lotus timing belt issue

[lostu]

hi was wondering about the grey area that surrounds the timing belt some say 2 years or 24k miles as this is the same data given 30 years ago.surely lotus supplied belts have moved in time with modern technolegy yes 25-30 years ago and we have still got our lotuses,but all the new belts surley must have a better life and exchange time. due to the long winters the uk had and maybe the belts sitting on a store shelf a couple of months,then another few months possibly before fitted.my lotus belt is just over 2 years and only done 500 miles with low revs and load.why has the esprit belt got to be changed at such short intervals.my tension feels ok and all the writing in white and yellow can still be seen,the belt is dry,please help me to understand this,i can understand if the car is being driven on the limits etc anyway all advice i will take on board thanks

[andydclements]

I think that while other car manufacturers new spec belts are made with different compounds, the current belts by Lotus aren't that different to when originally specified, but we really need Ralph on that since so much of his job involves drive belt specs.

[lostu]

ok andy, thanks for that i feel someone with the expert knowledge and related experience,ye 24k is alot of miles on this type of car but its this 2 year time span,what if the new belt is fitted after 1 year it was bought so 12 months later it has too be changed again ?

[andydclements]

Apparently there is a shelf-life built in, the reason being 2 years of use is (supposed to be) lots of hot-cold cycling whereas sitting in a box on a shelf is fairly constant temperature, so it's a year or two on the shelf plus a couple on the car.

OK, that's the theory and the good practice.

My Turbo esprit (later round tooth belt) had a "new" belt fitted and I then ran it for 3 years (and boy did that engine get hot a few times) with no real concerns.

I've just replaced the belt on an Excel (again round tooth) that has been standing for 5 years, the only issue was the sprockets had started to rust and the belt had formed to the shape of the crank sprocket.

I'm happier running a round tooth one longer than specified because they wear less but the older square tooth ones wear the teeth away and I've seen the result (not so much the head damage as we all know what that can look like) the lack of teeth, not by being ripped off, but by being warn away until they are just flaps of rubber.

If the belt is a in good condition all round it;s length with no tooth wear, no cracking, no chafing then I'd personally not worry, but then if my engine was to detonate I'd be doing the rebuild myself using parts I probably have stored in the shed. If you'd need to employ an engine builder an get new parts, then I'd be a bit more cautious for the sake of a few £s Vs several hundred of £s for a rebuild.

Andy

[GavinT]

JAE offer a Gates racing belt, so called 'blue belt', for the later round tooth sprockets. I think these are good for 100,000 miles?.send Jeff at JAE an email and he will give you the full spec.

www.jaeparts.com

As Andy says...I understand that the reason for the service interval was related to the heat cycles. I also know that a belt on an engine that has been left for extended periods of time without use can be just as much a liability. I just replaced mine after 2 years and about 2000 miles of use.

I'd rather be safe than sorry.

[Sir Paolo]

I recall that Lotus ran a belt for 100,000 miles (don't know if it was round or square tooth, but probably sq.), and apart from tension checks it was ok.

So given your situation 24k should be ok, as long as tension is retained, and you carry out a good visual check (as far as is practicable in as Esprit!) at regular intervals.

[lotusesprits2]

This subject is certainly one of the most frustrating elements of Esprit ownership (and there are many!).

There’s no doubt that it’s normally the 24 months that catches most of us out – not the mileage. Most of us struggle to hit a quarter of the ‘maximum’ mileage, and 24 months comes round ever so quickly.

I’ve run a belt with less than 2000 miles on it after almost 4 years without an issue BUT I did this with my eyes wide open and with a full appreciation of the risks. I would NOT recommend anyone to do the same.

When the car is lying idle, I always rotate the crank (and belt!) manually, as standing still is also an issue as already pointed out.

The most infuriating thing for me is that the job itself isn’t difficult (if it was right in front of you) but I simply can’t get my hands or head around it in its very cramped location. As such, the challenge for me is finding a garage I trust and not leaving it too long so that I don’t incur the transport costs to and fro.

My belt has been on since 2007, and the car has been off the road since then. My next belt change will involve a trailer or similar – clearly I don’t practice what I preach.

If you are thinking of 'leaving it' beyond the recommended intervals - don’t chance it!

Will.

[GavinT]

Although it may appear a bit of a task to change a belt on any Esprit, it's really not that bad on an S1/S2. I did mine in about 4 hours working slowly and very methodically. It was in-fact my first ever solo timing belt change. I found that the process, once I got stuck in, was far easier than I had thought. If you are confident in your abilities than I would try to change it yourself. If your a touch unsure pay someone to do it for you but assist in the operation so next time you know what to do. This is what I did. Tony K's a pretty good teacher

[lotusesprits2]

I like your approach Gavin. It never entered my head that I could watch the experts in action!

As I say, if I had it in front of me I'd do it without a moments hesitation. I guess it's the confidence - especially around the tensioner. Having said that, I suppose once the alternator's out of the way it's much easier to fumble and dare I say it 'see.'

One day......

