TR6 Can you identify these metal shavings in the oil?

[MTribe]

OK guys... I sent oil in for analysis, and dropped the pan tonight.

With a quick visual inspection I noticed wear and what looks like galling on the camshaft. See photos.

Notice there is a slight groove where the fuel pump arm rides on the cam, and the tops of most lobes look galled. This is a Goodparts GP2 camshaft I installed 6k miles ago, along with new tappets, rebuilt head, etc.

Any idea what's going on?

 

[M_Pied_Lourd]

Wondering what oil you have been using for initial break in and afterwards.

Cheers
Tush

 

[Rut]

Two things come to mind, break in oil and procedure along with cam lube on install and hardness of the tappets. With that kind of wear I'm surprised you didn't see big changes in valve settings.
Rut

 

[TomMull]

Sorry, this is not the news I'd hoped for. It's good you persisted with going inside and it would appear that the culprit is apparent although the information conveyed by a photograph is limited.
If you confirm the suspicions, it would appear that the cam/lifter issue has raised it's ugly head again, with questions of ZDDP oil, assembly lube, and hardness of both the cam and lifters.
I would begin by contacting Goodparts. I am sure they are aware of the issue.
Tom

 

[M_Pied_Lourd]

You don't have the tappets/lifters out yet right? I would be interested in seeing those...

Cheers
Tush

 

[MTribe]

Here are a couple photos that show more detail...

- 6k miles since rebuild, used Castrol 10W-30 synthetic with four changes.
- Haven't checked valves since 1k miles.
- Did not use ZDDP.
- Was meticulous with cleanliness and assembly lube.
- Haven't taken the head off/tappets out yet.

The fact that the fuel pump is causing scoring make me think it's either a lubrication issue or cam issue? The pressure the fuel pump puts on the cam is so low compared to tappets?

 

[TomMull]

Perhaps you've seen this thread on a similar topic:
https://www.britishcarforum.com/bcf...r-failure-in-TR6-s&highlight=camshaft+failure


While I'm sure the 2000 rpm run in and addition of ZDDP will mitigate these cam/lifter problems, the cynical side of me would say that there is more to it, namely poorly engineered and or poorly produced cams and or lifters. The fuel pump lobe would seem to support that cynicism. There is very little load on that lobe.



Other than oil chemistry, I think you can rule out lubrication problems. Most of the oil that lubricates the lobes comes from sump splash and there is not much that can go wrong there. Weep holes in the lifters my add something but they were never needed on the original engines. My 55 year old cam is back in the engine untouched and still good.



I would like to see some hardness data on these failed cams. Also wonder if the manufacturer includes run in and oil recommendations.

Tom

 

[MTribe]

Tom--really appreciate that thread. Had not seen it.

I've done some research, talked to Richard, talked to a british car mechanic, a very knowledgeable friend, and unfortunately haven't come up with much. So I'm going to assume it was a bad cam, add the external oil feed line kit, and just try again.

Do any of you have recommendations for a mild street cam? I was happy with the GP2, but just wondering if there's anything with a similarly good reputation out there?

 

[poolboy]

Why not late model TR6 cam ?

 

[Brinkerhoff]

If the cam lobes are wearing prematurely the lash would be getting loose on the offending lobes, is that happening?

 

[Nobbster77]

Did the right number of shims go under the distributor pedestal, if not the housing rubs on the distributor drive gear and loads of cast iron is passed around the oil galleries
The "shaving" looks like it could come from the thrust washers .
I wouldn't bother looking to Oil Condition Monitoring and spectrographic analysis as you would have to use ferrography to determine how the wear was produced... better to spend the money on an engine strip.
Looking at the amount of ferrous material you have found I think its safe to say you have a problem that requires an engine strip but you can drop the sump and look at a the journals/thrust washers just to make sure though !

I have seen a number of Triumph GT6 and Triumph 2.5 engines that have failed due to lack of spacers under the Dist. housing after rebuilds, as its not some thing people check, if the housing is removed the gap should be measured using feeler gauges and spaces fitted (cant remember the clearance though) if not, 200mls after the build, the mains and big ends are shot .
Hope you sort things and I hope I am wrong for your sake.
Steve

 

[MTribe]

Thanks for the tips... I will double check some things.

Do you guys have any suggestions for turning the engine over to check valve clearances now that I've dropped the pan and there's no oil in it? Are there any tricks or easy ways to turn it by hand? Just want to be careful not to damage anything.

 

[poolboy]

I don't have a level surface to roll the car in gear like so many people seem to do, so I remove the spark plugs, tighten the alternator belt, put a socket and ratchet on the alternator pulley's nut and turn the ratchet counterclockwise when viewed from the front of the car.
I use the rule of 13 to check and adjust the valve lash that is described in the Haynes and Bentley manuals.
Don't forget to reset the belt tension when you get thru.