Solid crank pully ... Myth busters style

We've all heard the crank pully debates and how the OEM must be used ect ect. So 2 years ago on the 12th I fitted a solid alloy crank pulley to an na-t running at 380bhp. In a few weeks this engine is comeing out and I'm sending it to r engineering. ( high performance engine specialist) for a full health check and have all the mesurments ect taken . the car has hard a pretty hard 2 years. Few track days. Euro trips and is generally driven by a nutcase. I'm very exited to see what they say.

Did you notice any difference driving the car with the solid alloy crank pulley vs OEM?

No difference in feel at all. Its not my car so I've had limited driving in it but honestly felt the same to me

It's not really comparable until 80k+ miles is done, akin to how well a stock one keeps the engine safe.

People only buy solids because they're too cheap to pay for a damper. Much rather buy a big wing or oversized wheels lol

Its done 19k. I'm just curious to see is thers any unusual/ excess wear on anything.

Its done 19k. I'm just curious to see is thers any unusual/ excess wear on anything.

Definitely worth a look

Good planning taking all play measurements when first fitting its almost like you planed it

Just a thought, have you got all the stock dimensions? Also if there is any wear, how can you link that to the solid crank pulley? It could just be years of no servicing?

What does this place do regarding the health check on this engine, will they be stripping it ?

I would have thought it would be best to measure the wear to the thrust and crank bearings as these should show up the fact that there is no harmonic balancer to damp out the load transmitted vibrations form the ancillaries, and also the crank itself.

Makes you wonder if all engine designers fit one as a matter of course, just based on past research on older engines, or because of testing of that particular engine, as the size, weight and damping necessary would be easy to calculate without testing.

Why would you expect unusual wear from fitting a solid damper pulley? So long as it is in balance it won't affect bearing wear. It is, as its name suggests, a harmonic damper.

They fit them for a VERY good and VERY important reason, car makers do not fit expensive engine parts needlessly Far from it. The fact that nothing obvious has occurred in a

relatively few miles doesn't make their removal a good idea.

From the sounds of it, its just a cheap alloy pulley, so wont be balanced, and my comment was half tounge in cheek and half serious because practically all engines are fitted with a harmonic balancer pulley, the pulley just needs to be balanced and decoupled to work, so my point was that I wonder just how many engines could function correctly without failure, without the benefit of a pulley.

These days a lot of modern engines simply don't need to drive any ancillaries bar an alternator and some not even that.

Surely if a balanced and damped flywheel is fitted, this could do the same job?

No, a long crank like on a straight six is very prone to twist, and the twisting is cyclic and has resomant frequencies. The front damper is there protect the crank from failure due to torsional excitation. The dampened flywheel protects the gear train from excitation.

It also does a fair job of making a bad manual driver feel fairly smooth to his passengers.

I would have though excess twisting of the crank could cause uneven baring wear . I'm basicly going to get all the gaping and tolerances measured before striping it for inspection and measurements. I know its not an exact science because the engine has done a70 k previous. But ive taken a fair few apart now and I've a good idea how a healthy one should be. And its something to keep me interested

It would be more relevant to have the crank Magnafluxed and X-Rayed. Sounds expensive, but isn't that dear.

If that's a service they offer I will. Just all from my own curiosity really.