Camshaft faillure

[Menno van Rij]

Right! Struck by lightning, bad karma, I don't know. The main thing is: my engine suffers from camshaft faillure.

 

Let me explain:

 

During the last few months, tappets became more noisy. I adjusted the tappets as stated in the manual, but things started to become worse (noisy) in just a few miles. Although being in denial, I know that there was something wrong. Listening with a engineer's stethoscope made clear the the noise came from inside the engine, about halfway down, near cyl. #4.

 

Before I go any further: yes, I used the much praised ZPPD additive when changing the oil every year. (There's only one place to get it in Holland and that's 10 mls from my house).

 

So I rang the guys who rebuilt my engine during the restoration back in 07/08. And they reacted like you want from a supplier: 'Come over to our place, so that we can assess what's the problem'. And yes, they agreed that there was something wrong. We made a deal: I would dismantle the front end etc. (all non-engine related parts) and after that I would bring the car on a trailer for further examining. 'And we will take it from there if it has something to do with us and our products'. So I did: I trailered the car 25 miles east. (Thanks to a neighbour with a Volvo XC90)

 

Earlier this week, the guys started to work on the engine. Off with the front cover of the engine, the dizzy, fuel pump, head etc. and yes... the last two lobes (is that the correct word) were severely worn! I dug out the bill the workshop had sent me back in 07 and yes, there it was: new camshaft, new cam followers etc. The whole bunch! Again, the motor builder reacted positively. 'It's our problem'. So, moneywise, it's not a big deal.

 

But we don't know what caused the problem!

 

I've called various well respected TR owners around here and they came up with a lot of info. In no particular order:

 

- a reworked cam has markings on the back end. An original one has no markings.

- perhaps the cam followers were too large (thick) and blocked in the holes

- what markings are on the cam followers

- Did M**s supply the parts back in 07? Another home restorer had the same problems a year back

- Go for a well known quality cam, like Kent's TH12. That's a good quality product with matching parts like the followers etc.

 

So, you can see! More Qs. than As. And as always, most of the knowledge can be found on the forum. So, gentlemen... take your time to come up with your ideas or answers. As far as I can see, Winter will be with us for the next month or so. So there's no hurry.

 

Horror pictures later this week; I have work over the next few days.

 

Menno

 

EDIT what do you want to see on the pics apart from the camshaft itself?

Edited December 8, 2010 by Menno van Rij

[vivdownunder]

Menno, sorry to hear of the premature engine failure.

 

It could be the cam followers at fault as we've seen repro's without the correct hardening. Also without the correctly ground bottom profile so they rotate properly for even wear.

 

Were they run in correctly ?. They need special lubrication and up to 20 minutes initial running with the engine held at about 2000rpm. It sounds like the engine is howling, but that's what it takes.

 

If replacing the cam and followers I'd consider Neil Revington for a solution. You might pay a bit more, but you get a tried and tested product with a lot of engineering thought behind it.

 

Regards,

 

Viv.

[Ashley James]

Most likely a manufacturing problem, hardening no good as suggested. I'm very sorry, what a bloody pain!

 

Ash

[Don Elliott]

When your engine re-build shop has the cam out, ask them to measure the bores for the cam bushings. Maybe the problem started there. Were they replaced when they re-built your engine ?

[Menno van Rij]

When your engine re-build shop has the cam out, ask them to measure the bores for the cam bushings. Maybe the problem started there. Were they replaced when they re-built your engine ?

 

 

That's an idea. But what references (sizes, measurements) are there?

 

Must tell you that translating terms from Dutch to English and vica versa isn't very easy...

 

Menno

[james christie]

Menno, this is bad luck , but unfortunately it does happen that a lobe, several lobes or cam followers weren't heat treated as they should have been.

After verifying that there is no collateral damage you need to change cam bearings, cam followers and camshaft. Preferably all bought from the same supplier

I have a Fast Road Camshaft from Neil Revington in my 3A and have never regretted it in 9 years.

Neil is not the cheapest and has no pretensions so to be but in my view he is by far the best and in my experience, will hold your hand (virtually) while you put it all together again

 

james

[88V8]

what do you want to see on the pics apart from the camshaft itself?

