I have been through the mill attempting to keep the M7 2% crankshaft pulley working on my '02 MCS Works engine.
Randy from Webb Motors has helped as much as he can and here is my problems.
1st M7 2% pulley shipped:
OEM crank pulley comes off with out much drama with the judicious use of a good pulley puller. We cleaned up the shaft with some degreaser and expected the new pulley to require a lengthy careful pressing back on the crankshaft - but it just falls on, bottoming out against the end of the shaft. We replaced the crankshaft pulley bolt and torqued it to 85 ft lbs and started the engine up after reinstallinf the belt - all seemed very Kosher at this point. So, I'm tooling down the road and about six miles from home the pulley loosens up from the crankshaft and allows the crankshaft to spin inside the pulley, thereby stopping all other machinery powered by the belt - alternator, supercharger, etc. So I have AAA tow it home.
Call to Randy, we can't figure it out and he sends me another M7 2% pulley directly from M7 (Peter).
2nd M7 2% pulley shipped:
We remove the other M7 pulley to discover thet the crankshaft had not really done any damage at all but the spinning crankshaft pulley bolt had messed things up some on the outside.
The new pulley again just drops on, no pressing required, no coaxing, nothing. In fact this one actually wobbles in my hand as it has bottomed out againstb the crankshaft. I go no further figuring a replay of senario #1 and resinstall the OEM dynamic balanced pulley and it requires significant judicious and careful pressing on to get it back on the crankshaft.
So - something is wrong here and I can't figure what.
Any ideas would sure help.
Thanks!

 

Have you tried giving the alta crank pulley a shot? Or are they both the same size for where the crank slides into? Just a thoguht.

Best of luck!

Garrett

 

I think you are the first one to have a problem like this???


Very interesting though because that pully is on my list for the next mod to do.

 

IMO wait and watch - I am planning to wait one year until we have more data and then make my decision. From what I heard the crank pulley gives you very little increase in performance but IMO the final word is not out regarding long term effects on engine life. There are many other great mods to do first.

 

I am astounded!

You mean that the thing doesn't have a keyway???!? It's supposed to just press on and be held by a bolt?

Looks like somebody went through basic machine design with a flaming "F" There are ways to re-machine shafts in place and even cut keyways, but there's not nearly enough room to get the equipment into that space.

When you spun the pulley on the belt, how much scoring did the crankshaft snout get?

If the OEM pulley spins, don't mention any aftermarket crank pulley installation attempt to your dealer when you take it in for repair! It sounds like your crankshaft was made at the low end of the tolerance for diameter. The odds of getting two crank pullies with oversized holes is mighty slim.

Let us know how this turns out.

Rawhyde

 

oh i know, theres a list of things in my head that have it spining

 

As I removed the first M7 pulley it was obvious the softer aluminum M7 pulley received what little damage that occurred.
I guess it is possible my crank was turned at the lower tolerences and therefore is smaller than the aftermarket pulleys. It would be great to know from someone if they have the original size that the crankshaft snout should be.

BTW - no key way on shaft - purely a pressure/friction fit.
Randy says he has done 30 or 40 installs and has never seen my problem yet.

My next attempt will be with the ALTA crankshaft pulley.