TLC for my GTD (rebuild), IT RUNS! - page 1 - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• TLC for my GTD (rebuild), IT RUNS! by wil892 on 27 Oct, 2011 13:21
• Hi guys
  
  I know i've had a few threads about certain parts of this engine but I thought it might be best to have one thread I can report and ask questions about rebuilding my engine.
  
  Basically I have an 80hp 1.6l Turbo diesel engine, made in 1991 code SB. Here is a list of what I am doing to the engine:
  
  Block:
  Bored 0.5mm over
  Kolbenschmidt 0.5mm OS turbo diesel pistons with rings
  Standard new KS main bearings, with new KS separate thrust washers
  Standard new KS con rod bearings
  Febi new con rod bolts
  Elring gasket kit
  
  Head:
  8 new guides
  4 new Genuine exhaust valves
  Seats recut
  4 new AE turbo diesel prechambers
  Head faced, prechambers faced to protrude slightly from head
  new elring stem seals
  new valve cotters
  
  My first question is about the con rod bolts. I know they are stetch bolts hence replacing them, but I am reading a lot about having the rods re sized. I sort of understand what this is but don't know if it is necessary on this engine if I am just replacing the bolts with Febi stretch bolts rather than ARPs. Is re sizing generally expensive?
  
  The machine shop who is doing all the work has said the intermediate bearings look fine and he wouldnt replace them. There is no flaking or rough areas, only polishing on the loaded side. I never overtighten belts so wonder if its better to just leave it as is?
  
  I will get some pictures up soon, and will be updating as I start to build the engine up. I've put a LOT of money into this engine as I would like this to be a very long term car, so I am pretty nervous about putting it all together. There will no doubt be a lot of small (maybe silly) questions, even though I always search first!
  
  Here are some pictures of the car:
  
  
  helper
  
  
  
  
  Will
  
• #1 by rallydiesel on 27 Oct, 2011 13:31
• Beautiful cat.
• #2 by rodpaslow on 27 Oct, 2011 13:51
• Nice!  Just wondering what the thing just above the oil filter is that has an electrical connection?  Do the GTD have an auxilary water pump or is that something else?
• #3 by wil892 on 27 Oct, 2011 13:55
• Haha thanks, yeah his name is Harris, he's a character!
  
  The GTD has a water cooled turbo, it has a sensor on the turbo which turns on an auxilary electric water pump when it reaches 110 degrees I think. It usually runs for 5-10 minutes after I turn off the car.
• #4 by wil892 on 10 Nov, 2011 01:33
• Ok quick update
  I'm getting the block and head back tomorrow, the head will be built up but the block is bare. It has been bored, and is being hot tanked tomorrow morning before I pick it up. Obviously the hot tank will remove the machining swarf but i'm not expecting it to be clinically clean.
  My plan is to take it in to work where we have a compressed air line and a parts washer. I will wash it with the parts washer first, rinse it with brake cleaner, then wd-40 it and use crank wipes to clean it. I will then brake cleaner it again, use compressed air, and finally wd40 the bores and journals before I transport it back home.
  Does this sound sufficient? I have never prepped a block before so I don't know what to expect really, just not wanting to screw it up!
  Will get some pictures
• #5 by Mark(The Miser)UK on 10 Nov, 2011 01:57
• I'd leave the intermediate bearings. The engine  is clearly still happy with them after 160000 miles, and not likely to change much. Let's hope all this cleaning is worth it. Don't let something else catch you out.
  
  Check condition of the clutch cable. This one is unique, and aftermarket sends you to the non intercooled versions which don't fit. VW were selling them quite cheap. Get one and hold it in reserve. push grease up the old one. Remember VW designed this  as LHD.
  
  Does the front just bolt on? Alas Quantum/mk2 Passats are welded.
• #6 by sdwarf36 on 10 Nov, 2011 03:21
• What I do (working at an auto machine shop) Is first clean the bores with a water based cleaner (like simply green) to clean any vomit left from the part washer (hot tank) then i wipe them down with Acetone. I have in other places used hot soapy water with good results.(I have a co-worker that swears by using ATF) The finish test is wiping with WD-40 on a clean lint free paper towel-keep doing it till the rag comes up clean (no grey on it.) Your method sounds fine. You can never get a cylinder too clean.
• #7 by wil892 on 10 Nov, 2011 04:09
• Thanks mark, yes i'm being quite proactive trying to reduce the number of things that could potentially wreck havok with this very expensive bit of metal! The cable was actually a new one from VW a few years ago, as the previous owner serviced it there for its whole life. and yes the front just bolts on and off, which is great!
  
