Tappet Noise or is it a cam follower issue?

[GT6M]

they be like this , ill put LooT onit

 

Ive seen cams wid a v big offset to follower

some cams , even OE ones, are NOT all slightly off set that same

and, ive fun oot, that a cam wid a wee off set, can rotate as much as one wid a lott of offset

 

Ive got 1 an 12 not rotating at the moment, been dooing this for aboot 2,000 miles

its not noisey, butt, I gotta keep adjusting the gaps,

seems t, wear a 1,thou over 1000 ish miles, BUTT, lobe lift is the same as dam it on all at full lift.

and looking inside I cansee this pattern,

so its gonna ev,t come oot soon

 

The prob wid aftermarket cams is they got alot moer lift than an OE cam,

the follower tries t,dig into the side of lobe, butt, just the slightest wear point, an it,ll stop it rotating

 

Me own cam is an OE 25/65 one, and it wont be the first time that thee,s ev worn t, this shape

AND, not always on same lobes / followers.

the OE cam seems to be v v good at not wearing away

 

on olde engine, the followers went on other cyls, this time its on 2 ende ones

 

An article I read on ST site, regarding the use of fully syth

was that even if ye got yer hands on a decent oil wid plenty of ZDDP/ sulphur init

the cams, butt moer often followers wear oot

this seems t,be for the reason the oil is slippier, so not causes as much frictionee,

so follower no rotates as much, so get a rut init sooner.

 

And Im running fully synth 2,200 PPM ZDDP oil

SO, is there some merit in this theory,

 

M

[iain]

I'd like to say the Good, the Bad and the Ugly, but frankly there is no Good!

 

[Guest ntc]

Thats bad,skip fodder

[RogerH]

Hi Iain,

that is an interesting chunk on the 1st pic 4th from left follower.

 

Wow - How did that happen !!!

 

Roger

[GT6M]

Some of them been rotating, some not,

ones no rotating are wid the scuff marks in one directionee only

 

Them followers the black,ns wid holes in em,

I had a set in a while back, was told they wer the best on the market, butt just aboot every one went.

some had pits all over em, butt they wer rotating in bore

 

4 had stopped rotating,and had a wear groove in em, quite deep, 15 thou at least.

thee,s type are supposed t,be tuffridded, an a coating applied to help break in.

 

So, join the club.

 

That one that seems t,be cracking up, thats not good news at all.

 

whats the cam like, as it may have been worn a bitt too,

so new followers may wear even faster, !!

 

I,d be asking for a new package frae Kent

4 cams of Kent in the past, all went, one after 500 miles.

 

not too impressed with their stuff at all after thee,s runins

I did get a new one of them for the one that lasted 500 miles

butt, the others they said it was wrong run in procedure,or wrong oil

 

they would,nt shift on this

There is some thing amiss, cos this cam an follower break doon is moer a modern thing than what happened years ago.

never have OE cams an followers going off so soon

 

M

Edited January 17, 2017 by GT6M

[iain]

Hi Iain,

that is an interesting chunk on the 1st pic 4th from left follower.

 

Wow - How did that happen !!!

 

Roger

If only I knew!

 

All turned freely on commissioning. All had Penrite cam lube on assembly. Used Penrite running in oil for first 100 miles and then changed to Penrite 20/60 for the next 200, then changed again at 500. Each time with a new filter.

 

Penrite ZDDP content is supposed to be very good so I don't think its that.

 

All Bo£&"^£%$!

 

Time to start again.

[Tom Fremont]

Cams and followers look to be the Achilles heel of the TR engines. My '250s each have failed (2) cams so are on their 3rd. Cambridge Motorsports supplied the driver's " 150 " cam and its followers circa 2001, 80K miles ago - no issues in that time and mileage. The other's failures were due to poor oilways on the journals of the camshaft, too little and then too much, plus crowned followers with the latter. Doing OK after 4000 miles using a Piper cam with Newman steel followers, which will never give me confidence as it's a collision cam with 292 degrees duration ( it's a rip-snorter though ).

