1.9 AAZ Head clean-up =) - page 1 - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• 1.9 AAZ Head clean-up =) by 8v-of-fury on 02 Mar, 2009 19:52
• Ok so this past weekend I met up with Tyler (Burn) and he gave me an AAZ head. It's got some minor pitting and gunk built up around the valves, which to me doesn't even seem that big a deal. I will post up a few pics of everything to see what you guys think..
  
  
  
  
  
  
  
  
  
  
  
  
  I think if i were to clean it up a bit, and in the end run a metal HG with some studs... I wouldn't have to get it machined.. lol Which is what im aiming for here.. Cheap as physically possible..
  
  So after cleaning it, even if it is a little rough, it will still be a step or two above the stock 1.6 head. Hopefully this plus the Superpump I wish to get in the near future, will really wake the N/a up
  
  What do you all think? any good words of advice how to clean it up? and so on? Everything is welcome!
  
  Jeremy
• #1 by jtanguay on 02 Mar, 2009 20:04
• hmm maybe scotchbrite on the sealing surfaces, and then use a dremel to port & polish  
  
  the 1.9 MLS won't mean a perfect seal if its warped though...
• #2 by 8v-of-fury on 02 Mar, 2009 20:15
• Quote from: "jtanguay"

  hmm maybe scotchbrite on the sealing surfaces, and then use a dremel to port & polish  
  
  the 1.9 MLS won't mean a perfect seal if its warped though...

  
  
  This is true. I don't think it is warped.. I will have it tested for it's trueness I suppose and then if it does need it, see what it will cost..
  
  Port and polish baby! WOOT WOOT lol thanks Jon
• #3 by AudiVWguy on 02 Mar, 2009 23:35
• I was just curious, does anybody know about welding the cracks between the valves. Is that the correct solution? Before a person was going to take it to the machine shop?
• #4 by TurboJ on 03 Mar, 2009 07:43
• If the cracks are really huge, then they should be welded shut.
  If the cracks are small, just let them be.
  No matter how well you weld them up, they will always crack again within minutes. That's just how VW IDI heads are, they will always, but always, have cracks between the valves.
  
  Luckily the cracks need to be big indeed before they have any real effect on how the engine runs.
• #5 by 8v-of-fury on 03 Mar, 2009 14:19
• Progress! It cleaned up fairly well! Or so I think, I've never done this before lol.
  
  
  
  
  
  
  
  
  
  
  As you can see the pitting is only on the first two cylinders, and the second two are in good shape. I was told as long as the pitting is not where the gasket needs to seal, it should be somewhat ok? lol Also the cracks between the two with the pitting are somewhat larger, but don't seem to be that bad... what do you think?
  
  I'm not done cleanin it up yet, just wanted to get the main parts done to get some pics up. Tell me what you think!!
• #6 by RabbitJockey on 03 Mar, 2009 14:36
• i think those cracks look pretty bad i wouldn't personally use that head, i know you wanna be cheap, but if you were given that head u could always buy a new one off ebay and swap the valve train over, yeah thats 300 dollars but that head looks like hell and a new one will surely bring less headaches.  i don't think the pitting would keep it from running fine but the cracks could i definitely get that head pressure tested if i had planned to use it.  honestly i've never seen cracks as bad as cylinders one and two.  looks like someone needed new injectors or had a ***ty pump tho.
• #7 by 8v-of-fury on 03 Mar, 2009 18:20
• Quote from: "Trev0rbr"

  i think those cracks look pretty bad i wouldn't personally use that head, i know you wanna be cheap, but if you were given that head u could always buy a new one off eBay and swap the valve train over, yeah that's 300 dollars but that head looks like hell and a new one will surely bring less headaches.  i don't think the pitting would keep it from running fine but the cracks could i definitely get that head pressure tested if i had planned to use it.  honestly I've never seen cracks as bad as cylinders one and two.  looks like someone needed new injectors or had a ***ty pump tho.

