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hspeck

X180 2.2 NA ignition timing

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I recently got my hand on a timing gun and decided to check my timing ...

and lo and behold I found something very weird.

at the cam pulleys, the timing marks aligned at 12° advance.

However, when I shot the gun at the flywheel, I got back 20°...

I cannot understand how it could be so ...

Unfortuantely, because my car is retrofitted with a power steering system, the access at the firewall is blocked and the power steering pulley is blocking the crank pulley. I am unable to hand turn the crank to TDC without pulling the engine...

The weird thing is, the car is running fine, no misfire, my colourtune shows blue for all 4 cylinders, I was able to synchronise the carbs. I cannot understand how it can so if the ignition timing is 20° BTDC ...

I have reconfirmed with the shop who rebuilt the car an they assured that the pulleys were aligned correctly when they adjusted the crank to TDC...

Appreciate any thought on how this can happen and any possible solutions ...

***** so I was told that the timing at the cam pulleys is different from the timing at the crank/flywheel. please verify that the correct ignition timing should be read at the crank/flywheel and not the cam pulleys?

Link to the video :-

Thanks

 

 

flywheel(01).jpg

this is when the gun was set to 20° advance, showing TDC

flywheel(02).jpg

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The cams are set statically when the flywheel is at TDC.  So if you did use the gun on them (you shouldn't need to) it should be adjusted to 0 degrees.  Simply rotate the engine so that the flywheel shows TDC, then check cam alignment.

If you are lighting up TDC when the gun is dialled to 20 degrees, then you need to back off your distributor.

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7 minutes ago, Sparky said:

The cams are set statically when the flywheel is at TDC.  So if you did use the gun on them (you shouldn't need to) it should be adjusted to 0 degrees.  Simply rotate the engine so that the flywheel shows TDC, then check cam alignment.

If you are lighting up TDC when the gun is dialled to 20 degrees, then you need to back off your distributor.

Hi Sparky,

So am I correct to say that the timing at the cam will not be the same as that at the crank? I am very new to this so beg my pardon if it sounded silly ...  I have only had cars with EFIs ... 

And in this case my ignition timing is 20° BTDC and not 12° BTDC as was claimed?

The distributor cannot be turned to reduce the timing anymore as it is sitting at the end of the adjustment. Meaning to say I can only turn one direction, and it will increase the timing at the crank..  

I am unable to hand turn the engine unless I remove the engine from the car ....

Thanks

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14 minutes ago, hspeck said:

I am unable to hand turn the engine unless I remove the engine from the car ....

Put it in 4th gear & jack up one wheel to turn over the engine. :thumbup:

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I'm sorry i dont really get what you mean.

As in when the engine is off? As i can't see how i can jack up 1 wheel when the car is running in 4th gear?

 

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I don't really understand what you mean, but obviously the Cam wheels run at 50% of crank speed (as they are twice the circumferance - so if the crank travels 20 degrees, the cam will have only travelled 10 degrees?   Not sure why you are pointing timing gun at cams, other than to see what happens.   All ignition timing is with reference to crank only. 

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As Jon says, engine off, hand brake off, Jack up a rear wheel so off the ground and manually turn the wheel with your hands in 4th gear. This will rotate the engine without having to start it. Spark plugs out makes the engine easier to turn this way also. 

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Or, just put it in gear, handbrake off, on a level surface and rock the car back and forth until TDC is achieved on the flywheel.

Sound like you are indeed at 20BTDC.  If so, the belt has to come off and the aux sprocket needs to be aligned.  OR, as I believe was detailed in another thread, shift your plug leads around in the hope of turning the distributor the other way to achieve the desired number.

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1 hour ago, 910Esprit said:

I don't really understand what you mean, but obviously the Cam wheels run at 50% of crank speed (as they are twice the circumferance - so if the crank travels 20 degrees, the cam will have only travelled 10 degrees?   Not sure why you are pointing timing gun at cams, other than to see what happens.   All ignition timing is with reference to crank only. 

I am very new to these cars, so am still learning. It was suggested to me to check the ignition timing by shooting the gun at the cam pulleys.. Guess he was tryng to smoke me..

Was also told that both timing should be same, hence the initial post.

I guess not then...

