Solid Crank Pulley

[MoggyTech]

I got one of these from ESM today, and was wondering if anyone has used one, and if so, what do they think of it.

Unlike the old two part riveted pulley, this solid type is machined from a single billet in steel! nor aluminum as is the norm with engine tuners.

For some reason they have left a weighty amount of metal at the front of the pulley, and this I would imagine will sap power from the engine, as it's a fair mass to get spinning.

Fortunately it is well balanced so shouldn't put any strain on the crankshaft front main bearing.

I am thinking of having the extra front portion machined down to reduce the weight (I would guess the pulley weight is about 8Lbs as it stands)

Thoughts ladies and gents?

[bmcecosse]

Got a picture Ray ? The normal thing to fit here is the vibration damper type pulley - I used to break crankshafts on my old Rally Minor until I fitted a crank damper! The damper type pulley has a heavy outer ring - mounted on rubber to the solid centre. I wouldn't worry about any extra mass - it's at a very small radius and is insignificant when compared to the flywheel and crankshaft whirrling mass!

[MoggyTech]

Cheers Roy,

Pic below, and weight estimate was way off, stuck it on my precision scales, and it's exactly 4Lbs 1 Ounce



Nice piece of kit, just wonder if reducing weight might help the output power at the crank.

[alex_holden]

I don't see how it could reduce the power output. It might reduce the rate of acceleration very slightly.

[MoggyTech]

I don't see how it could reduce the power output. It might reduce the rate of acceleration very slightly.

Exactly what I was thinking Alex, but probably nothing too obvious since as Roy says, compared to the mass of the flywheel it's not much extra weight.

Was thinking it might have a noise damping effect though. Only one way to find out I guess.

[simmitc]

Quite frankly, it looks unfinished, as if the machinist forgot to turn it round in the lathe and take of the rest of the rod. Check the picture on ESM's own web site, there should definitely be less metal there.

The Morris Minor Centre in Birmingham also do a solid pulley, and I've fitted several - they are a much close match to the original.

[alex_holden]

Good point. Perhaps worth emailing the pictures to ESM and asking why it looks a lot thicker than the one on their website.

[Luxobarge]

That looks exactly the same thickness as the one on my 1275 Midget (which is standard) - not sure there's anything wrong with it TBH.

[Judge]

Good point. Perhaps worth emailing the pictures to ESM and asking why it looks a lot thicker than the one on their website.

Which reminds me, I must call them to see if they have modified their apparently incorrectly manufactured Morris/Ford speedo drive cables.

[bmcecosse]

Are you sure that's NOT a rubber mounted crank damper Ray ? Looks like a wee line around the edge of the thick steel section where it joins the 'pulley'. Either way - it looks a fine bit of kit - just fit it!

[MoggyTech]

Definitely not a dampened pulley Roy. The line you see is just a milling edge where they stopped forming the pulley v edge. I'm going to contact ESM on Monday and will report back. Gut feeling is they may have designed it for noise damping at the front end.

[bmcecosse]

Well the original damped pulley was supposed to help the life of the timing chain - and the crankshaft! This may be ESMs effort at a re[palcement - since I believe the proper damped pulleys are no longer available. Not sure about benefit of a solid pulley - except it would give you a fine mount for a trigger wheel if going for Megajolt ignition ! One of the Mini lads made a crank pulley very like that for just that purpose.

[MarkyB]

Is there a timing mark notch in it?
Can't tell from the picture.

[simmitc]

Not sure about benefit of a solid pulley

They don't fall apart when the rivets fail!

[MoggyTech]

Is there a timing mark notch in it?
Can't tell from the picture.

Yes, and it's in the right place

Have e-mailed ESM to see if they are all like that, or if this one is unfinished.
I guess too much material is better than too little.

[MoggyTech]

Update,

ESM e-mailed me back first thing, the pulley is correct and designed that way.

Thanks to everyone for the input.

[bmcecosse]

Good - you'll be looking forward to much improved 'smoothness' from the engine then Ray!

[MoggyTech]

OK troops here's an update. I fitted the solid crank pulley today, what an amazing piece of kit. Despite having a duplex timing chain, my car always had timing chain rattle on over-run, not any more. This will be the inertia of the solid pulley keeping the timing chain under tension.

Must admit, I didn't fancy hanging 4Lbs of weight to the crank, so I machined off 11mm from the face of the pulley, taking it down to 2Lbs 8Ozs

Still a fair weight, the old pulley was just under 1Lb in weight.

Engine sounds very sweet indeed, well happy.

[RogerRust]

my feeling is that they gave the machinist a damped pulley and said 'make some like that but solid'! It looks like the same dimensions as the damped one I had on my minor.

Having said that I've just looked at the undamped solid pulley on the B engine and it looks like the same item only a wee bit bigger. Perhaps its designed like that so it only fits on one way round.

[Kevin]

so I machined off 11mm from the face of the pulley, taking it down to 2Lbs 8Ozs

Its alright for those with a lathe at home.......................