1.6d N/A timing/valve question - page 1 - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• 1.6d N/A timing/valve question by NWVintage on 28 Feb, 2013 09:21
• Hey everyone-
  
  So, I just finished a major overhaul on my '81 1.6d N/A. Rod bearings, piston rings, cylinder ridges/hone, head deep clean, valve lap, stem seals (guides were in excellent shape), all new gaskets from the head gasket up, timing belt/tensioner.
  
  At the end, I reset the timing and I'm wondering what people think about different advance settings. For the early 1.6's (through '81) Bentley says .88 +/- .05. Later - IIRC - are .95 +/- .05. I went with .93, being that it's within both ranges. I haven't actually driven in yet but warmed it up to operating temp twice yesterday with some revs, followed by an oil/filter change to get any crap out of there before I start driving. Seems to run great but its a little diesel-smokey (white/blue, smells like diesel only). With the advance pulled, the smoke is barely there but with the advance in, it's fairly visible. I am using a different cam and didn't have new shims, so I didn't even measure the lifter clearance. They sound like one or two might have a little too much gap but nothing terrible.
  
  Would improper lifter clearance cause significant smoke or should I advance the timing a bit? I am planning for a valve job in the next month or two but I honestly can't afford a shim kit at the moment.
• #1 by wolf_walker on 28 Feb, 2013 11:08
• Drive it first.  I've had that smoke on fresh motors just sitting, even warmed till when the fans cycle, and it went away after a real drive.
  
  Pump timing varies, it's partly preference for clatter, partly what the motor will start well at, etc, etc.  Lot of variables unless everything is textbook new.
  And even then, fuel isn't what it was.  I'd set it to .90 or thereabouts and adjust it around after the motor is broken in and settled. 
  
  My 2C
  
  
• #2 by air-cooled or diesel on 28 Feb, 2013 13:58
• you must drive first to seat/break-in rings. before you do this the first thing is to break in cam, at FIRST start up after a new cam/lifters, rev up to about 2000rpm for 20 min of hot run time to break in cam, you also NEED new lifter shims w/a new or another cam as old shims will transfer wear old pattern to new/another cam.
  after re-ringing, it takes 500-1000 miles to break in new rings(alone).bearings take about as long too.
• #3 by theman53 on 28 Feb, 2013 16:12
• If it were a brand new cam then I would agree. Follow the cam MFG recomendation. If not I would start the engine, check for leaks, then get it driving to seat the rings. They need load.
• #4 by ORCoaster on 28 Feb, 2013 20:00
• NWV... So it runs?  Great but you need to figure out the valve clearance thing.  You don't need to buy a whole kit.  You know, or can measure the distance between cam and shim right?  And you can figure out the thickness of the shim by either removing the cam again, or getting the special pliers and tool to press the lifters down.  I have them and they save taking all the caps off and timing belt crap you would have to go through.  
  
  So once you know the shim and the clearance then simple math can give you the proper shim thickness that you need and you can just buy those from a parts place or a repair shop.  My local guy sells them for like 2.50 each.  and he had quite the selection.
  
  Once you get the valve clearances well in hand I expect that the smoke will be less just from that.  But break in is needed as well.  
  
  by the way the money for the cam was reinvested to another here for a cruise control.
• #5 by NWVintage on 01 Mar, 2013 08:02
• Thanks for the info guys!
  
  Yes ORCoaster, it runs! Thanks again for the cam!
  
  My initial warmups were with the idle screw turned up (after I started it) to hold it around 2k rpm. The only reason I did it twice is that I wanted to get the oil changed before I started driving and I didn't have time to change it right after the initial warmup.
  
  I got out for a couple good drives yesterday with an 8 hour cool down between. It seems better all around after. The valves sound much better and the smoke situation is also much better. Maybe both were due to a little low compression resultant of the as-yet-unseated piston rings?
  
  How important is it actually to replace all of the lifter shims as it pertains to cam wear? I don't have extensive engine rebuild experience, but I've done a couple prior to this and I have never heard that before - of course I've never replaced the cam before either... I visually inspected each of the shims and they were in very good shape. I realize that I need to get them to the right thicknesses but is it really necessary to replace them all? I suppose its cheap insurance, though...
• #6 by wolf_walker on 01 Mar, 2013 12:36
• People been using second hand shims on cam setups like that forever, they are not a VW specific thing.  Never seen or heard of wear because of it.
  The book might say use new shims, never even seen that though myself.
  