  
  
  I don't want to be cheap, I want to be inexpensive. :lol:
  
  I don't plan on running boost or anywhere near high horsepower. Pressure Testing, what is this? How is it accomplished? If it checks out from being pressure tested will it be okay? The cracks are nowhere near as bad as the pictures make them.. The are no bigger then 3&4. They don't even extend in to the valves at all, it just looks bad because the area has been eroded. Is the pitting tell-tale damage of bad injectors and bad pumps?
  
  

  Quote from: "Andrew"

  X2 on having it pressure tested. Also tip it up so the ports are facing up and pour some form of solvent in the ports. WD-40 would work even. Then check to see if it leaks out onto the combustion faces. I'm most curious whether or not the exhaust valves on the first two cylinders are leaking. I have a theory bounding around in my head that leaking exhaust valves on a boosted engine can cause engine melting temps without registering high EGTs on a gauge and could cause that type of erosion without any damage to the other two cylinders.
  
  Andrew

  
  
  It leaked out of 2 of the 8 ports. 2 that are slightly open. One of the badly worn cylinders is open.. but the other three of those cylinders didn't leak. So you think that maybe the two badly worn cylinders exhaust ports leaked causing the heat to stay in the combustion chamber longer than desired on every stroke? causing premature failure? H mm sounds intriguing
• #8 by Rabbit TD on 03 Mar, 2009 19:00
• I wouldn't even consider putting an old head on an engine withot pressure testing it, making sure it's flat and at least hand lapping the valves and putting new valve seals on it assuming the guides are good also.  VW heads are usualy not on an engine for a reason so don't put yourself through a lot of agravation by not getting it checked and by all means do use the studs like you said.
• #9 by 8v-of-fury on 03 Mar, 2009 19:03
• Quote from: "Rabbit TD"

  I wouldn't even consider putting an old head on an engine without pressure testing it, making sure it's flat and at least hand lapping the valves and putting new valve seals on it assuming the guides are good also.  VW heads are usually not on an engine for a reason so don't put yourself through a lot of aggravation by not getting it checked and by all means do use the studs like you said.

  
  
  hand lapping the valves, how is this accomplished? If this gets done, and it is pressure tested, checked for its flatness and new valve seals. It should be good to go.. right?
• #10 by subsonic on 03 Mar, 2009 19:13
• Send it to the diesel head magic man:  Franko6.  That guy needs to be a registered vendor over here.  His head work is Mag-fn-nificant!
  Either way, rebuild or buy new, it's gonna cost you some coin to do it right.  Your time is free, but nothing sucks more then dumping hours and hours plus an ample amount of knuckle skin into a rebuild just to have something that was marginal fail and take something else out in the process.
• #11 by burn_your_money on 04 Mar, 2009 04:59
• I askde Franko6 to join about a year ago. He said no one wants IDI heads... :roll:
  
  You can check the flatness yourself fairly easily to save some coins
• #12 by arb on 04 Mar, 2009 05:34
• Quote from: "libbybapa"

  
  
  Hand lapping is accomplished by placing a small amount of valve grinding compound between the valve and seat and using a suction cup tool to rotate the valve in the compound.  It basically works similar to sandpaper and helps the valves to seal completely.
  
  Andrew

  
  
  Its implied that you remove the cam, lifters, and springs prior to lapping. And, yes, lapping is a very very good idea. I would also be a little concerned about the erosion next to the precombustion cup on that first cylinder - looks like it might affect it, maybe not.
• #13 by 8v-of-fury on 04 Mar, 2009 08:16
• Quote from: "arb"

  I would also be a little concerned about the erosion next to the precombustion cup on that first cylinder - looks like it might affect it, maybe not.

  
  
  What are your views on this, what do you think it will cause to happen? Not askin to be a smart ass, just because i simply don't know
• #14 by truckinwagen on 04 Mar, 2009 08:26
• it might cause it to be loosened and fall out.
  
  if you do use the head I would aggressively peen around the prechambers to keep that from happening.