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Techspy

Crap.. Lost timing belt today while running... Now what?

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The frustration never ends.....

 

Pulled the gas tanks today. I can't imagine trying to do that with the engine in... What a pain in the farking azz.

 

One had moderate rust on it but doesn't seem deep enough to need fixing. I will of course sand out the rust, double check, spray with rust inhibitor and repaint it. The other one (passenger side US) had no rust at all. I will scope both of them once the gas fumes dissipate.


John
94 S4

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haha yes when I saw earlier you said you were going to I didnt like to mention its not the easiest job to do! I dont know why they should be made so hard to remove and replace! Thats Lotus design for you!

 

Buddsy  :D


 

"Belief is the enemy of knowing" - Crrow777

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How may of us drive cars, other than the Lotus, which have timing belts and the engine was designed in/ before the early 70s?

I suspect none of us.

 

The 4 cylinder engines were designed with the square tooth belt, and then after a decade or so, amended to the HTD type, so they were improved, considering the cars were stopped being produced in 1999, they've been legacy models for nearly 1 1/2 decades now, and most manufacturers do not re-design parts for legacy models. Lotus have done work on the dampers, but only because the original parts had ceased being available.

Chain drive is not without issues, in fact if you go back to 1970s engines with OHC and chain drive, you get quite a few issues with tensioners, chains stretching etc, so these belts aren't bad.

There are upgrades that could be done, Ralph on here has trialled an improved belt which uses modern belt technology (materials, coatings, construction techniques etc) to fit the old design. The challenge always comes that any re-designed belt needs to have a certain amount of tooling-up costs covered, so a minimum production run / minimum profit built in, and doing this as an after-market action is difficult, especially when so many of us are doing one of the following:

  • Using Lotus genuine belts, will not trust anything else.
  • Using gates belts which are very similar, on the basis they're probably as good and any reduced life because of the width is negated as long as you change it frequently.
  • Using any belt that can be sourced, cost / availability is the driver.

 

Given the three above, is there really a market for a non-genuine improved belt, one that would require considerable start-up costs? Then what happens the first time one fails, say a piece of stone gets in there and snaps it, I suspect there'd be a civil claim for thousands of £s for a replacement engine, or a lot of bitching and advice to never use one because......

 

 

 

 

If we were driving cars that had engines still in production, there's a chance the belts might be officially re-designed by Lotus, but only if engine failures in the USA meant that it was financially better to re-design rather than replace failed engines (100,000 mile minimum life for belt).

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I would think the cost of testing a new belt would be greater than the tooling cost. I mean you would need maybe 10 engines? And tests including destructive tests. And run them for I dont know how many miles in the lab in environmental chambers of differing condition and then in the real world. I just dont see for the 10,000 (?) 9** series engines still in use that it would be anywhere near cost effective?

 

Ive been doing work for a local company who makes a type of switch for the automotive sector and the level of testing is incredible. I just dont believe parts were tested like this in previous decades. Shock testing where the units are raised to 140 deg C then thermally shocked down to minus 20 deg C before being raised again to 140 deg C. Over and over again. Its a killer on all kinds of bonding agents but this is why cars are more reliable.

 

Buddsy


 

"Belief is the enemy of knowing" - Crrow777

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I second what Buddsy said - I work as a testing/development engineer at Scania's R&D HQ and the amount of testing on modern vehicles is unprecedented - to the point that it would appear overkill. I don't think that Lotus ever have had or will have the resources for testing on the scale of other industrial behemoths (which incidentally is why small-scale manufacturers often take so much flak for producing "unreliable" vehicles).

 

On the other hand when original parts need to be remanufactured a large amount of testing will have to be performed regardless as one needs to assess the quality of the subcontractor. It seems to be an industry norm that sending away even simple widgets for manufacture will yield 3 results from an equal number of subcontractors. So basically the vehicle manufacturer has to check that their business partner has done their homework and delivered to spec.


Vanya Stanisavljevic '91 Esprit SE | '91 Elan SE | '97 XK8

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Ok guys, looks like I have some feedback on the damage. All valves in one cylinder, and 4 more spread out. Looks like no damage to the pistons but the nikosil looks to be warn on the tops of all liners. he is still taking measurements etc. I may end up having to change all liners for the new iron ones.

 

Anyway, I have finally gotten the transmission clean. There was 20 years of gunk in all those holes and it was a pain to get clean. Still isn't perfect but as good as it will get.

 

I got in the POR 15 sealer today for the tanks but am wondering if it is necessary. There are bits of rust in the inside but it just looks like freckles in places and doesn't seem to be anything more than flash rust on the surface. I have since found that the interior of my header tanks are pretty bad and am wondering about using the POR15 on that. I am concerned about getting it on the water sensor in the bottom though (doesn't appear they are removable). I cant really see a way to get the corrosion etc out of the header tank. Maybe I can find a small wire brush with a longer shaft to put on my drill.

