Going out on a limb here - I purchased this today. Expired Ebay Listing

Despite my efforts I still cant determine if it will fit, but here goes anyway.
It would appear it has a stock number but the seller swears black and blue its a 178mm pulley (+larger water pump pulley).

Reasonable price (I ended up with free postage as well)....so we'll see.

 

You can buy that part No. from original MB parts sellers. If legit the seller used those numbers to show what it replaces. No way to know for sure until you have it in hand.

Les

 

Wow , 178mm pulley = Stage 2 amg, good score !
this could be what also required the sl55amg fuel pump in Germany as an option from AMG.
dave

 

I am pretty sure it is a custom pulley. it was build from a stock crankshaft pulley. a stock pulley (same part no.) looks like this: http://bilder3.eazyauction.de/YourCa...lder/47495.jpg
you can see the difference in height from the pic if you compare yours.
AFAIK ASP takes a new stock pulley to build a 178 pulley.

Damned I missed the auction !

Steven

Berlin Germany

 

I agree as on the back side you can see the two set screws that are meant to stop the slipping of the new outer grooved ring that has been pressed onto the stock pulley which has had the original grooves machined off.

 

What doesn't make sense is the "bigger water pump pulley" part. It should be smaller, way smaller than a stock water pump pulley to compensate for the bigger crank pulley diameter. I have a SolidWorks blueprint I drew up for a 162mm crank which would compliment a 65 SC pulley perfectly. I did disassemble a cracked unit to get the proper groove measurements. Maybe it's time to machine it now.....

 

You should think about that statement, a smaller pulley would increase the revs of the water pump as the belt is travelling faster with one revolution of the engine with a bigger crank pulley.

 

Sorry I couldn't advertise the auction since I was going in myself.

Thanks
I can see the link between aftermarket mod and original PN's.
Might have to check it for balance??
I guess there's no way of knowing who did the work.
I'll recontact the seller as he might have a bit more information now he knows he's sold it.

I'm looking for 'round town bottom end grunt (ft.lbs) rather than redline hp.

 

Now this is funny. My buddy is building a 163 mm pulley for me from a stock new piece because I would like to keep my 65 SC pulley as well. BTW the stock pulley is not a "special" AMG part. It is a mass production part, build to fit many Mercedes V6 engines and could be purchased as an aftermarket part for about $60.

We are still not sure if we keep the vibration damper on the pulley or not. The crankshaft pulley is a wear part and balancing a construction with a plastic vibration damper between 2 steel rings is kind of tricky and makes no sense to me.The pulley runs out of balancing tolerances sooner or later when the damper worns out.

So i wouldn`t be focused too much on balancing the 178mm ebay pulley as well.

In my opinion it would be the best to build a kind of a solid "2 - piece" crankshaft pulley with a hub and a set of different sized pulley wheels - of course.

Something like this (seen on eaton superchargers).

http://i.ebayimg.com/images/i/380114...-1/s-l1000.jpg

Steven

Berlin Germany

 

onehundred80, the bigger crank won't allow a stock water pump pulley because of how close they are to each other. Forget the water pump RPMs, there's no room or option but to go smaller. I made 3 aluminum water pump pulleys that are 12-16mm smaller than stock and they're working fine on all the cars.

No2fast, look into Mustang Cobra or MB 55K crank pulleys. Same design you described and available in many different sizes. Tighed1 runs a 192mm crank pulley....nucking futs!

 

You are correct of course.
Never realized they were so close already.
Makes the SC pulley a better idea, upping the revs on the pump will shorten the life of it.

 

Yes .....
All pulleys (incl. PS/Alt etc) will be running +15% faster on average (178/155)

My rough numbers measured from a graphic I have are telling me the water pump crank setup is
Water pump 120mm
Crank 155mm
Separation centre to centre = 155mm (approx)

Now for the 178mm case...
adding 23mm/2=11.5mm to the crank would mean taking 11.5mm from the water pump = ~10% smaller + 15% increase from above = 10+15=25% faster overall
.....unless I'm missing something.

b22b

 

Hi,
yes, you might have to check it
here is a short video of today: stock brand new crankshaft pulley on the lathe. I hope you can see the imbalance. Can you imagine how a stock crankshaft pulley runs after 100.000 miles?



Steven

Berlin Germany

 

That is one of those videos that can strike worry and fear into the hearts of many.....there is no way that could be "normal"....100,000 miles like that would be impossible for sure.....???....wouldn't it....:>(

No2fast...is it "No to Fast" or "Not too Fast" or "Nitrous fast"?.....

 

Hey Billy22Bob,
no nitrous .
No2fast is just a pun.
Some years ago i was experimenting with standard alone efi systems. I was using the not2fast turbo calculator http://www.not2fast.com/turbo/glossary/turbo_calc.shtml and found it helpfull. I guess I was inspired by it.


Steven

Berlin Germany

 

My roadster's pulley looks to be running pretty true just from the naked eye, with 37K on it. My coupe's pulley isn't by the naked eye with 22K on it. I have a new replacement that will go on this week with a few other upgrades. This is an area that needs to be looked at along with constant observation of aftermarket s/c pulleys. If you are running for performance that is. Under normal driver conditions, I would think stock would run for a long long time.

 

Pulley arrived today. Confirmed 178mm
Possibly an ASP if what you say is right about them using stock cranks to make larger ones.
Water pump is 110mm which is in line with what I calculated in post 12.
I'm thinking 2 pulleys not a bad deal for $360USD incl.post to Oz????