1 hour ago, Steve4012 said:

As Jon says, engine off, hand brake off, Jack up a rear wheel so off the ground and manually turn the wheel with your hands in 4th gear. This will rotate the engine without having to start it. Spark plugs out makes the engine easier to turn this way also. 

 

46 minutes ago, Sparky said:

Or, just put it in gear, handbrake off, on a level surface and rock the car back and forth until TDC is achieved on the flywheel.

Sound like you are indeed at 20BTDC.  If so, the belt has to come off and the aux sprocket needs to be aligned.  OR, as I believe was detailed in another thread, shift your plug leads around in the hope of turning the distributor the other way to achieve the desired number.

I was told i can also put it in 5th and roll the car to turn the engine to TDC. Never know we can do that.

I was also told that i have to ensure that it is on the compression stroke on cylinder 1.

Learned new things today again.

Thank you very much to all.

First thing is to get the engine at TDC and see what happens.

Will keep this thread posted.

Cheers!

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hspeck, sorry, let's try and make this a bit simpler...

First, camshaft timing.  Get the flywheel to TDC (I would do it by selecting 4th (engine off), releasing handbrake and rocking car forward or back until you can see the flywheel marking aligned to the pointer.  Then. if the camshaft marks aren't facing each other, then the camshaft timing is incorrect and you need to remove the cambelt to adjust.

Second, ignition timing.  Adjust the timing gun until you can see TDC against the pointer.  The value on the digital readout is your timing advance value.  If this is 20, then you should first try rotating the distributor to compensate.  Looking from the BACK of the engine, you need to turn the distributor anticlockwise to reduce the advance.  If you can't turn it in this direction, then you need to assess whether you can turn it around 80 degrees clockwise instead, and then move all leads one space anticlockwise on the cap.  If this isn't possible, then the only way to resolve it is to dismount the cambelt and adjust the aux pulley to its correct alignment.

Hope that makes sense...

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58 minutes ago, Sparky said:

First, camshaft timing.  Get the flywheel to TDC (I would do it by selecting 4th (engine off), releasing handbrake and rocking car forward or back until you can see the flywheel marking aligned to the pointer.  Then. if the camshaft marks aren't facing each other, then the camshaft timing is incorrect and you need to remove the cambelt to adjust.

You might like to add, TDC on the compression stroke for cylinder no1.

Let's hope @hspeck 's Cambelt isn't already on the floor.

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28 minutes ago, Steve V8 said:

You might like to add, TDC on the compression stroke for cylinder no1.

Duh.  I took too much for granted!

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Hspeck,

Forgive me if pedantic but, as the gents have summarized, please distinguish between addressing the cam timing and the ignition timing. It's imperative that no mistakes are made in tinkering with timing the cams, a meaningful error there will cause great engine damage. You have some latitude in messing about with the spark timing, though it too is not something to fiddle with in ignorance. The crank position, as Sparky and Steve V8 have noted, is what you must regard singularly when exploring spark timing and what is most important is that the maximum advance be near optimum. Idle advance in the neighborhood of 20 degrees may be a little excessive but far better that than 20 retarded.

Your flywheel markings should serve in the setting of spark timing figures which are specified in various Lotus Service documents, notably all the Service Manuals. Rule of thumb numbers for an engine such as yours would be low-mid 30's total advance, all in by 2500-3000 rpm, idle advance in the realm of 10. If the position of the distributor is such that rotating it to correct idle advance is not viable then you must deal with the challenges of extracting the distributor to permit rotation of the auxiliary cogwheel one tooth before re-engaging the drive dog. I have no experience in this so invite others speak to the challenges inherent in this exercise. 

As your car is running fine and Colortune shows happy carb idle settings you are off to a good start. Maximum advance is important, so get that checked above all. Simple matter of revving the engine past 3000 with timing light checking flywheel for the rate of, and limit of advance, done with car stationary in garage or curbside.

If the engine power curve is as expected, pulling hard past 6500, your cams are likely in the ballpark, at least. On the other hand, given perils of error in cam-crank relationships, take time to understand the more complex matter of sorting them out and then investigate with great care.

Cheers   

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10 hours ago, Sparky said:

hspeck, sorry, let's try and make this a bit simpler...

