Triumph Crank Damper Pulley Survey
Discussion
I retired a while ago, and since then I've gone back to college, where I'm now studying for a degree in Motorsport Engineering. I need a research project and chose to investigate the crank damper pulleys that Triumph fitted to all the six-cylinder engines it made. The crank damper was needed to suppress 'torsional', twisting vibration in the long crankshafts, and has a rubber layer between the inner hub and outer ring. They were suspect even in the day, when they were new. Kas Kastner described in his Handbooks his technique to ensure that the outer hadn't shifted, which would make the timing marks on them completely false. Worse, a faulty damper could lead to crankshaft failure!
Today, none of those dampers are less than forty years old, and many show the rubber to have deteriorated. How many still work as timing indicators, let alone to suppress crank vibration?
My study has two parts: In the workshop, I'm building an engine rig with sensors on the pulley and flywheel to detect vibration, and I'm asking Triumpheroes about their experiences with the dampers. Please help me by completing the short survey questionanire I've put up on Survey Monkey?
Go to https://www.surveymo...co.uk/r/GPTCDSG There are only five questions and it will take you less than two minutes!
Thank you!
John
PS I'm posting this on several websites, to catch as many people as I can but no need to complete it more than once!
Today, none of those dampers are less than forty years old, and many show the rubber to have deteriorated. How many still work as timing indicators, let alone to suppress crank vibration?
My study has two parts: In the workshop, I'm building an engine rig with sensors on the pulley and flywheel to detect vibration, and I'm asking Triumpheroes about their experiences with the dampers. Please help me by completing the short survey questionanire I've put up on Survey Monkey?
Go to https://www.surveymo...co.uk/r/GPTCDSG There are only five questions and it will take you less than two minutes!
Thank you!
John
PS I'm posting this on several websites, to catch as many people as I can but no need to complete it more than once!
I messed about with a lot of Triumph straight sixes, 2000 and 2500 engines. I honestly don't remember any of those composite pulleys falling apart, or being loose outer to inner. I do remember that the timing marks were ALWAYS only an approx. guide, and I always used to 'trim' the timing by adjusting slightly after several road trips. That little screw adjuster was BRILLIANT !. I really missed it on later Ford lumps....
The other thing I did see a couple of times was that the woodruff key could shave a little of the channel in the pulley (especially if someone didn't check the fit and just got the spanner out) and so the whole pulley could be slightly loose on the woodruff key - again affecting timing marks...and possibly this is relevant for your study ? I saw this on some Ford V6 engines too....
I always thought the 6 had a natural smoothness anyway - 2500 rougher (longer stroke) but not all THAT much.
extra -
The 2.5 always seemed prone to bearing knock (IMHO), even on 4 star. Probably the long stroke, but unleaded made it worse !
Never had the thrust bearings fall out, but did fix an engine with a LOT of crank float, which did knock quite a bit (new bearings helped)
Here in New Zealand I see most of the surviving 2500TC are actually low compression MM engines....
Hope this info helps you !!
<did survey too>
The other thing I did see a couple of times was that the woodruff key could shave a little of the channel in the pulley (especially if someone didn't check the fit and just got the spanner out) and so the whole pulley could be slightly loose on the woodruff key - again affecting timing marks...and possibly this is relevant for your study ? I saw this on some Ford V6 engines too....
I always thought the 6 had a natural smoothness anyway - 2500 rougher (longer stroke) but not all THAT much.
extra -
The 2.5 always seemed prone to bearing knock (IMHO), even on 4 star. Probably the long stroke, but unleaded made it worse !
Never had the thrust bearings fall out, but did fix an engine with a LOT of crank float, which did knock quite a bit (new bearings helped)
Here in New Zealand I see most of the surviving 2500TC are actually low compression MM engines....
Hope this info helps you !!
<did survey too>
Edited by RCK974X on Wednesday 31st January 23:11
Thanks!
Of course, an engine is a complex system, with many factors that can add up to error.
It seesm to me that the state of the damper pulleys is one that is ignored and little understood.
That's why I'm asking about that, and only about that - the survey is very simple and wil take less than two minutes to complete!
John
Of course, an engine is a complex system, with many factors that can add up to error.
It seesm to me that the state of the damper pulleys is one that is ignored and little understood.
That's why I'm asking about that, and only about that - the survey is very simple and wil take less than two minutes to complete!
John
I've tried to access the survey site but get an error www.surveymo...co.uk’s server IP address could not be found.
Will you be developing a new crank pulley damper as part of your research?
Very best of luck.
Chris
Will you be developing a new crank pulley damper as part of your research?
Very best of luck.
Chris
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