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Turbo S3 gives clouds of blue/white smoke


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Thanks Simon,

I will strip down the wastegate and send you some pics.

I want to get it split from the gear box and mounted on my engine stand to make it easier to work on.

my week off work has come to an end so will be back to evenings and weekends for a while so progress will be slow.

John

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Have you removed the ex manifold yet? - certainly my most hated job if it hasn't been removed for a long time!

Engine mounts definitely not supposed to fall apart!

The swiss cheese mount is fairly normal, I would take Bigsi up on his offer!

The cheery soul was indeed correct. The original LC pistons were cast and were fragile in the areas you describe. Virtually all replacement options are now forged.

cheers Steve

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Hi

Ref your Engine mount heat sheilds. If you still have the orriginal ones then they tend not to last very long. You can either buy a pre-made set from SJ, which cost about

The need for speed can be found with a Lotus

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Update

Found the problem - disintegrating pistons!

Question - comparing to the pictures in the service notes - these look like the 8.0:1 CR pistons - aren't they supposed to be on the HC engines - yet mine is an 84 LC engine?

Also the liners look like they have a coating - Nikasil?

Its taken a small chunk out of the cylinder head - I hope that can be put down as a 'battle scar' and won't mean a new head!

pictures below, I had to edit them - they're too big at the moment

post-4536-1210269377.jpg

post-4536-1210269364.jpg

ok hopefully you can see these, reduced resolution so that they would fit

Edited by Mr_John111
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Nikasil liners and HC pistons, hmm, previous rebuild?

If the liners are alloy rather then iron then they will be Nikasil, and the HC pistons pair up with them (they run closer ga p tolerances).

Now that liner looks FUBAU.

Head is likely to be OK, but best to have it checked out

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HC Pistons are superior as they are forged. The Nikasil liners may be considered superior as they run with closer tolerance (less noise, better oil control?). It is however they are expensive.

The option of 'any' forged pistons with steel liners is likely to be much cheaper and still 100% reliable.

I personally would not mix & match old and new pistons. Unless they are of identical manufacture you may struggle to get them within 2 grammes tolerance and the compression pressures could be a little different.

NB I run oversized forged Venolia pistons in rebored steel liners, this cost be about

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They look like HC Piston and liners.

There is no problem replacing the damaged pistons only as long as they are the lotus ones, to be honest without balancing the rest of the engine the small difference in the piston weight will have little effect if any.

The damage to that piston looks like detonation, is it number 4 by any chance?

When you remove it can you clean it up and post pictures, If it is detonation you will have to sort this once the rebuild is complete or you will be in for another....I speak from experience.

If you would like to have a chat about it and the saga to reduce it PM me and i will give you my number. Too long a story to post!!!!

Andy

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What I forgot to say was, if they are HC liners, then they will need to be replaced by HC liners as they have a larger spigot than steel.

As per earlier post in thread, if this engine does have compression of 170lbs, I think you will need to reduce that before you put it back together. That could well be the underlying cause of your problem.

I still reckon it would be false economy to mix and match the pistons, all 4 have been exposed to similar conditions

Steve

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I wasn't too worried about the high readings as the compression test was done on a cold engine with a heavy 20/50 oil.

I agree Steve that I need to consider this carefully as too high compression could easily contribute to detonation.

Any other opinions?

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Is your engine original?

For what I know, you need to rebore the block to fit the nikasil liners as they are 1mm bigger than the iron.

If it is, you can't use new iron liners in your engine but you can have them recoated to save some money.

Cheers

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ghe67,

Unfortunately I can only assume that the block has been machined to accept the alloy liners as I have recently purchased and do not have a particularly detailed history. The block has an 84 stamp confirming the year so that ties in with it being modified.

All of the top compression rings were broken, some more than others.

So it does look like all 4 pistons & liners are required.

Presumably I am now restricted to replacing with alloy liners and HC pistons? (as Iron liners would no longer fit?)

Does anyone have any for sale?

John

Edited by Mr_John111
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  • 2 weeks later...

Update for any interested souls......

Following a rash decision - I now have two broken engines. ^_^

Steve at SJ Sportscars offered me a replacement (from a crashed car - internal condition unknown) at

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you going to get it all port grinded etc as well john? might be a good idea while its off being done. also get the valve lguides upgraded to the broze ones with the little pit holes insilde to catch the oil and hold it for lubrication. i had mine upgraded at my head shop.

paul matty has multi layer varied thickness head gaskets at his shop, that may be of use to you for your original head if you need to uses that at any point. however make sure you measure your liner lip before you rebuild it.

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John

Dont get too paranoid. Although the manual says 'nil' is the maximum acceptable skim, Lotus previously told me that upto .015" is acceptable. Also bear in mind that the current type of head gasket is thicker than the original version, so you have a little to play with there. But I would agree that you should avoid skimming unless absolutely necessary. NB the head should also be skimmed with the cam towers bolted up for maximum rigidity.

Bigsi has previously mentioned that Paul Matty sells laminated esprit head gaskets, I have not checked, but I would assume that these are to allow correction of 'overskimmed' heads.

Any chance of a photo of the mystery bulges? If it pressure tests OK, then maybe nothing to worry about?

cheers

Steve

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post-4536-1211221345.jpg

As regards the 'glassy' bubbles - worrying about nothing!

I took a sharpened lolly stick to them (always worried about using metal scrapers on an alloy head) and they disappeared into dust leaving behind a flat but slightly darker grey stain on the head.

But.... this success has led to the latest trial - ''I'll just take the spark plugs out......'' - i've now discovered that spark plugs can snap in half leaving the thread in the head, me with the electrode in my hand and and a stupid feeling! Oh well at least the engine shop will be able to charge me for something else.

Edited by Mr_John111
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Keep putting lots of easing oil (plus-gas or what ever) onto those plugs, every bit of help you give will save you money because the engine shop will be able to get the out easier.

Also, the oil will help to loosen the carbon deposits.

Andy

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