First, camshaft timing.  Get the flywheel to TDC (I would do it by selecting 4th (engine off), releasing handbrake and rocking car forward or back until you can see the flywheel marking aligned to the pointer.  Then. if the camshaft marks aren't facing each other, then the camshaft timing is incorrect and you need to remove the cambelt to adjust.

Second, ignition timing.  Adjust the timing gun until you can see TDC against the pointer.  The value on the digital readout is your timing advance value.  If this is 20, then you should first try rotating the distributor to compensate.  Looking from the BACK of the engine, you need to turn the distributor anticlockwise to reduce the advance.  If you can't turn it in this direction, then you need to assess whether you can turn it around 80 degrees clockwise instead, and then move all leads one space anticlockwise on the cap.  If this isn't possible, then the only way to resolve it is to dismount the cambelt and adjust the aux pulley to its correct alignment.

Hope that makes sense...

Thank you Sparky. That is very precise instructions.

However I was told not to rock the car backwards when in gear, so I am keeping that in mind will only roll the car forward. Otherwise I will just jack 1 wheel up and turn till I get TDC.

The distributor cant be turned anti-clockwise as it is already fully anti-clockwise at 20° BTDC. I can only go clockwise which will increase the timing..

And, do you mean to assess if I can turn it 180° clockwise or 80° clockwise? That is by physically releasing the distributor and turning it ?

Can I move the leads to get the same effect?

9 hours ago, Steve V8 said:

You might like to add, TDC on the compression stroke for cylinder no1.

Let's hope @hspeck 's Cambelt isn't already on the floor.

I was told I will have to open the distributor cap to check that the rotor arm aligns at cylinder no. 1.

Any other way I can ensure that?

7 hours ago, drdoom said:

Hspeck,

Forgive me if pedantic but, as the gents have summarized, please distinguish between addressing the cam timing and the ignition timing. It's imperative that no mistakes are made in tinkering with timing the cams, a meaningful error there will cause great engine damage. You have some latitude in messing about with the spark timing, though it too is not something to fiddle with in ignorance. The crank position, as Sparky and Steve V8 have noted, is what you must regard singularly when exploring spark timing and what is most important is that the maximum advance be near optimum. Idle advance in the neighborhood of 20 degrees may be a little excessive but far better that than 20 retarded.

Your flywheel markings should serve in the setting of spark timing figures which are specified in various Lotus Service documents, notably all the Service Manuals. Rule of thumb numbers for an engine such as yours would be low-mid 30's total advance, all in by 2500-3000 rpm, idle advance in the realm of 10. If the position of the distributor is such that rotating it to correct idle advance is not viable then you must deal with the challenges of extracting the distributor to permit rotation of the auxiliary cogwheel one tooth before re-engaging the drive dog. I have no experience in this so invite others speak to the challenges inherent in this exercise. 

As your car is running fine and Colortune shows happy carb idle settings you are off to a good start. Maximum advance is important, so get that checked above all. Simple matter of revving the engine past 3000 with timing light checking flywheel for the rate of, and limit of advance, done with car stationary in garage or curbside.

If the engine power curve is as expected, pulling hard past 6500, your cams are likely in the ballpark, at least. On the other hand, given perils of error in cam-crank relationships, take time to understand the more complex matter of sorting them out and then investigate with great care.

Cheers   

Thanks drdoom. I was initially very confused wrt the cam timings and ignition timing. I thought both were the same. I hope I know better now with all the inputs and information from all here and in FB..

I am not gonna mess with the cam timings, as I have no reason to. I just want to make sure the ignition timing is as per spec.

Although the car runs fine now, I just can't rest well knowing that something is off ....

And regarding the timing at 3000rpm, I did try to check. it does advance when I rev the engine, but unfortunately I did not take note of how much ...  I will do that..

But now, to get the crank to TDC

 

Thanks everyone for the very valuable information.

Got much more to learn.

Having owned close to 30 cars in my lifetime, so mundane some wild, the Esprit really holds onto it's own .. I really would like to get it sorted to truly enjoy it..

Will keep this thread updated.