  If they were one piece hyd lifters I'd say replace them, they are usually half crapped out anyway.
  
  A lifter is supposed to stay with the cam lobe it started life with, by the book.
  In my experience if there is no observable wear on the cam or lifter face, it'll be fine.
  I'd only do that with something fairly cheap and/or easy to replace a cam in though, for the record.
• #7 by ORCoaster on 01 Mar, 2013 14:26
• I gotta go with Wolf.  Use what you have if they are the proper thickness for job.   I have swapped shims all over the cam and not had a problem.  Number side down is my only rule.  As long as there is no wear on it I think it will do fine. 
  
  Now that you are an expert on rebuilding how about doing the rings in mine?  I can't seem to break free from the job long enough to get time for myself these days. 
• #8 by air-cooled or diesel on 01 Mar, 2013 17:08
• like wolf said, a lifter goes with a cam lobe, but old shims with new lifters doesnt sound critical, but its not expensive, it has new lifters, a different cam; just seems smarter to measure valve clearance and use new shims, the cams wearing surface is riding on this surface, like he said insurance.
  the trick to adjusting mechanical valves (lifters) is the intakes can be closer to min clearance, but not right up on it. the exhaust can be a bigger clearance. works really good for air cooled valves. i havent had a mechanical head in a lot of years, but in an air cooled you notice just a little jump in power from doing this (as intake is a tad tighter and you can get more air in; just a little) and you cool the exhaust more (by it being closed a tad longer). much less critical in a water cooled, but as long as the intake and exaust measurements are reasonable it cannt hurt anything and your exhaust can cool a little longer (per cycle). exhaust measurement like the half way point in the book. (?.001-.002??looser than half way)
  measure off the old shims and you should be able to find a parts dealer and get the exact size you measure. using one of those lifter compression tools makes it easy, while using tool make sure you have clearance at the pistons, your pushing the valves open some; dont have a piston in the way.
  the measurement trick would work better with new valves/springs/etc.; though.
  keeping an eye on the valve measurement will give you an idea if a valve has had it, if the gap keeps tightening up the valve stem or the lock on the stem is stretching and you may want to take care of that at that point.
• #9 by wolf_walker on 01 Mar, 2013 21:04
• On a semi related note, I hate adjusting valves.  They run better and the lifters don't fail, but I still dislike the damn things.
  If I never have another, which I will I'm sure, it'll be too soon. 
  The least annoying have been old BMW with the eccentric cam, or Merc diesels if you have the skinny wrenches.
  I'd still rather replace lifters every few years and give up a few ponies. 
  Maybe I'm getting old.
• #10 by 745 turbogreasel on 01 Mar, 2013 21:30
• IMO lifters are not tied to the cam lobe, they don't contact or care about the cam.  They do like to stay in their native hole in the head.
  
  I'd not drive without at least checking  I had minimum clearance on all valves, it doesn't take long to burn one if it isn't closing.
• #11 by air-cooled or diesel on 02 Mar, 2013 09:18
• every other type of lifter (solid/mechanical, and hydro; 1 piece) are directly tied to a cam lobe as it first runs, to change up a lifter(s) that have 'run' on a cam (lobe) to another lobe will fail.
  thats another reason im in favor of keeping shims on an individual lobe(also). as the shim does more than 1 thing, it determines your valve clearance (and effects valve timing just slightly; tight clearances open valves slightly longer; looser clearances valves are closed slightly longer, allowing a little more cooling); also shims ride on cam surface. partly integral to cam / lifter operation.
• #12 by 745 turbogreasel on 02 Mar, 2013 14:37
• If this were true, VW would specify that shims must only ever be reused on their native lifer, but they don't, because it isn't a problem.
  lifter to bore wear match in the alloy head is the only  reason to keep them in one spot for us.
  
  Roller lifters which are better anyway can go on any lobe or roller cam.
• #13 by theman53 on 02 Mar, 2013 15:17
• Air cooled, I do not believe what you are saying. Do you have a bentley or some manual to back it up? IIRC our manual lifters never touch the cam, the lifter has the shim and the bucket deal on top of it, then the cam IIRC. It has been 2 years since I adjusted mine and I could be off on that.
  
  To the OP: if you don't know the values then you should before running. The way I read it before was you knew that it was in spec but at the end of spec...now I see you didn't know what values you had.
• #14 by TylerDurden on 02 Mar, 2013 16:01
• Shims are swapped around regularly.
  
  IIRC, the shims/lifters contact the cam lobes slightly off-center to rotate the lifter as it operates.