My 91 R100gs, now with 115,000kms, showing no signs of problem, is now showing signs of age,,,,the pushrod seals are leaking fairly regular now. So it's off with the heads and barrel to renew everything. The local airhead guy [Shail's] has all the parts in stock, and I'll do everything no problem. He mentioned that I might want to have a look at the valve guides at the very least. Probably a good idea. So I had a look around at the possibility of a set of new valves. Holy Crap!!! The OEM ones are friggin' expensive, $151 exhaust, and $90 intake, each. This $60 renew of seals could very well grow to well over $750 if machining is needed on the heads. Are there any other valve suppliers out there besides Kibblewhite's Black Diamond line? What's the feedback on these? Steve
When I renewed my valves on my R80GS a few years ago at 100,000 miles I bit the bullet and bought genuine BMW but a friend with a mega high mileage R100, 425,000 miles when he sold it, always used Intervalve from Motorworks and said they were good for 100,000 miles.
Another interesting thread on the subject. Good Luck. http://www.advrider.com/forums/showthread.php?t=825135
When my 90/6 engine was rebuilt, Jim Cray's recommendation was to bite the bullet and use BMW valves. Overevving on my other bike did result in a dropped valve, not nice, but I'm fairly sure that it was due to operator error! At your mileage I would replace the exhaust valves
Drop the cash and get the OEM valves. Quality valve brands are the Swiss Intervalve and German Elco. Ya pays your movey, ya takes your chances with economy aftermarket parts... --Bill
I agree with you as far as the exhaust valves are concerned as that's a pretty tough punishing application and the welded two piece valve that BMW sells really is the "right" one for that application despite its hefty price. The intake valves have a much easier time and I don't think it's worth paying BMW's big price for those when plenty of aftermarket options are suitable in that application.
This is almost exactly what Snowbum and some other experts say on the subject. Buy the BMW exhaust valves and then buy other brands such as SI for the intakes.
Very Good Point. Exhaust, yes. Intake, maybe. Almost 40 years and a couple of top ends and I'm still able to re-use the original intakes. --Bill
Ted Porter uses a different German supplier that he says are good and cheaper than OEM. If you call, they will sell you what they use. Just another option.
I think Ted actually buys them from the same factory that makes BMW's valves. I can't remember for sure, but his exhaust valves are a welded two piece design like BMW's. There are remarkably few valve manufacturers out there. Most brands are just rebranded and resold from one of the few companies that actually MAKE valves.
A 'few' can be defined as less than four. That leaves three or less suppliers of BMW valves, if discussing airhead cylinder head parts. Where in fact, there is at least five or more manufacturing facilities for airhead engine valves. That is actually a decent amount of suppliers for engine valves to fit an out-of-production engine. To further, and in a more accurate way, discuss valves they should be reviewed also by material type and not only by 'one piece' vs 'two-piece'. German OEM supplier BMW exhaust valves are made in more than one material combination. For example, in some applications the exhaust valves have one combo for the 30 degree valve design and another for the 45 degree valve design. Carl
I'm not really into splitting hairs here, but since you seem to want to, I said there are "remarkably few." I did not say there are "a few." Also, I'd love to know where "a few" is defined as "less than four." If a few is defined as less than four lets see here: 3: sure that could pass for a few, 2: no that's "a couple", 1: well that's just one. So, really you're saying "a few" means 3. If you have something to add about valves, feel free to add it, if you just want to mince words, then save it. Also, I wasn't just referring to airhead valves, I was referring to ALL valves. There are not that many companies in the world that make valves, let alone companies IN EUROPE that make valves. Yes, Carl, more than 4, so not "a few" I guess, but fewER than most people would think. Yes, you can find many many brands of valves for sale on the internet, but when it comes down to it, a LOT of those brands are made in the same few factories.
Thanks for the info on valves. Sounds like the OEM valve is the one to go with, should it be worn out. I'm still waiting to get time off work to go and buy an exhaust nut wrench,,,,never been off,,,and yes I've read the exhaust nut threads and have my torch ready. Have the rockers off, really happy at the clean-ness of the top end, you sure can tell the exhaust side has to deal with way more heat, there's a light brown hue up front. Hope to get the right side off tonite if I can get to the shop in time for the wrench.
I'm not sure I read what you mean to say or you say what you mean? You have the rockers off? And now are going to take the stuck exhaust nuts off? The nuts holding the rockers on are also holding the heads on the cylinders and the cylinders on the block. If you try to take the exhaust nuts off with those nuts off it is very likely you are going to break something. Put the rocker nuts on before you loosen the exhaust nuts. Torque to 25 ft/lbs. Maybe I miss read what you said?
Maybe YOU should just save it... When you reference ALL valves, and not just BMW airheads, the quanity of manufacturers becomes relatively large in number. Based on being in this field and dealing directly w/ the manufacturers I find the suppliers for the 'many many' brands of valves do not originate from the same few factoiries. Few is a word that is relative to quantity. You're posts on this subject are misleading. Also, who knows what peple (whomever are the people) are thinking on this subject? Maybe people (whomever are the people) don't care form where the valves originate? Carl
Sorry for the confusion. The right side exhaust nut came off easy with my Norton exhaust nut wrench. So I pulled the right head. The left exhaust nut is not moving, so have yet to pull anything there. Picked up the bmw wrench, now everything will be off tomorrow. That is unless it's sunny, then the Norton's out for the afternoon.
Pulled the right head and barrel off tonite. Funny to note that there was no barrel to block o-ring installed. Found everything to be very clean. There is a slightly higher carbon buildup in the combustion chamber. Cleaned all mating surfaces with acetone. Will take the head to the machinist to see what he says about th0e valves and guides. Checked with my airhead guy, he uses Intervalve valves and guides exclusively for over 20 yrs, not one failure. And 1/2 the price of U.S. sources oem valves. Shopped around for a decent valve spring compressor that will work on the airhead head, and Norton head. Not much out there on Sunday. Steve
