Looking for any help/experience with this, searched archive but not finding anything.
I just received a new S&S Super Stock Crankcase for Shovelhead, and am in the process of assembling it. I ran into a problem with the breather valve. I'm reusing the stock metal HD breather valve, but it will not insert fully into the S&S crankcase. I used 1000 grit wet/dry on the breather valve to make sure it is burr free, and it measures at 1.1235 to 1.1240 at all locations. The valve will insert OK at the opening end, gets snug through the screen area, but at that last 3/4" past the screen, it binds up solid. Since the valve measures OK near as I can tell, possibly the breather bore is too tight at the far end?
Any ideas? I did not see this with the S&S instruction sheet, but do S&S cases require the S&S breather valve?
thanks,
JW
JW I've used a few S&S Shovel as well as S&S Evo cases over the years. I've never seen where the bore for the breather valve needed to be modified. Might you have another valve to try and fit? Possibly the one you have has issues, and some where down the road your old cases were made to fit?
Yeah, definitely a possibility. AMF era, who knows what went on when these motors were put together. It fit nicely in the stock case, and the bore was perfect, no damage at all. Dunno. Hate to spring for a new breather valve ($100) and find the same issue with it. Would like to analyze this a bit to find the culprit. I only have the valve I have to measure, and there is no spec in "the book" as to what the OD is supposed to be, or what the clearance in the bore is. Just end play.
Will ping S&S, see what they have to say.
-JW
If it were me I'd call S&S customer service and see what they had to say.
Quote from: billbuilds on January 14, 2022, 06:04:55 PMIf it were me I'd call S&S customer service and see what they had to say.
Yeah this is the way to go but IMHO I'm glad JW mentioned it here for the rest of us.
Measure the breather hole bore with a bore gauge or snap gauge at several depths to check for taper. And mic the breather.
Yep, did that.
Equipment: Brown & Sharpe 1-2" micrometer, Starrett telescope gauge
S&S Breather Bore.jpg
I took measurements in two axes, 1/2" apart down the length of the breather gear and case bore. Now I don't have the specs on what either of these are supposed to be, or the tolerances, but a wild ass guess is the gear is supposed to be a nominal 1.124" dia, and the bore a 1.125" diameter, for a .001" slip fit.
The gear never exceeded 1.1240, and in in places just a couple-ish tenths under, probably from wear. The bore, however, is under 1.1250 in the last 1/2" of depth (where the gear gets bound up), and appears to be a .0001 interference fit. Now, I don't have a tremendous amount of faith in my ability to make zero error measurements, nor do I particularly trust the accuracy of telescopic gauges, but in this case, the data seems to follow the symptom.
The bore in the case is under size in the back.
So what to do? Will call S&S on Monday, but if the solution is with the cases, that either means take to a machine shop to clean up the bore, and who knows how many days/weeks delay in the project. OR, replace the cases, and again, how much delay will that be in transport time?
The only other possibility is to get busy with some emery paper and whittle down the breather gear at the end where the binding is, and call it good. This is not a mission critical part, there is no load bearing on it, and with oil on it and in the bore, it will seal the crankcase exhaust just fine.
Jeez. Time for a beer...
-JW
There's no way I'd start whittling my breather gear down to fit in a brand new set of cases but that's just me. Pin gauges would work to determine where titeness is in breather bore. A machine shop near you might possibly have some that large. Yes I'm glad that this was mentioned and looking forward to hearing what S&S has to say.
Well, my feeling is that the breather valve is easily replaceable, and I indeed went ahead and tried to sand it down where it appeared to be tight in the bore. I don't know what that gear is made of, but damn, it's hard! Sandpaper would not hardly touch it. I ended up taking a cylindrical stone in a Dremel to it, and shaved off about .001" at the end. It will now insert all the way into the bore, but still very tight to turn. Going to put it on hold now until I talk to S&S. Stay tuned...
