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Esprit Turbo project car - part3 - the further continuation

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Oil Pump

Well I can confirm the replacement rotor is in fact manufactured incorrectly. I measured the end float with plastiguage, previous readings on here. I have just measured my old rotor on the inside where there is no wear and the new one. Heres the result, in inches - no I'm not American but I find it a lot easier! I concluded from the plastiguage I needed to take of 1.5 Thou from the rotor. I did not adjust these figures they are straight of my digital micrometer.IMG_1296.thumb.JPG.4a43d4fc465ce71fc428a0acab88820a.JPG

 The new rotor is exactly 1.5 thou thicker than the old one! The solution of using two gaskets cannot work as it puts the pump out of spec. With my pedantic engineering hat on I plan tonhave the machine shop adjust the rotor to the correct thickness. Beware of any off the shelf parts for this car. I have found so many issues with them. On another note I have to say Dave Changes has been keeping a close eye on this build, for which I am very grateful. Thank you, very much appreciated.👍

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My mate didn't have a grinder. Oil pump rotor now 0.5023 inches. Done with wet and dry paper 400/800/1200 and a flat surface with a digtal micrometer. I took measurements of all sides constantly to ensure it was brought to spec evenly. It took a couple of hours. Placing pressure only on the centre and rotatary motion. Alll reassembled now and spot on brand new end float and tip clearance specs.

Now packed with graphogen and ready for install! 

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On 09/04/2020 at 12:44, Lotusfab said:

Was the wet bike in the movie? Odd its there otherwise!

yes it was actually the first ever wet bike!

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Amateurs built the Ark

Professionals built the Titanic

"I haven't ridden in cars pulled by cows before" "Bullocks, Mr.Belcher" "No, I haven't, honestly"

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One of the used camshafts I bought is unusable! I believe they can be welded and machined back to spec, but I don't have any experience of this and its bound to be expensive. I measure the diameter of each bearing and cam housing opening. Interestingly I found the bearings are all different diameters reducing from front to rear. It was designed like this probably to help inserting the shaft in the housing. One cam shaft was about  0.05 mm smaller than the other camshaft, due to wear. With the housing cleance being 0.05 to 0.09 mm I cant use this camshaft. So guess I'm looking for another one! 

There is an internal grub screw inside each camshaft. This must be removed so you can clean all of the oil ways. 

Getting there though. Like all these things if you are going to do it properly you have to take your time and it takes as long as it takes. I would be streets ahead on this now the big problem being getting parts due to the lockdown.

 

 

 

 

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Gearbox

remember I rebuilt this. It was smooth, gears worked really well and it was quiet. When I took the engine out I drained the gearbox oil and found glitter like flakes on the sump plug. This might well be ok, but I took it to a specialist. I asked them just to check where the flakes were from the pinion height, backlash and preload. When I got there they stripped it, so I couldn't take it away and said it needed a full rebuild- which I was sceptical about. Anyhow, they rebuilt it and found some issues.

We had some disagreements in between, probably because I know a lot about it! Anyhow when I went to pay them they said they had taken their replacement bits out and were returning the box! I asked them why and they said it was because I was liable to find a problem with their work. Interestingly they offer no gaurantees on their work, just parts! Very strange behaviour indeed. Be careful who you pick for these jobs. I gave them a fully serviceable gearbox and ended up with a pallet load of bits! Anyhow, they do know their stuff they just have an unacceptable way of doing business. They did identify issues that I had missed. As usual stuff that isn't in the manual. Anyhow I have forgotten about them now and am rebuilding the box again. Like the engine build I now know so much more. I already have the pinion shaft all back together and installed. I need some parts. Could easily rebuild it in a day if I had all the bits.

Heres what I gave them and what I got back.

IMG_7304.thumb.JPG.40071b7be7bd8067b7aef49699e04f94.JPGIMG_1228.thumb.JPG.bb21202091fc535dd2536e12c23d9e89.JPGIMG_1229.thumb.JPG.ad1e79282209a14df30f1091b89af79f.JPGIMG_1231.thumb.JPG.596e211cfe1efe503dab5469f85facac.JPGIMG_1232.thumb.JPG.7a164a92d285505b262ff9e70de0c2f2.JPGSo for anyone who wants to rebuild their gearbox its not difficult if you spend time studying the manual amd the internet.

Heres the bits you won't find in the manual.