 

My next build will get a factory " 150 " grind as it has the longest track record by far ( and I've got a stack of T-shirts where cam replacement is concerned - if you want to swap one with head and sump attached let me know ). In my dotage I've settled on 1 HP / in3 for these engines, doable with TRIUMPH designed cams. Virtually every case I've come across where more power was obtained reliability was sacrificed. Much as I enjoy wrenching on these I prefer to drive them.

 

Cheers,

Tom

[Motorsport Mickey]

If only I knew!

 

All turned freely on commissioning. All had Penrite cam lube on assembly. Used Penrite running in oil for first 100 miles and then changed to Penrite 20/60 for the next 200, then changed again at 500. Each time with a new filter.

 

Penrite ZDDP content is supposed to be very good so I don't think its that.

 

All Bo£&"^£%$!

 

Time to start again.

Ian,

 

You probably know but I think the first 30 mins of the camshafts life decides what's happening to the life of the camshaft and followers.

 

I ALWAYS jump in the car with an emergency toolkit water and oil and a mobile phone and drive it on the road keeping over 2000 revs on the clock avoiding traffic lights etc. If you are in a built up area and the lights change in front of you make a right or left turn around the block and sidestep. Assuming the camshaft and followers have been prepared and fitted carefully with the correct lube (as recommended by the cam supplier). Keeping the revs over 2k helps avoid the camshaft "galling" (dragging or smearing material from the camshafts) whilst it's in it's very important initial breaking in phase.

If you don't fancy the open road make an appointment at a local rolling road for an hour session and do it on the rollers.

 

Mick Richards

[iain]

Mick

 

the only difference to your procedure was to run it without any load, but the revs up at about 2200. for 20mins as per Kent's instruction's.

 

You clearly prefer some load?

 

Iain

[Guest ntc]

Mick

 

 

 

You clearly prefer some load?

 

Iain

N/A

Edited January 17, 2017 by ntc

[Nick Jones]

It is normal, even necessary for the cam lobes to be offset from the follower centres on these engines as this is what promotes the spin of the followers. The amount and consistency of the offset depends on who made the cam blank. The OE ones are fairly consistent whereas the Newman cam I have in my Vitesse was variable enough for me to query it with them. They said it would be fine and it seems so. It has maybe 6k miles on it now - they normally fail sooner if they are going to.

 

It is also true that the follower quality is an issue. I was actually supplied crowned followers by Newman but luckily I checked before fitting and queried this also. They switched them for (considerably more expensive) hardened steel ones at no extra cost to me even though it was two years since I'd bought the original set so all credit to them.

 

Nick

[Tom Fremont]

It has maybe 6k miles on it now - they normally fail sooner if they are going to.

 

 

 

I had one cam let go ( made a rattling sound ) at 25K miles, and its replacement at 10K. The first signs no doubt would have appeared before, but actual failure can take a while. I'd say 50K miles and you're in the clear!

 

Cheers,

Tom

[Nick Jones]

 

I had one cam let go ( made a rattling sound ) at 25K miles, and its replacement at 10K. The first signs no doubt would have appeared before, but actual failure can take a while. I'd say 50K miles and you're in the clear!

 

Cheers,

Tom

Thanks for these cheerful thoughts - I thought I was the pessimist!

 

Can you remember whether it was lobes at either end of the engine (ie 1 or 12) that were the problem(s)? I have a theory that these see less lubrication as most of the failed ones I've seen have been one of these two.

 

Nick

[iain]

Well the cam is out.

Bearing journals unmarked.

Cam lobes look ok will mic up tomorrow.

 

Will photo in daylight

Iain

Edited January 19, 2017 by iain

[Tom Fremont]

Thanks for these cheerful thoughts - I thought I was the pessimist!

 

Can you remember whether it was lobes at either end of the engine (ie 1 or 12) that were the problem(s)? I have a theory that these see less lubrication as most of the failed ones I've seen have been one of these two.

