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Lifter failure

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Doc250 Avatar
Doc250 Chris Holliday
Honeoye Falls, NY, USA   USA
1968 Triumph TR250 "Little Red One"
1975 Triumph TR6 "Lbc II"
So there I was. 57 degrees in upstate NY in Jan. Great opportunity to exercise my newly rebuilt TR 6 engine. Off I go and get a 1/4 mile and it starts backfirering. Get it home and start checking. It's only the front carburetor and the wiring looks good since 90% of all carburetor problems are electrical. Pull the valve cover and what to my wondering eyes do I see but the No. 1 push rod has dropped about 3/4 of an inch from the rocker arm. I look in the hole after removing the push rod and the bottom of the lifter is gone.

I just pulled the head and here are the pictures of what remains of the lifter and the cam lobe. I'm figuring I'll find the rest of the lifter in the oil pan.

Anyone what to offer their opinion why the push rod broke the lifter in half? Valve is not stuck and the push rod in still straight. Engine was just rebuilt and has only about 2 hours on it. Ran great up until failure. I'm guessing all the cam lobe damage is from the push rod riding directly on the lobe.

No question in my mind the cam has to come out and be replaced. The only good out of this is the cam can be replaced without pulling the engine. Still a job but l can do it by myself.

Thoughts on causes? assemble? lubrication? parts failure? .......................

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tapkaJohnD Avatar
tapkaJohnD John Davies
Lancaster, Lancashire, UK   GBR
Recent' thread on TR Register about failure of TR4 lifters. Concluded faulty lifters.
http://www.tr-register.co.uk/forums/index.php?/topic/64631-musical-engine/#entry563400

Clue in yours is "Engine just rebuilt" - new lifters?

John

wbclassics Kai Radicke
Syracuse, NY, USA   USA
In reply to # 1507422 by tapkaJohnD Recent' thread on TR Register about failure of TR4 lifters. Concluded faulty lifters.
http://www.tr-register.co.uk/forums/index.php?/topic/64631-musical-engine/#entry563400

Clue in yours is "Engine just rebuilt" - new lifters?

John

I'd say reground original lifters. The most obvious clue is the varnish stain at the bottom of the intact lifter, that varnish takes considerable mileage to develop, and you wouldn't have that on a "newly rebuilt" engine if the lifters were new to begin with. The second clue that these are reground originals is that there is no chamfer at the edge of the lifter face. Nearly every new lifter on the market has a chamfer here of 0.010-0.020" width.



Edited 1 time(s). Last edit at 2018-01-14 01:55 PM by wbclassics.

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Doc250 Avatar
Doc250 Chris Holliday
Honeoye Falls, NY, USA   USA
1968 Triumph TR250 "Little Red One"
1975 Triumph TR6 "Lbc II"
Ok, this just got worse if that's possible.

To Kai Radicke: I may have misled you. The complete lifter shown in the picture was meant to be just a comparison of where it broke. It's actually a lifter out of my TR 250 that I rebuilt 4 years ago. It is not out of this engine so the varnish is not a clue. Sorry my bad.

So I dropped the oil pan and found the pieces of the rest of the lifter. Ugly.

Now, how concerned do I have to be about all the little pieces I didn't find?

btw, it's a '75 TR 6. Again, sorry I left that detail out.


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Krom Avatar
Krom Paul K
San Rafael, CA, USA   USA
Sorry for your trouble. I'm wondering if I am seeing this correctly: it appears from your photos that not only was the bottom of the lifter worn all the way through, but the top had broken off about halfway up as well? Also, not sure if I'm seeing it right, but it almost looks like the intact lifter next to your broken one is surfaced on a bias/slant? Maybe just the photo...As was mentioned by prior authors, it appears that your rebuild included reusing your old lifters and perhaps, resurfacing the face that rides on the cam. If so, that's not good procedure according to the advice I have received. Also, what was done by the machinist to ensure the same lifters stayed in the same bore? I would examine the bore of the offending (and the others as well) lifter to ensure it is true/in spec. Finally, given the level of disintegration of that lifter and cam lobe, I would spend a few moments imagining finely ground lifter particles being sucked up by your new oil pump and those fine particles migrating through your oil galleys to your main and rod bearings. You are certainly not looking to redo and expensive and difficult project. Just saying that maybe pulling the motor and doing a complete cleaning of the oilways will give you some peace of mind after this episode.

