Scored Piston and barrel - 1.9 AAZ Vanagon

[Gizmoman]

Regarding the bores of each cylinder, is asking the shop to bore to match each piston and number the pistons getting a bit too silly?

As I currently still have the crank in the block (rolls over very sweet with no apparent play) and I have read where having the caps torqued while it's being bored - should I leave it in? If so, what about the oil squirters?

[theman53]

I don't know of any trouble with Goetze rings. Grants maybe, but not Goetze rings. My machinist had to do more than twist my arm to not use them over the Klobenschmidt that came with my pistons. I still don't know if I made the correct choice.

Not only did I not have to file but every ring I put into the bores and measured was dead on.

[Gizmoman]

My machinist had to do more than twist my arm to not use them over the Klobenschmidt that came with my pistons. I still don't know if I made the correct choice.

Not only did I not have to file but every ring I put into the bores and measured was dead on.

That also speaks to the machining job quality as well. What are your thoughts on the crank. I've never had a block bored but as I've read the caps (I'm assuming the ones that hold the crank and bearings) need to be in the block and torqued to spec to insure the bores are dead on at final assembly.

Is this true or not? and if so, does that mean just the caps and not the crank? Sorry to ask so many questions but I really want to get this right.

[theman53]

Yeah just the main caps. The crank actually rides on oil and not the bearings, so it wouldn't matter if it was in or not.

[Gizmoman]

Great - 'spoze I should machine the end of the crank then while it's out then eh?
I still have the stock one and the notorious "key" that often fails. It was tight though when I took it off but as I said - I'm looking for dependability 1st.

I also read that there are better ways to drive the alternator than the stock v-belt and heavy harmonic balancer. Any info on that?

 - I know I'm just full of questions 

[theman53]

It cost me 20.00 to machine the end of the crank for the D sproket. You may not find a machinist that cheap, but IMHO you are an idiot if you could get it done for under 100.00 and don't. Even if you are running Vbelts, the added security is worth it.

Top of the page, see the FAQ link. Look for serp setup.

[CrazyAndy]

These are all great questions, as I'm going through the same issues or have done them already.  YES get that crank D-cut, but supply the TDI sprocket with the crank when you take it to the machinist.  That way he can get it cut exactly but still make sure the crank is properly cut before recieving it after the work is done; ask me how I know.  

As for the alternatives to a v-belt setup, you can use an ABF serpentine belt setup or a setup for one of the TDIs IIRC.  Mine looks liek a mk3 gasser-style setip, but for a diesel, just can't rememver the engine it came off of right now.  I'll get the PN and find out later.

ANd to back theman53 up, yes allways have the block machines w/ main caps torqued.

As for the Goetze ring concern, I'm afraid I'm gonna have to personally back up the end gap concern.  Got a set of 4 for 0.5mm over, and the gaps measured from 0.28-0.30".  Anyone using sealed power or other manufacturers could probably chime in here, but I hope I'm an extreme minority.  Gonna try getting 1 ring set from someone else and see whet they read out to be.

[libbydiesel]

For boring the block, any machinist will very likely want only the bare block, main caps and bolts.  The crank should be removed.  The oil jets must be.  Don't torque the main caps down.  The machinist will want to do that after cleaning the block.  As far as them cleaning the block, they won't want a block that has grime caked on.  Get most all of it off first.  In my experience, they will want to do the final cleaning.  Depending on what process they take on cleaning it, you should replace the galley plugs, intermediate shaft bearings, oil pump bushing and freeze plugs.  If memory serves, the galley plugs are 14mm.  The freeze plugs are something like 36.5mm.  They are not a whole number...

As far as ring end gaps being out of spec, did you mic the bores?  Any increase in bore diameter will show up multiplied by three in the end gap.

If having the crank nose machined, have it trued up first with a minimal of material removed.     

[theman53]

  As for the Goetze ring concern, I'm afraid I'm gonna have to personally back up the end gap concern.  Got a set of 4 for 0.5mm over, and the gaps measured from 0.28-0.30".  Anyone using sealed power or other manufacturers could probably chime in here, but I hope I'm an extreme minority.  Gonna try getting 1 ring set from someone else and see whet they read out to be.

Yeah, but your machinist also completely messed up your bores, right? I wouldn't put the blame on the Goetze rings as bad as your guy was with the block. I know and 2 others I know personally have used the Goetze rings and have had 0 issues with the specs being off and close to 0 oil consumption. I have heard many internet stories of the same.

[CrazyAndy]

  As for the Goetze ring concern, I'm afraid I'm gonna have to personally back up the end gap concern.  Got a set of 4 for 0.5mm over, and the gaps measured from 0.28-0.30".  Anyone using sealed power or other manufacturers could probably chime in here, but I hope I'm an extreme minority.  Gonna try getting 1 ring set from someone else and see whet they read out to be.

Yeah, but your machinist also completely messed up your bores, right? I wouldn't put the blame on the Goetze rings as bad as your guy was with the block. I know and 2 others I know personally have used the Goetze rings and have had 0 issues with the specs being off and close to 0 oil consumption. I have heard many internet stories of the same.

Yes, but not so much as to create such large ring gap numbers.  Even if the bores were spot on then the gaps would still be too big.

And on that alt bracket I mentioned, PN is 028 903 143 AB, which is a TDI alt bracket after all.  just make sure that when going for this setup you get a VR6 water pump pulley and a water pump w/ a 30mm hub to match.

[Gizmoman]

This is such a great forum - thanks everyone for all the informative replies!

OK, It's clear as to what I'll be taking to the machine shop. I haven't bought the "Prothe" pistons yet as I'm still not sure if the next size will clean the scratched bore on #4. I think the next size up will, but I'm not the guy boring it. That means I will need to take it to the machinist, get his professional opinion (as to the bore required to clean up), order the pistons and then hand them to him with a page from the Bentley, and make very clear that he needs to hold the .001" spec over the piston diameter.

It cost me 20.00 to machine the end of the crank for the D sproket. You may not find a machinist that cheap, but IMHO you are an idiot if you could get it done for under 100.00 and don't. Even if you are running Vbelts, the added security is worth it.

Top of the page, see the FAQ link. Look for serp setup.

As to my crank nose (man some of those threads in the FAQ on serp belts, alternator clutch pulleys, etc. got real warm ).
It may sound crazy (yes, I could be an idiot) but I'm leaning to just getting a new stretch bolt and properly installing the stock set-up. Firstly, the v-belt is much more forgiving than the serp (if it's not over-tightened). Plus, the current fit of the key-way is like brand new - no wobble whatsoever.
Personally, the one-way clutch is something I will stay clear of as I have had several similar devices let me down. Generally they work well in principal but are just not robust enough for this type of application. The door isn't closed yet on this "D" sprocket as I'm a fer piece off from putting belts on, but that's where I'm standing today.

The machining of the crank is a non-issue as I have a sweet Lagun mill about ten feet from me now. Maybe I'll just do the sprocket and not all the other stuff. Theman53 - any links or some direction as to the bolt on "D" style sprocket?

Thanks again everyone.