Interesting to note the difference between the stocker on the left and the Andrews cam on the right. The Andrews is a higher lift, shorter duration cam designed to improve mid-range which is where this motor will spend the majority of it's time. Stock cam at 240k kms was in perfect condition, btw. Show me another air-cooled motorcycle engine design that originated in '69 that can produce a cam looking like that at 240k kms? Honda 750K, you say? Fahggeddaboud'dit.
For a motor that was severely overheated, muddy oil contaminated and maybe even oil starved... the pistons look remarkably good.
Squish band might be a little tight, though. Carbon doesn't seem to get much of a chance to find a home. Either that or it's just working so efficiently it "swirls away". Hah hah hah... That's a joke, son.
Now the rings are telling me a couple of interesting stories... First: I'm going to have to dig around to refresh my memory on the ideal end gap, but I'm thinking 0.003" - 0.004"/bore inch should be spec for these rings. Which tells me these are severely worn showing 0.027" at the major thrust point of the bore. Orta be closer to 0.012" - 0.016", *I think*. (famous last words). Secondly: Measureing the ring end gap at the unworn portion at the bottom of the bore and then again at the major thrust point about an inch below the top of the bore reveals a ring end gap difference from 0.0235" to 0.027", or 0.0035". If we devide 0.0035" by pi we learn the bores have a tiny bit more than 0.001" of taper. Translation: Who cares? That's not enough to worry about. Though I do have a fresh set of barrels that were cut for these 1050 pistons at the same time as the set that's in use. Why? Because pistons don't usually wear very much. It's the rings and iron bores that do most of the wearing. ie: New rings and the the fresh cyls and these pistons could go back to work at practically new spec. But for 0.0011" taper, I'm not done with the old ones yet.
Those are my favourite feeler guages. Can't find them like that anymore. Lost the 0.0015" a few years ago when I loaned them to a workmate. Here's a good shot of the relief or "counter bore" in the case that Anton was talking about in Notrex's thread. If you can imagine the corresponding shape on the base of the cylinder spigot, you'll understand what he needs to turn down before he can fit the nikasil cylinder to the earlier case which has no relief or "counter bore" segment.
A pair of Jesse bags arrived in the mail the other day and reminded me I've still got a GS/PD disemboweled in the basement. :huh Stay tuned, things are gonna start happening around here. Someone loan Flug an airhead until he figures it out.
Oh, I got sidetracked riding the Buell and prepping the R50/5 for sale and riding the R50/5 and regretting selling it and... You know how it can be.
Not sure about this, guy I bought it from used the word Rennsport. That said I did check the number but I don't recall, but I think it was a 336 stamped on the end. Snowbum briefly talks about it hear: Mods. At any rate, my bike kicks in at about 4Krpm like no other airhead I ever rode. It's a real blast to ride.
That's right. The 336 cams for bikes made after '79 had 336 stamped on the end. Stock 308 cams have 308 stamped on the end. What sort of top end are you using on your bike? iirc, US model R100GS's and PD's used a small valve head and 32mm carbs. Is that the arangement on your PD? Have you done anything to increase compression over stock? These motors really cry out for more compression and heavier breathing. With the 1050cc Venolias and modded '77 RS heads I'm running about 12:1 cr. With the stock cam it'll idle up a wall. The high lift, short duration Andrew's cam should increase the midrange urge even further. I'll keep you posted. fwiw, Lornce
They'll probably work even better on the bike. btw, the build quality of these Jesse bags is astounding. I haven't seen another ally pannier that comes close to the robust design and attention to detail of these pieces. (Micatechs look interesting, but I've not seen any in the metal). Factory pannier systems don't match up and costs are similar. +1 for the Jesse equipment. Very nice people to deal with, too.
Hey thanks for the photo. I didn't know you could still get the Jesses for an R100. I have an older style on mine.
I didn't know either. They don't advertise them on their website so I called and learned they occasionaly build small batches if they have enough demand. I really can't say enough about them. There's NOThing out there to compare with this sort of build quality. The closer you look at them the more you'll appreciate the thought and experience and effort that's gone into them. The spring racks to secure loads inside the lids are a perfect example: a clever idea executed in a simple fuctional manner that'll work for years. The hinges and latches are similarly original and clever - and robust. I like this stuff. Lornce
