An expesive day

[not done it yetParticipant @notdoneityet]

I’ve no real experience of high speed chain drives over multiple sprockets. Slow speed systems seem to works OK. Chains just around a couple of sprockets seem to work OK – and at very high engine speeds. I’ve not heard complaints of motorcycle cam drives, particularly.

The Peugeot 2 1/4 DOHC diesel engines utilise a dry toothed cam belt to one cam and the second cam is chain driven from the first. We had a belt failure but the chains do not seem to fail. Go figure.

As I see it, chain drives are noisier than belts, but I expect duplex chains would be too heavy and too expensive for long runs. The A series engines (mini, minor, etc) are often fitted with duplex chains to avoid chain-wear problems.

Simply having a small gauze plate as a coarse filter (before the oil pump) looks, to me, to be a disaster waiting to happen. Historically, that coarse filter was of far greater surface area. I believe there is a high power (audi, bmw, merc?) engine which can suffer from a tiny fine gauze screen embedded deep in the engine! If it is not checked/cleaned on higher mileage engines it can cause expensive repair bills.

Computer designed engines can sometimes get things wrong…

[blowlampParticipant @blowlamp]

The video seems to show a few shortcomings in the design of the engine.

This engine has a very short toothed belt driving the oil pump, driven seemingly at crankshaft speed, which in turn drives the anti-vibration balance shaft. This is done in an oily environment with extremes of hot and cold as well as quite high stress.

Once the teeth start to detach from this short belt, they inevitably find their way to the oil pickup pipe gauze and begin to restrict flow. When enough teeth are lost, all drive to the oil pump and balance shaft is lost and seizure of the engine would likely happen soon after.

Martin.

[Michael HornerParticipant @michaelhorner54327]

Slightly off topic, does any know jf a Fiesta Haynes manual does cover replacing the fibre timing belt?

Or simply says you need £1000 of special tools, take it to a Ford garage!

Wife's Eco Boost is 10 year old next year, working ok but so was Bev's until it wasn't!

Cheers Michael.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by blowlamp on 14/06/2023 23:47:24:

The video seems to show a few shortcomings in the design of the engine.

[…]

.

Quite so, Martin

and that was the point which boggled my mind earlier.

We have something similar to what is widely known in the Aircraft industry as a
“Jesus” [nut/bolt/pin/whatever] … see Wikipedia

[ apologies for any offence caused to devout Christians … I am simply stating a fact ]

If the engine was properly designed and engineered; those belts would be readily accessible for inspection … which is exactly what they are not.

MichaelG.

 

Edited By Michael Gilligan on 15/06/2023 06:00:36

[Mark RandParticipant @markrand96270]

Posted by not done it yet on 14/06/2023 22:38:13:

I’ve no real experience of high speed chain drives over multiple sprockets. Slow speed systems seem to works OK. Chains just around a couple of sprockets seem to work OK – and at very high engine speeds. I’ve not heard complaints of motorcycle cam drives, particularly.

The Honda 400 fours were very early adopters of Hyvo metal cam chains. They had a well deserved reputation for sawing through the cylinder block walls as the tensioners wore out and the chains wore looser . Easy to diagnose due to the noise they made in the process.

A small mech screen pre-filter isn't a bad idea in itself. Having it located in a way that it can't be removed and cleaned simply from the outside is recall/group action territory!

[not done it yetParticipant @notdoneityet]

Posted by Mark Rand on 15/06/2023 06:10:29:

The Honda 400 fours were very early adopters of Hyvo metal cam chains. They had a well deserved reputation for sawing through the cylinder block walls as the tensioners wore out and the chains wore looser . Easy to diagnose due to the noise they made in the process.

A small mech screen pre-filter isn't a bad idea in itself. Having it located in a way that it can't be removed and cleaned simply from the outside is recall/group action territory!

Back in my motorcycling days, I only came across the CB160, CD175, CB72 and CB77 and CB450 with cam chains. I can’t remember any chain problems with those roller chains. I recall that the crank sprocket on the CB450 had fewer teeth (only 17?) than advised in engineering circles. That worked OK for Honda, even though it drove two cams.

There were engines (back in the 1930/40s) that had a cotton-waste filled oil filter that could clog up the large area of the oil pump intake. Mine still has that cotton-waste filter, but clearly not used much these days. Also, I think a contortionist would be able to clean the screen without major engine dismantling (via the crank inspection covers).

[HopperParticipant @hopper]

My 2010 Toyota Corolla 1.8 litre has a cam chain with spring-loaded tensioner. Toyota does not schedule any maintenance on either. They are rated to last the lifetime of the engine — an expected 200,000 miles. Many seem to go longer than that to 250,000 miles. Not many people do more than that in a car before all the plastic and rubber bits fall apart, regardless of how good the engine and gearbox may still be. Which is good because to replace the chain (or fix an oil leak in its cover) you have to pull the engine out. Mucho moneys.

Just about every Japanese motorcycle made since the 1960s has chain driven cams and they seem to run for phenomenal mileages without problems. Only BMW has managed to fit cam chain tensioners that wear or break early — and you have to split the engine crankcases to replace the tensioner blades. Doh!