I think I'll opt for the professional approach when it's due, which by my reckoning, and reviewing the list of outstanding jobs, will be 2021....

Still, I will ask if I can watch said operation.

Thanks,

Will

[GSimpson]

Changing the belt is a good opportunity to check things out like the alternator, cooling hoses and of course the tensioner. I get a belt from the local Nissan dealer. (same as Maxima)

[lostu]

ok has anyone at the moment driving around with a high milage belt or over 5 years or more on the same belt ,what does it look like condition wise as this data has being going on for 30 years . is the modern belt of today not alot tougher and of better manufacture materials than when this was a topic say 20 to 30 years ago surely thanks.

[GavinT]

From Tim Engel on the subject of belts and change intervals:-

One of the 907's timing belt issues is that the belt has minimal wrap on

each of the pulleys. The intake pulley, for instance, only has about 87

degrees of wrap. Less wrap means fewer teeth are engaged and sharing the

load, so each tooth is working harder. I wouldn't look to the Nissan

engine as an indicator of how far the 907's belt will go, or of what the

repair costs might be if it fails. The cost-reward ratios are completely

different for the 907 and VG30E engines.

Most Lotus don't get driven enough to reach the mileage limit before the

time limit. If 907 owners waited for the mileage limit to come up, there

would be some seriously old belts in service. It may have made more sense

for Nissan to use only a milage limit and not mention age, since most

Nissans get driven as every day cars and pile on the miles in short order.

Yes, the newer belts are supposed to age better. "IF" I were going to

stretch the service interval, I'd go longer on time (pure age related) and

keep the mileage limit the same (mechanical wear related).

Anyone wishing to go longer needs to make the "how long" call themselves.

Lotus won't make that retro call for the old cars. JAE and the other Lotus

parts vendors won't make that call. I've talked to Gates rubber and they

won't make that call. I'm not going there with my own engines, so no one

should be expecting me to take the burden off of them. Anyone wanting to

go there just needs to make the leap and report back how it went for them.

I care more about my cars than I do the cost of belts.

CA 100K emissions laws never applied to the trapezoidal belt, nor to the

HCR HTD belt, so it's an acedemic question. It was the pending

implementation of those durability laws that prompted the 2nd generation HSN

belts. But even then, Lotus and many manufacturers were not comfortable

enough with the new HSN belt's better performance to apply the 100k standard

outside of that one state... either in the US or around the world. They

had the choice of warranting the belts for 100k in CA, or not selling cars

in CA, so they warranted the belts under duress.

I have no idea what the track record was for belt failures in CA verses the

rest of the world. But the key point was that the auto manufacturers paid

for them up to 100k miles, not the owners. If I were an owner in

California after the 100k warranty expired, there's no way I would continue

on the 100k schedule with my wallet on the line.

Do you drive without insurance? Or with only liability insurance? It

would certainly be less expensive to do so... up to the point of the first

accident. The HCR trapezoidal belt is like liability insurance only...

the minimum. An HSN belt is more like liability + comprehensive. The

HNBR belt, if it comes, will be like full coverage plus increased medical

liability, no deductable glass, towing, rental car expense. And then

there are the uninsured drivers still running the 10 year old belt that was

in the car when they bought it.

Would I buy the $165 HNBR belt? Another acedemic question since it's not

happening (the coming upgrade belt is HSN for significantly less cost).

The short answer is yes.... just deleted a long paragraph of suppporting

opinion.

For the more realistic HSN belt that will be available soon, the cost is

not a lot more than standard and I'd stick with the 24k/ 24mo interval.

The incremental cost over the cost of the base belt, spread out over the 24

mo interval is only going to be a buck or so per month. Most of us spend

more on soft drinks per day.

The cost of the belt itself is a minor part of the total cost of replacement

if you pay someone else to do the work. Shop labor and profit margin are

the big killers. If someone is struggling with that expense, then the

belt is not the problem, the hired shop is. If the only reason someone

can see for a better belt it so extend the service interval and spread the

fixed cost over a greater time period, and if no one else is stepping up to

extend the service interval for them, then I can understand that they might

be disappointed with the new belt. But their expectations are really not

the belt's fault. The upgrade belt takes better care of the engine

(insurance policy) for the period that it's on the engine. How long it's

on the engine will have to be the owner's call.

Regards,

Tim Engel

I installed an HSN belt from JAE this last summer. Cost for the belt was about $65 IIRC. I'm sure JAE will post overseas and I think TLF gets a small discount.

www.jaeparts.com

Edited December 22, 2011 by GavinT

[molemot]

Despite trying to stick to the 2 year replacement interval, there was a period of more than five years when I ran the same belt. Not much mileage, but far longer than the recommended change time interval. I still have this belt...and it exhibits cracking along the root of some of the teeth...it's of the trapezoidal variety. I have also had a belt snap on the engine...this was a week or so after I had bought the car. It came with a "full service history" from Bell and Colville...the last service should have included a new timing belt. After it had snapped, I replaced it carefully, avoiding any possible further damage...and the engine had survived OK. The tensioner bearing was completely shot, so the belt was probably the original from when the engine was built! The belt that snapped appears perfect, no cracks or damage to be seen...except where it had parted, right across the width of the belt...with nothing to suggest imminent failure. So I think that inspecting the belt, however carefully, can't be relied on to indicate whether it can be safely left and not changed.

