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TroopThrowback
01-15-2010, 10:50 PM
Alright, here's my issue. Did a total rebuild myself with my pop's guidance this summer, renewed motor 650 with 9:1 JCC pistons, lightened valvetrain, etc. Nothing crazy, but a quick revving 650.

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Break in ride #2, tried to put a good hundred miles on her since the first 15 and retorque. About 20 miles in at 50 mph, power dropped off about 40% and started smoking out my crankcase breather, white. Bad juju. Trucked her home after waiting three hours in the rain for my lovely wife to rescue me.

Pulled the head and this is what I find:

Right side not looking too healthy:
http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4124.jpg

Definitely got some noncombustibles in the right cylinder...

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4122.jpg

I'm still smiling, I love this stuff! To finally have my own 2 car garage ( we just bought the place, our first) is awesome. I can't help but think of the potential it's got...

http://i470.photobucket.com/albums/rr66/Sinner6T/IMG_4132.jpg

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4240.jpg

Left (Drive) side Piston vs. Right (Timing) side Piston
http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4249.jpg


You think oil's getting past these rings? Wait a minute, what rings?


Bam! Ring land collapse on the rings and some serious scrubbing/seizure on the cylinder wall.

Those initial ring lands did look a little thin to me during assembly...

Measured them with calipers. On the left is the failed JCC at .046 inch. On the right is Hepolite at .076 inch. Anybody have any experience with this? I'm told modern oil is the culprit (by the very reputable distributor/family friend who sold me the pistons) during assembly. Can this be? Only 30 miles on the clock on a total rebuild, doing it the way the Johnson Motors Triumph factory school in Duarte, CA taught my pops so many years ago. Is it possible oil is to blame?

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4264.jpg

wllgmr
01-16-2010, 9:30 AM
Man, that sux. I just put a new top end in my tr6. It is the first top end job Ive done. I hope it works out better. What does "9:1 JCC pistons" mean? Is that the same as .090, 90 over? Did you get a fresh bore on your cyl.?Shit, now im worried that mine wont work. Keep us posted on what u find to be the problem.

Torch
01-16-2010, 10:06 AM
it is hard to do an autopsy on a seized piston. the piston will change shapes from all the heat and presure. Most of the time they are larger than they were new. your piston did seize. usually it is caused by incorrect clearance issues. did you measure the clearance? it should have been 4.5 thou. and you should always check the work from the machine shop, don't just take their work that they are correct.
at this point you need a new set of pistons and a re-bore.

Choppedtriumphs
01-16-2010, 5:38 PM
What does "9:1 JCC pistons" mean? I.

9:1 is the compression ratio,...JCC means oval chinese pistons,..

Sorry 'bout your luck Sinner I know a lot of work was put into this build...

KT
01-16-2010, 5:44 PM
Wow that sucks ... I usually take a short ride retorque take justa little longer ride retorque so on so on till I can then go for a decent ride ....But I retorque probably 5 or more times on the head and such with in the first 200 miles .... not that it looks like it would have made a difference in your case ...Something was'nt right there from the get go ...Run oil that has Zinc from my knowledge these old Triumphs like a high Zinc count in the oil helps soften valve train wear and such through out the engine....Sorry you have to rebuild the top end ...I'd just check things over and over like others said don't take the machine shops word for anything .....Check it yourself and then you will know for a fact instead of what someone told you .... Good Luck =)

Jethro
01-16-2010, 6:22 PM
Forged pistons need a little more clearance than cast. .0045-0050 would probably be right. Are those hardened rings? Meaning they don't look like the grey cast or dark cast "soft" rings originally used in Triumphs. What hone did you use for the final hone. How did you clean the cylinders after honing? And what ring gap did you use? I guess what I'm really asking is can you give us more info on they mechanics of the build, the numbers you used, and the suppliers.

Also, is there any heat/combustion marks on the bottom of the piston.

I'm sorry to see that damage. As an aside, what are you planning on doing for the rebuild. Do you plan to separate the cases and look at the main bearings?

