AAZ rebuild (broke down in Maine)

[theman53]

http://www.idparts.com/catalog/product_info.php?cPath=29_74&products_id=1907

I just did this to the TDI this morning. I have been running the car since I bought it with re used mains and rods. I just sent a text to the PO and asked him if he replaced them when checking the clearances. 3 days later he responded with "no" So all morning long I have been at it and finally finished. Those were the best I could find on the internet in the little searches I did.

Point is, it is a one time use bolt and I wouldn't do it. The ones I sent you were reusable older style. If you could massage the main cap and use them I would. If not I would order the stretch ones. That is if the AAZ and ALH use the same, that I am not sure of. I could measure my old bolts later if you want.

[RockOcean]

Today I got new stretch main bolts from the dealer. When I torqued them down and did the 1/4 turn the crank was completely locked up. So I decided to put the older style bolts in again, torqued them down to 48 ft lbs. crank spins perfectly. The Bentley says not to do the quarter turn on the older style bolt - so I assume I am ready to move on right? 

[theman53]

Should be able to if the older bolt sequence was followed.

[RockOcean]

It does not say anything about a sequence in the Bentley. But I did torque the bolts from the center out just like you would the head bolts.

[theman53]

I meant the torque...if there is a 22 then 48 kind of sequence. You should be fine. My only thought is 2 people have had mains fail on aaz's on this forum. Both were the #2 IIRC Jimfoo was one of them. Apparently they made a longer bolt that was 80mm? If I do my aaz I am going to have the machinist tap it 15mm more so I can fit the 80mm bolt and line bore it so I feel more comfortable at night.

[RockOcean]

Bentley says just to torque to 48 ft. lbs. I did as I always do, tightening down the bolts a little at a time before doing the final torque.

Finally have the pistons in, and have my measurement for piston protrusion. The numbers are on the low side of a 1 notch .0270 being the highest and .0249 lowest which is actually lower then what the Bentley says for a 1 notch.

Also my brother is having a hard time finding a 1 notch for an AAZ he has one come up but it says its for an AHU any difference here?

Could I just put in the 2 notch despite the numbers calling for a 1 notch - I had valve marks on my old pistons and am thinking this wouldn't happen if I used the 2 notch that I have. I have heard as long as I am not in a cold environment it should not have a problem starting.

[burn_your_money]

Do not use an AHU headgasket, it won't work. Everything will line up but there is no support for the precups.

[RockOcean]

I am just going to use the 2 notch unless I can find a 1 notch and have it here on Friday.

[libbydiesel]

Valve marks will not ever happen if the correct gasket is used provided the engine is timed properly as well.  Additionally, using a too-thick gasket will not ensure against piston to valve contact if someone does not time the engine correctly. Using a too thick gasket disturbs the squish (proper turbulence) which is probably not a big deal on an IDI, but also the quench which occurs during the time when the piston crown is closest to the head and transfers a significant amount of heat to the head which is cooled by the engine coolant.  That quench time is an important part of cooling the piston.  Increasing the distance between the head and piston at TDC by fitting a too thick gasket has a big effect on quench and will mean that your piston crowns will consistently run hotter.  Because the piston crown is the part that of the engine that will melt first with combustion temps too high (even if everything else is perfect), IMO it would be wise to give the crown as much help as possible in remaining cool especially in a 4,000 lb vehicle with the aerodynamics of a brick.  

The reason your piston protrusion is too small is probably because oversize pistons typically move the wristpin bore closer to the crown in anticipation of having the deck resurfaced at the same time as boring.  If you don't have the deck surface milled the same distance that the pin is moved to the crown, the protrusion will change.  I would pull the rotating assembly and return the block to the machine shop telling them how much to mill off the deck to have the protrusion solidly land right in the middle of the range for the 2-notch gasket.  

As an aside, to avoid that predicament when I am rebuilding an engine, I measure the protrusion of the old pistons first.  Then I pull the assembly and measure the wrist pin to crown height of the old pistons.  I then measure the wrist pin to crown height of the new pistons and do the math necessary to tell the machinist how much to trim the deck while I am having them bore the cylinders.  That saves considerable time (and possibly TTY fasteners) and results in the protrusion I want.  

[theman53]

I got a 1 notch from Myke w that is now taking orders from NH or Connecticut.

[RockOcean]

Andrew thank you for your amazing knowledge of these motors especially in a Westy. As much as I would love to get the head decked and have it perfect I am running out of money and time.

I haven't heard from Myke W today, anyone else know where I can get a 1 notch for my AAZ?

[libbydiesel]

Just for clarity, you would surface the block, not the head. 

[burn_your_money]

Myke_w sold the business
http://www.vwdiesel.net/forum/index.php?topic=29808.0

You are looking for Nathan_b

I can call the local VW shop around here in the AM if you need. There is a guy from the forum coming up for a visit, he might be willing to ship it to you once he is in the states on Saturday. IM me if you are interested.

[RockOcean]

Yes the block is what I meant. I have found a one notch here:

http://www.autohausaz.com/search/product.aspx?sid=ahc35ur0jdp3dkadu2slby45&makeid=800026@VW&modelid=1283958@JETTA%20TDI&year=1996&cid=20@Engine%20Parts,%20Seals%20%26%20Gaskets&gid=5412@Cylinder%20Head%20Gasket

But they list it at 1.45mm where other websites list a one notch at 1.53 I believe the AHU 1 notch is 1.45 so I hope they do not have things mixed up.

Has anyone ever heard of someone melting their pistons from using .04mm too thick of a head gasket?

[libbydiesel]

That IS A MISTAKE at AutohausAZ.com.  For whatever reason the parts database shows the AAZ for '96 and yet the head gaskets shown are for the TDI.  They do sell the 2 and 3 notch gaskets, but the WRONG parts are listed if you go by the application engine.  If you search by part number the correct gaskets come up, but no 1-notch.  For future reference, the AAZ gasket part numbers are 1-notch 028103383BH, 2-notch 028........BJ, 3-notch 028........BK.