912 motor valve settings

[SSA ELAN ESPRIT]

Do the 2 x dots on the inlet / exhaust cam sprockets, when correctly aligned mean that the valves are closed? With the cambelt off can I safely turn motor [ engine is out ] to tdc position for no 1 cylinder knowing the valves are now correct.

[Sparky]

With respect, if that's your level of understanding, walk away and find someone knowledgeable before you break your engine.

[SSA ELAN ESPRIT]

Sorry Mr Know It All, maybe you should come out here to Botswana and cast your magic.

A simple answer would suffice instead of being a smart ass.

[Sparky]

I'm deadly serious.  You've demonstrated that any explanation could lead you to misunderstand and damage your engine.  Google how an internal combustion engine works, then come back.

BTW if you want me to come to Botswana and fix it, just pay up and I will.  It's what I do.

[Dan E]

19 minutes ago, SSA ELAN ESPRIT said:

Sorry Mr Know It All, maybe you should come out here to Botswana and cast your magic.

A simple answer would suffice instead of being a smart ass.

Mr @SSA ELAN ESPRIT he really does know what he is talking about,  so i would actually listen and reading the comment I don't think there was any "Smart Arse" about it 

[SSA ELAN ESPRIT]

Well he can't answer the question that was asked. 

[Dan E]

1 minute ago, SSA ELAN ESPRIT said:

Well he can't answer the question that was asked. 

Sorry I think he did. I have known Sparky for 10 years maybe more and you won't find a more helpful chap as many on here will attest to (Sparkles you owe me a pint 😃) 

[SSA ELAN ESPRIT]

Its a very simple question are the 2 aligned dots meaning the valves are closed? We don't have Lotus  'experts' here, trying to save time checking taking off cam covers to check lobes. 

[Sparky]

Ok.  NO. Absolutely not.  DO NOT TURN THE CAMSHAFTS OR CRANKSHAFT IF NO BELT IS FITTED.  Find someone who understands internal combustion engines and their firing sequences, or use Google.  This is not Lotus-specific; it involves an elementary knowledge of engines which you clearly don't possess.  Only when you understand the basics should you go near that engine.

Clear enough?

[Chillidoggy]

From personal experience of working alongside him, when Sparky talks Esprits, I guarantee he knows exactly what he’s talking about, and the best course of action to avoid any expensive issues is to listen to what he’s saying.

[Dan E]

21 hours ago, Chillidoggy said:

From personal experience of working alongside him, when Sparky talks Esprits, I guarantee he knows exactly what he’s talking about, and the best course of action to avoid any expensive issues is to listen to what he’s saying.

agreed he once fixed my Esprit by telepathy and i still wish that wasn't true

[Escape]

@SSA ELAN ESPRIT, it may not have been the answer you wanted to hear, but it was the answer you NEEDED to hear. On an interference engine with multiple cilinders, like the Lotus engines, there is no safe position to turn the crankshaft unless (part of) the valve train has been disassembled. This is elementary knowledge. If you're unsure about that, the risk of doing serious damage working on such engine is too high, despite all the good advice we can provide. So you're really better of letting someone else do it. But by all means, if you get the chance, stick around and watch the work done carefully, you will learn a lot!

Filip

[SSA ELAN ESPRIT]

Maybe I should of been slightly clearer with my question, are the valves closed on 'compression/ignition' stroke when dots are aligned. Valves are always closed on this stroke. Its the compression/exhaust stroke where there is valve overlap. Trying to avoid taking off cam covers as they are a swine to seal on the 912na motor. Ended up taking them off anyway.

[Sparky]

Your above remains ambiguous.  Had your question been "are the valves for cylinder 1 closed?" then this would have been a much shorter conversation.  Is that what you meant?

[Escape]

If the dots on the cam sprockets are aligned, the engine should be at TDC, so no need to turn the crank. A small amount of adjustment is no problem, but you can't turn a full revolution without hitting valves on other cylinders.

What are you trying to do? Replace the cambelt?

[mike.griese]

With the cam belt removed, there is no safe way to turn the crankshaft - at least some of the valves are open.  You have to move the cams in the appropriate direction, just like the belt would to rotate the crankshaft. 

If you put the crankshaft at 90 degrees before or after TDC, you can safely move the cams without hitting pistons.  Handy for measuring and setting valve clearances.

[CHANGES]

On 01/04/2024 at 10:18, SSA ELAN ESPRIT said:

Maybe I should of been slightly clearer with my question, are the valves closed on 'compression/ignition' stroke when dots are aligned. Valves are always closed on this stroke. Its the compression/exhaust stroke where there is valve overlap. Trying to avoid taking off cam covers as they are a swine to seal on the 912na motor. Ended up taking them off anyway.

Basically yes...  1&4 TDC the dots should align .. one cylinder will be valve closed the others on the rock (overlap) ..  But no one has mentioned the auxiliary pulley ..  on the 912 this with have a dizzy and this must remain in time with the TDC and cam timing .  This may sound picky but the dizzy's don't like re-orientation .. they will rotate a bit but too much and you wont be able to get the clips undone easily .. This is where all the skin comes of the back of your hands .. 

But of course the pulley dots may not line up at TDC because of previous  head skim etc ..  you also need to establish the accuracy of TDC with DTI.. if this is the case to insure you find the best timing option without fitting adjustable pulley's  ..   This is where it gets technical .. 

Like @Sparky i have thrown a few spanners at these donkeys and what he was trying to point out is they can be fiddly little shits.. We hear so many sob stories of simple but very expensive mistakes ,, please don't be one.. This forum site will give you the best advise you will get anywhere on these engines ..   There are threads on here that will cover details that you should be aware of with regard to cam trimming set up and belt change ..  hope that helps    

[SSA ELAN ESPRIT]

Thanks - I was hoping to avoid taking the cam cover off, but have done so. All sorted.