1978 R100/7 Topend Overhaul

[20774]

I have interest to know what the HEAD JOB cost with Ted P. .?

I have an email into him right now to get a quote. I asked him about this in February 2011 when I was thinking about it, but put it off. It was $685.00/pair and he said he uses the Euro two piece exhaust valves and the steel alloy intake valves.

[Walking Eagle]

Not suggesting that anything be "driven" -- that might dislodge the tubes from the heads, which is a very bad thing to do! Either a little hand pressure, or LIGHT taps of a plastic hammer is the ticket.

The PVC tool is probably "optional" but does "ease" the lubed seals into the cases quite nicely, whilst snugging-up the two LOWER nuts as everything comes together, cylinder always being kept parallel to the cases.

If you've got an older manual, which you do, it won't include the "latest" base-sealant info, which is to use Loctite 510. As with the dreaded oil threads, everybody has a different opinion; many base-sealants/"gasket replacements" will work just fine. Me? I always ask: "What would Oak do?. . ."

For other pressing questions in my life, I always ask: "What would Willie (Nelson) do?"

The price quoted by Porter is probably still in the ballpark, and includes NEW "everything" -- valves, machine work, seats, springs. . .etc. (but strangely not the keepers - send him yours if you dis-assemble the heads). Some of the advertised prices for head work (adverts in our various periodicals) ONLY include the machine work and seat replacement, so be sure you (the "collective" you) understand the menu pricing. Never heard a complaint about the quality of Ted's work, only about the turn-around times. The heads are returned fully assembled and ready to rock.

Walking Eagle, out

[DennisDarrow]

Though I totally resist tearing down further than needed to fix what's wrong, IF IT AIN'T BROKE DON'T FIX IT, as long as you are down into the internals really nothing wrong with checking out the rod bearings. PLASTIGUAGE is readily available at most engine speed shops or overhaul outfits. Using this stuff is a tried and true method for checking bearing clearance and wear......

For me, measuring Ring End Gap, pretty much tells me what I need to know in deciding whether to bore, replace rings, or just leave it be. Have you done a compression test to check out if you even need repair/replacement?......It really is worth the effort before disturbing the current "seal" your rings, cylinder, and piston is making. OOOOPS, you already have it torn down. So no compression check; but easy to check that end gap and put some calipers to the piston/cylinder.........God bless.......Dennis

[20774]

Have you done a compression test to check out if you even need repair/replacement?......It really is worth the effort before disturbing the current "seal" your rings, cylinder, and piston is making. OOOOPS, you already have it torn down. So no compression check; but easy to check that end gap and put some calipers to the piston/cylinder

The "need" in this case was many miles on the leaded upper end and general concern about dropping a valve. The valve clearance has remained fairly steady, although just weeks prior to heading for the Bloomsburg rally, I found the valve clearances had closed up. I decided to reset them and ended up checking the valves at various stages along the way...only to find them remaining where I had reset them. I didn't like that feeling, not knowing if I was sitting on something about ready to explode.

I mentioned the occasional pinging...probably due to the build up in the chamber...also probably due to the additives I was adding to stave off valve recession, or the possibility of it. Once I do the top end, I don't have to worry about that anymore.

I'm not going to go at this by doing the minimum...I've gone this far so I figure it's no big deal to do a complete refresh or at least take the measurements. Peace of mind. If I got this 100K in a little over 30 years, I suspect if I do this right, the next refresh will be someone else's problem!

[ROGERMANSFIELD]

Thanks for posting this. I plan on replacing pushrod seals right after rear main seal/oil pump o ring as soon as I can get the clutch out! I did a pushrod seal replacement before and didn't use any tool to set the seals, just pressed them in place. They seem to be working still after several years. Maybe beginners' luck!

[kwb210]

