How much damage is due to poor servicing?

[TT Tim]

This is an interesting one.

Not, as you would expect by the title, that damage is caused by lack of servicing, but rather the amount of damage caused by poor quality servicing.

I ask this as I've started to strip down a pair of heads to refresh/rebuild, and one of the first things that I came across was the damage to the cam-caps. As you can see from the photo there are no bearings in the cam carriers rather the cams run in the alloy. Cams are obviously removed each time the car has its valve clearanced adjusted and the damage that you can see is possibly caused by dirt/grit being present on the journal when the cam was replaced. This, IMHO, is avoidable and maybe due to shoddy workmanship and lack of cleanliness when replacing the caps.

So, at the end of the day a service history may mean nothing if the people carrying out the servicing aren't careful when they carry out the work.



Tim

Edited by TT Tim on Wednesday 10th January 22:24

[mark r skinner]

indeed. I`ll post some pics of my old cams when I get the car back. Looks like it`ll be next week.
Do you know all of you car`s history?

[ridds]

Or low oil pressure, cylinder heads are the last to see the oil and if you're running low pressure and driving hard (possibly creating aeration) then you have a home made reciepe for that effect.

[TT Tim]

These are from a pair of s/h heads. Not sure what state mine will be in when I strip those.

I know that my car went through a period of neglect prior to my ownership.

I'm still sorting problems caused by it.

This damage, I'm sure is due to the caps being replaced when the journal was dirty.

Tim

[mxi933]

You know I've heard some horror stories on this forum about the unreliability of Cerbs. Didnt care. I bought one. I've had it a week and I knew instantly that it was the right thing to do. But get this for a motoring horror story.
My Girlfriend bought a 325 convertible 3 months ago from a dealer in Bradford (Mistake #1)
She ran it for a 3 days and the head gasket went south. Not only that but when they took the head off they found a whole load of S**t and recommended she have the whole head replaced (Its a good garage - very trustworthy) Got it back cost £1300.
She drove it for 2 days and the crank went. The garage recommended a second hand engine. She had to wait whilst they found one. Put it in - cost £930. Picked it up from the garage and noticed oil coming out of the gearbox. In it went again. This time a replacement torque converter and a new seal. They were taking pity on her cause they only charged her £117 and it was ready today.
Get this - I picked it up at 2pm today and it lost drive completely at 2.30pm.

Now thats unreliable. (I dont really care cos its her car and I have my Cerb)

[mars]

Hi. I've only had mine for (less than) a week too. It's like Christmas and a honeymoon in one.

Edited by mars on Wednesday 10th January 16:19

[GreenV8S]

TT Tim said:

Cams are obviously removed each time the car has its valve clearanced adjusted and the damage that you can see is caused purely due to dirt/grit being present on the journal when the cam was replaced.

And you know this how?

[mark r skinner]

GreenV8S said:

TT Tim said:

Cams are obviously removed each time the car has its valve clearanced adjusted and the damage that you can see is caused purely due to dirt/grit being present on the journal when the cam was replaced.

And you know this how?

What about over-revving a cold engine?

[TT Tim]

GreenV8S said:

TT Tim said:

Cams are obviously removed each time the car has its valve clearanced adjusted and the damage that you can see is caused purely due to dirt/grit being present on the journal when the cam was replaced.

And you know this how?

Ouch! That was aggressive without being constructive.

I was only hi-lighting this as a potential problem for fellow owners, maybe making sure that should they decide to set the clearances themselves then they need to be meticulously clean to avoid any potential problems. I haven't accused anyone in particular of causing this damage, I do not know the history of these heads.

Okay my reasoning for my assumptions: Looking at the damage it appears that there are concentric grooves evident on both cap and journal, similar to damage that I have seen once before on an engine that I've stripped. The centre journal also appears to have sustained similar damage. There is an oil feed to No.1 journal but not to the No,3.

I would welcome other suggestions as to why/how this damage occured, I am in no way an expert in engine building, but I have built a few, from numerous old Triumph 4 pots to RV8s and motorcycle 4-strokes.

This post wasn't meant as an argument - I leave that to Ash

Tim

[TooTall Paul]

The cap looks like it's been starved of oil, not dirt!

[ridds]

It would be a very shoddy garage that replaced a cam cap without at least wiping it before replacement. Quite unlikely in my eyes.

[byker28i]

Wrong grade of oil or more likely not changing the oil regularly? At £50 for a gallon maybe the old owner was cutting costs?

What's the filter like to change. If it's awkward this sometimes gets left on.

[byker28i]

Oh and if you want unreliable, how about I had a new engine in my 5 month old Primera under warrenty as it was using all it's oil in 600 miles. But I had to fight the dealer to get it done under warrenty...

[TT Tim]

I stand corrected, I still suspect some 'muck' was involved but hey, ho, maybe it was a contributing factor.

I guess we should change this topic to 'Look what happens if you rev a cold engine or skimp on oil changes'. It's still a warning to look after your pride and joy.

As for shoddy garages, there are plenty out there and some of the big ones have some pretty dreadful service levels sometimes, I should know I was nearly caught out by one! So, anything's possable and plausable.