TigerChris
01-17-2010, 11:42 PM
Ophhh man....

Piston clearance wouldn't do that. no matter the clearance, the piston expands tight to the bore when engine is fully warmed. In fact, the bore is the only thing from keeping the piston from expanding further... that looks like ring end gap too small/or mega detonation on 1 cyl...

You got boyer or points?

did you gap the rings? pop a good ring in the still good bore and square it in the middle using the good piston,
then check the gap

your rings should be 180* out from each other with the gaps facing left/right, (gap at wrist pin) this minimizes the effects on the rings from the pistons rocking in the bore while cold.

TroopThrowback
01-18-2010, 9:40 AM
Alright. I let a day go by to collect some responses, while I rebuilt the top end.

As far as mechanics go, it was all me and my pops. I did the rebuild myself, with my pop's guidance and expertise (proprietor of British Cycles Ltd, Torrance, CA 1971-1986, two-time factory trained Triumph mechanic at Duarte, CA HQ) this summer. Running points, Tympanium, E2R capacitor. 9:1 pistons with .004 inch clearance, American rings gapped as per the factory manual (.0010-.0014), lightened and polished rockers (a la racers pop built for Ascot), polished connecting rods and 500 lifters with alloy-tech special pushrods. Stock clutch and duplex chain primary. Single Amal Concentric 30mm with 230 main jet, K&N filter, middle needle position, float checked for correct height and all gasket surfaces flat and true. Open high pipes (MCM style), 3134 cam on intake, mild exhaust cam tuned for torque and TR6 specs. The failure was after an initial break in run, hard throttle and up through the gears with no high revs for about 20 miles. Re-torque, valve adjustment at .002 intake and .004 exhaust. then another 15-20 miles at same formula as first 20 miles then pooooooo. 40% reduction in power and white smoke out the crankcase breather. Pulled over immediately and she died. Looked her over and kicked her once, started right up. Shut it off and called the wife with the pickup. Waited three hours in the rain. etc. etc. etc.

This was my first Triumph rebuild, definitely not the last. I just want to know what's up. I've acid washed the cylinder of aluminum deposits today, honed a 60 degree crosshatch ( old clearance was at .0040, new clearance at .0045 after honing), re-fitted new Emgo pistons and rings at 120 degrees separation (ring gap was around .024, is that nuts?) and am buttoning her up as we speak. Should I fear a similar mishap? I'm not ready to grenade my bottom end (matching frame and motor, but not a resto, a mild custom "chobber") on this. Assembly this time was NO oil on the pistons or rings (as per instructions from Bill Getty himself), 30 wt non-detergent on the wrist pin bushes and in the tank (and crankcase, obviously), and the advice was the same for break-in. Hard throttle up through the gears again and again for 30 miles, then re-torque, valve adjust, etc.

So what do you say? The failure was timing side piston, rear face (high pressure area). The drive side was showing evidence of scuffing, as well, though it had not yet failed and the rings were still free. Also, no real high heat indicators on wrist pins or piston bottom.

My suspicion, supported by my pop, was that the initial ring land was too thin ( half a hepolite 9:1) and collapsed under the load, pinning the first compression ring allowing heat to build and the piston to expand. I'm being told that oiling the cylinder walls with modern variable weight oil disallowed proper heat transfer through the cylinder wall and that caused the seizure.

All this and I have to finish her in the next three weeks so I can put her up while I go to Afghanistan for a year. They called me out of my civilian job to do it, six months after my discharge! Thanks in advance,

wllgmr
01-18-2010, 11:17 AM
are you saying that you think it failed because you pre oiled the cylinder walls?

Tikipunx
01-18-2010, 12:38 PM
Sorry to hear about your troubles, and thank you for posting. I've just got my cylinder and top end back from Don Hutchinson, and he informed me not to oil the cylinder walls when reinstalling, although if I'm not mistaken I think on Wes's video he dabs some oil on the cylinder tubes. What would the pros and cons be to either?
Thanks again for posting and thanks for your service!!! Have a safe tour!