-JW
JW, keep in mind they do make an oversize breather + 0.030". It may be easier for a machine shop to make a clean straight bore by going oversize. Just in the event S&S says to fix it local.
https://www.sscycle.com/products/breather-gear-030-1948-1977/ (https://www.sscycle.com/products/breather-gear-030-1948-1977/)
Thank Ohio, if it comes to that then that would be a good solution. I know Jims USA makes a ream to cut the .030 over hole, might see if my local shop dude has one. But indeed, will see what S&S has to say about all this. I hope they take care of it, they also did right by me in the past.
-JW
Not to change the subject but while your cases are bare are you going to go with a stock oil pump or move up to an S&S pump? You are aware that you'll have to plug an oil passage if using a stock 1980 and earlier oil pump? Just something to give some thought to if you hadn't yet.
LOL! Yes, I got the S&S oil pump to go with this set of cases. Learned my lesson with the Ultima cases I got for my EVO, stock oil pumps just don't work with aftermarket cases.
So the new conundrum... I was setting up the camshaft end play before putting the bottom end together, and lo and behold... when I put the nose cone on, the cam would bind up like a rusty vise. Jeez, what else can go wrong? So what, the bushing is not aligned to this set of cases? It worked fine in the stock cases. I have an old "chrome" nose cone laying around, and checked it out, no issue. Will take the right side case and nose cone to my local shop tomorrow to get it align honed, hopefully that will address it. Will do this AFTER I talk to S&S about the breather gear. And I thought this would be easy. Jeez...!
-JW
That's really strange. I've never seen a cam lock in a Shovel or Evo like that with a used cover, unless a new bushing had been installed in the cam cover. They need to be align reamed when new as you know.
I think I'd try to get those cases replaces. Think about it, that's two separate bores from the same side, the oil breather and the cam bearing bore that both may be skewed due to poor machining. Loose fixturing, or what ever caused it.
QuoteI think I'd try to get those cases replaces. Think about it, that's two separate bores from the same side, the oil breather and the cam bearing bore that both may be skewed due to poor machining. Loose fixturing, or what ever caused it.
I'm no machinist but I've seen plenty of "stuff" happen in production. I agree with Brian, suddenly everything is in question and it'll rob you of your peace of mind.
OK to be fair, the nose cone that I'm using is one I got from eBay, was a non-plated one as I like polished aluminum. I had polished it, then had the cam bearing replaced. Same shop I'm going to take it to today, but he used some other right side case to align hone it. It's very odd that the old original nose cone bolts on and came spins free as the breeze. So I think the problem is not with the cases, but the nose cone bushing. Let's see what an align hone will do. If the tool wasn't so damn expensive, I'd just buy one and do it myself.
-JW
I talked to S&S. Not much help, just the typical "never heard of that before". He could not find any info regarding the correct dimensions of the stock breather gear, or what the breather bore diameter is supposed to be. He thought perhaps someone installed an oversize breather gear in this engine sometime in the past. I never heard of a 1 thou oversize breather, only a 30 over to fix damaged bores. He suggested to get an S&S breather gear. Yeah, sure, but what if that binds up too? When I take the case & nose cone to the shop, he probably has an S&S gear or something else to test with.
-JW
I'm disappointed and it's not even my set of cases. At minimum they should be able to give the finished bore size for the breather.
Well, just not my day. The shop did not have a cam bushing align hone. (so what did he do when he installed the new bushing a couple years ago???). So, hell with it. I ordered one.
He also didn't have a single breather gear lying around. I get the impression he's more or less completely divested from anything but Twin Cams and M8s. I get it. This area has a gazillion Harleys, and you don't see anything but TC or M8 on the road around here. His shop was jam packed with bikes getting performance upgrades or overhauls. Oh well, need to find a new machine shop somewhere around here that still does work on old iron.
So... new S&S breather gear on the way.
However, he told me he has seen this king of thing before. He uses DyeChem, identifies the tight spots, and sands 'em down. Guess that will have to be the solution if the S&S breather is indeed tight also.
One step forward, two steps back...