I think the appeal of wet timing belts includes quieter running to help get past noise laws, and less friction to help get past fuel economy laws. Every little bit counts. Can't see any other reason they would go away from the dead simple external belt method which yes it needed changed every 60,000 miles but in most cases it was not a huge job, albeit a bit awkward between the end of the engine and the wheel well on smaller bodied cars.

But if you Google Ford Ecoboost Timing Belt Problem, the tales of woe are legion. Would make me think twice about keeping it after repair.

[Nick WheelerParticipant @nickwheeler]

Posted by Michael Horner on 15/06/2023 00:25:44:

Slightly off topic, does any know jf a Fiesta Haynes manual does cover replacing the fibre timing belt?

Or simply says you need £1000 of special tools, take it to a Ford garage!

Wife's Eco Boost is 10 year old next year, working ok but so was Bev's until it wasn't!

 

You can buy the timing tools for <£100, but that doesn't include the torque multiplier for the crank bolt. It's a job I really wouldn't want to do without a lift. Ford took over a week to deliver half the ordered(in advance) parts when ours was done last year.

Many mechanics suggest it saves time to remove the engine on Fiestas.

 

A properly designed timing chain isn't noisy until the rest of the engine is so knackered you'd be rebuilding the whole thing. Jag 6s and Rootes 4s are good examples. But they have tensioners; Rover V8s and A&B series don't, and exhibit noise and wear as a result.

 

I'll be getting rid of the Focus at the first opportunity, but my mother(it was her car) and sister have managed to damage every panel lower than the bonnet so the value is badly affected.

 

One thing we haven't mentioned in all the nostalgia is that cams do work harder than they used to, driving more valves, through oil driven VVT mechanisms, often at higher speed into high compression cylinders. And that's without considering the high pressure fuel pump for the direct injection.

Edited By Nick Wheeler on 15/06/2023 08:34:23

[John Doe 2Participant @johndoe2]

Don't worry. All such concerns will be a thing of the past when we are all driving electric cars.

(Runs away……………)

[Robert Atkinson 2Participant @robertatkinson2]

Posted by John Doe 2 on 15/06/2023 11:36:06:

Don't worry. All such concerns will be a thing of the past when we are all driving electric cars.

(Runs away……………)

Funny you should say that…
Earlier this year I paid several hundred pounds to sort out a blocked strainer in the electrical coolant circuit of my Plug-in Hybrid. Caused by gel formation causing blockage. Needed acid flush and a right pain to bleed apparently. No recall and extended warranty company didn't want to know as nothing was broken. Seems I should have waited until it blocked the control valve as they would have covered that…..

Robert.

[Nick WheelerParticipant @nickwheeler]

Hopper, BMW are not alone in failing to produce reliable timing chains. VAG, Jaguar and Nissan are known for similar problems.

Current hydraulic tensioners don't seem to be compatible with modern oil usage, and the plastic guides they tension for the chain to run on are worse. And then there's the curious decision to put the chain on the back of the engine

[bernard towersParticipant @bernardtowers37738]

Problem is with someone else as none of them produce chains, they just give a spec to suppliers

[Andrew EntwistleParticipant @andrewentwistle]

Just had the timing and oil pump wet belts changed on our 9 year old 1.0 Ecoboost C-Max at 60,000 miles. Looks like there was a good chance of it failing before the 10 year / 150,000 mile interval! There are multiple cracks half the belt thickness deep, across the full width. Ours has always been serviced by me with the correct Castrol Magnatec Ford approved oil and I never used any additives or flushes that some say can attack the belts. According to the garage and talking to work colleagues there are many wet belts failing after only five years and as little as 40,000 miles, don't know how many as a percentage though.

[Derek DroverParticipant @derekdrover32802]

There's a guy on Youtube who does "engine teardowns", he's done the 1.0Ltr Ecopoo and it failed due to the wet belt stripping.. he wasnt very complimentary with Ford's design. His videos are very interesting to watch.

[SamsarandaParticipant @samsaranda]

Andrew

One wonders how much of the belt has shed in the way of particles into the oil system as your photos show the belt beginning to deteriorate. Dave W

[lee websterParticipant @leewebster72680]

My 10 year old 54,000 mile citroen c3 has just had a complete clutch kit fitted at a local garage (it included the thrust mechanism, which was totally worn out). Total cost was £540. My 90 year old Austin seven has probably had several new clutches in its 300 to 400,000 mile life. But is still fitted with the same clutch thrust mechanism. Perhaps citroen should buy used A7 parts?

[Andrew EntwistleParticipant @andrewentwistle]

Hi Dave, the sump had to come off for the job anyway so the oil pickup gauze was checked but all found to be spotless. Apparently in worse cases than mine even when the belt debris is picked off the gauze there can be some higher up which causes failure after the belt change.

[Andrew EntwistleParticipant @andrewentwistle]

Lee, the same C-Max clutch slave failed at <40k and I think at 5 years old, costing £500.

[James AlfordParticipant @jamesalford67616]

Posted by lee webster on 03/08/2023 18:11:59:

My 90 year old Austin seven has probably had several new clutches in its 300 to 400,000 mile life. But is still fitted with the same clutch thrust mechanism.

I am currently rebuilding the back axle of my Austin Seven and I am amazed how little wear there is in any of it. The only things that really needed attention were the oil seals; or lack thereof.

James.

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