Jashole
01-18-2010, 1:31 PM
dang that sucks man. good luck fixin her up

TroopThrowback
01-18-2010, 7:14 PM
Sorry to hear about your troubles, and thank you for posting. I've just got my cylinder and top end back from Don Hutchinson, and he informed me not to oil the cylinder walls when reinstalling, although if I'm not mistaken I think on Wes's video he dabs some oil on the cylinder tubes. What would the pros and cons be to either?
Thanks again for posting and thanks for your service!!! Have a safe tour!

This is what I'm trying to confirm. I've never heard of assembling without oil on the rings and on the piston skirt, with a light film in the cylinder walls, so that's what I did. And that is where I was told I failed.

I am now instructed to assemble dry (which I have, second time around), with oil on the small end connecting rod bushes.

TigerChris
01-18-2010, 7:40 PM
Did you put a ring in upside-down? that would do that in no time.

fouraceswes
01-18-2010, 9:30 PM
If I had had a failure every time I built a motor and oiled the cylinder walls, I would have had to re-rebuild every motor I ever did. Different guys have different advice for this kind of stuff all the time. The guys who taught me said oil the wall and the rings. One guy likens it to poking your girlfriend or wife before she is wet, it just makes it difficult and hurts everybody. On the other hand I am not gonna sit here and tell you Don Hutchinson is wrong, he is a total guru in his own right. Obviously it has worked his way all these years.

I never run a new engine too hard or too fast for at least 100 miles. I baby the motor, I start it up, run it for five or seven minutes then check the torque on the head and rocker boxes, then start it again, making sure it is pumping oil, even doing an oil pressure test sometimes if I don't see it pissing back into the oil tank. Check torque, run more, re-check valves, redo valves if necessary, start it up again and when I am really really ready, I take it for a short hop in the parking lot in first and second. Remember everytime you retorque if the bolts turn, then you need to recheck the valves.

My experience is that valves tighten up after some initial minutes of start up, why i am not sure, but they do in my experience. I redo them and then re-check them again. Only when I am good and ready and confident in the motor do I take it out for a gentle spin around the block. I go faster and faster then hammer it some after 50 or 60 miles.

Rings either seat or they don't, 9 times out of ten, they are either shitty rings or installed upside down. I am not saying 6TSinner did anything wrong in his procedures, clearly he is getting different advice than I would give, but I know Bill Getty and he built a lot of bikes and motors over the years when he had his shop. I don't know what happened to that motor because I am not looking at it.

As far as zinc in the oil, I don't wanna be a dick, but that is absurd. Who did the scienticic testing to see about that supposition? Did some big oil company commission some research company that tested hundreds of Triumphs and other motorcycles and decide that was the best type of oil for an old Triumph or did some young guy or old guy say that in a moment of drunken incoherence? I would believe the latter before the former. How could an average mechanic ever test that theory and come up with any clear data to prove or disprove? last time i read an oil bottle, there was no list of ingredients.

TroopThrowback
01-18-2010, 9:36 PM
Did you put a ring in upside-down? that would do that in no time.

Nope, non-directional rings were used.

I've addressed all the simple things possibilities, just because of the care with which She was assembled. Like I've said, though I'm new to Triumph motor rebuilds, the ins and outs of its instructions have been a mantra I was raised with. Pop's always found ways of slipping "don't let your connecting rods contact the case studs" or ".002 intake .004 exhaust" into totally unrelated conversations all through my life. With him over my shoulder the whole way I'm convinced the problem is either materials, construction of those materials, or some wild card. The wild card in this case has been identified as the "modern oil" phenomenon.

Has anybody had a similar negative experience using modern oil (I'm talking off the shelf variable weight, not syn or syn blend) during motor assembly?

Torch
01-18-2010, 10:28 PM
24k ring gap is a lot, I mentioned this about Tiawan pistons in a previous post,
If it was mine I would get another set of rings

Torch
01-18-2010, 10:33 PM
Nope, non-directional rings were used.