  Great info on the cleaning. It turns out I can use the mecwash here at work which is basically a giant block washing machine, and its all filtered, so i'm sending it through at for 40 minutes then will give it the WD-40 cylinder check.
• #8 by wil892 on 10 Nov, 2011 05:17
• Has anyone replaced the conrod bolts? If so what was their method and did you find the rods needed resizing afterwards?
  The machine shop said they would not replace them, however I have bought some new FEBI ones and am quite tempted to fit them for piece of mind.
• #9 by sdwarf36 on 10 Nov, 2011 09:44
• I replaced mine with ARP's-we're a dealer + they were cheap enough. There seems to be debate that there are either 2 different bolts--or at least 2 different listings in the Bentley-between a "stretch" bolt and a reusable one. ALL BOLTS STRETCH-THATS WHAT PROVIDES CLAMPING FORCE! The question is are they made to stretch + return the original length--or stretch once -like the head bolts.
   The ARP's are a little large for the holes in the rods-I think i left 1 bolt in + silightly reamed the other hole-tightened + did the same for the other bolt. The rods are pretty beefy-they really shouldn't move with new bolts installed BUT..... Ask you machinist to just measure the big ends after you put the bolts in and torque them (should only be a couple of bucks) if they are still round + to size, leave'em alone. 
• #10 by Mark(The Miser)UK on 10 Nov, 2011 12:24
• Quote from: sdwarf36 on 10 Nov, 2011 09:44

  I ALL BOLTS STRETCH-THATS WHAT PROVIDES CLAMPING FORCE!

  I agree wíth what you are saying, except for the above, which has me confused.
  
  My understanding is that stretch is what limits the clamping force, and especially plastic stretch which halts it. Friction of the wedge of the threads is what holds the bolt, without which the bolt would undo, hence Loctite...
  Crikey I'm turning into 'Eraserhead', or was it Eraser-thread
• #11 by sdwarf36 on 10 Nov, 2011 12:56
• picture 2 bolts-one mint clean + oiled--and one rusted to hell. You screw the clean one in by finger till it bottoms--the rusted one you need a wrench + some force to turn it. You get down to the last 2 threads + you really have to crank on the rusty bolt. Now you put 30 lbs force on both. 20 of the 30 lbs on the rusty one is just overcoming friction--which has more clamping force? you have 30 lbs on both. That 30 lbs on the clean bolt went into stretching the bolt.
   According to a tech I talked to at ARP about rod bolt torque-"I dont care if you use peanut butter as a lube-and tighten with a monkey wrench -stretch is the ONLY thing that matters".
• #12 by sdwarf36 on 10 Nov, 2011 13:17
• http://www.roymech.co.uk/Useful_Tables/Screws/Preloading.html
• #13 by rallydiesel on 10 Nov, 2011 13:39
• The proper stretch of bolts, especially rod bolts, is what keeps them from breaking. ARP doesn't even recommend tightening the rod bolts to a certain torque value. Instead, they recommend the much more accurate and meaningful method of measuring the rod bolt length before install and the tightening it until it reaches the proper stretch by measuring it's length with a micrometer or similar device. On removal, if the bolt is permanently stretched greater than .001" it is no longer good and may break if used again.
• #14 by wil892 on 19 Nov, 2011 14:55
• Just a quick update to this. I got the engine back from machining, it looks brilliant!
  Heres what they did:
  Block:
  Bored 0.5mm oversize
  Plateau honed
  Cleaned in heated engine pressure wash
  Con rods had new bolts installed and resized
  
  Head:
  New prechambers fitted (see my other thread)
  8 New guides
  Valve seats recut
  new stem seals
  Very very slightly faced
  
  I'll be building the engine in the coming weeks so no doubt some silly questions will be asked!
  
  original paint!
  
  plateau honed
  
  
  head face
  
  
  slightly rust conrods(will be cleaned)