exterior color match siebenrock to BMW head?

[jjwithers]

I'm throwing this out to get some thoughts/opinions.
I have perfectly clean BMW heads and a brand new Siebenrock cylinders.
My issue is that the exteriors don't match.
Any ideas what siebenrock does to their exterior and how to get the BMW head to match the cylinder?
polish? paint?

Thanks in advance.

[SteveD]

Three choices I guess
1. gspd's method
2. rub 'n buff
3. some sort of blasting.

http://boxerworks.com/forum2/viewtopic. ... f&start=10

[Deleted User 62]

"...paint it black."

[jjwithers]

I did a rub on style sliver paint on the case. I'm debating on if i should do the cylinders and heads the same. A reason against it is because the paint i used is discontinued. I have some left but i was hoping to use it for touch ups, if needed.
Ideally, i'd like to leave the cylinders alone and somehow figure out what siebenrock did and match it.

And black doesn't match my 'theme'... but painting the heads/cyl all black was the first thought that crossed my mind.

Is there a media that would blast the heads and have it look like a silver luster (like the cylinders)?

Oh, and what is the gspd method?

[SteveD]

Oh, and what is the gspd method?

Click the link in my first response...read my first response in that, which was something I kept when gspd, the mechanic from hell, posted it. Melville swears by it and has been using that method in his meticulous reno.

The rub 'n buff is also good, but use "silver leaf" if you use it. Make up for motorcycles! If you start off sparse with the rub 'n buff you can creep up on the match easy enough. Here's an example that I did on the disc hubs.

[jjwithers]

Thanks for the replies.
It has probably been discussed before, but what are the long term results of Rub n Buff?
How does it do with the engine heat?
I'm more inclined to use something rated for high temperatures.

[Major Softie]

Thanks for the replies.
It has probably been discussed before, but what are the long term results of Rub n Buff?
How does it do with the engine heat?
I'm more inclined to use something rated for high temperatures.

Yeah, I too am curious about its use on heads (because of heat).

The black paint suggestion was not, I believe, for both cylinder and head, but just for the cylinder. Black cylinders (which don't get as hot) with raw heads is a classic look for not only BMW's, but many older bikes. It comes from the days when most motorcycle engines had iron cylinders and aluminum heads. The iron cylinders had to be protected by paint, but the heads would be left raw for better cooling.

[Deleted User 62]

"The iron cylinders had to be protected by paint, but the heads would be left raw for better cooling." Huh, I didn't know that, thanks Major. Learned something new today, and yeah, I meant paint just the cylinders, R90S style.

[SteveD]

Thanks for the replies.
It has probably been discussed before, but what are the long term results of Rub n Buff?
How does it do with the engine heat?
I'm more inclined to use something rated for high temperatures.

It's a good question. I'm yet to read any negative comments about it, except that if you use too much it might look more painted than an oem appearance. Sparse application is the go. Longevity of the finish hasn't been an issue that I've read, but time may change that? It sure gets used by many, as evidenced by multiple threads on bike forums. Application on the heads would be time consuming and fiddly.

[SteveD]

Here's a response re: the short term look ...from George Strong in the UK. bmbikes forum.

Barrel fins seem OK with the silver leaf rub'n'buff even after prolonged heat - doesn't look any different after about 500 miles. Same with base of barrel and crankcase ... I'm still on the first tube after covering everything alloy, with a spare on the shelf.