I've addressed all the simple things possibilities, just because of the care with which She was assembled. Like I've said, though I'm new to Triumph motor rebuilds, the ins and outs of its instructions have been a mantra I was raised with. Pop's always found ways of slipping "don't let your connecting rods contact the case studs" or ".002 intake .004 exhaust" into totally unrelated conversations all through my life. With him over my shoulder the whole way I'm convinced the problem is either materials, construction of those materials, or some wild card. The wild card in this case has been identified as the "modern oil" phenomenon.

Has anybody had a similar negative experience using modern oil (I'm talking off the shelf variable weight, not syn or syn blend) during motor assembly?

is it a coincidence that racing oil has zinc added

fouraceswes
01-18-2010, 11:07 PM
I would love to see some data on zinc as it relates to old Triumph motors

rhythmOil
01-18-2010, 11:40 PM
are you sure oil was getting through to the journal on that side?

i don't know shit from shinola. but isn't that the piston that's gonna seize if there's a problem getting oil through the "how do you say it--sludge thing?"

Gepetto
01-19-2010, 12:41 AM
I would love to see some data on zinc as it relates to old Triumph motors

A engine is an engine, either a car or motorcycle. If you research, engine builders around the country are having problems with new cams going flat during break in periods. Major cam manufactures have not changed their cams, as far as materials go, but fairly common to see new ones go flat during break in. What has changed in the world of gas powered engines in the last 30 years? Leaded gas and oils. Oils are constantly being reformulated and reformulated all the time, the oil you bought 5 years ago is not the same as the stuff you bought yesterday, and that is a cold hard fact! It certainly is not the same oil that was around when these bikes were new. With the price of crude oil on the rise, oil companys are looking for cheaper additives because they are already behind the gun with higher cost and more strict enviromental concerns. Oil has changed big time and will continue to get worse for our small market of vintage iron, being that we are not the target of oil companys, modern cars are.
That being said, I only run racing oil with a high zinc content for my Triumph and old cars. Zinc use to be in all motor oil 15 years ago and if that helps my stuff from being another victim of modern oil than that is what I will run. There is a reason that high end cars only run Mobil 1 in them from the factory, not that it is just fucking expensive, it's because it is a high quality of motor oil. Would you take an Aston Martin to Jiffy Lube and tell them to put regular old oil in it?
That's why my bike has oil with a high zinc content. Before you reply that I'm an idiot and have no cule what I'm talking about, google it for your self and come to your own conclusion.

Your ring gap seems a little on the huge side, and I have put several sets of JCC pistons in many bikes and never had a problem. Yeah the top ring land seems a bit small but I've never seen one do that. Every now and then a bad one goes through Q.C., I've seen a brand new Amal carb come apart on the inside and get sucked into the engine. Good luck and remember to take it easy on brake-ins.

TroopThrowback
01-19-2010, 8:49 AM
Thanks for your responses. I know this brings up heavily debated topics. I'm looking for the experience points on this one, more than simply theory, but each response is helpful to me.


are you sure oil was getting through to the journal on that side?

i don't know shit from shinola. but isn't that the piston that's gonna seize if there's a problem getting oil through the "how do you say it--sludge thing?"

That's true, however I rebuilt the bottom end, and though nobody can guarantee the impossibility of some freak mishap, the big end bearings don't have any signs of excessive wear, heat build up, or any other sign of potential failure. The only signs of heat are on the piston itself. No undue heat even to the small end bushes let alone connecting rods. Maybe it's only because I immediately pulled over and cut it off, to lessen the damage.

Some possibilities for causes that I'm considering after having heard all the responses (and some of the bickering!) are:

1. too little piston to cylinder wall clearance (a possibility because I don't recall personally checking the machine shop's bore job for .004 inch clearance)

2. ring gap too small for the hardened, American made ( I don't remember the manufacturer) rings at .0010-14 inch.

3. Piston initial ring land too small for combustion pressures generated. The only reason I include this one is because though the motor's not a total beast, she is quite a torque monster with all the lightening I've done to the valve train.

