gt550 crankcase finishing

[redroadster]

Hi, I am new to this forum, I have recently bought a 1975 GT550, I now have the engine in bits and have just colected the crankcases, barrells and head after being shot blasted, can anyone tell me what sort of finish I should apply, lacquer, paint etc?

Thanks

[cyclebuster]

I would probably paint it in hi temp aluminum silver or aluminum finish, after its all done, except the chrome. you need an etching primer to get most paint to stick, so there must be a case paint that etches available.

[Suzsmokeyallan]

If the cases were blasted its already etched enough for the paint to adhere, apply just enough thin coats of metallic silver to cover it properly, THEN clearcoat it to protect the paint.
Thin coating is best here since the cases get hot and so you want it to bake in and not crack or peel when you first 'condition' the paint by running in the engine.

[H2RICK]

Welcome, redroadster......and congrats on owning a great Suzi. Some would say I'm prejudiced about 550's......but what do they know!!!

When you say "shotblasted" do you mean with real shotblasting grit....or do you mean glass beads ??
Either way, it looks like whoever did the job didn't bother to mask off the case main mating surfaces OR the bearing housings.....which could be problematic when it comes time to put everything back together.
Hopefully it'll work out for you. Don't forget to use Three Bond 1194 case sealer on those main case mating surfaces when you reassemble everything.....

[Wingspan]

I'm in the process of rebuilding a T500. I decided to paint my cases. I cleaned everything, then bead blasted the exterior surfaces. I then cleaned everything again and again, and again...make sure all that blasting media is gone! After cleaning I masked everything off and painted the cases with Duplicolor "cast aluminum" and then clear. I then baked everything in an oven. Duplicolor says the paint doesn't need to be baked, that the engine heat alone would cure the paint. I decided to bake it as a precaution. If the paint was going to blister or flake off the first time it got hot, I'd rather know now, before it's reassembled. So, I first baked everything at 200F for 20 minutes. Then I cooled the parts to room temperature and baked them again at 300F for 20 minutes. Nothing peeled or flaked, but the clear did yellow a bit in some areas. It seems to be only where the clear was a bit on the thick side, so go lightly on that step!

Parts ready for paint:



Painted:



Curing:

[gt-keith]

+1....H2RICK,

I don't think shotblasting everthing is really recommended.

Surely Bead or Vapour blasting is the way forward.

[redroadster]

Trying to find someone local with a bead blaster was impossible, I am thinking of investing in a cabinet and compressor, has anyone just put a coat of clear on? I am waiting for a couple more parts to arrive then I will start to reassemble the engine.

[H2RICK]

Wingspan, you lucky rascal!!! Now THAT'S my idea of a proper oven. Heck, you can even bake your own frames in there......or heat up cylinders to press new sleeves in or out....or put engines in there to heat them up for disassembly.....
The possibilities are endless.....

[Wingspan]

Wingspan, you lucky rascal!!! Now THAT'S my idea of a proper oven. Heck, you can even bake your own frames in there......or heat up cylinders to press new sleeves in or out....or put engines in there to heat them up for disassembly.....
The possibilities are endless.....

The oven isn't mine, but I do have access to it through my father. He teaches aviation maintenance and the oven is in the university's composites lab. One of the perks (for me) of all the extra hours he puts in on the weekends is that I can tag along to do things like this.

[redroadster]

Crankcases now coated in lacquer and a tube of Three Bond 1194 on order as recommended by H2RICK, its annoying when you see it priced at $8 in the USA but here in the UK you have to pay £14.00 approx $20. New bearing fitted to the crankshaft so the rebuilding can start next week

[H2RICK]

but here in the UK you have to pay £14.00 approx $20.

Wow !! Who knew that freight costs were so high from Japan to the UK ??

That's a ridiculous price, IMO. It would actually pay you to get one of the guys in the US to buy a half dozen tubes and mail them to you. You'd be able to sell 5 tubes at a discount price to your buddies and end up with YOUR tube for free.