I think I wiped out my GP2 cam........

[70herald]

Two views of bad lobe

Bill <span style="color: #FF0000">what is that line across the cam lobe? is it present on the other lobes?</span>
I don't have a camshaft handy right now but I don't think there should be a line across the lobe like that. looks to me like it might be ground improperly causing to the lifter to jump which is what caused all that pitting. The wear on the other side would the have been caused later as a result of damage to the lifter.

 

[70herald]

I almost think this is a component failure as it is contained to one (1) lobe.

If it were oil related or a driving issue, you would probally see wear on other lobes.

It might be the cam, lifter and/or something on the top end of the valve train. Are you using stock valve springs?

As a mechanical engineer who had spent the last few years in failure analysis I would have to agree that this is most likely a component failure. My guess looking at the pictures is that either their was a casting defect in the raw camshaft which left some sort of porosity at the cam surface or that the individual lifter was defective. It will be very interesting to see exactly what it looks like.



I would like to shed a bit of light on two other issues here

1. the break in cycle @ 2000 rpm is needed in order to ensure that sufficient oil reaches the cam shaft. The oil lines which reach the camshaft only supply oil to the camshaft BEARINGS. There is (and only should be) a small amount of oil in the engine head. This oil has no effect at all on the camshaft lobes or bottom of the lifter. The little hole drilled into the side of some lifters slightly improves the lubrication between the lifter bore and lifter. This is not the problem in Bill's case.

While these or any other engine for that mater are running there is an absolute tornado going on inside the crankcase. Oil flung off of the crankshaft is what provides the oil to the cam shaft lobes and lifters. At low RPM, this is simply insufficient to properly oil the cam particularly for long periods of time.

2. The reduction in ZDDP. ZDDP (it is the combination of the zinc and phosphorus which protect the metal surface) was with us since approximately the 50's. Modern good quality oils now include other additives which accomplish the same effect. In particular there is Molybdenum disulfide which similar to zinc will stick to steel surfaces and protect them.

Now in the hot rod world where most of the talk about oil / ZDDP has come from there are a bunch of other things going on. Many engine builders are adding scrapers windage screens and all sorts of other stuff to their engines to reduce power loss to airflow in the crank case. ALL of these additions have the side effect of starving the camshaft of oil. Add that to the problem of poor quality parts etc, and lots of camshafts are going to fail. In my opinion I am rather less than convinced that the problem is with the oil than with all sorts of other changes people are making to their engines without understanding what all the side effects are.

 

[Monkeywrench]

Here is a post from that https://www.speedtalk.com thread I referenced ..

I'm not sure of the TR4 tappets, here is a bit of info stemming from my research and testing of TR6/Spit tappets.

The Spitfire/TR6 requires a dead flat lifter face. The camshaft lobes are ground with zero taper. Rotation of the lifter is achieved only through the offset of the lifter centerline in relation to the lobe. It is quite possible that this is the case for the TR4 as well.

A while ago I conducted a lifter survey of the TR6 lifters, including two NOS (New Old Stock) lifters I had on the shelf from 35 years ago. Here are the results:

(EDIT: Sorry for the image, but I couldn't get the table to show correctly as plain text in the message)

"A" and "B" designations are different lifters (either different brand or
different all together) from the same supplier.

Radius is given in inches.

All of these TR6 lifters being ground very convex is one of the reasons for the high rate of failure over the last few years coupled with individuals building street engines with excessively high valve spring rates.

You'll note that even the used lifters have wear, I knew that one of them
had pretty severe wear, and I could see it. But I don't know the full
history of that motor, the used lifters were pulled randomly from two
different parts engines in the shop. But one thing that is consistent from
the used and NOS lifters is the trouble Triumph went through to polish the
lifter face to provide a very smooth surface finish.

It seems Triumph was rather unique in their approach to grinding tappets dead flat. MG T Series lifters were also ground flat, but even Austin MG changed their approach on this matter and for instance the B Series tappet should have a 32in radius.