The Synchros have a radial sequence. There are three detents inside each of the synchros. They must line up with the ball bearings so there is a synchro neutral postions. The synchros can be measured for wear by the gap between them and the gear. 

The sychros take some sideways loads and have a thrust face. This needs to be checked when you inspecting them.

the selector shafts can only be pulled outbone at a time unless you remove all of the interlocks, which isnt necessary! 

Pinion height is set uing the lotus tool. No one has this. So look t the end of the pinion. On it is scribed a number. This is the distance from the face ofvthe pinion head to the line of the gearbox face. So there are many ways to meaure the pinion height. I used a straight edge cross the gerbox half and had made a piece of plastic rod 63.95 mm long using a micrometer. I used this tomcheck the pinion height. Before you measure you must hve the distance washer installed in the shaft, the speedo nut done up to torque and the pinion shaft pushed fully forwards so the rear bearing is in contact with the rear housing.There is no reason other than wear why the pinion height should be wrong. 

After that you set preload. There are two methods. A spring balance or mathmatical. Its difficult in the manual to understand what you are trying to achieve as it always refers to dial guages and lotus tools. Well they overcomplicate it and its very simple.

Bearings have to be squeezed together slightly when they operate for optimum performance and life. This is called the preload. Method 1 in the manual means putting distance pieces and shims next to the diff bearings to squeeze them together just the correct amount. Lotus decided if you squeeze the bearings into a distance which is 0.3 mm too short that is the correct loading. This is all method one is trying to achieve. Measure the distance there is between the two bearings and select the correct size distance pieces and shims to squeeze the bearings together.

You can them wrap a cord around the diff, pull it with a spring balance and read of the breakaway loading. Its not clear in the manual whether this figure is with or without the pinion shaft engaged? This is my only remaining question concerning the gearbox. 

The last thing to do is set the back lash. Read easily witha dial guage and adjusted by moving the shims around. These just move the crown wheel closer and farther away from the pinion which affect the free movement ( backlash of the CW). If the back lash is correct the crownwheel must be in the correct place. Lastly smear marking compound on the CW and rotate the CW whilst holdingbthe input shaft to stimulate a load. Look at the tooth pattern. There should be a mark middway on the tooth and central. Job done, easy! 

Im not pretending to be an expert but just writing down what I have learned that may be useful to anyone else who is rebuilding their gearbox. It is of course much easier to take it to a specialist If you know one you can trust!

 

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The only other thing I would say is these gearboxes are nearly forty years old. You could fault lots of parts that arent perfect. You have to decide what is acceptable and what isn't. For me if its is smooth, quiet and works properly why replace it? If its not broken don't fix it! Hope this helps.

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You took it to a gearbox specialist because you found glitter flakes in the oil, but that was OK, because there was nothing wrong with it? If there was nothing wrong with it, there shouldn’t have been any glitter flakes in the oil, which could well have been gear case-hardening failing.


Margate Exotics.

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The flakes were on the plug. I only took it to a specialist because they said they would check the pinion height, backlash and preload in a day, so I could take it away the same day. When it was taken apart it was clean, apart from some flakes on the ledge next to the reverse gear. I let someone drive it when I took it to get the suspension adjusted. They crashed my reverse gear. I suspect this is where they came from. I wanted a cross check of my measurements and thought it would save me time as I'm rebuilding the engine. It was a big mistake taking it there and would still be in the car if I hadn't had to take the engine out. Still never mind I now have the time to reassemble the whole thing. They even took the diff apart!

Heres my bearing removal to replace the diff bearings. And the detents in the IMG_1354.thumb.JPG.cdff8ae24a08c7cc051615b01ffb2353.JPGIMG_1355.thumb.JPG.367f91029c042e947e7904c9c80b9df4.JPG ring.

 

 

 

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On @CHANGES "412BHP that will do nicely" thread two people mentioned glitter flake build up on the magnet in relation to GTO gearbox upgrades as being perfectly normal, its only big slivers that should cause concern


Normally Aspirated - and lovin' it!

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10 minutes ago, Choppa said:

On @CHANGES "412BHP that will do nicely" thread two people mentioned glitter flake build up on the magnet in relation to GTO gearbox upgrades as being perfectly normal, its only big slivers that should cause concern

Thanks Colin. It didn't worry me too much after a full rebuild. Still I have the chance to rebuild it and replace some parts. They might have worked perfectly well ffor the next twenty years, but because its out might as well change them. I managed to get a brand new 3/4 synchro. The diff bearings are so cheap I'm replacing the old ones - even though they are serviceable. I get a second chance to measure the preload and set the backlash! 