Maybe consult with the person who "helped" you rebuild this motor and get some detail on their procedure for this rebuild. Did they reuse/resurface the lifters? Did they use assembly lube in liberal quantities on the cam and lifters? Given that this motor was just rebuilt, what sort of warm up/break in (besides the breaking of the lifter/cam) did the motor get?

Doc250 Avatar
Doc250 Chris Holliday
Honeoye Falls, NY, USA   USA
1968 Triumph TR250 "Little Red One"
1975 Triumph TR6 "Lbc II"
Krom;

Excellent observations. The rebuild was done by a very reputable shop that had done many engines for club members as well as local racers. I trust his work. All the lifters were new as well as the cam so no need to maintain same lifter same hole. All parts from BPNW. As you can see from my other latest post I am equally concerned about metal bits inside the engine. I really don't want to pull the engine if I can avoid it but may have to. sad smiley sad smiley . Is there any way to "flush" all the oil galleys with the engine installed? I will defiantly pull the oil pump and inspect and clean or just replace it.

I believe the cam shaft is splash lubricated so is there any way the cam wasn't getting oil? Also, as i understand it, oil drains from the head down through the push rod access holes to lubricate the lifters. The rocker shaft supplies the oil to the rocker arms and that oil drains down through the lifter access holes through the engine. In the process it oils the lifters and cam shaft. Correct?

poolboy Avatar
poolboy Ken D
Sandy Hook, MS, USA   USA
Yours won't be this bad so I'm only posting this picture from one of my engines so you can see that it is possible that tappet debris can make it's way to bearings.

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tapkaJohnD Avatar
tapkaJohnD John Davies
Lancaster, Lancashire, UK   GBR
Does your engine have no oil filter? Why the worry about anything drown stream of that?

The pump may have been damaged.

igdboss Gene Levy
Laguna beach, CA, USA   USA
I too had a new lifter fail recently.

Mine put a hole in the block.

Also purchased from BPNW.

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Tonyfixit Avatar
Tonyfixit Tony M
Duncan, BC, Canada   CAN
About 20 years ago I had my lifters fail, about 500 miles after a rebuild. but not as drastically as yours. I had had a head gasket fail (Felpro) and while the head was off I decided to pull a lifter.

All the lifters were very pitted. The engine had been properly broken in with the recomended cam lube, and an oil that would have had (at that time) a good amount of ZDDP.
It was later found that the lifter had insufficient case hardening and possibly was able to flex in the contact area during operation. This lead to surface cracks which would join together below the surface.

The lifters used were the basic offering from BPNW.

To their credit BPNW made good, and provided their HD lifters in the replacment.

Their HD lifters were black colour and had an oilway in their flank.



Edited 1 time(s). Last edit at 2018-01-14 05:02 PM by Tonyfixit.

rjc157 Avatar
rjc157 ralph c
pearl river, NY, USA   USA
I don't know looks pretty bad you might have to pull the motor and bring it back to the machine shop if you don't get all the metal bits out you going to have a problem I think it might be the quality of the parts

roncohudd Avatar
roncohudd Gold Member Ronald Huddleston
Muenster, TX, USA   USA
1967 Triumph Spitfire "Lucy"
1969 Triumph Spitfire MkII "Lucifer"
1997 Ford Ranger "Little Red"
2001 Yamaha MC XV1600A "NOT THE HONDA"    & more
Just rebuilt is the clue. Maybe failure to use a good break in opp for the cam and lifters?

Tonyfixit Avatar
Tonyfixit Tony M
Duncan, BC, Canada   CAN
In reply to # 1507443 by Doc250 Ok, this just got worse if that's possible.

To Kai Radicke: I may have misled you. The complete lifter shown in the picture was meant to be just a comparison of where it broke. It's actually a lifter out of my TR 250 that I rebuilt 4 years ago. It is not out of this engine so the varnish is not a clue. Sorry my bad.

So I dropped the oil pan and found the pieces of the rest of the lifter. Ugly.

Now, how concerned do I have to be about all the little pieces I didn't find?

btw, it's a '75 TR 6. Again, sorry I left that detail out.

You have the oil pan off, so I would pull off the bearing caps and perhaps the oil pump and check for damage.
Realistically I think that is all you can do.
Hopefully nothing got past the oil filter as the 'event' happened when the engine was past it's cold start and hopefully the filter was not in by-pass mode.