:kick:
-JW
That's pretty bull :turd: that S&S couldn't have been more help to you. As Brian said, they should have at least given you the size they shoot for in respect to the breather valve bore. There's got to be at least two tools involved in machining that bore, one to rough it out and a second to finish it. Wondering how they QC those cases? Machine tools do get dull and need to be changed out.
How will that new breather gear fit? :pop:
You missed one honing. Honing a blind hole takes more skill than pushing buttons.
Cant believe S&S machined the case and didnt test fit a breather.Hope you can get in touch with them.
The tech guy on the phone is probably so far removed from anywhere those get machined.
As in any idea of the dimensions.
Even the guy loading them in the machining center probably doesn't know the bore dimension unfortunately.
As you're on your own so to speak at this point it appears.
A few touches with a brake wheel cylinder hone, in the bore perhaps?
If the stones reach the full depth.
Or a small dingle ball hone.
If no, just cram the breather in there and give it a few spins and burnish (https://en.wikipedia.org/wiki/Burnishing_(metal)) it to size. :SM:
(I'm sort of being sarcastic, but have seen machine shops use roller burnishers to size precise bores)
I have a new S&S breather gear here, 33-4241 for L1977-99 BT. Gear end the barrel measures 1.1225, open end measures 1.1223 with properly calibrated Starrett 10ths mic.
Quote from: HD Street Performance on January 18, 2022, 07:22:33 AMYou missed one honing. Honing a blind hole takes more skill than pushing buttons.
Didn't know that hole was final honed. If it was you'd think that they'd measure it to be sure they were w/in spec. It doesn't take a lot of skill to run a couple of go/no go gauge pins into that hole of every Xth case half that gets machined then honed to check.
I don't know that for sure, a proper boring job to begin with would have been ready to use and on size. It appears the solution is a new S&S breather based on the dimensions provided.
Quote from: SP33DY on January 18, 2022, 08:47:18 AMI have a new S&S breather gear here, 33-4241 for L1977-99 BT. Gear end the barrel measures 1.1225, open end measures 1.1223 with properly calibrated Starrett 10ths mic.
That is interesting. Implies a very slight taper from gear to open end. Which, if my measurements of the bore are any way accurate, would probably work. The gear I have is completely cylindrical. I have an early style S&S breather gear in the mail, will see what happens with that before I touch the case.
One odd thing to note also, this breather gear I have has a tiny little hub on it (where the spacer sits on), like maybe 1/8th inch? The spacers have more like a 1/4" hole, so I had to make a centering sleeve for the spacer when both were in the stock cases. Ever heard of that? I don't know what the stock pre-77 breather gears look like, I assumed this was one. But maybe not?
-JW
The factory changed the pitch diameter of the breather gear, cam gear and pinion gear in the middle of the 1977 model year. Early and late parts shouldn't be mixed so it's important to know which series of parts you have.
I looked through my limited supply of factory bulletins from back then and found it. Service Bulletin M-743 from April 3, 1979 has the details. Unfortunately it only gives pitch diameters of cam and pinion gears, nothing about the breather measurement.
You need a pair of 0.105" gage pins to make your measurement across the gears. The difference is enough to identify which series you have.
1954 to early '77
Pinion gears range from 1.4440" to 1.4490"
Cam gears range from 2.7665" to 2.7715"
Late 1977 up
Pinion gears range from 1.4710" to 1.4756"
Cam gears range from 2.7324" to 2.7394"
Yeah, I knew about the gear teeth change in late '77. That's why I pressed my original cam gear onto the new Andrews #2, and am keeping the stock pinion, oil pump drive, and breather gears. Also, I believe the L-'77 and later stock HD cam gears have an annular groove in the side, the E'77 and earlier do not.