 

Another pain is how much grease and grime is on the chassis. I have tried engine degreaser, purple stuff, simple green etc and nothing seems to cut through the grease. Anyone have any suggestions?

 

Also, I have always hated the fact that I can't get any descent size speaker in the rear bulkhead and am considering modifying the box while I have access with the gas tanks out. I only want to go up to an 8" (have 6" in it now) and would need to make the box more square as opposed to the angle it is at now. Does anyone know how much space is between the gas tank and the back of the speaker box?


John
94 S4

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At work, we did a project on ways of detecting belt failure before it goes for a client a few years ago. It's hard to do, that much I remember. However, your failure doesn't look at all normal to me. I'm not sure I can say that for sure if the belt has a weird square profile (by modern standards), but it does seem to be due a mechanism which is not conventional or normal. Belts are usually specced for 2-3 times the life that's quoted, largely because of the magnitude of the damage that failure causes. However, it's a bell curve, and personally, I always change belts when I'm at the low end of the curve, and I don't push my luck. Ever. I stick to the recommended change times, even though I'm 99% sure it will be fine for thousands more miles.

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"New Iron Liners"????  where did you hear that from?

 

A little wear at the top of the liners is normal, since the rings stop up there.  I had mine re-plated with new Nikasil... and that was a mistake!  They would have been better of leaving them alone.

 

Mine looked like this after 74k miles (pretty ok wear)

P4161978.JPG

 

After I had them re-plated, one came back pitted.

 

The Nikasil is pretty tough stuff!  If it isn't damaged, then I would leave them alone.

 

Another mistake was to clean the pistons with Simple Green, which stripped the chrome plating off the domes of the pistons.

 

 

The metal dual coolant tank sensors are removable, and you will need new rubber grommets.

 

IMG_2787.jpg

IMG_2789.jpg

IMG_2795.jpg

IMG_2796.jpg


Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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Ah cool, thanks for the info on the header tanks. Did you reuse the same sensors? Did you get direct replacement grommets or find a generic one? How are they held in, just press fit?

 

I was just hypothesizing about the iron liners and expecting the worst. They may be fine. I will know what the consensus is shortly.


John
94 S4

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Where did you get the new grommets?

 

So, the header tanks have been refurbed and painted and the same with the gas tanks. I reinstalled the gas tanks today and they went in a lot easier than they came out thankfully. I finally feel like I am making some forward progress. I have received some of the replacement hoses, all red, but am still waiting on the main hose kit. I also received the silver foil/fiberglass heat shielding that I am going to install on the engine bay sides. I still have to flush the main and chargecooler radiators/lines as well as the oil and PS lines. I finally got the gearbox degreased. It took about 6 different sessions with engine cleaner, simple green etc and a few brushes, I still have to finish degreasing the chassis and engine bay area. There are a few odds and ends I need to order from JAE but I am waiting until my mechanic gives me the first parts list he needs. Also, when I dropped off the engine my he noticed a small crack starting to form on the exhaust manifold. He said it isn't all the way through and may last quite a while as it is. I wouldn't mind replacing it with something better but don't really want to spend that much $ on another stock one. The current one was installed when I first bought the car in 2003 so it has lasted 10 years. Why are these so fragile? This can't be the most demanding conditions asked of an exhaust manifold. Anyone have any suggestions on a good header? I understand the SS ones are a bit of a crapshoot and can crack just as easily (?)

 

I bought my first Lotus, an 87 Esprit Turbo, in 2000 and have owned a Lotus ever since then (with the exception of a year that I was out of the country) and this is the first time I have had my Lotus un-drivable for more than a couple days. The first time it hit me was about a week after I pulled the engine. I had a particularly bad day and it was finally a cool evening. I just wanted to get out and drive but I couldn't. I try to keep from having materialistic things define me and being too much of life but my Esprit feels like such a big part of me. I can handle another month before I get it back together but I just hope there are no major issues getting her running again. I know there will be some little things that will pop up but if there is some inexplicable running issue or God forbid damage from something not done right, I will be seriously bummed. Besides getting her running again, getting my garage and shop cleaned back up will be a major relief.


John
94 S4

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I bought my first Lotus, an 87 Esprit Turbo, in 2000 and have owned a Lotus ever since then (with the exception of a year that I was out of the country) and this is the first time I have had my Lotus un-drivable for more than a couple days. The first time it hit me was about a week after I pulled the engine. I had a particularly bad day and it was finally a cool evening. I just wanted to get out and drive but I couldn't. I try to keep from having materialistic things define me and being too much of life but my Esprit feels like such a big part of me. I can handle another month before I get it back together but I just hope there are no major issues getting her running again. I know there will be some little things that will pop up but if there is some inexplicable running issue or God forbid damage from something not done right, I will be seriously bummed. Besides getting her running again, getting my garage and shop cleaned back up will be a major relief.