Realizing that the new rings (softer, oversize gap) are not the same in material and construction as the higher quality (and possibly incompatibly sized) American made rings that were destroyed last time around, am I asking for trouble by changing too many variables?

My biggest fear is a repeat. Even though the right piston destroyed itself, the left showed signs of following suit. It was like a race to failure, one I don't want to repeat.

Again, thanks for all the ideas and for sharing your experience. I'll keep you posted...

Jethro
01-19-2010, 10:38 AM
I don't think I said it before, and if not, then first off, I want to thank you for your service over there in Afghanistan. Please watch your ass.

Now, that new ring gap you posted ealier, I think it was .024 is too large, unless you are using some new technology I'm not aware of. Also, looking over your original post, I realized you may have not ridden the bike HARD on break in, which I think is important. The only area I would avoid on break in is LUGGING the motor, and something tells me you already know that. But, "ride it like you stole it". Also, I would recommend a straight 30w non detergent oil from Napa or some other place for break in. Lastly, I'm sure you strobed this new motor after using a degree wheel to get it close in order to avoid timing too advanced.

fouraceswes
01-19-2010, 11:18 AM
I am not really in the business of telling anyone they are an idiot. Your experience with bikes (more than your googling of random information) is valid here at my shop, in your garage or in any bench racing session I would want to take part in. That being said, Triumphs performed back in the day like the race winning champions they were. They did it with a lot of non-fancy oils and stuff. If cams are generally made with the same materials then the improved oil should give improved life. I just get a little irked when guys grab random facts or suppositions and use them to explain catastrophic events like this one.

There is the possibility that this set of pistons were inferior to the other JCC Pistons floating around. Plenty of JCC Pistons have not failed, but I have seen some new components that are "the bad apple" in the bunch.

I cannot help but think basics on this one, or at least back to basics on the new set of pistons that are going into this motor since diagnosing the failure of the one is difficult at this point. Timing, carburation, bore clearance, etc. Could you have had a fuel starvation problem? I also agree that the gap should be smaller on the rings, but I don't think that in itself would have caused this failure.

KT
01-19-2010, 2:20 PM
well damn didnt mean to start a pissin match on oil types sorry for jackin the thread with it

All in all good luck getting it going be safe over seas ...Sounds like your pops has a good handle on it go with that =)

fouraceswes
01-19-2010, 6:22 PM
Thanks to a couple guys on here through PMs I have learned some about zinc and modern oil. I may be older than most of my Triumph riding peers, but I can still learn a thing or two. i am still gonna oil my barrells and rings tho upon assembly.

KT
01-19-2010, 8:03 PM
. i am still gonna oil my barrells and rings tho upon assembly.

I'll have to go back and watch the Video but I think Hughie Hancox uses oil on them in his unit reassembly Video ...Don't quote me on that have not watched in a year or so ...I consider that man to be my hero . When it comes to Triumphs

wickedblockhead
01-19-2010, 8:08 PM
i dont understand why you wouldnt oil up first. just seems dangerous to me. what do i know... ive only built one british triple.

TroopThrowback
01-19-2010, 8:17 PM
Thanks for all your thoughts.

So I'm thinking it's cause #2. As a result I'm going to try the large gap, softer rings. If I'm an idiot, please tell me now!!!

I've got about another week of constant rain, so I won't be riding until it clears, so no break-in yet...

Jethro
01-19-2010, 8:39 PM
I think Wes's thoughts on oil bear listening to. I know he speaks from experience, and I TRUST his judgement. Here is a related discussion on zinc and oil, though I do NOT want to hijack this thread, but since this thread really is about building and BREAKING in a motor, I think this discussion is relevant. Also, I think that the idea of just "googling" your way through building and engine and breaking it in, or discussing your thoughts in a shop would probably be stupid, NONTHELESS, there is a lot of info out there right now on the Internet that pertains to our bikes, and there is more to follow.

http://home.comcast.net/~roadwarrior3/Oil.pdf

Also, Brit cycle has posted some thoughts in another forum on oils and break in, and here is a tech article that carry on their site...

http://britcycle.com/Manuals/bcs_oil_recommendations.htm

KT
01-23-2010, 9:44 AM
Sure enough Hughie adds graphite paste to the rings then sets the gaps at the rear in a staggered pattern then oils the tops of the pistons and barrels..... so now you know... Wes's way matches with one of the main guys at Triumph R&D from back in the day ....