Cheers

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hspeck - definitely 80 (eighty) degrees - approximately.  What you're trying to do here is get the distributor into a position where the ignition timing would be correct.  The distributor cap is just 4 poles at 90 degrees spacing, and you want the spark to travel to the correct pole at the correct time.  If you can't get it to turn, say, 10 degrees anticlockwise (as viewed from back of engine), then there's a chance you can turn it 80 degrees clockwise.  If you can do this, then you can move each plug lead 90 degrees anticlockwise.  So you've shifted all leads along by one pole (90deg offset) then rotated the distributor clockwise (80deg reduction in offset), thereby achieving 10deg retardation in ignition timing.

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38 minutes ago, Sparky said:

hspeck - definitely 80 (eighty) degrees - approximately.  What you're trying to do here is get the distributor into a position where the ignition timing would be correct.  The distributor cap is just 4 poles at 90 degrees spacing, and you want the spark to travel to the correct pole at the correct time.  If you can't get it to turn, say, 10 degrees anticlockwise (as viewed from back of engine), then there's a chance you can turn it 80 degrees clockwise.  If you can do this, then you can move each plug lead 90 degrees anticlockwise.  So you've shifted all leads along by one pole (90deg offset) then rotated the distributor clockwise (80deg reduction in offset), thereby achieving 10deg retardation in ignition timing.

Noted Sparky!

I understand now!

Cheers!

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Ok.. So i turned the engine to TDC and the cam pulleys alignment 

Am unable to check the aux pulley as it is blocked by the undertray. 

Maybe i should rotate the distributor clockwise and relocate the plug cables by 90° ?

20181206_120215.jpg

20181206_120238_HDR.jpg

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Is it a big deal to remove the undertray?    I also recall there being anillustration of the corect position of the rotor arm at TDC in the manual?

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31 minutes ago, 910Esprit said:

Is it a big deal to remove the undertray?    I also recall there being anillustration of the corect position of the rotor arm at TDC in the manual?

Not really, but i need to find a place to hoist the car up..

What does the position of tge rotpr arm tells us?

Apologise if this sounds stupid..

Thanks

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It will tell you that the Aux sprocket is correctly aligned, without needing to look at the timing mark on the pulley.

NB - I don't have a hoist but can easily remove the undertray  (as long as you are happy to lie on the floor).....

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1 hour ago, 910Esprit said:

It will tell you that the Aux sprocket is correctly aligned, without needing to look at the timing mark on the pulley.

NB - I don't have a hoist but can easily remove the undertray  (as long as you are happy to lie on the floor).....

Thanks 910Esprit, i will take a look at the service manual regarding the position of the rotor arm at TDC.

I probably will need to jack the car up to slip under the car if i want to remove the undertray.. But i think it will be easier to find a hoist this weekend...:p 

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I suggest we already know the aux sprocket is misaligned, as the distributor can only be rotated to achieve 20BTDC. Removing the cap is a load of aggro to prove what's obvious. Likewise the undertray, unless the belt is to be removed to make changes.  And that's only necessary if the 80 degree turn can't be done.

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On 03/12/2018 at 22:08, Sparky said:

hspeck, sorry, let's try and make this a bit simpler...

First, camshaft timing.  Get the flywheel to TDC (I would do it by selecting 4th (engine off), releasing handbrake and rocking car forward or back until you can see the flywheel marking aligned to the pointer.  Then. if the camshaft marks aren't facing each other, then the camshaft timing is incorrect and you need to remove the cambelt to adjust.

Second, ignition timing.  Adjust the timing gun until you can see TDC against the pointer.  The value on the digital readout is your timing advance value.  If this is 20, then you should first try rotating the distributor to compensate.  Looking from the BACK of the engine, you need to turn the distributor anticlockwise to reduce the advance.  If you can't turn it in this direction, then you need to assess whether you can turn it around 80 degrees clockwise instead, and then move all leads one space anticlockwise on the cap.  If this isn't possible, then the only way to resolve it is to dismount the cambelt and adjust the aux pulley to its correct alignment.

Hope that makes sense...

He's getting his knickers in a twist. Same questions being asked on the Facebook Lotus page and almost similar answers being provided. 😨

Unfortunately, the Esprit isn't suitable learning ground for a beginner.

 

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Give him his due, he's getting there!  Baptism of fire though...

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11 minutes ago, Sparky said:

Give him his due, he's getting there!  Baptism of fire though...

Agree. Cut him some slack, there’s progress. It’s been a learning curve for most of us. 

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