Kai @ Wishbone Classics

 

[DrEntropy]

In my opinion I am rather less than convinced that the problem is with the oil than with all sorts of other changes people are making to their engines without understanding what all the side effects are.

So true.

I think we're lookin' at the source of the "clatter". I would be VERY reluctant to just schtupp in a cam/lifter replacement. The oil filter cannot be counted on to catch all the residue from that failure. Engine out, disassemble. Clean/check everything with a bearing surface. That missing lobe material is spread thru the rest of the engine.

rats.

 

[tomshobby]

That missing lobe material is spread thru the rest of the engine.

Doc, yer saying like a failure waiting to happen?

As far as the Goodparts lifter surface being flat or curved. I remember opening the package of Goodparts lifters and noticing that the lifters were stuck together if the surfaces the cam contacts were together and only came apart easily by sliding them apart. I did not check beyond that but it tells me those surfaces are smooth and flat.

 

[Monkeywrench]

That missing lobe material is spread thru the rest of the engine.

Doc, yer saying like a failure waiting to happen?

I alluded to that in my first post. Those peices of metal are small enough to travel through oil gallery's throughout the motor. It could be ugly if they make it to the crank...

 

[vettedog72]

That missing lobe material is spread thru the rest of the engine.

Would this material have to pass through the oil pump and oil filter (assume the bypass is not open) BEFORE it reaches other pressure lubed parts?

 

[Guest]

You guys bring me such joy!

So, let's have a survey. Jerk the engine and rebuild or just schlup in a new cam and lifters.

My biggest problem with a total take down is there is no one, I repeat, no one within 150 miles of me that will do such. I would have to trail it to Mississippi to a guy that is, let's say, hard to deal with.

What a revolting development.

(My thoughts are leaning to schlupping......)

 

[Guest]

Pardon me, "Schtupping."

 

[Tinster]

no one within 150 miles of me that will do such.

Bummer bad for you Bill.

Now, you offered me much sound advice with no one
within 1,200 miles of me to help me. Ask yourself what
advice you would give ME if I had posted the photos of
that wrecked cam?

regards,

d

 

[TR6oldtimer]

You guys bring me such joy!
....
(My thoughts are leaning to schlupping......)

Get out your tools. Make your life easy, yank the head so you can have the valve train inspected. Yank the oil pump and clean. Yank the cam and replace.

Put it all back together and get on with it.

Work with the vendor to determine what caused the cam to fail.

Look at this as a toothache. Just take care of it.

At least where you live it is not snowing.

 

[RonMacPherson]

Has anyone else researched the claim that STP has ZDDP in it. Just heard that from another forum, haven't had the opportunity to check it out myself. If so, it seems an interesting resolution to the lack of ZDDP is available.

 

[gjh2007]

Just a note on poor quality components, or defects, as I cannot attest to Richards product. But I had a new 4.0 short block installed in my '88 Range Rover by a factory trained Rover mech a few years back. I decided to have a slightly modded cam (Erskin) installed to get a little more HP for towing my boat.

Well, $6500 latter, including a bunch of other stuff I gets me truck back. Installed a VDO oil gauge as did not come stock on the truck. Pressure good all around. A week after I got it back I was sitting in the truck idleing for 10-15 mins & could hear a slight clicking in the top of the engine. After the shop listened, they tore down the top end & found by micing that there was a bad lobe on the cam right out of the factory.

A rather nasty job to do it all over, including Johnson Bros adjustable pushrods.

Ended up going back to OEM factory stock cam & never had the prob.

My shop tells me he had 4 out of 7 bad cams on rebuilds he had done in 6 mos.

Fortunetely it wasn't a wear issue & no major rebuild was necess.

Good luck with your problem, keep us posted, we are all thinking of you.

 

[tomshobby]

I understand what you are saying Gary, but are there even any NOS OEM factory stock cams in existence? I would think they would have long ago been used up and all that is left now are after market replacements.