I knew Wes had it right but wanted to wait till I reviewed the video to post on it ...This method is done for Pre unit and unit alike...

TroopThrowback
01-23-2010, 10:21 AM
Thanks for the update. I'd never heard about graphite paste, though. Is that the Hughie Hancox video I have heard about? Where does one get it?

TroopThrowback
01-23-2010, 11:54 AM
I'm all set with non-detergent oil now, She's pretty much buttoned up and ready to go. Now I just need a sunny day...

The process:

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4292.jpg

What a good 60 degree crosshatch looks like:

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4271.jpg

Cleaned aluminum piston deposits out of the bores with muriatic acid from the pool supply. Cleaned up really well with minimal scoring. Now she's ready to go. No oil, as recommended, bone dry:

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4270.jpg

The Master. My mentor. Only a true professional rebuilds a motor in a suit!

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4290.jpg

Took the chance to get my rocker spring eliminators installed. On top are the springs the spacers below replace:

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4266.jpg

Didn't realize how much more difficult assembly would be with no friction on the rockers! I dropped pushrods four times during re-assembly. What a pain. It would be much easier with later model head with joined rocker covers so you can see what's going on as you assemble.

Rethought my exhaust mounting. Trial ride out I stripped my left cylinder exhaust flange out of the head. Vibration was the culprit. New flange, JB welded in holds much better. So I tripled my mounting points. It's much more rigid now.:

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4297.jpg

Crossover:

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4298.jpg

Center Mount, the only one I had originally. Made use of the swingarm pivot most people cut off:

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4300.jpg

End mounts:

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4305.jpg

Now I just need to black out the bottom of the mounting tabs, so they disappear:

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4303.jpg

And that's it for now. Set the valves and go! Come on sunshine...

Jethro
01-23-2010, 2:17 PM
I had the same problem with my exhaust spigot coming out on one side. I had put the spigots in the freezer, and then used a wooden board across their faces to protect them, and then drove both in with a very heavy hammer. THey went in flush, but with a good tight fit. Nontheless the left one loosened with hard riding after about a year. I have now mounted my drag pipes with three points, two of them to the frame.

KT
01-23-2010, 2:36 PM
Thanks for the update. I'd never heard about graphite paste, though. Is that the Hughie Hancox video I have heard about? Where does one get it?

http://www.walridge.com/section/view/?fnode=52

Halfway down there is the pre unit DVD, unit DVD and classic carburation .

I have all three and they are well worth it , You combined these with Wes's videos and you have it covered unless your doing something Like I am then you gotta dig or pick the brains of others that have done Mod stuff that doesn't fall under basic builds....

TroopThrowback
01-23-2010, 3:53 PM
Thanks KT. I'll have to save some more coin...

59
01-24-2010, 3:56 AM
Just some thoughts;
without any defo' reason for the original failiure are you happy that the rebore was done square. Thre is a debate in another forum about slack set up using boring bars, that are not central to the bore in the throat of the crank case, or worse, it is leaning away from the vertical thus putting additional strain on the con rod and piston.

Also goes on to discuss bore s being done to match supplied pistons and not just a +0.020 over.

Piston alloys nowadays being a bit of an unknown and that co-efficients of expansion should be checked.

Too bad the piston supplier couldn't see there way to supplying repalcements as a 'goodwill gesture', but there you go.

Just thought to add a bit more room for thought on an interesting thread.

All the best.

TroopThrowback
01-24-2010, 8:47 AM
I am confident that the bores were done to size, I supplied the set of pistons with the barrells with specific instructions, I got reassurance they were followed. .004 clearance was what I ran, perhaps too tight for this alloy?