 

Just keep your mind on the goal of having a better sorted Esprit and you should be fine! Having said that, I know the feeling - it stings not being able to drive when you really WANT to, especially so when you see others driving around in their enthusiast cars. I also get the part about the Esprit being a part of you - we Esprit owners don't generally settle for other mundane vehicles for this very reason. Other people buy high-end cars simply because "it's what you're supposed to buy to look cool and successful", and in doing so pick predictably (many of the BMW/Audi/Mercedes/Porsche owners I know seem to have this mindset). 

 

And in addition to the above..you know what they say about having your cake and eating it....

 

I say, buy two cakes. I'm gonna look into getting an S4 or an Elise this Xmas to drive while I restore my SE. :D Because chances are I'll need to do what you're doing sooner rather than later.


Vanya Stanisavljevic '91 Esprit SE | '91 Elan SE | '97 XK8

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I was actually considering buying another fun car to have in the mean time but reality set in :)

 

Hey guys, is upgrading to the S4s intake valves worth it?

 

Also, I was looking into the green dot cam sprockets but was told swapping the intake sprocket with the oil pump/charge cooler pump sprocket and changing out the exhaust sprocket with a 104 MOP cam sprocket does the same thing. Anyone have any experience with that?

 

Thanks
 


John
94 S4

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yes you can move your oil pump pulley green dot to the intake cam (looking at the front of the engine you want the "IN" on the intake  tower, with the "IN" near the green dot.  It is possible to flip the cams 180 and have the EX on the front of the engine on the intake cam, and that would be bad.

 

NOTE:  From the rear of the engine, the intake cam will have "EX" near the green dot!  that is correct.

 

Front of engine. "IN" near green dot (engine is at 30 before top dead center for belt tensioning via acoustic method here.

IMG_4856.JPG

 

Back of engine.  :NOTE "intake cam has "EX" near green dot, and exhaust cam has "IN" near blue dot.  I will do the green dot cam swap soon...

IMG_4869.JPG

 

 

The pulleys are aluminum, don't pry on them!!!  There is also some silicone sealant inside the end of the cam shaft where the cam bolt goes.  It is a good idea to put some fresh silicone sealant on the bolt when replacing it.


Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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Not sure the larger intake valves are worth it...  Mostly just on the chance that the machine shop will screw them up.  I think you would need to source the correct sintered steel valve seats, and new valves for the shop... or else they will use some Chevy valve seats!


Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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I'm swapping cylinder heads soon, going from SE type head (so same as your S4) to Sport 300 (so same as S4S) but with valves enlarged beyond Sport 300 spec. I think those work out cheaper than going to Sport 300 as they are non-genuine.

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Thanks guys. I have decided to skip the larger valves just to be safe. I am going to do the cam pulleys though. I hear it can make quite a difference with offboost normal driving around. Parts all ordered today. Hopefully it wont be too much longer.

Edited by Techspy

John
94 S4

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Couple more questions;

 

- Whats the best way to flush the coolant system? Should I just wait and after installing the engine just fill it up, run it and then empt it and refill it?

 

- Same question for flushing the oil lines. I think this one would be a bit easier as I can just connect to the oil lines connected to oil filter adapter and flush it.

 

- First startup procedure. Should I just pull the fuel pump fuse and turn it over until I see some oil pressure or is there a better procedure?

 

- Fuel system. Should I use the old filter for awhile, first purging the lines to get any debris out, then replace the filter after a little while?

 

Thanks


John
94 S4

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You can flush with engine out. just remember that there are several hoses for the water to come out.

 

Oil lines are more difficult.

 

If you had small metal bits come off in the engine, then they usually say to replace the oil coolers, since they are nearly impossible to clean, and the metal may come out later and damage the engine.

 

For cleaning the oil coolers, I removed mine, but there is risk there, since you can easily damage them trying to remove them.

 

 

For startup, make sure you have oil in the oil cooler lines if you drain them.  And oil in the cams (remove covers and pour in oil) and the sump.

Definitely crank the engine with spark plugs removed and fuel pump fuse removed.  You probably won't see any real pressure on the gauge.

Then put plugs and fuel fuse back in and start.  The rebuilt engine should have oil or assembly lube with moly to protect the parts for that first start.

 

Just replace the fuel filter now.


Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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John,

 

I would flush the two main supply/return coolant lines now, easy to do with a hose and you can also do the charge cooler lines as well. Make sure you have good flow and don't go crazy with the water pressure so as not to damage the radiators.

 

Also, that heat shielding you spoke of for the engine bay side walls, put some on the firewall as well. It will make a noticeable difference on the heat on your back when driving.

 

Jim

 

 

 

enginebayinsulation.jpg

Edited by lotus4s

1995 S4s

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Re the cooler lines. When I did mine I pushed a electricians cable puller up through the lines and attached a  clean oil soaked rag to the end and pulled them through so they were clean as a whistle as well ( plus new cooler).

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Just catching up on this story, a great read - sounds strangely familiar!

Did you end up do a leak down test when the belt came off? I have a tester, when I rebuilt the top end after a belt off, I did a test so I can keep an eye on the engine. You could do one and check what a great job you've done to make a tight engine :)

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