 

Pics of the underside of the followers, especially from the failed lobes.

 

When building the engine, the followers should fall smoothly in the bores. RogerH has written in the past that he found much variation in follower sizes when building his TR4A engine. The supplier (Moss in this case) had them all in one bin regardless of size.

Hardening seems to be a problem with cams and followers. Cam followers should have 50/55 Rockwell 'C' hardness. Cam lobes about 60 Rockwell.

If the supplier won't document the hardness, don't buy.

The followers should be bought from the same supplier.

 

Newman cams have a good reputation.

Here on page 33 are their TR3 cams.

http://www.newman-cams.com/pdf/triumph.pdf

Their cams and followers are made with chilled cast iron. This has resistance to wear that far exceeds any other type of cast iron.

 

As Viv said, the running-in procedure is also very important. If the engine was allowed to idle at all during the first 20 minutes of running, the damage is done....

 

Some notes I stored:

 

'Do not use synthetic oil for running-in. Synthetic oils are too slippery and do not promote proper rotation of the followers. Lack of rotation will cause camshaft failure.

 

Coat the cam lobes, distributor drive gear and the bottom face of the followers with cam lube. Lube the sides of the followers with engine oil. Oil the pushrod ends with engine oil before installing.

Put paint marks on the pushrods to allow you to check for pushrod rotation on engine start-up. Lack of follower rotation will cause cam/follower failure. If a pushrod is not spinning – immediately stop the engine and find the cause.

 

If possible, drill prime your oiling system. Rotate the engine at least one complete revolution to assure oil gets to all valve train components. Do not crank engine to prime oil system. This will deplete cam lube from the cam and lifters & cause a dry start condition which may lead to cam and follower failure.

 

It is important to start the engine with as little cranking as possible. Cams rely on oil splash from the crank assembly for their lubrication supply. There is insufficient oil supply to the cam and followers until the engine fires up and attains at least 1500rpm.

 

Fire up the engine and immediately bring the revs to between 2000 to 3000 rpm. Warning – do not let the engine idle! Do not worry about getting ignition timing set perfectly at this time.

The rocker cover should be left off to verify pushrod rotation. Get the engine running fairly smoothly and vary the engine speed between 2000 to 3000 rpm in a slow to moderate acceleration / deceleration cycle. During this time check for engine leaks or unusual noises. If something doesn't sound right – shut engine off and locate the source of the noise. Upon restart resume the high idle speed cycling. Continue the varying run-in speed for 20 – 30 minutes. This is necessary to promote proper follower rotation to mate the lifters to their lobes.

Let engine cool and then change oil and filter. At this point initial run-in is complete. Drive the car in a normal manner – but avoid prolonged idling. Change oil and filter again at 1000 kms. Mineral oils are best with flat tappet cams. If synthetic oil is your preference – run the engine for 8000 kms before changing. '

 

Ivor

 

[Menno van Rij]

Thanks for the all the advice and good ideas. Alec pointed me into the direction of Simon from TR Enterprises. Simon has appears to have a thorough approach. Before he sends me a new camshaft and other parts, he first want to have some questions answered. And without wanting to be 'pedantic': let's make it an educational thread. I'm sure some other TR folk will be confronted with the same problems in the (near) future.

 

His email:

 

Menno,

 

We need to know what has caused the camshaft to fail.

 

How many km's had you done before the cam started to wear (ie when the tapping noises began)?

 

Are the two failed lobes from the same piston?

 

Are the rockers worn? (the two relevant ones)

 

Are there any signs of 'hammering' on the tip of the relevant valves?

 

Regards,

 

Simon

TR Enterprises

 

Some things can only be answered by taking pics. The engine had done about 3000 kms before the tapping started. From that point on, things became worse very fast. 'Exponential' is the correct word, I think.

 

I asked the guys at Revington for the same advise; in fact I sent them an email like the one I sent to TR Enterprises. I hope they will send me an answer tomorrow or Friday.

 

On Saturday, I'm going to take my portable photo studio with me. (Mostly, I use that for taking pics of watches) and I will try to get visualise the answers.

