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Engine Clean and Machine - 1981 Turbo Esprit Dry sump Restoration - The Lotus Forums Jump to content
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Engine Clean and Machine



It's been a while since I've revisited the Esprit, I've been trying to get some additional finances together to pay for the engine rebuild.

When the sun comes out it seems to motivate me to do things, so I striped the engine down to constituent parts and tried to catalog everything by taking pictures, although my iphone seems to lose pictures all the time, what is with that! Anyhow all the castings were sent off to get vapour blasted and have returned shiny like new, a thing of beauty I can tell you.

The Main casting has been sent to the machine shop to get Hone bored to take the +0.015"/-0.02" engine bearings which were the only ones available. Unfortunately this block was one of the 100 to 1 blocks that was rebored to +0.015", and subsequently a right pain in the **** to get bearings for! The crank also needs to be reground from -0.01" to -0.02" and then be balanced, with the flywheel, its fixings, the cam belt pulley wheel and washer. At the same time I've given the machine shop the new series 4 ball bearing for the spigot shaft on the transmission to put in the crank shaft. I've also given the pistons to the machine shop to clean up for me, along with the Cylinder head, which I asked to be bolted onto the block whilst it was machined, it gives the block added rigidity that can only help. Now just awaiting the return of this so I can get on with the rebuild. Update to follow, hopefully shortly.....

So now I have the block back and the pistons, crank and flywheel plus all the periphery that went along with it, I can crack on with the assembly. Yay!


I don't know if any of you have had this problem but it is a right b*gger to get the dry sump off the main block. It's tightened down with 10 x M12 nuts and about 10 x M6 nuts, and once released will come off with a beating from a dead blow hammer......usually! But not this time. I gave up after about an hour and decided to put the little grey cells to use rather than my rather aching muscles. I've now come up with a spreader which I have manufactured using the ends of the casting and 4 M10 bolts to pries them apart. Pictures will be coming shortly.....if it works. And it does....sort of!


So after being partially defeated by the main casting I thought I would put together the pistons, how hard can this be! I seem to be thwarted at every turn at the moment. In the manual it clearly states that the gudgeon pin is a finger push fit, well I defy anyone who can push these gudgeons in with their fingers! They came out of the pistons, albeit with a bit of persuasion :wallbash:. I measured the internal diameter of the piston 24.1mm and the outside of the gudgeon at 24.5mm so I suspect that the internal diameter of the piston has bulged a bit. Will be taking it back to the machine shop to get a little bit of material removed and I'll get them to check and assemble them too.

All in all a fairly unsuccessful foray into engine building! Will try harder next time! 

Some small successes this weekend, the spreader tool worked to a degree, I managed to separate it to a point then tried to pull it apart with my hands. That thing was trapped, can pull it up 5mm one end then go to the other a pull that up 5mm too, only to have the first end drop by 10mm. Got a bit frustrating I can tell you. In the end I resorted to getting two car jacks at both ends and separated it that way!

on another note, had the machine shop clean the engine block after machining but there's still swarf and grit in there so I'm going to have to clean the whole block myself, hate that job with a passion ?. Still at least I'll be able to trial out my new parts washer!


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