stripped the threads out of the throttle rod. There was just no way around it. So I just drilled and taped them the next size up which was 8-32 and installed SS buttons head screws and ground what was left sticking out the backside with a dremel tool. Then is a simple matter of reassembling it again. Also make sure that you blow out everything very good with compressed air because there will be some glass bead particles inside where the throttle rod slides in. Hit the rod with some lube. Here are some pics.




Sorry its not the best step by step how to but its all I have to offer. Hope it helps.

[DaveK]

Thanks, that's very helpful. Much appreciated. I hadn't even thought of the cam chain guides

Q: Would the mating surfaces where the gaskets go need masking also?

[rhipsher]

Originally Posted by DaveK

Thanks, that's very helpful. Much appreciated. I hadn't even thought of the cam chain guides

Q: Would the mating surfaces where the gaskets go need masking also?

Yes. You don't want those areas to get powder coated. Just the exteriors. The only interior that I had powder coated was the throttle body coolant cavity and the plate that covers it.

[carter200]

Originally Posted by rhipsher

Yes. You don't want those areas to get powder coated. Just the exteriors. The only interior that I had powder coated was the throttle body coolant cavity and the plate that covers it.

Why not just replace the plate with a CT machining Billet throttle body plate and be the coolest kid on the block.

Don't forget to send the coolant pipes after they are coated to CT Machining to have them engraved to match the Billet throttle body plate engraving. Oh baby, you'll be rockin then!

[Daniel_Mc]

THAT. SILVER. LOOKS. GOOD.
And the port work!!!!

[rhipsher]

Originally Posted by Daniel_Mc

THAT. SILVER. LOOKS. GOOD.
And the port work!!!!

I did it myself for my own car and a few others for some extra $$$ on the side but decided to get out of the porting business because of the small amount of money made for the amount of work involved just wasn't worth it to me. Bob G. Paul W. And Pete are the guys to go to if you want it done.