 

 

Menno

[Guest ntc]

Sorry to see that Menno their's another S

Edited December 8, 2010 by ntc

[sidescreen]

Menno,

 

A very disappointing stage after such a short mileage ! Why aren't they farbicate, unwhile they fabricate, proper qualities ?

Wishing you all the best of luck you can get to solve this problem.

 

Regards - Raymond

[Andreas]

Hello Menno,

 

I can recommend you David Newmann ! He build me the TR3A cam , super quality.

 

The cups, but also to r cam fit! Yours sincerely, but the cups (Stößelbecher) have to fit to the cam.

 

Kind regards

 

Andreas

 

[Menno van Rij]

Okay, I took some pics earlier today. I wasn't too pleased with the view.

 

Lobes #6 and #8 are pitted; #6 a little, #8 real bad. cam follower #8 is also heavily pitted in a circular pattern, I think indicating that the cam follower was free to move around. (I've read somewhere that a rectangular wear pattern on the cam follower indicates that the lobe has hit the bottom of the follower at the same position all the time - correct me if I'wrong)

 

As said: lobe #6 is also a little pitted, but there little signs of wear on the follower.

 

Menno

 

Anyway, here are some pics... As always: I really would like to read your comments!

 

 

identification number

 

identification number

 

lobe without markings

 

lobe #8

 

cam follower #8 and a small part of follower #6 (Dark spot on the follower is the figure '8' marked by a felt pen)

[foster461]

Okay, I took some pics earlier today. I wasn't too pleased with the view.

 

Lobes #6 and #8 are pitted; #6 a little, #8 real bad. cam follower #8 is also heavily pitted in a circular pattern, I think indicating that the cam follower was free to move around. (I've read somewhere that a rectangular wear pattern on the cam follower indicates that the lobe has hit the bottom of the follower at the same position all the time - correct me if I'wrong)

 

As said: lobe #6 is also a little pitted, but there little signs of wear on the follower.

 

Menno

 

Anyway, here are some pics... As always: I really would like to read your comments!

 

 

 

Menno, good job with the pictures. To my untrained eye it looks like the #8 cam follower was bad and it took out lobe #8 on the camshaft.

 

Stan

[Ashley James]

It looks to me as though the bits of camshaft have welded themselves to the tappets.

 

As long as oil supply was as it should be, you have no option but to replace the camshaft and tappets and hope. However I often have parts made for cars (not camshafts) that require hardening, the machine shop I use has the old part tested and gets the new one hardened the same. Possibly you could find someone locally who could test the new bits before you fit them as an insurance policy.

 

Ash

[TomMull]

Menno, good job with the pictures. To my untrained eye it looks like the #8 cam follower was bad and it took out lobe #8 on the camshaft.

 

Stan

 

From the point of view of another untrained eye, it would seem a chicken or egg dilemma. Since lubrication comes from runoff from the cam journals, drip from the top and splash, I don't see any opportunity for failure there. I don't believe that improper break in would cause this in 3000 kilometers. I've never managed to break in a new engine "by the book" and never had a premature cam failure. For good measure, I'd carefully check the rest of the valve train but you've probably already done that. I think that about eliminates everything but a bad (soft) cam and/or followers. Good luck with this, Menno. Tom

[Robin Powell]

From the pictures the cam followers do not seem to have a hole drilled near the bottom which quite a few do these days. The thinking is that this improves the oil supply to the camshaft lobe and reduces the weight of the cam follower at it isn't full of oil all the time.

[Guest ntc]

I reckon thats a Piper cam by the numbers, from Moss?

[RogerH]

...The last set of cam followers I bought were from the TRShop.

They had the drain hole and were matt black all over - not the shiney polished jobs usually found. Still going strong after many miles.

 

Roger

[Mychael]

Looks bad Menno, sorry about your engine. Like someone else said before I've never done a 'proper' running in of an engine and expereinced that sort of problem that you have.

 

My engine is pulled down at the moment after ???? miles and years and there is just the begining of some pitting on a couple of the followers and cam lobes.

 

I bought some more followers 2nd hand and I'd assume they are original followers and along with the unmarked ones from my engine had them all hardness tested and re-faced. Most passed well with Rockwell over 53 as I recall but two were rejected as they were in the 40's but without pitting. I find that to be interesting as assuming they were original stock then even at Rockwell 40's they had survived well into later life so when then new parts are failing on cars it makes you wonder how soft they must be.