Tim

[jensena]

Service History is important, but what is more important is WHO serviced it. What you want is someone who knows Cerbs inside out, its perfectly possible for someone to take their Cerb to some local Garage, who will change the Oil and Filter, check and replace break pads, top up the Gearbox, and hey presto, the book is stamped - Full service History! You want someone who knows what to look for on a Cerb, and knows how to do th job properly.
Mine is serviced by Steve Howard at Euphoria, I know he does a good job, and I'm happy, and in all fairness pleny of people on here are also happy with the likes of APM, Austec, etc etc, they are the ones to use.
Also too put our 'Expensive to maintain' Cerbs into context, a mate at work has just had his 3 yr old Ford Ka serviced, and been told it needs needs a new steering rack, and hes been quoted £450 to replace it!!

[GreenV8S]

TT Tim said:

Ouch! That was aggressive without being constructive.

You seemed to have made quite a big assumption, without even acknowledging that it was an assumption. Personally, I think it's fairly unlikely that this damage was caused by dirty assembly, and I think i would be quite hard to prove this had happened even if it had - it's certainly far from clear that this was the cause in this case. More likely potential explanations IMO are that the bearing has started to pick up, or had swarf carried into it from damage elsewhere in the engine. I don't think it would be possible to tell the real cause with any confidence just from that picture, and certainly not clearly enough to start blaming previous fitters of the sort of gross incompetance that would be required to assemble it with grit in. If you think I was being aggressive then I apologise, I was just trying to question what seemed (and still seems) to be a false assumption being presented as established fact.

[TT Tim]

GreenV8S said:

TT Tim said:

Ouch! That was aggressive without being constructive.

You seemed to have made quite a big assumption, without even acknowledging that it was an assumption. Personally, I think it's fairly unlikely that this damage was caused by dirty assembly, and I think i would be quite hard to prove this had happened even if it had - it's certainly far from clear that this was the cause in this case. More likely potential explanations IMO are that the bearing has started to pick up, or had swarf carried into it from damage elsewhere in the engine. I don't think it would be possible to tell the real cause with any confidence just from that picture, and certainly not clearly enough to start blaming previous fitters of the sort of gross incompetance that would be required to assemble it with grit in. If you think I was being aggressive then I apologise, I was just trying to question what seemed (and still seems) to be a false assumption being presented as established fact.

Thanks Peter,

I fully understand that you have a huge knowledge of TVRs and building 'interesting' cars. I bow to that superior experience.

You post could have been more constructive in your initial reply. Maybe you could have said that it may have been caused by other problems, etc. etc. But, can you say without doubt that this damage was NOT caused by dirty assembly? No, I think not.

I have said that I was maybe wrong and jumped to the incorrect conclusion.

Your comments would have been welcomed.

As for gross incompetance, I nearly had a diff wrecked by the neglegence of a garage to fit all the bolts into the casing, so these things DO happen. I was only hilighting a possible cause of damage.

Shall we let it rest there? This thread wasn't meant as a witch-hunt it was a 'what if'. Really wish I hadn't started it now!

Tim


PS, have edited my initial post to the following, so I hope it's now better.

'Cams are obviously removed each time the car has its valve clearanced adjusted and the damage that you can see is possibly caused by dirt/grit being present on the journal when the cam was replaced. This, IMHO, is avoidable and maybe due to shoddy workmanship and lack of cleanliness when replacing the caps.'

Edited by TT Tim on Wednesday 10th January 22:24

[byker28i]

Back to topic, it's interesting that the cams run in the cam followers without bearings. My old Honda superdream ran like this (probably cost reasons) but none of my more modern bikes do and i have to reshim them at service time.

Is there a reason it's been done this way. Cost, or just not required as it should run on a coat of oil.
Either way it's just another reason for regular oil and filter changes (oh and quality oil).

[mxi933]

byker28i said:

Back to topic, it's interesting that the cams run in the cam followers without bearings. My old Honda superdream ran like this (probably cost reasons) but none of my more modern bikes do and i have to reshim them at service time.

Is there a reason it's been done this way. Cost, or just not required as it should run on a coat of oil.
Either way it's just another reason for regular oil and filter changes (oh and quality oil).

I'm learning so much about these cars. Now I understand why its important to take it easy on start up until the oils had a chance to get circulating

[simonsparrow]

mxi933 said:

byker28i said:

Back to topic, it's interesting that the cams run in the cam followers without bearings. My old Honda superdream ran like this (probably cost reasons) but none of my more modern bikes do and i have to reshim them at service time.

Is there a reason it's been done this way. Cost, or just not required as it should run on a coat of oil.
Either way it's just another reason for regular oil and filter changes (oh and quality oil).

I'm learning so much about these cars. Now I understand why its important to take it easy on start up until the oils had a chance to get circulating

Been a a while since I last had a bike, but I recall at the time that they all ran the cams in the alloy of the heads with no seperate bearings. But we're talking old iron like GPz1100, XS1100s etc.

Do modern bikes have bearing shells or something these days? Always used to worry me, as the alloy bearing surface is easy to damage (as Tim's photo shows) and difficult to repair.