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[Marks DTM Calib]

The theory is based around the power stroke and works on the principal that on a true power stroke the big end is heavily loaded until later in the stroke, with no power its a lighter load (the only pressure being that of the compressed air in the cylinder).

So what you get normaly is a faster unloading of the big end journal (as the exhaust valve opens) with no power, this unloading is a lot less sudden and hence a reduction in the 'knock' is expected.

[2woody]

i think the knock sound is emitted at TDC and BDC, when the piston is reversed by the con-rod.

[feeutfo]

i think the knock sound is emitted at TDC and BDC, when the piston is reversed by the con-rod.

the frequency is about right as you describe it seems to me, but type of noise is too....piercing, too sharp, theres no depth to it.

having a good listen and almost climing in the engine bay, its top end, we've done tests to eliminate loss of movement in bottom end in Alton.

To me, its top end in pot 1 or 3, possibly exhaust going by the noise. Have to say though its not the same "tok tok tok" lifter noise my 3.2 made when i got it with its neglected vx service intervals.

Its a clack, not a tok. But if it has a week lifter in that area, gota go with it....

All in my limited experience of course. :-/

[Marks DTM Calib]

i think the knock sound is emitted at TDC and BDC, when the piston is reversed by the con-rod.

Not at TDC it does not as the top bearing is loaded during the full compression and firing stroke until the exhaust valve opens 

[Marks DTM Calib]

i think the knock sound is emitted at TDC and BDC, when the piston is reversed by the con-rod.

the frequency is about right as you describe it seems to me, but type of noise is too....piercing, too sharp, theres no depth to it.

having a good listen and almost climing in the engine bay, its top end, we've done tests to eliminate loss of movement in bottom end in Alton.

To me, its top end in pot 1 or 3, possibly exhaust going by the noise. Have to say though its not the same "tok tok tok" lifter noise my 3.2 made when i got it with its neglected vx service intervals.

Its a clack, not a tok. But if it has a week lifter in that area, gota go with it....

All in my limited experience of course. :-/

Remember though that its quite possible there were 2 noises.....as we have already found an exhaust leak in this area (rectified).....and now there is a very cammy sound left.

[TheBoy]

Remember though that its quite possible there were 2 noises.....as we have already found an exhaust leak in this area (rectified).....and now there is a very cammy sound left.

Which may be what threw us - the thing, to my ears, purred into the garage sweetly.

The EGR, yes, we did disturb that, so I can see why that happened.  But the lifters, thats just coincidence?

[TheBoy]

Deal done on a set of known good lifters.

Oil should be fine....it will only take 3 hours or so to fit them and jobs a good un

Not sure I understand why letting it roast would/could quieten down more than running for a few mins (surely after a few mins, the oil should have pumped up lifters (as I assume that lifters aren't clogged with old oil, given the oil service strategy))?

But, give it a ragging and the oil pressure runs higher until the pressure relief opens

When does it not have a good ragging in TB's ownership? 

Not between here and Silverstone, and not between BP and here - I like to give it plenty of time to fully get oil hot before spirited driving, and give it time to cool nicely before switching off.  I'm a good boy like that.  I would like to think from an fluids point of view, that is one of the cleanest engines around.

[Marks DTM Calib]

Remember though that its quite possible there were 2 noises.....as we have already found an exhaust leak in this area (rectified).....and now there is a very cammy sound left.

Which may be what threw us - the thing, to my ears, purred into the garage sweetly.

The EGR, yes, we did disturb that, so I can see why that happened.  But the lifters, thats just coincidence?

Lifter, I am pretty sure its only one.

Parts have arrived any way so will make a start this evening

[TheBoy]

Remember though that its quite possible there were 2 noises.....as we have already found an exhaust leak in this area (rectified).....and now there is a very cammy sound left.

Which may be what threw us - the thing, to my ears, purred into the garage sweetly.

The EGR, yes, we did disturb that, so I can see why that happened.  But the lifters, thats just coincidence?

Lifter, I am pretty sure its only one.

Parts have arrived any way so will make a start this evening

Hope that solves it, as I'm really looking forward to getting it back

Then to persuade Kevin Wood and chrisgixer to touch it again to get the LPG up and running - thats got to be worth a poll at some point, will they or won't they

[tunnie]

thought most of the LPG was done, can't be much left to do?

[TheBoy]

thought most of the LPG was done, can't be much left to do?

Most of front end got removed as we backtraced our steps....

[tunnie]

thought most of the LPG was done, can't be much left to do?

Most of front end got removed as we backtraced our steps....

Another good days work there then 

[TheBoy]

thought most of the LPG was done, can't be much left to do?

Most of front end got removed as we backtraced our steps....

Another good days work there then 

Yeah, reckon a very 'easy' day inc the setup and calibrations etc, along with tea breaks, talking bollax and so on.  All the (in my mind) hard work has been done

[tunnie]

thought most of the LPG was done, can't be much left to do?

Most of front end got removed as we backtraced our steps....

Another good days work there then 

Yeah, reckon a very 'easy' day inc the setup and calibrations etc, along with tea breaks, talking bollax and so on.  All the (in my mind) hard work has been done

Not working Monday if that helps 

[Andy B]

Can we have a precis of the last 28 pages? I lost the plot very early in! 
Is the car now fixed?  :-/
What was the problem?  :-/