[Sparky]

I agree with John - no amount of visual inspection will give you a clue as to belt longevity. The belts are a lot tougher than most will give them credit for, but it ain't a bad job, so why take the risk?

[lostu]

thanks for all the info. my belt is now 2 years old and only 500 miles but i`ll get it changed in the new year merry christmas & a happy new year too all.

[rogerch]

I'm with Sparky, cost of belt-vs-cost of engine re-build, where's the problem ?

[Sir Paolo]

From Tim Engel on the subject of belts and change intervals:-

One of the 907's timing belt issues is that the belt has minimal wrap on

each of the pulleys. The intake pulley, for instance, only has about 87

degrees of wrap. Less wrap means fewer teeth are engaged and sharing the

load, so each tooth is working harder..................

Regards,

Tim Engel

This raises an interesting point - the similarly conceived Chevette HS/HSR engine has an idler pulley between the aux drive and inlet pulleys, for far greater belt/pulley contact.

Pity Lotus didn't adopt a similar design (upright dizzy drive notwithstanding).

[juki75]

Hi!

It's been 6 and half years (21000km) since my timing belt has been changed.

I'm going to change it before summer.

Jukka

[Roger 912]

The Nissan Maxima belt (Gates) on my red Esprit Turbo is now 5 years old and the car has done 13 000 kilometres with the new belt. I check the belt teeth and tension regularly. My main reason for not changing it is that there is not a garage that I would trust to do the job locally. The only one that I would trust is in Cape Town, 600 odd kilometres away. I shall have to take a trip down this year though to get it done.

[s2mikey]

Interesting this thread came up. I just talked to Jeff at JAE about this very topic. My '87 has the Gates blu racing belt which was specifically designed for hotter temps and sportscars. The full major was done on my car in the Spring of 2009. Well, since that time, the car has had about 15K miles or so and will get another 5K this driving season which means the belt will have about 20K since replacement by next spring and roughly 4 years. I feel at that time that we'll do the major again and the belt will get replaced. Jeff agrees that doing the Gates blu belt every two years is way early and gains nothing. He sells belts too so there is no reason for him to fib. So, Im sticking with the 3.5 to 4 year plan and every 20K miles. My car gets used regularly and only sits for about 3-4 months during the winter. Shes a driver!

As for two years....thats very frequent for such a thing. People say its easy - but its not really easy since you'd be foolish to just do the belt. Might as well replace this and this and that, etc, etc. Then, you end up with apile of perfectly good parts in your garage that are now useless. I dunno.

Edited March 7, 2012 by s2mikey

[Mesprit87]

I agree with you Mike, even in the light of the other thread about the snapped belt, I think experience and common sense should prevail.

I also disagree with people saying it's an easy job, nothing really complicated about it but messing anti-freeze and dismantling everything to access it cuts on the pleasure. Add to that the chance of damaging something and four years sound good.

The only regret I have is not installing a blue one but then again, that won't keep me up at night, the one I removed was 22 years old... Now that's scary!

Luc

[s2mikey]

I agree with you Mike, even in the light of the other thread about the snapped belt, I think experience and common sense should prevail.

I also disagree with people saying it's an easy job, nothing really complicated about it but messing anti-freeze and dismantling everything to access it cuts on the pleasure. Add to that the chance of damaging something and four years sound good.

The only regret I have is not installing a blue one but then again, that won't keep me up at night, the one I removed was 22 years old... Now that's scary!

Luc

Yep - its not easy at all. Not much room to work in there and then of course the old "while you are in there" starts to take place. Then, you've just replaced 15 parts that are 100% fine and pissed away two weekends worth of driving time. Not doing it.

The blue belt is the way to go, just do it next time.

[Mesprit87]

I will!

Good for me, I have winters so the time is well spend.

I think the part I enjoyed the most is getting the tension just right...in the boot, underneat you go, turn...hope...in the boot...underneat you go...

[lotusesprits2]

Although it may appear a bit of a task to change a belt on any Esprit, it's really not that bad on an S1/S2. I did mine in about 4 hours working slowly and very methodically. It was in-fact my first ever solo timing belt change. I found that the process, once I got stuck in, was far easier than I had thought. If you are confident in your abilities than I would try to change it yourself. If your a touch unsure pay someone to do it for you but assist in the operation so next time you know what to do. This is what I did. Tony K's a pretty good teacher

Good man Gavin - spurred on by your comments, I have now chnaged the belt (successfully) - as suggested, working slowly and methodically. Checked tension with a borrowed gauge and what a sense of satisfaction!

Will.

[GavinT]

Outstanding Will, good for you and well done. Us S1/S2 owners may suffer from a slightly less refined Esprit than the later ones but when it comes to DIY we do benefit from car with much simpler mechanics and a slightly more spacious engine compartment.

Edited June 17, 2012 by GavinT