Vako's AAZ rebuild

[Gizmoman]

I can almost hear it clack!
Keep at it.

[vako]

i generally love cars and motorsports. (i'm a layer by profession ) but the process of  assembling the engine is my favorite part    starting it up after the rebuild brings you the feeling that cant'n be compared to anything other related with cars

still i have to wait for at least 2 weeks for my head bolts and piston rings to arrive from the uk

[vako]

i forgot to answer turbogaser about pisron ring grooves (that were deformed previously), after overheating the outer edges of the groove just moved a bit closer to each other. only few moves of needle file were enough for setting the right width of the groove ( 1.8 milimeters if i'm not mistaken). also i wet sanded the scorings very lightly  (without changing overal geometry)

[vako]

my engine block surface was flat so it was not resurfaced. how should i remove old gasket residue ? should i use sandpaper?

these are mu bearings  
main bearings are from petrol engine (with 6 grooved bearings and 4 plain bearings), diesels have 5-5 grooved -ungrooved bearings. as far as i know it wont cause any issues in 70-100k kilometers. my new engine had that configuration and lower grooved bearing on 4th journal looked very well

[Gizmoman]

There are many posts (here) on this subject with some good info.

What worked well for me was a large mill-bastard file. Holding it flat against the surface and moving it in a circular motion with your finger tips.  Squirting a bit of W-D40, paint thinner or diesel fuel on during the process. Obviously that was after removing stuff with a putty knife. Use some good de-greaser like acetone or brake cleaner when your done and just before you spray it with hylomar (or your sealer of choice). Don't even touch the surface with you fingers once it's clean.

BTW, some guys use no sealers between the surfaces at all. In my opinion, that is OK for brand new surfaces but once used, you need all the help you can get. - again, just my opinion.

[vako]

there are some news according to block and piston protrusion.

today i  assambled the block with old bearings and installed the crank, to check if new con rods all were of the same size and also measure piston protrusion. measurements showed that pistons all pistons only protrude from 0.48mm to 0.53-54 mm-s :|  then i installed old rods on new pistons and protrusion went up to 0.80-0.85mm-s. with old piston and old rod protrusion was 1mm.

can i run 1 notch head gasket with that figures?

I also plan on resurfacing the block. i don't want to have head gasket leaking problems again (new bolts an gasket cost more than 50$ :|), so experiments are not for me by now. and it will cost 18$
 block resurfacing will also increase protrusion by 0.1 milimeters (i hope)

[vako]

there are some litle scratches around cylinders (seen well on the pics)also the place from where the aold gasket leaked does not look perfectly flat.  resufracing will solve all the problems i think...

[vako]

could piston to valve contact shorten ALL conrods by 0,2 millimetrs?

i have measured now and all new pistons are lower than old sdt size pistons (distance from piston pin hole to piston top) . most likely to compensate for block deck resurfacing during engine rebuild ))

also i have a question about main bearing cap bolt torque. i have 2 kind of bolts, bolts with thread on all length from new egnine and bolts from old engine with thread only on the half of the bolt.    shoul both types of bolts be tightened 65 nm + 90 degrees? or 90 degreesecondary retoque only refers to fully threaded bolts? if you have bently manual could you please help me and give an info about that  i have hyens manual and dont like it very much. there is not written should main bolts be tightened dry or lubricated :|

[CrazyAndy]

Fully threaded shank bolt (non-reusable) tighten to 65 Nm (48 ft-lb) plus 1/4 turn
Partially threaded shank bolt tighten to 65 Nm (48 ft-lb)
Do not mix bolt types.

Haynes manual is not very well described in engine and transmission work; get the Mk3 Bentley manual.  You'll thank yourself later.
http://www.amazon.com/Volkswagen-Jetta-Golf-GTI-Platform/dp/0837616603/ref=sr_1_1?ie=UTF8&qid=1382844337&sr=8-1&keywords=bentley+manual+mk3+vw

P.S:  Maximum allowable height on AAZ engine pistons is 1.02 mm; 0.48mm to 0.54 mms is within both piston protrusion deviance and 1-notch head gasket thickness tolerances.

[vako]

CrazyAndy
thanks for the info about bolt torques. in hayens it was given very strangely...
for aaz 65 + 90 degrees
for abd, abu engines
with full threaded bolt 65 +90deg,
for partialy threaded bolts 65nm...
but there was not written if those figures for aaz were for fully or partially threaded bolts

are those bolts installed dry or lubed ?

 
you mean that 0.48-0.54 piston protrusion is normal for AAz, yes? that's very good   hayens manual gave the figures for protrusion above 0.65mm thats why i was interested if smaller protrusion is acceptable. anyway after block resurfacing i think that protrusion will increase at least by 0.1-0.15 milimeters

[vako]

today i brought my engine parts back from machine shop. block was resurfaced, 0.35 mm was taken off the block. as the mechanic said. (i hope that now i will be within 2-3 notch gasket range). also the crank was machined and polished, ball bearing fitted to the back side of the crank and spocket side resurfaced.   all this for 30(crank)+18(block resurfacing)+12(fitting ball bearing to the crank) dolars ))   after that i wen to another shop to machine crank nose for tdi style spocket . 2 milimeters were taken off the crank nose and tdi spocket fitted fust fine. (for 7 dollars).