As far as squareness, I've got no assurance there. However, there's no sign of undue strain to my bottom end (free play, wiggle, etc) or my connecting rods whatever. I can only assume then I'm somewhere close.

So I'm going to install a Bendix points plate today, time her again, and then we'll see the first sunny day we get!

bhead1968
01-24-2010, 9:03 AM
Thanks to a couple guys on here through PMs I have learned some about zinc and modern oil. I may be older than most of my Triumph riding peers, but I can still learn a thing or two. i am still gonna oil my barrells and rings tho upon assembly.

Thats how I've learned...and how I did my trump

Jashole
01-24-2010, 1:51 PM
hahah DOPE. congratz man. hope everything works when the sun comes out... it should be a sign.

Gepetto
01-25-2010, 12:49 AM
".004 clearance was what I ran, perhaps too tight for this alloy?"

That was what I was thinking, we usally try to shoot for .0045 and have the barrels honed to the pistons and then labeled so they go in the correct hole. If they only measurered 1 piston, you've got a 50/50 chance they mic'ed the larger piston. Once we instructed the machine shop to do our machine work this way, we have almost a 100% sucess rate. Hope it works out for you this time.

TroopThrowback
01-25-2010, 8:39 AM
".004 clearance was what I ran, perhaps too tight for this alloy?"

That was what I was thinking, we usally try to shoot for .0045 and have the barrels honed to the pistons and then labeled so they go in the correct hole. If they only measurered 1 piston, you've got a 50/50 chance they mic'ed the larger piston. Once we instructed the machine shop to do our machine work this way, we have almost a 100% sucess rate. Hope it works out for you this time.

I gave the same instructions, and got back a satisfactory answer from the shop when they gave back the barrels and pistons. I can only assume they did what they said they did. I'm not a regular though, nor are Triumph barrels their cup-o-tea. I hope to establish a better rapport in the future. You gotta start somewhere, right?

I don't blame the shop, they did good work. I'm thinking that clearance was too tight for what these pistons are made out of. I'll get it dialed in, hopefully the process won't include any more catastrophic results.

The shame of it is, she ran when I tore her down!

Gepetto
01-25-2010, 10:11 AM
They usally get mad when you take them apart when they run fine!!!

TroopThrowback
01-25-2010, 12:24 PM
damn, I guess so. The curse of the slighted Triumph?

SMChewy
01-25-2010, 1:28 PM
Good luck getting it back up brotha. Just wanted to chime in and say congrats on the new house. Me and my old lady just got our first house back in June. And same thing! Within 6 mos. there is a 75 XL almost put back together in it, and a 71 XS1B basket case with parts all over the place! Still building back up my tool supply. But man I missed this! Used to live close to my big brother and wrench in his garage on anything and everything in the hood! Needless to say, his garage is still where most of my tools are. But it's now in Savannah GA, and he's in Afghanistan. Little to far of a drive from Colorado. Ha ha ha. Good luck my man, happy building!

59
01-26-2010, 2:46 AM
so what will you do re the pistons, measure them cold, chuck them in the oven then measure again to figure out the change,is that how it's done??

TroopThrowback
01-26-2010, 8:26 PM
If you hope real hard it's just as good as measuring...so I hear

I'll run them and see. She's all back together, replaced the original points with a bendix setup, retimed, and waiting for some sunshine promised tomorrow.

TroopThrowback
01-30-2010, 11:35 AM
All's good, though I'm nervous when I take her out. Did about 30 miles yesterday, after properly seating the rings the day before. She ran good, but I'm easy on the throttle until I get confident. Now it's just oil change, re-torque the head, and set the valves again. Sunday I'll be out with pop and my brother for a proper break-in ride.

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/Rebuild/IMG_4368.jpg

Ran into a fellow Triumph fan on the road, he told me a story about his 68 bonnie burning pistons until he figured out his right Amal idle jet was clogged, running her lean at every throttle position shy of 3/4. I know my passages are clear, but maybe a little lean mixture, added to the minimum piston/cylinder clearance, added to the modern oil was my problem? Like a nightmare bad combination...