 

Nick

Sorry - no recollection, and I didn't keep pics of the failed ones. Note these happened circa 2002; subsequent failures (2) had to do with oil journal issues but the last one of those had pitting after 150 miles ( crowned followers ): one seized and its replacement gave abysmal oil pressure when hot. The lobe failures were at least (4) out of the total, probably (8) if you count the slightest blemishes.

 

Cheers,

Tom

[LGFromage]

Iain,

 

Hopefully the following will prove useful.

 

I was so interested in the backlash on the distributor drive on your engine that I removed the distributor on my car and found the gear backlash to be negligible. This is with a Kent high torque cam so, on this basis, I would suggest that you have a valid claim for a replacement Kent cam as the gear on your removed unit has been machined with too small a tooth pitch diameter.

 

As for the type of cam you state that yours has an inlet/exhaust setting of 0.016 to 0.018 in. According to my Kent booklet that is the setting for the high torque version. The fast road setting is 0.022 to 0.024 in. It does not really matter which type you have because the are both good profiles but I chose the high torque version as power is achieved lower down the rev range. Previous experience of cams with power at high revs resulted in a broken crank, but I suspect there may have been some abuse along the way.

 

In the past my car has also suffered worn cam lobes and followers and it is difficult to say which failed first. In order to reduce the possibility of further failures I now look to the cam manufacturers to supply both the cams and the followers under the assumption that they know best how to make them. Kent do not do followers for 4 cylinder TR engines but Newman and Piper do. I chose Piper but Newman's induction hardened ones should be just as good.

 

You did not state what type of valve springs your engine has but I would avoid competition ones as they are stronger than standard and put the lobes and followers under greater stress.

 

Finally you may care to note that a friend with a TVR recently paid good money to have his V6 Ford engine overhauled but the cam/followers failed at less than 1000 miles, so it does not just happen to TRs.

 

Good luck with getting your motor fixed.

 

Tim

[iain]

The cam is fine.

The followers are not.

 

Some have picked up and stuck. Apparently these phophated jobbies need thorough cleaning, even with 1200 W and D. Then cleaning with paraffin,then test fitting to check rotation and clearance, then final install with cam lube.

The phosphating salts are still on the surface ready to undo all your good work.

 

So guess who didn't known about step 1 and 2.......Would be nice to have this info with the bits.

 

A more informed Iain

[iain]

Tim

 

Thanks for the info. The springs are standard.

 

The gear backlash still annoys me I will speak to Kent directly.

 

Cheers

 

Iain

Edited January 19, 2017 by iain

[Peter Cobbold]

The cam is fine.

The followers are not.

 

Some have picked up and stuck. Apparently these phophated jobbies need thorough cleaning, even with 1200 W and D. Then cleaning with paraffin,then test fitting to check rotation and clearance, then final install with cam lube.

The phosphating salts are still on the surface ready to undo all your good work.

 

So guess who didn't known about step 1 and 2.......Would be nice to have this info with the bits.

 

A more informed Iain

Well that's news to me. Guess that's one way of selling more....

Supplier was Kent, right?

Hardly 'fit for purpose' - more unfinished.

Peter

[Guest ntc]

Well that's news to me. Guess that's one way of selling more....

Supplier was Kent, right?

Hardly 'fit for purpose' - more unfinished.

Peter

+1

Fob off

[iain]

No Kent do not make cam followers for our 4 pot engine. These are the commonly available uprated side drilled hardened/phosphated followers from most purveyors of Qestionable Quality parts for our cars. They come in a box branded County.

 

I was waiting for the " there is a funny aroma around here".....comments

 

Iain

Edited January 20, 2017 by iain

[Stanpartmanpartwolf]

I'd like to add just a few thoughts on the perennial cam/follower failure issue, if I may?

These, although based on thirty-six years experience of TR engines, are of course only my observations.

1. It is extremely rare to find any problems with camshafts.

I've encountered some, though:

Rear journal oil relief hole absent, leading to expulsion of the rear core plug- very messy indeed!

Kent, for around 18 months once, were hobbing the skew gears on their new chillcast blanks at the wrong angle, causing some awful total failures, and ruining plenty of PI & carb oil pump drive gears. Despite much protestation, this took far too long to acknowledge & correct.