when i came home i found that spocket had 1 or 2 degrees of play when fitted on the crank...  after fitting 4 foil layers on the  tdi spocket tooth the play dissapaired...  taht meant taht the surface ws machined just 0.05 milimeters more than it was needed. after 3 or 4 light taps (with a tiny hummer) on the spocket tooth (seen on the pic) the pulley deformed and now it fits perfectly on the crank 



i removed oil galley plugs from the block and washed everything with petrol few times, now it is as clean as  new  tomorrow i'll start assembling the the block (fit the crank, squirters, seals and timing belt spocket.)

i think my rings and head bolts will arrive next week and then i'll be able to assemble pistons and fit the cylinder head.


i will torqure main cap bolts up to 65 newton meters. my friend who worked as an engine mechanic for many years also told me that non stretch bolts should never be tightened as strech bolts, otherwise they will most likeky snap after heating up..


hope they do not come loose (fingers crossed)
 

[vako]

tight bearings, before and after editing with piston ring edge. it seems that n2 and n4  main bearing caps have some kind of distortion. amd after tighteniong the bolts up to 56 newton meters the cranks was hard to rotate.

after inspecting old bearings from my engine it seems that they suffered from same problem... but no one had tried to solve the problem before starting the car up. so after few turns of the crankshaft it rubbed off the top layer and worked like that till i took it apart.



these are main bearing journals in the block, by the wer pattern (after rotating the crank by hand today) it seems that they are not distorter as the caps, and seem to be quite in a good shape.

[CrazyAndy]

Just wanted to say that the main bolts are tightened dry.  Lubrication would cause false torque values in this case.  Also here are the piston protrusion measurements for all AAZ head gasket thicknesses.

0.66 - 0.86 mm: 1 notch
0.87 - 0.90 mm: 2 notch
0.91 - 1.02 mm: 3 notch

I'd also recommend adding some filler around the deformed area of the crank sprocket to support near the ends of the D flat; the distorted area might rub flat after a while.  Just a paranoid man's bit of advice.

As for the main bearing concern, t might be time to check the alignment of your main journals, assuming you actually used some oil or assembly lubrication when  spinning the crank while the caps were partially tightened.  Was this the engine that had had it's journals already over-sized?That might explain the markings due to poor machine work done during the original rebuild.  And are you sure you had the main caps aligned correctly?  Just asking.

[vako]

Just wanted to say that the main bolts are tightened dry.  Lubrication would cause false torque values in this case.  Also here are the piston protrusion measurements for all AAZ head gasket thicknesses.

0.66 - 0.86 mm: 1 notch
0.87 - 0.90 mm: 2 notch
0.91 - 1.02 mm: 3 notch

I'd also recommend adding some filler around the deformed area of the crank sprocket to support near the ends of the D flat; the distorted area might rub flat after a while.  Just a paranoid man's bit of advice.

As for the main bearing concern, t might be time to check the alignment of your main journals, assuming you actually used some oil or assembly lubrication when  spinning the crank while the caps were partially tightened.  Was this the engine that had had it's journals already over-sized?That might explain the markings due to poor machine work done during the original rebuild.  And are you sure you had the main caps aligned correctly?  Just asking.

i was tightening them oiled :|
i'll wash the bolts an the bolt holes with petrol and reassabmle it that way. have you used patially threaded bolts on your engine?   65 nm-s still seem a bitloose to me 

i run light serp belt pulley on the crank. damaged old style spocket was there for 3 years already and signs of wear of crank nose fail  during the dissasembly tightening the main bolt 90 newton _90 degrees helps a lot   

main caps were installed correctly  bearing lock on one side and numeration from timing belt, i never mixed new engine caps with my old ones.  my engine seems to be rebuild already  and the journal problem was there during that rebuild.    we do not have bore alignement tools here in tbilisi. as far as i know machine shops can't even measure one that new engine block seems not to have journal problems (by bearing wear pattern, but still i do not want to mix the bearing caps, even for experiment

my engine seemed to work fust fine (for three years, during many competitions and in expeditions) like this and teardown reason was just blown headgasket. so i think that it will be good for another 50-100 k kilometers

after scraping of some material from tight bearing surfgace (the polished sports) now the cranks spins freely even when toruqed to 68nm-s. in the begining it was starting to "bite" after 30 nm-s

[vako]

today i finished "fine tuning" tight bearings. as a result cranks spins freely even after 70 nm-of bolt torquing.

after measurements it seems that i have removed 0.01 mm from one bearing and 0.015 from another 


tomorrow i will toruqe the bolts to 65-68 newton meters, not lubricated.  one more question? should i use locktight on crank bolts? or it is not needed at all?

i will definately use them on flywheel bolts and i have already locktighet the squirter bolts (as it was written in manual).