AAZ head and MF block questions

[libbydiesel]

I want to point out that you are going through a lot of effort in order to install a knock-off cylinder head onto a 1.6TD block.  Although I believe it is doable, it is both risky and the end result is questionable (low compression, poor combustion, hard starts).  I don't think you ever replied about whether or not you actually measured the cracks between valves and compared that to what Bentley says is acceptable.  Is this still going into a Vanagon?  In Montana?  In that situation, I would pursue the MF head further before opting for the aftermarket AAZ head.  If the MF head was indeed unusable I would see if I could find a usable OEM solid lifter head.  Failing that I would opt for an aftermarket solid lifter 1.6 head.  I would not opt for the aftermarket AAZ head until those prior options were exhausted.     

[dontdoemyourself]

I want to point out that you are going through a lot of effort in order to install a knock-off cylinder head onto a 1.6TD block.  Although I believe it is doable, it is both risky and the end result is questionable (low compression, poor combustion, hard starts).  I don't think you ever replied about whether or not you actually measured the cracks between valves and compared that to what Bentley says is acceptable.  Is this still going into a Vanagon?  In Montana?  In that situation, I would pursue the MF head further before opting for the aftermarket AAZ head.  If the MF head was indeed unusable I would see if I could find a usable OEM solid lifter head.  Failing that I would opt for an aftermarket solid lifter 1.6 head.  I would not opt for the aftermarket AAZ head until those prior options were exhausted.     

Its not going into the Vanagon anymore, back in the old MK2 Jetta, which will then be headed to its new owner who lives in WA . I didn't measure those cracks.. I will do that today. I also am concerned about the amount of effort I'm putting into this potentially worthless head.. I'll measure those cracks and see what they turn out to be, and maybe make a plan to use the original head if it's in useable shape. If they're too big to be useable, what would be recommended from there..? I just need to get this thing all put back together and on the road, my Vanagon is my main goal to complete, but I also can't cut any corners, as I want this to be a reliable 1.6
Thanks again for all of your help gurus, looking forward to completing this and getting to enjoy it.

[dontdoemyourself]

I want to point out that you are going through a lot of effort in order to install a knock-off cylinder head onto a 1.6TD block.  Although I believe it is doable, it is both risky and the end result is questionable (low compression, poor combustion, hard starts).  I don't think you ever replied about whether or not you actually measured the cracks between valves and compared that to what Bentley says is acceptable.  Is this still going into a Vanagon?  In Montana?  In that situation, I would pursue the MF head further before opting for the aftermarket AAZ head.  If the MF head was indeed unusable I would see if I could find a usable OEM solid lifter head.  Failing that I would opt for an aftermarket solid lifter 1.6 head.  I would not opt for the aftermarket AAZ head until those prior options were exhausted.     

I used some feeler gauges to see how bad the cracks between the valves on the stock 1.6td head were, from 1-4 they are .020" .019" .018"and .020" respectively.. I also could not find the tolerances in my Bentley's. Though I do have older ones for Rabbit's (from 1984, includes the turbo diesel) and Vanagon diesels.
 Any one have a source on a 1.6td head to replace mine? At this point you guys are totally right and I've put a bunch of time and money into it already, I should just buy a refurbed head and call it good.. I saw a guy out of Cali selling them on thesamba, anyone have a better source for the price?  thanks again.

[libbydiesel]

I think the crack width sounds fine.  That's ~the thickness of my thumb nail.  I thought I had seen a spec from VW which was ~the thickness of a dime which is over 2X what you say.  I looked in the Mk2 Bentley and could not find a spec listed so I might be mistaken about it being listed. 

[dontdoemyourself]

cool, good to know i've got a little wiggle room there. I might de burr the ones that are close to intake valves. Ill get this resurfaced this week and get it cleaned up to be reinstalled. its dirty AF. welp, it'll probably work better than the other one. Anyone have a use for the other 1.9 head.. ha.

[libbydiesel]

At this point I am no longer in favor of having the diesel heads resurfaced by a milling machine.  I believe that the process loosens the pre-combustion chamber inserts and makes them more likely to fail in the future.  I have had good results from hand lapping the head gasket surface with 120 grit paper spray glued onto a piece of flat polished granite.  That process is gentler on the inserts and actually leaves them slightly proud of the rest of the surface which is what you actually want. 

[dontdoemyourself]

120 grit, is that a typo? 1200? seems coarse! would a piece of 1/4" steel stock work in place of granite..?

[libbydiesel]

120 grit is not a typo.  That's plenty smooth.  It does not need a mirror finish.  I have installed several heads treated in that manner without any issues.  I use the paper from an 8" wide roll so I do not have any seams.  You could finish it finer if you wanted to but it is not necessary in my experience.     

You would want the 1/4" steel supported solidly and flat also or it will flex but if true and flat it will work.  I solidly support the piece of polished granite I use to keep it from flexing.  I lube the paper with WD40 or the like and use a good technique of keeping the head flat when moving it and altering the direction.       

[dontdoemyourself]

 I will be spending some time on it this weekend. sounds like my workbench surface should work fine, its topped with the big piece of 1/4" steel , probably 12x24" and I can just buy a roll of 120 to stick to it, perfect.

[dontdoemyourself]

cylinder head resurfaced, hopefully only a few weeks til it runs!

[libbydiesel]

Nice!  Fingers crossed.

[dontdoemyourself]

its all timed, torqued and on the hoist ready to drop in the bay tonight, any recommendations for break in oil.. ? I have some Mobil 1 or some shell 15-40 synthetic, some 20-50 conventional.. thanks

[ORCoaster]

I'd run the conventional for the first 500 miles then change the filter and switch to the synthetic.

[libbydiesel]

I don't recall what all you have done to it.  If you have new rings, then do not use synthetic oil for the first few thousand miles.  It can prevent the rings from seating properly. 

[dontdoemyourself]

bored .020" over, new pistons, rings, bearings, new HG, ARP studs, windage tray, AAZ injectors. Decided to keep the stock K24, have an EGT and boost gauges to install as well as a smaller IC from an Audi 2.7T I think. planning to fire it today. Cranked it over last night to prime it with oil before I bled the fuel system.. didn't make any crazy sounds.. so I think ill go for it today.