 

[2wrench]

Bill: I am so sorrowful that I hardly know what to say.
Everything we do is subject to some element of risk.

I think you really do know what to do. Assess your
risks and proceed.

My concern? Is a pitted lobe and appertenances all
there is to the problem?

I know I'm not the mechanic, so I rely on common
sense in forming my questions.

What makes a pitted lobe cause a clanking noise
(or however described) and then it goes away?

Does heat cause expansion correcting the problem?
I mean, I really don't know. Just seems quizical.
In any case, I know you don't like it and you want it
out.

Dang, it's kinda like telling a Cover Girl model
she's got to lose that canine. Choices? Flipper?
Implant? Nothing? Cut down more teeth and do a
bridge? How's the bone look?

Sorry, Bill, really sorry.

PS: I'd still love to hear the noise. Guess I won't
if the pan's off, huh? Just a little selfish, I guess,
or maybe someone would recognize it?

Wishing you the best always,

 

[Moseso]

Last spring I tore down my TR3 motor. This motor was probably rebuilt in the early '80s. I bought the car in '83 -- drove it about 2000 miles that year, and then put it up until I could address it's problems. (Yes, it's been that long...) The motor seemed strong. Last spring I found a very clean crank, -.010"; good main and con rod bearings; 87 mm pistons and jugs within spec, and showing no serious wear. The head had more problems: Stem and guide wear, seat pocketing, a grooved up rocker shaft -- the things one would expect to find.

Also, a cam shaft that had one lobe that looked just like Bill's and another one headed in that direction. The lifters associated with those lobes were hacked too.

I've been following the cam/tappet/lubricants/break-in threads with great interest. I am putting in an Iskenderian "TR-23" cam: .440" lift, 260 duration, and new "heavy-duty, lightened" tappets from BPNW. This motor probably won't get fired-up until late summer. I am armed with all sorts of good recommendations for oils and break-in procedure. Boy... I hope I don't see another cam lobe like that any time soon!

 

[2wrench]

Can't leave it alone. How about you pull the head,
take two aspirin, contact us the next morning with
what you see and I'll bet you'll be guided to the
next step and the next and......

Don't throw that mouse, Bill, don't throw that mouse!

 

[martx-5]

Has anyone else researched the claim that STP has ZDDP in it. Just heard that from another forum, haven't had the opportunity to check it out myself. If so, it seems an interesting resolution to the lack of ZDDP is available.

Moss motors now carries ZDDP additives and motor oil with ZDDP. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

 

[DrEntropy]

I've seen 'em go that way from poor maintainence, tight adjustment, poor quality control et al. I've fitted Crane cams with good success. No experience with the Kent ones. Talking with the company rep's is a good start. Photos are good enough to show the problem, too. The oil likely went to 50W as temp increased so cushioned the "shock" a bit to make the noise less evident.
Just my guess. /bcforum/images/%%GRAEMLIN_URL%%/smirk.gif

 

[Guest]

And just now I find out that GoodParts has no GP2 cams in stock on don't expect them for a couple of weeks. TRF handles their cams and is out as well (waiting for Richard to send them some). So I am dead in the water for at lest 3 more weeks. So much for the New Orleans car show at the end of March. Does anyone have a spare new GP2 cam laying around for an early TR6? Brosky??

Spoke with the owner of British Frame and Engine, for an hour (nice guy, man can he talk, 75-year-old) and got a lot of info on lifters. The really high end ones need to have the block bored, for the lifters yet. That ain't gonna happen.

Spoke to others (Dave, Richard) at length and have come to the conclusion that there are no super lifters out there, at least for my application.

So now I am torn between taking the head off, as suggested above, or just try the magnet trick with the head in place.

Taking the engine down completely is not an option, not yet.

So, there she sits, up on jack stands, all lonely in the garage. I think I might put my garage stereo on low and put some Smashing Pumpkins on low and chill.

I'm sad.