KT
01-30-2010, 2:11 PM
Looks good man ...glad to hear all is looking up ...enjoy it ...

Jethro
01-30-2010, 6:50 PM
Good to hear it is going well, bud. NICE looking, clean functional bike, and my favorite color!!!!

TroopThrowback
02-01-2010, 11:20 AM
Sunday was my Farewell Ride with my pops and two brothers (one out from Santa Rosa, the other a Freshman in high school). Sinner ran solid, no hiccups, but due to too much piston ring gap I'm blowing past the rings a little. So rather than being scary quick like she was prior to meltdown she's more docile.

She ran good enough for a good 80 mile ride with my family in the foothills.

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/IMG_4414.jpg

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/IMG_4416.jpg

http://i470.photobucket.com/albums/rr66/Sinner6T/the%20Sinner/IMG_4423.jpg

Nothing to prevent me from riding when I can, I leave on Sunday morning. I've got a backup set of barrels my pops promises to prep while I'm gone, so I can slap in a good set of Hepolites and quality rings and really rip it up upon my return.

Jethro
02-01-2010, 2:16 PM
That is great, bud... happy for you... :)

wickedblockhead
02-01-2010, 4:33 PM
im glad to see all is well, man! been following this with some interest!

TroopThrowback
02-05-2010, 10:33 PM
So it's official, she runs great, no more problems.

Call this thread complete, she's a finished project. I'll chalk the failure up to modern oil in the barrels and a slightly lean mixture during break-in. I've learned my lessons!

So some friends and I jammed out midweek as a farewell ride, ended up meeting a complete character and seeing some trippy shit... Well, see for yourself.

The proof is in the pudding:

http://i470.photobucket.com/albums/rr66/Sinner6T/On%20the%20Road/Epic%20Moonshine%20Ride/IMG_4482-Copy.jpg

http://i470.photobucket.com/albums/rr66/Sinner6T/On%20the%20Road/Epic%20Moonshine%20Ride/jared054.jpg

http://i470.photobucket.com/albums/rr66/Sinner6T/On%20the%20Road/Epic%20Moonshine%20Ride/jared057.jpg

http://i470.photobucket.com/albums/rr66/Sinner6T/On%20the%20Road/Epic%20Moonshine%20Ride/jared060.jpg

Had a great ride to see some far-out old stuff. Took a half mile dirt road up a mountain to get there, in the rain, slipping and sliding all over the place. Dude on this old Knuck kept up, scraping the ground all the way to the top:

http://i470.photobucket.com/albums/rr66/Sinner6T/On%20the%20Road/Epic%20Moonshine%20Ride/jared046.jpg

http://i470.photobucket.com/albums/rr66/Sinner6T/On%20the%20Road/Epic%20Moonshine%20Ride/IMG_4487-Copy.jpg

http://i470.photobucket.com/albums/rr66/Sinner6T/On%20the%20Road/Epic%20Moonshine%20Ride/IMG_4492-Copy.jpg

http://i470.photobucket.com/albums/rr66/Sinner6T/On%20the%20Road/Epic%20Moonshine%20Ride/jared043.jpg

http://i470.photobucket.com/albums/rr66/Sinner6T/On%20the%20Road/Epic%20Moonshine%20Ride/jared033-Copy.jpg

And a Patriotic Farewell. See you in a year!:

http://i470.photobucket.com/albums/rr66/Sinner6T/On%20the%20Road/Epic%20Moonshine%20Ride/jared053.jpg

KT
02-05-2010, 11:38 PM
stay safe!

Pete
02-06-2010, 7:11 AM
Good luck.

Jethro
02-06-2010, 10:08 AM
Good luck, my friend...

wllgmr
02-07-2010, 9:55 PM
good luck to you

Moparkevin
02-20-2011, 3:23 PM
great thread.. I hope the best to you stay safe.
I sure hope that I don't have the same issue.