 

Mychael

Edited December 11, 2010 by Mychael

[Menno van Rij]

Thanks guys for all the heartwarming respones. The jury is still out... I have contacted TR Enterprises and Revington. Both have replied on my email. TR Enterprises wanted to have a look at the pics first, before they are about to suggest a solution (professional thinking!). I haven't decided yet.

 

My engine builder is quite p*ssed with the situation. He's trying to get his money back and he's facing a brick wall (well known supplier overhere - I will not mention the name. Now it's his problem). The fact is, that he rebuilt two engines at the same time. One for a mate who runs a TR4 and mine. He used the same parts for both engines from the same source. My mate's car has done 12000 kms since, without any problem! That makes things even harder to analyse. I've pointed him towards the responses here on the forum, so that he can read more about bad experiences with certain parts...

 

Now we're facing a new challange: who to trust for new parts. Apart from the TR Enterprise email, all other main suppliers appear to have their own solution to the problems: hardened parts, tufrided parts, Rockwell 60 parts etc. Must say, things are getting confusing.

 

One of our fellow forum members sent me an email suggesting that it's best to completely strip the engine and thoroughly clean all to get rid of the swarf. Given the fact that we're already half way, we will do so. Mind you, the engine already need a complete gasket set etc. A few bearings aren't the end of the world!

 

I performed a search before I posted the first message a few days back. I would like to point you to this message: Interesting read about camshafts and followers

 

Menno

[Les]

To me, lobe #8 looks as though it may have had it's surface built up before being ground to the correct profile. the surface seems to have lifted from the underlying metal!

Edited December 12, 2010 by Les

[88V8]

Now we're facing a new challange: who to trust for new parts.

From the pics it does look like lack of hardness. As has been said, the cam has micro-welded itself to the follower, which, as you comment, has been revolving just fine.

 

New parts - I've yet to hear of any complaints about Newman Cams.

 

Ivor

[MadMarx]

Hello, seems that you guys have the same trouble as we in Germany.

 

I did some investigations over the last 3 years and found out:

 

An improper mixture of different cam and lifter systems!

 

Have a look on that manual from Ford:

 

There are cams with taper grind and cams which are dead flat grind design.

In Europe 99% of all cams are dead flat cams (roller cams) which needs flat lifters.

 

Unfortunately there are only domed lifter available which only fit to taper cams and taper cams are only made in USA.

 

Pattern runs off lobe:

The reason for insufficient rotation, high stress on the lifter center and high stress on one lobes side. Ideal for a short lobe life.

 

The same cam lobe after a racing season with dead flat grinded lifter surface....that is as it should be:

 

And how I did get to this knowlege (okay - I'm an engineer, but that's not the reason) - I have a set of stock lifters in new condition.....

and have a look on the difference of the wear pattern:

 

NEW--------------------OLD STOCK (=dead flat)

 

RESULT:

 

Buy a cam from Newman or Kent, Piper and so on......purchase the lifters.

Give the lifters to an engine shop and let them grind dead flat on a crank grinding machine.....like this:

 

Worn lifter..........after grinding:

 

And then you get this kind of wear pattern......2 seasons of racing and 2000 km of road traffic:

The surface is so smooth that the camera cannot focus it...

(the lifter is County made)

 

Cheers

Chris #74

Edited December 13, 2010 by MadMarx

[Ashley James]

For many years in the late forties and early fifties, Rolls-Royce ground cams so that they rotated the tappets. However when they checked to see what was happening because there were wear issues, they found that if they were it was in the opposite direction to that which was expected, so they made the lobe wider knowing that it might stop any rotation and now when the engines are stripped down, camshafts are often still in spec after several hundred thousand miles.

 

As I said before, in this instance the problem has to be poor manufacturing quality, probably hardening because good cams and tappets last well.

 

Ash

[MadMarx]

I found no evidence for a lack of hardness on my lifters, only wrong design as they were domed.

But there might be bad lifters around wich are not hard enough - don't know that.

 

I also would recommend to let lifter and cam nitrate hardened.

Chilled cast seems not good enough in my opinion.

 

cheers

Chris