Crank pulley query, probably just me (again)

Post by **chewbacca** » 09 Feb 2021, 10:27

Hi all

Still in the process of fitting my new engine, another quick question has popped up again.

My old 1.9dg had a 3 way pulley on the crank, I believe for the factory air-con. This has all long gone.

I thought I may as well get a new single pulley on the new engine, which I now have.

The centers of the 2 pulleys look completely different though. The new pulley will fit on the crank, it's the right size etc, but I'm not sure if there should be any mounting hardware. The old pulley is machined very differently & the washer from that doesn't look a very special fit on the new pulley. (See the photo.) The smaller hole on the new pulley doesn't seem to perform any task, other than be a more sensible size hole for the bolt. I actually wondered if it's an insert that needs tapping out & fitted to the new pulley!

Can anyone shed some light in this please?
Cheers

Post by **weimarbus** » 09 Feb 2021, 10:37

The crankshaft machining is the same for both pulleys, the three belt pulley has an 'O' ring that sits in the machined bore on the back of the pulley, the standard single belt pulley does not have this, you will need the bolt and washer from the single bolt pulley to mount to the crankshaft, the three belt pulley has a longer bolt.

Post by **weimarbus** » 09 Feb 2021, 10:42

If using the single belt pulley, make sure that there is not an 'O' ring remaining on the crankshaft to the outside of the oil throwing disc. If you look at the back of the pulleys in your picture, the single pulley bolts up to (squashes)the oil thrower. The three belt pulley bolts up to the end of the crankshaft at the end of the stepped bore.

Post by **chewbacca** » 09 Feb 2021, 21:24

Thank you for the replies mate. That makes a lot of sense. Looking at the pulleys, the single clearly needs to go on slightly further compared with the triple, to line up the pulley belt centres. The photo below says it all. There's also a clear recess for an O ring on the triple, so that all makes sense.

The old engine has gone, so I can't check that for an seal, but it appears there's nothing on the new engine.

The bolt looks right to me though. I put the washer onto the bolt, then pushed the bolt through the hole in each pulley. The same amount of thread seems to poke through. Is there a lot of difference between the bolts?
Weirdly Mocki helped in my build thread with reply to something else. A photo he posted showed a single pulley with a washer that looked like mine, I thought it must be thicker with the size of the hole it goes over.

Post by **weimarbus** » 10 Feb 2021, 08:22

The correct bolt stops 8mm short of the depth of the pulley, I think that the longer one will bottom out in the crankshaft hole before securing the pulley

Post by **chewbacca** » 10 Feb 2021, 13:54

Thank you.

Sounds like I need to start a wanted thread!
Glad I asked now!

Post by **DoubleOSeven** » 13 Feb 2021, 14:34

I’ve got one in my stash you can have.

60Nm

Post by **chewbacca** » 13 Feb 2021, 22:48

Sweet.
I'll pm you mate.

Post by **DoubleOSeven** » 14 Feb 2021, 09:06

Just need an address to send it to via PM ...

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