4-cylinder shafts ground with lobe peaks taller than the rear journals!

Slightly offset front boltholes, annoying, but rectifiable by judicious filing of the chainwheel.

I have never encountered any production problems that would cause lobe failure per se & can say with confidence that camshaft wear is virtually certain to be caused by other factors.

2. Followers:

4-cyl first- quality over the last thirty years has been variable & that's being kind.

County, unbelievably, were actually selling cheap steel examples in the late 80s-early 90s, to go with the reprofiled OEM cams that were all we had then. These would reduce a performance cam to a stick in twenty minutes!

Then came NOS Hillman Avenger- chillcast, phosphated & fine quality, but we had to alter the pushrod tips' radius to suit.

AFAIK, the Rootes tooling then went to Iran & production has continued to this day, with the correct TR pushrod radius ground in after.

However, further to foregoing remarks, I've encountered serious quality problems with these in the last four years, particularly in the face finish & no longer use them, sadly.

 

Never use TT shortened examples with high-lift cams. Tuftriding IMHO is not the best surface treatment here either.

Luckily, with the emergence of decent chillcast cam blanks, it's now possible to run steel followers reliably.

Newman's are excellent, but excessively heavy; they are the go-to nonetheless.

 

6-cyl: OEM were made by Clancy & first-class they were. I was lucky enough twenty years ago to buy a large batch of NOS from them which they kindly then nitrided. Hundreds sold & never a problem. I believe Bastuck bought the remainder & that was that.

 

So, back to County & TT; neither very nice, but acceptable for low load situations.

I have always fitted oversize chillcast followers to my racing engines & even at .350" cam, (not valve), lift have not lost a cam even with 1.65 ratio roller rockers.

 

There are now Bastuck phosphated examples available that are well-made & reliable, plus steel ones also from Newman's.

I'd not use a steel follower with an OEM hardenable iron camshaft.

 

Most importantly, after buying the best parts you can afford, be absolutely diligent in measuring total valve lift, crush & fitted length of springs, static & over-the-nose pressures & so on.

Use Smith Bros tubular pushrods in 6-pots, & OEM or SB in 4-pots.

Excessive spring loads (TT 1207 in particular, as an example), spell death to TR cam trains.

And you waste a heap of torque compressing springs for no purpose, which in turn generates heat & will lead to spring failures in engines with vestigial top-end oil supply.

 

That brings me to valve stem seals & rocker oil feeds- another topic entirely.

All the foregoing info regarding lubrication I'd agree with; but remember how poorly the cam lobes & followers are lubricated.

Then consider how to size your crank journals....

That's more than enough waffle for now.

Pip Pip

SPMPW

Edited January 21, 2017 by Stanpartmanpartwolf

[iain]

Well it's been a while but it's all back together and has had two 20 minute running periods at 2250 rpm and then today I ran it for about 20 miles.

 

So far so good. Oil pressure normal, water temp normal ,tappet noise normal....Fingers crossed that's the end of it.

 

Iain

 

PS Kent call this Cam High Torque.....Revingtons call it Fast Road. What's in a name?:-)

Otherwise identical.

[RogerH]

Hi Iain,

so you have a four cylinder that was creating a lot of noise.

What did you change? Cam, followers........

 

I have a single tap at the front of my 4A engine.

I'm pretty close to taking the head off and possibly removing the cam and putting the previous one (good condition) back in.

 

Should I take the sump off and remove pistons #1 and #2.?

 

Roger

[iain]

Hi Roger......A thorough strip down revealed the cam followers were fooked!As per images earlier in the thread.cam was fine. Replaced with new followers fetlled to perfection so they rotate and drop freely with oil. Then re installed with cam lube etc etc.

 

My guess is you have a sticking follower as well. Did you go through the performance outlined in my update in post 167?

 

The followers had galled due to being phophated and not thoroughly cleaned off I guess. Apparently phophating is known to cause this problem.......... Wasn't by me but is now!

 

Iain