But what about this:
Breather Gear Spacer.jpg
See how this breather gear has a tiny little nib on it (3/16") to center the steel end play spacer, yet any spacer that I have ever seen has a larger (5/16") hole in it. You can see how I had to make a centering sleeve (out of a piece of rubber tubing) for the spacer in the lower right. WTF is with that? Are ALL early style breather gears like this? And did they make "special" spacers for the pre-77 breather gears? Guess I'll go dig around in the parts book, but I sure ain't ever seen anything but steel, or plastic. Not steel with a small hole...
-JW
You need shims for 1970 to early 1979, for the small nub on the breather gear. Late 1979 and up were larger.
25314-50 0.120 '70 to E'79
25315-50 0.125 '70 to E'79
25316-52 0.110 '70 to E'79
25313-50 0.115 '70 to E'79
Got it, thanks Ohio! Since I'm going to try the S&S breather gear, hopefully it uses the later style. Guess I'll find out soon enough.
-JW
I was wondering that too, what part number breather did you order?
S&S 33-4246 for 48-77 Big Twin.
-JW
I would think that one will use the smaller ID shims.
Early and late Shovelhead breather gears are easy to identify since the early ones have a flat face and the late ones have the recess milled into them. Both of the gears in the first picture are aftermarket. The second pic is a stock early one with spacer. (I mean shim).
Cool, this is good info. It appears these two aftermarket gears use the late style spacer with 5/16" hole. The gear faces follow the same marking as the cam gears, i.e. old = flat, new = annular groove. Will see what this early style S&S ends up, either way (small hole spacer or large hole), I have my little rubber centering sleeve to use the late style, regardless.
-JW
Well. Well, well, well, well. All's well that end's well. Right?
:crook:
My new S&S breather gear came today. It dropped right in like a round peg in a round hole. I measured it, near the gear is 1.1230, near the hole at the other end 1.1220. PLENTY of clearance. The S&S tech was correct, get the S&S breather gear. Would have been real nice of them to put that in the notes for the cases, but oh well. Problem-o solved-o.
Thanks for all the feedback and comments. Learned something new. Again.
:baby:
-JW
Good news, but strange.
There must be some answer, I mean they sell that breather for stock replacement. :scratch:
Well, all I can do is chalk it up to "it's from the AMF years". Who the <cuss> knows what came out of the factory in that period, and how well dimensions and quality were controlled. AMF Harley-Davidsons had a bit of a bad rep, now and even back in the day. I think quality was all over the map, Monday or Friday bike, some OK, some not OK, that kind of thing. Typical situation when you ramp up production without making the corresponding investment into the factory infrastructure.
Anyway, tis on all of use AMF Shovelhead owners to "un-AMF" them. Once that is done, they're damn fine machines.
Oh, and the spacer nib on the S&S Gear... the big one (5/16"), uses late style spacers. Yay! That's all I have!
-JW
It amazes me how many wanted to go in the hole without checking the real problem or want to blame the manufacturer.
All said and done and solved.
In all this though, are you 100% that it is indeed a OEM breather you took out of this 45 year old bike?
You kind of hit the nail on the head with "45 year old bike". After 45 years, who can be sure of anything that was done to it in the past? No, I have no idea if this is the breather gear that was in it when it rolled off the assembly line. It looks like OEM, but I have no idea who else makes breather valves for early Shovelheads (that one was definitely not S&S), or why anyone would have replaced it in the past. The breather bore in the stock case was pristine.
-JW
Hard to say, if it is or not OEM.
Who knows who all made them back then also.
Sifton? :crook: LOL
Little story.
I know Sifton got bought out by Taiwan Tedd cycle.
So no comparison to the old days perhaps.
I inherited an Evo job where the guy claims the oil pump went out, he started the tear down, got in over his head, brought it to me.
He bought a Sifton oil pump kit, included the breather gear for whatever reason.
The breather was about as round as a football. :SM:
Only origial HD parts on my 76 are flywheels ,and cylinders. Rods are S&S.
I'm right there with ya, Capn. Wheels (not shafts), rods, cylinders, nose cone, rocker boxes (not the innards) are now the only original HD parts. Everything else is S&S, Jims, Andrews, KB, Cometic.
-JW