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Metal granules could come from the reverse gear being crashed. Every gearbox I have looked at (which admittedly is not a huge number) has the "points" on the sides of reverse idler worn off to some extent, where it has not engaged properly.

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Thinking of adding a fire supression system before I put the engine back in. In my S1 I installed a life line 4.5 Litre racing system. Would be easy to insall now before all the trim goes in.

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New paint coming next week for the ski racks. You may remember the Lotus paint formulation for this car A19 which is now the wrong colour - due to changes in the formulation. It also has to many metalic flakes and the colour is slightly off. The paint I  used is a laboratory match to the original 1981 colour. As checked by a visit to the museum! Cant wait to get the ski racks painted and on. Little bit of prep work first though! 

Should finish the bottom end today and then just waiting for the cylinderhead to come back and the wastegate. 

Wastegate refurb

I couldn't get a copy of the manufacturors refurb guide. So I'm using an engineering comapny. The problem is the valve has pitting due to corrosion, because the car was of road so long. The guide is also pitted. We looked at inserting a new guide and decided to be a workable fix the old guide needed to be removed. It was risky to do this as it might have cracked the casing. A much better solution was to clean up the original guide and make a brand new oversized valve. Its being made of the same material as the new exhaust valves. These valves are manufactured by Lotusbits. They are made of a new material,  I can't remembervthe name of. It has excellent heat transfer properties and makes the sodium valves obsolete. Because they are solid they avoid the breakage risk of the hollow valves. 

We decided on a 10 thou gap to ensure it wont seize. It will be coated in ultra high temp nickel grease that was only available from the USA. I will report back on its performance. The Turbo pipe was also damaged so Lotusbits  remanufactured a whole bunch of them, if anyone is in the same boat? 

The wastegate is one of the most critical  parts on this car. If it fails its a massive bill.With all the money invetsed in this build I'm not taking any chances. The weak points of this engine are the timing belt and the pistons. I have addressed both of these with this new build. I am about to install the fixed tensioner and have new round tooth pulleys. The piston problem solved by using forged pistons which can tolerate an overboost without melting. Will be interesting to see how it performs. I should be able to stand a £1 coin on the engine with no issues with the amount if balancing I have had done! 

I'm quite enjoying the build and am hoping like last time it fires immediately and more importantly the oil pressure comes up! 😄😄😄😄👍

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Oil pick up pipe olive

Cover in oil. Ensure the end of the pick up pipe is in perfect condition. Check its seated correctly before torquing up. 19 mm Hex socket needed. Heres what it should look like.You can't afford to get this wrong! I have done this twice and learned from thevfirst attempt. WHen the pipe end is deformed you can feel it when you tighten the olive.IMG_1375.thumb.JPG.a1c92edd4f0124c0935dc23e3167baac.JPG

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Another gotcha. The main oilway grub screw has to be removed for oilway cleaning. IMG_1376.thumb.JPG.e56e5f8157ea80bd1ab28849b560c617.JPG. Miss this out and on start all the oil will come out over the clutch!

 

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7 hours ago, Lotusfab said:

I should be able to stand a £1 coin on the engine with no issues with the amount if balancing I have had done! 

Been there done that , but with a washer..  

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39 minutes ago, CHANGES said:

Been there done that , but with a washer..  

No problem a washer it is with  some superglue! 😄😄😄👍

Sump back on. Loctite 518. Bolts are different lengths, becareful they go in the correct places. Torque setting 5 foot pounds, doesn't seem a lot?IMG_1379.thumb.JPG.7e0693f8f44aa55a2fab0a874403ee03.JPG

IMG_1380.thumb.JPG.562d417ba88432eb2759575be9897d9d.JPG

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IMHO, 5 ftlbs doesn't seem like enough for that size fastener. My manual shows 16-18 ft lbs.  Of course the sealant has set by now...

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IMG_1381.thumb.PNG.57bf4caa15054e830097302e2744e156.PNGYep your correct, better get out there! Luckily I just did it! I was reading this.

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15 minutes ago, snowrx said:

IMHO, 5 ftlbs doesn't seem like enough for that size fastener. My manual shows 16-18 ft lbs.  Of course the sealant has set by now...

Thanks Thomas. Luckily 4 hr cure time.IMG_1382.thumb.PNG.765894a40256b767b0e768c00176cd20.PNG

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