Piston Q's

[Lando]

I recently picked up a CK short block and just got around to pull it completely apart and measuring everything.

Here are the extreme measurements:

Cylinder:             1              2              3              4

Bore:              3.0128      3.0130       3.0122       3.0130
Piston:            3.0082      3.0080       3.0046       3.0083
Clearance:       0.0046      0.0050       0.0076       0.0047

Here are pics of the pistons in order from 1 to 4:





It looks like I need new pistons.

Bores are good enough to hit with a dingleberry hone.

The only pistons I can find are at http://www.partsplaceinc.com/products/product-detail.aspx?keyword=VW+Rabbit+diesel+piston+set+68-198-65&s=88&&sku=15586

It says they are standard but I dont know which hone group they are (76.48, 76.49 or 76.50).  I would prefer the 76.50 based on my bore measurements.

Does anyone know of a more trusted website that supplies the dimensions of the pistons?  I also found on hansdieselparts.com some standard pistons 76.50mm for 1.6D with rings for cheaper but I don't believe the wrist pins are the same size/distance from crown.  Here's the link: http://www.hansdieselparts.com/068107065AQPistons.htm

Can I use 1.6 pistons in the 1.5 with the 1.5 rods and crank?

What is the diameter of standard pistons for the 1.5?

Any other decent sources for these parts?

[libbydiesel]

Yes, you need new pistons.  On your worst bore/piston you are two and a half times the wear limit for clearance.  I am not really familiar with the 1.5s but I believe rod and piston are different.  There's a standard set of 1.5 pistons on eBay for $70 right now.  

I'm not one who likes to rain on someone else's parade, but if you do a full quality rebuild you'll have upwards of $1000 in parts and machine work.  I can't imagine spending the time to build a 1.5 with an 11mm block, much less the expense of new pistons and having it bored over.  You can get a good used TDI for about that now, complete and running well.  

[R.O.R-2.0]

Yes, you need new pistons.  On your worst bore/piston you are two and a half times the wear limit for clearance.  I am not really familiar with the 1.5s but I believe rod and piston are different.  There's a standard set of 1.5 pistons on eBay for $70 right now.  

I'm not one who likes to rain on someone else's parade, but if you do a full quality rebuild you'll have upwards of $1000 in parts and machine work.  I can't imagine spending the time to build a 1.5 with an 11mm block, much less the expense of new pistons and having it bored over.  You can get a good used TDI for about that now, complete and running well.  

well, oversize pistons for the 1.5D are about impossible to find, and if the pistons are worn that much, i imagine the bores arent in much better shape, and definitely not still stock bore size..

the 1.5 pistons have a much lower pin height than the 1.6 pistons, because of the stroke..

you might be able to mate up the pieces, but it would never have enough compression to run..

[VW_Commuter]

Hansdieselparts.com is one of Prothe's many websites.  Do a search here on 'Prothe' to learn more about what other members think of him, his numerous websites, and the quality of the parts he sells.

[Lando]

Bores are all within the specs for largest hone group in the standard size.  They are within eccentricity and taper specs.

The crank will not need to be ground.  All main journals measure 2.1250.  They are not eccentric or tapered more than .0002".  Rod journals are at 1.8101, 1.8103, 1.8102, 1.801 with eccentricity of less than .0004" and no taper.

The wrist pin bushing in the rods are .8662 .8663 .8664 .8662.

Everything is reusable except the pistons.  

Thanks for the tip about prothe I don't think I will be using his parts.

Libbydiesel, is this the ebay link you were talking about? http://www.ebay.com/itm/VW-Rabbit-Scirocco-1-5-New-Piston-Ring-Set-76-5mm-STD-/150593518110?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3AVolkswagen%7CEngine+-+Liter_Display%3A1.5L&hash=item231012ba1e&vxp=mtr

They are gasser pistons.

[R.O.R-2.0]

yup those are gasser slugs.

that still doesnt fix the fact that 1.5 pistons are made from unobtanium..

they are hard to find, and command a premium if the seller knows what they have..

[Lando]

I found a set Here: http://www.partsplaceinc.com/products/product-detail.aspx?keyword=VW+Rabbit+diesel+piston+set+68-198-65&s=88&&sku=15586

They aren't too steep.  I'll give them a call and see if I can haggle at all. If I go with a set of grant rings, I will be in this motor for less than 400 bucks.  People pay that much to get an alternator changed out on there fancy new appliance car.