When putting back together I might fit a magnetic oil drain plug.

Krom Avatar
Krom Paul K
San Rafael, CA, USA   USA
Chris- it sounds as though there are some repeated concerns about the quality of the tappets from the source you mentioned. You might consider communicating with Good Parts and inquiring about your situation. I believe Richard has a "good" bit of info on the hardness of tappets, cams and might be a valuable source for you. Hardness and flatness of tappets is important. It seems that there are varying qualities of parts like tappets. It is too bad if lower quality parts are put on the market, particularly for cars as old as ours. It's really not worth trying to save money if it means denigrating quality. Best of luck with your rebuild.

wbclassics Kai Radicke
Syracuse, NY, USA   USA
Tappets / lifter quality has been a problem for 10+ years.

The first market wide lifter test I conducted was back in 2007. Tappets came from BPNW, Moss, TRF, Engel Imports (at the time Engel wholesale only). I had some NOS British Leyland bagged TR6 lifters, and they were used as a reference benchmark. In that initial test, hardness wasn't a problem, but then again I think my sample size was only 15-20 lifter (just a few from each supplier). There were issues with surface finish, face geometry and other minor (correctable) things. We bought the hardest lifters and touched up the faces to fix the face geometry and then send them out for superfinishing to get the surface finish we wanted, then we had a usable lifter. I repeated the test in 2012, but the test batch was still about the same size, and the results were more varied this time for hardness in addition to the problems that already existed. Since the hardness is also an indicator of the chill depth on these chilled iron tappets, it is the one thing you cannot overcome or correct. We did our first from scratch production batch of 2000 lifters that year (2012), it lasted a couple of years, using them in the shop on projects, selling them to parts customers and also wholesaling them out to other British car shops we supply parts to. To insure the quality of what we producing we decided to add hardness testing and surface finishing as in-house QC abilities at the same time (previously hardness testing and surface finishing testing was outsourced to a our heat treater who had a large and well equipped metallurgical lab).

2014 came and our manufacturer was late delivering the next batch of lifters, and we needed some usable lifters badly. So I bought lots of lifters from a variety of sources. Now that we were doing the QC testing in house, and not paying by the piece for a 3rd party to check and write reports, we could quickly test a large number of pieces very quickly at relatively little expensive other than our time. So I massively increased the sample size of the testing pool (Easily was 100+ lifters). Now we were finding quite a few soft lifters (particularly in the regular replacement style of lifters, the ones that don't have the oil drain holes). The soft lifters were on the order of 10% of the total test batch size. There were a couple below 40HRC, some in the mid-40s HRC and couples in the low 50s HRC. 54-55HRC is about the lowest you want for a quality tappet, with most of the original Triumph lifters testing in 55-56HRC with the occasional one at 54 or 57. The "HD" tuftrided lifters are typically just a couple points higher... and this makes sense because tuftriding is a relatively shallow case hardening process, and so the diamond penetrator on the hardness tester easily punches through this. The HD lifters tend to be in the 56-59HRC range, some as high as 60HRC. But I don't ever recall finding any soft HD lifters (but they have their own set of other issues).

Anyway, I don't think there is anyone on the planet that has done as thorough of an evaluation of Triumph 0.800" lifters as I have done over the last decade. Particularly in 2007, 2012 and 2014. On our own lifters we maintain a sample testing rate of 10% of our batches (basically we test 1 out of every 10 lifters), and have never had a soft one from our manufacturer (although we have had some we have discarded for other reasons, like chips or voids).

If someone wants to see something cool, I've attached a picture of a test lifter we sectioned and then polished and etched the cut face to expose the depth of the chilled layer. This is from a few years ago, might be from the 2014 big lifter test. In the photo you can see the tightly grained chilled iron zone at the face, this is the area we need to be loaded with carbides. Then you'll see the transition into the mottled zone, where graphite flakes are starting to mix in. And then eventually, for the body of the lifter, which really isn't shown it'll be all plain gray cast iron. Surface hardness is only one criteria for the durability of the lifter face, the chill depth also has to be deep enough, and there is no definitive way to measure chill depth other then sectioning and etching and taking a measurement.

We've never had cam or lifter failure in an engine or any parts customer ever reporting such a failure back to us.



Edited 3 time(s). Last edit at 2018-01-14 11:55 PM by wbclassics.


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