Triumph Vitesse mk2 crank pulley

[JohnD]

My engine rig analyses the actual crank torsion vibration, so that it a damper pulley may be compared with a 'known good' one:

It produces charts like this:

The difference is obvious.   The calculations, by Holtzer Analysis, are tedious but well done by a spreadsheet.   What sort of analysis had you in min

Johnd?

[Josef]

21 minutes ago, JohnD said:

The calculations, by Holtzer Analysis, are tedious but well done by a spreadsheet.   What sort of analysis had you in min

With a data set and an example spreadsheet I could probably make it less tedious. I should be able to write something so you could feed raw data in and get the result data out rather than having to populate a spreadsheet. 

Might not happen super fast as I tend to get fed up after being sat at a PC all day and want to head in to the garage rather than program in my spare time too!

[johny]

Interesting, taking those two pulleys John was there a noticeable difference between them in the actual smoothness of the engine? 

[JohnD]

Josef,

   Are you familiar with Holzer calc?  It analyses the crank into a series of virtual discs and rods, then uses an iterative calculation to work out the harmonic frequencies.   Must have taken weeks when Holzer invented it, but once the spread sheet is written, the calculations become a doddle.  The sheet looks like this:

 

This is the graphical result

 

The torsion vibration charts however , are taken directly by a sensor from the crankshaft and processed using the Fast Fourier Transform.  This is a clearer image of some results:

It becomes very clear that dampers 1 and 3 are faulty and 6 on the way out!  Whereas the others conform well  to the profile of the Control, the "Chrome" damper.

I'm grateful for your offer, but this method is quick and effective!    As many as a third of all existing Triumph six damper pulleys may be faulty - I will be glad to test anyone's!

John

Edited August 30 by JohnD

[Straightsix]

@JohnD can I ask you what inlet manifold is fitted to the engine on your test rig?

I have that same manifold fitted to my Vitesse, just interested to know its origin.

Cheers

 

[GFL]

12 hours ago, Straightsix said:

@JohnD can I ask you what inlet manifold is fitted to the engine on your test rig?

I have that same manifold fitted to my Vitesse, just interested to know its origin.

Cheers

 

That's a late Triumph 2000/2500S Inlet Manifold with Inch & three Quarter HS6 Carbs.

supposedly more efficient than the standard Vitesse Manifold.

Gary

    

[Straightsix]

Thanks Gary that’s a mystery solved 👍🏻

[JohnD]

Thank you Gary!  Yes engine from a saloon, by the block number.   But beware, StraightSix - the saloon mounted the engine canted, that is tilted to the driver's right, for a lower bonnet line.   But the carbs need to be vertical, so the manifold has a bend in it so make them so.  Mount the engine vertical, as in a Vitesse/GT6 and this will lift those carbs and foul the bonnet!

 I bought that engine very cheaply without a head, with the bores full of water and the pistons unsurprisingly seized.    After pouring oil diluted with white spirit into the bores, I tried to turn it it by hand every day, to and fro.  Gradually over a week it freed, and with the addition of a head and other ancillaries it now runs sweetly in the rig.    Never had it in a car though!
 

John

[Straightsix]

That’s interesting John I will take a look regarding height of carbs in relation to bonnet clearance out of interest.

The bonnet has louvered vents, presumably to help with heat dissipation but maybe assists with clearance between carbs and bonnet too?

Need to hide one of the grandkids under the bonnet to check it out……I’m sorry your Honour I was JOKING!

[JohnD]

Ss 

I'm sure the Gks would LOVE to hide under the bonnet - mine would!   But a ball of BluTac, Platicene etc on the damper top will tell.   Mind you, witness marks on the bonnet will too.

John

Edited September 2 by JohnD