A couple of years ago I did the same work on my 1977 R100. The mileage was 84,000 and I had decided to refresh the topend in anticipation of many more trouble free miles. I sent the head, barrels and pistons (left them inside for shipping) to Bob's Motorwerks in MT. He has been an airhead mechanic for many many years. He replaced the valves and did the head work. On the barrels he wanted to hone the bores and replace the rings, advised against an oversize, which I agreed. At 84,000 miles and regular oil changes and air cleaner changes the bores were in great shape. Turn around time was very reasonable, can't remember the cost but at the time I was quite happy with the quote. Now at 105,000 miles the engine runs perfect, uses just a tiny bit of oil on a 1,000 mile trip. I leave the oil about 1/8 low on the oil dip stick. In the past I would always top it off after a few days of riding. Then it would go right back down a bit. Chris Canterbury at Boxerworks in CA sugested this idea, thanks Chris.
Regarding the connecting rod bearings, I did replace them, but in hindsight there was really no reason for doing so. Well, maybe it was because I had just got the tool to remove them and was iching to use it! Take a look inside the case and if it is clean and basically void of dark colors it is a good bet the oil change history has been good. Also give the rod a pull and push, should be no movement, there is a bit of sideways movement but that is okay if it is tiny.
I used Yamabond on the base O rings and push rod seals, so far after 21,000 mostly highway miles and higher RPM's there is zero oil leakage.
have fun with the project!
Kurt

[20774]

I've known about Bob in Roberts, MT, although his name doesn't pop up that much. If all goes well, my heads should be at Ted's today...he said it was about a 2 week turnaround, so hopefully I'll get them back later next month.

[lkchris]

Best thing to do is to fit Nikasil cylinders/pistons. Depending on how you do it, you'll either be over or under your current compression ratio but not the same.

[20774]

Best thing to do is to fit Nikasil cylinders/pistons.

If my current iron cylinders are out of spec, that is what I'll do. If not and I can rering, I'll do that...I doubt I'll get enough miles on it before the next overhaul....it will be an SEP (somebody else's problem!).

[GPr100rs]

I was happy to see that this Sep 1977 build /7 has no base o-ring and external circlips:

My May build r100rs had the internal clip which probably doubled my total job time. Started with the left, right side did go quicker once my "technique" was refined. Anyone attempting this job with the internal clips is advised to buy several extras- inevitably, you'll bend a couple if it's your first rodeo.

[Dave Backmarker]

I'm sending the heads off to Ted Porter. I probably won't do much in the next few months unless I get fired up to move forward. I need to clean up one side of the exhaust threads...a little bunged up but really not bad. I have one of those metric thread file tools - part K-D2228. I just need to figure out how to use it.

http://www.mechanicstoolsandbits.com...28-p-4189.html

I'll also be pulling the conrods and inspecting/replacing the bearing shells. At least that's what everyone says to do.

As some point, I'll pull the jugs and see what kind of shape the cylinder is. Again, not a great deal of experience, but I see some cross-hatching on the walls...not sure how deep it is. If I'm out of spec, I'll probably be heading for new Nikasil jugs and rings.

Kurt, May I suggest you do a compression and leak down test once you have the heads back to determine what you might need to do with the cylinders? I rebuilt my 1975 R90S (valve job done professionally) and then I honed the cylinders and installed new rings as the compression and leak down was pretty close to spec.

DaveM
1975 R90S
2000 R1100RT

[20774]

Dave -

I'll definitely do the tests, but more than likely I'll just measure the cylinders in the usual places and see what the dimension/ovality are and decide what to do. If they measure fine, I'll consider reringing, otherwise, I'll go for new jugs/pistons/rings. I'd rather not put it together just to check compression/leakdown only to have to take it apart again. That is what you're suggesting, right?

[20774]

Haven't done much since before the holidays. I did get the heads off and sent to Ted Porter...got a call over the past few days...the heads are done. Just need to arrange for payment and shipping time. That was pretty great turnaround!!

I'll probably begin to order things I must have - gaskets, o-rings, exhaust nuts, etc. Once I get some time, I can take some measurements of the cylinder and see where I go from therer.

[James.A]

Kurt,
Be sure to check the bores on both the top and bottom of the ring travel and on the horizontal and vertical planes. I found one of the cylinders on my R100/7 to be ovalled out at about 152,000 miles.

[DennisDarrow]

Have slept a couple of times since we talked about your rod bearings. Plastiguage them or just let them be?

Glad you are just measuring and checking out the bores rather than just blasting away at what doesnt need work or repair. Sometimes for me, like with plumbing, I go to fix one thing and then it escalates into the associated next thing and before I know it I am out at the well house turning off the pump.

You should be ready to rock and roll then in just a few days, I hope, and a cruise around FM1604 might be good..........lol....or is that still a road one cruises on. Was stuck in Beach Pavillion over at Brooke for MANY months what seems long ago. When I could get off the ward I would head out that way on my /2 or in my Porsche to just be alone and think......Now though, I hear that all that country is suburbs?????..........Anyway...God bless.......Dennis