airhead parts - the dark secrets revealed

[opposedcyljunkie]

Originally Posted by rtw02

I have used Real Gaskets valve cover gaskets for about 150,000kms now.
They have been on and off the bike 15-20 times,are still sealing fine, and have never leaked.

that's good to hear, now that i just took delivery of various gaskets from reak gaskets.

[Lornce]

Thought I'd repost my post from Randy's piston ring thread. It fits here.

Deves it is. Ed Korn doesn't make piston rings. You can find them (the rings ed korn sells you) yourself for a fraction of the cost.

fwiw, Hastings makes a ring set for a VW bus motor that's a dead ringer (heh heh heh) for R100 rings. They're cast so they'll seal faster than BMW chromoly rings. Yeah, they'll wear faster (but they're easier on the bore). Only last 100k miles instead of 125k. So that's when you can use that second pair you've had in the Hastings VW bus ring box for the last 20 years....

A Renault 4cyl Hastings set will retrofit a 600cc BMW and a SAAB set with do for the R90.

Guess I should have written all the parts numbers down over the years, but I didn't.

Who's gonna be a good little Airhead and go ring size searching on Hasting's very helpful website?

[datchew]

Originally Posted by Lornce

Guess I should have written all the parts numbers down over the years, but I didn't.

Who's gonna be a good little Airhead and go ring size searching on Hasting's very helpful website?

1...2...3... NOT IT! (but i'll put them on the front page if they get found)

[RandyB]

Originally Posted by datchew

1...2...3... NOT IT! (but i'll put them on the front page if they get found)

After all I've done for you.

[Lornce]

Hokay, so I did some digging around in my garage and found the left over rings from a couple of 900cc and 1000cc engine jobs.

Hastings has several available dimensions for overbores. Check to be sure when ordering or sizing from Hastings site (which is EXcellent). With used bores (ie: not perfectly parallel - common with the 900 and 1000cc iron lined barrels, not so apparent on the 750's and almost unheard of on the 600's: they don't make enough power/heat to wear much) it's a good idea to go one overbore size up on the rings and then carefully file the rings to get the required end gaps. BE SURE to get the end gaps right for the ring material you select. ie: cast rings require larger end gaps than chromoly rings. Check the mfg'r specs for end gap which is usually provided in 0.000" per bore inch. eg: 0.003" per bore inch would be approx 0.003" x 4" of bore for a 1000cc airhead.

I think I paid less than $50 for these rings and, of course, have enough to do two engines.

For the 900cc airhead motor, hastings part #5562 for a 4cyl Saab will work. Top compression ring 1.75mm, second compression ring 2.0mm and oil scraper is 4.0mm. After accurately measureing your bores check the site to determine the exact ring size you need to accomodate your bore's "special needs". They're available in incremental sizes to suit overboring etc.

For 1000cc airhead motors I've used Sealed Power (Federal Mogul) cast rings for a VW bus. Part #E-495X 5594. The cast rings work well in nikasil bores as they're soft enough to bed nicely with a well prepaired nik bore. Chromoly rings are so hard they often never seal entirely before the bores glaze over.

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). 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 nicely 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

[RandyB]

That was a huge help. I found Devens site and number today, as well as Hastings. I think I'll stick with Hastings, since one set will do two engines and the GS will need it one day as well.

Many thanks.

[RocketJ]

Originally Posted by rtw02

I have used Real Gaskets valve cover gaskets for about 150,000kms now.
They have been on and off the bike 15-20 times,are still sealing fine, and have never leaked.

The torque needed to seat them is minimal. If you need more torque to seat them that the specs, chances are your valve covers are warped.
To check your valve covers simply place them on a sheet of glass and see if they rock.
Cheers

Someone actually understands the use of torque.

[Stagehand]

Chateau La Neaurveaux 1961 Merlot works best, but just about any rotgut will do.

[datchew]

Originally Posted by Stagehand

Chateau La Neaurveaux 1961 Merlot works best, but just about any rotgut will do.

Yellow Tail - any type. THey have a nylon or something type cork that won't degrade as fast. You need some new fuel filters

[Lornce]

This may be old news to some, but I just hung a 4-pot Brembo caliper from my 1150GS's carcass onto the GS/PD. Had to remove 0.125" or 1/8" from the mounting bosses to align the caliper with the R100's rotor.

Took it to my favourite elfen Croatian machinist to have it milled nicely and he showed me around his shop apologising in his delightfuly accented voice he was sorry but he was just too busy and "how am I ever going to retire and abandon my customers" and etc. It was a grand performance.

So I took it to a buddy's place (we had to share a beer or two and watch Pedrosa make Hayden look silly in a taped Quatar MotoGP race, anyway ) and five minutes with his pedestal grinder got me to within 0.020" of my target. Finished it at home in the vice with a file. If you're careful and patient you can work to remarkable tolerances with a hand file. Not that remarkable tolerances are required for this job. But I digress...

[Stagehand]

Originally Posted by Lornce

This may be old news to some, but I just hung a 4-pot Brembo caliper from my 1150GS's carcass onto the GS/PD. Had to remove 0.125" or 1/8" from the mounting bosses to align the caliper with the R100's rotor.

Took it to my favourite elfen Croatian machinist to have it milled nicely and he showed me around his shop apologising in his delightfuly accented voice he was sorry but he was just too busy and "how am I ever going to retire and abandon my customers" and etc. It was a grand performance.

So I took it to a buddy's place (we had to share a beer or two and watch Pedrosa make Hayden look silly in a taped Quatar MotoGP race, anyway ) and five minutes with his pedestal grinder got me to within 0.020" of my target. Finished it at home in the vice with a file. If you're careful and patient you can work to remarkable tolerances with a hand file. Not that remarkable tolerances are required for this job. But I digress...

silly question, but does it Brake better?

[Lornce]

Originally Posted by Stagehand

silly question, but does it Brake better?

Not a silly question, Jason. Haven't actually been for a ride yet. It's 4C and raining and I don't want to try it badly enough to suit up for that. Theoretically it ought to work, though.

The larger total piston area of the 4-pot caliper will provide greater resultant force at the pads with lighter, more progressive action at the lever - ie: greater lever travel.

This part bears up in practice: The stock GS has a hard, "wooden" feel to the front brake lever. The stocker hits the "pressure point" and stops dead. In comparison, with the 4-pot caliper the lever feels softer and the "pressure point" is felt through a broader range of lever travel. This is because the larger 4-pot caliper requires the m/c to move more fluid to drive it through it's braking stroke.

Creating hydraulic pressure is all about piston area ratios. The greater the difference in area between slave (caliper) and master cylinder, the greater the resultant preasure. Applied pressure is multiplied by the ratio of the areas of the master and slave cylinders.

Braking force is the product of that created pressure times the area of the caliper's pistons. (divided in half if caliper pistons oppose one another).

I hope I helped it make sense. It's easier to "see it" in your head than it is to articulate.

[Stagehand]

Lornce-- so as not to hijack this thread-- see latest posts in Brakes thread:

http://advrider.com/forums/showthrea...67#post4367167

[Rapid Dog]

...O.K., where's the best place to by em, huh?
FEGV-S3802?

[RandyB]

Originally Posted by RandyB

1 5/8 hose makes a pretty good carb to intake fix for $3.49. So far, so good, on 32mm carbs.

Whoever said radiator hose wouldn't work was right. Despite assurances it was the same as the carb-to-cylinder hose, mine started to fade at about 2K miles. It'll work as an emergency fix, but should be replaced ASAP with the real deal. I replaced mine last night. Put this in the "roadside repairs" category.