Spanking the Cow- The continuing saga of an R100GSPD at the Races

[One Less Harley]

I might have missed this but why did you need new jugs and pistons?? Since you didn't punch it out. Mine had 100,000 miles and the cylinders and pistons were good, just needed rings. New circlips too.

Compression was low, but cylinders still had the cross hatching.

[CordR]

Originally Posted by Stagehand

Go team!







You sound crazy enough to do it. seriously? thats awesome. Race it in something. Win the Crowd That bike looks perfect. Ripe, if you will.
Could you fit a damper to the WP stuff? I must have seen that thread somewhere on here.

I have not checked on a damper yet but I'm sure there's something that fits.

Looking forward to seeing how the Siebenrock rocks.

Keep us posted.

C

[Stagehand]

Originally Posted by One Less Harley

I might have missed this but why did you need new jugs and pistons?? Since you didn't punch it out. Mine had 100,000 miles and the cylinders and pistons were good, just needed rings. New circlips too.

Compression was low, but cylinders still had the cross hatching.

This is an excellent question. Bike now has about 105K or thereabouts. The bottom end was reset 15K ago, the same time that the heads were reconditioned. Due to the way the universe works, I ended up putting one original piston and cylinder back in, and one of a completely unknown lineage, other than it had no more hundred thousandths to spare.

So when would be an appropriate time to finish that project and move up to 9.5 pistons? At the time of the rebuild, it was just a matter of getting it rolling. It basically just took this long for me to get around to it. No more sense riding around on lungs in the twilight of their years. It is a "racing commuter" after all Now that the valves were re-squared away, I now have a bike hopefully ready for the next 100K miles.

[Lornce]

Originally Posted by Stagehand

Dat here is my vorn for you

Hey, Stage.

Have you got any more pics of those piston crowns?

[Stagehand]

Originally Posted by Lornce

Hey, Stage.

Have you got any more pics of those piston crowns?

Thats it I think, I didnt get any profile shots of them. The valve recesses are pretty deep, I guess they get the extra compression from moving the piston face up higher in the cylinder?

[danedg]

[Lornce]

Thanks. That answers my question.

In that first pic above (the one I quoted) I mistook the cylinder wall for a squish band on the piston periphery.

Just wishful thinking on my part.



I'm in a conundrum at the moment trying to help a friend put a nice motor together and we can't find any decent '77 spec S or RS pistons anywhere.

We're either going to experiment with machining a flat periphery into a set of domed 9.5 pistons to suit a set of squishband heads. Or machine an angle into the squish shelf of a set of squishband heads to suit the domed 9.5 piston.

[danedg]

Originally Posted by Stagehand

swear to god I hit it with the pressure washer 3 separate times.

J, It takes FIVE quarters to make the pressure washer work...

[datchew]

Originally Posted by Stagehand

Having Dan Edg and Andrew both there was like having a devil and and angel on either shoulder. One: "Clean it." The other: "Screw that"

Awesome.

I'll have some VORN again soon in my /2 thread. I hope to have slugs and jugs this coming week. Waiting on the resurfaced lifters to show up.

[danedg]

[Stagehand]

[mykill]

Now that you have altered it... Let the obsessive jetting games begin!
If you are like me, you will question every burp, fart, stumble or hesitation and think Needle up? needle down? main? air screw? idle jet? carb balance? Could it be better? Am I missing something? What about that cursed carb circuit overlap?
Boxer OCD!

[Lornce]

Originally Posted by Lornce

I install rings completely dry and fire the motor and run at 3/4 full revs for 45seconds then shut it off and repeat twice more allowing it to cool in between.

Then suit up and leave on the bike immediately after starting (DO NOT let it sit on choke to warm) and turn the choke off AS SOON as possible (or sooner) while underway (this is very important, especially with nikasil barrels, to prevent cylinder glazing).

Go for a good ride of 40-60 miles of empty roads using the revs in the midrange off and on throttle to create pressure in the chambers to force the rings to bed-in to the bore. Your motors will seal nicely and won't use oil when the rings are broken in this way.

Don't be shy with new rings, it'll only lead to glazing and oil consumption. You're actually completeing the machining process when you bed-in new rings. Be aggressive about it.

Hope this helps,
Lornce

[Rapid Dog]

...FKN 'AYE I support my bru's...my ol' belly gonna look good in this...
U KNOW?!

[Stagehand]

Originally Posted by Lornce

I did get it off choke in about 45 seconds. I rode it around the yard to see if it would break right away All in all it got almost a half mile on it in little more time than the video shows.

Leaving for Africa today, had no real time to get it bedded in. Just enough time to insure that it works... When I get back it will get the full treatment. Needs a carb sync pretty fiercely.

Also needs a final drive overhaul. I can only assume its the great big bearing on the back that is very very tired, but being that everything else on this thing is worked over the coals, I bet it'll have to see the tapered needles behind the big one, too.