New Guy, New to VW, New to Diesel, kinda. - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• New Guy, New to VW, New to Diesel, kinda. by cajafiesta on 06 Aug, 2022 06:14
• Hey everyone, apologies in advance for the long-winded post.
  
  Long story short, I find myself taking possession of an 82 rabbit diesel today.  The car has been gone through by the previous owner, and he seems to have done a pretty decent job fixing some "driver-quality issues."  Brakes, wheel bearings etc. The engine is unknown in year and origin, but is most certainly a 1.6 idi NA motor mated to a 5 speed and engine has been rebuilt.  Seems like a stock rebuild with the exception of a 20 thou overbore. The young dude that did all the work seems competent.  He was able to rattle off the static timing procedure from memory, so I have more confidence in his abilities than I would of those of a paperweight.
  
  
  That brings me here. Hi to everyone!
  
  
  I'm not new to cars, I'm not new to old halfway raggedy cars that are still on the road.  I'm not new to gasoline and I'm not new to forced induction.
  
  But I am new to diesel, to some degree, and I am new to NA/Forced Induction diesel.
  
  
  I'm an information sponge, and I've been captivated by trying to absorb as much as I can about these little, old IDI motors.  I love simple, mechanical stuff.  I said, for the longest time, that if I could drive an old tractor around my town, I'd probably just buy one to mess with.  Then I realized that an old idi diesel VW is, more or less, exactly that.  A tractor drivetrain in a car body.  So that's that.
  
  Being that these engines are now old and fairly obscure, they're proving a bit difficult to come across on the used market. ( this is all leading somewhere, I promise.  Thanks for sticking with me!)
  
  So here I am, reading about IDI performance mods.  I have no doubt some more power will be needed, and as silly as it is, turbos just sound cool on diesels. 
  
  So I've landed at turbocharging an NA IDI.  I have some factory turbo parts coming with the car- exhaust manifold with what I gather is the K14 flange, turbo intake manifold, oil pan etc. I'm more than capable of physically installing components.
  
  
  I'm gathering details and putting pieces of info together.  Can someone please let me know if I'm on the right track with what I "know" ( or think I know) so far?
  
  Fueling- I've spoken to Giles briefly regarding injection pump options and selection.  Giles is adamant that I need a turbo pump.  So I suppose I'll have to take his word on that.  ( although the eco diesels seem to use a NA pump on a turbo setup.  I suppose the goal there is to run it as lean as possible from the factory?  Hence the lack of diaphragm on the pump for a boost reference?  I assume that boost diaphragm is fuel enrichment under boost?  Is it "a thing" for people to run NA pump on NA engines that have had a turbo bolted on?  Does it work?  I have no idea what "inputs" these pumps use to modulate fueling other than the obvious mechanical linkage tied to the throttle.  Are the NA pumps using something opposite the turbo pumps, like vacuum enrichment?  Will these diesels even make a vacuum signal at high rpms?
  
  Injectors- again, kinda ignorant here.  But I gather these are just, essentially, a ball and spring sort of concept.  They relieve at a specified pressure.  So I'd assume the three things that influence "what" and injector does comes down to input pressure from the pump, oriface size in the injector and duration of time from injector open to injector close.  Is there a difference in NA vs turbo IDI injectors?  What is the difference?  Are the NA injectors adequate for a stock turbo setup making stock, or slightly better, power?
  
  Turbo stuff- This is all self explanatory.  Plug and play.  This part doesn't allude me.  It has to physically bolt up, you need an oil supply, you need an oil drain. The turbo needs to be clocked in a manner that makes sense for the physical space constraints present. No big deal
  
  Keeping the rotating assembly cooled- I gather THIS is where the hiccups lie.  I've read a lot and there seems to be some conflicting information available.  This is the internet, after all.  People say that the lack of oil squirters in the NA blocks is the end of the world.  People say it wont last under forced induction fueling. But then I've read other accounts of people saying the NA short block lives a perfectly happy life under boost, if EGTs are kept below 1400ish. So I'm looking for some hands on input regarding that.  If that's accurate, and 1400f EGTs are the max for a NA short block to live, then I'd like to have some way to quantify what to expect out of 1400deg EGTs. What does that correlate to in terms of power.  What sort of EGTs does a stock, non turbo make?  If these motors live at 1300 deg wide open under max load, then it seems like forced induction would immediately have the impact of putting EGTS over the edge once the motor was loaded up. I don't have a way to quantify expectations and correlate these numbers into a real world scenario. 
  
  Additional cooling I've also read that some "add-on" cooling can have an impact, perhaps significantly, on managing the "EGT danger zone." Folks have said that intercooling and a big oil cooler will do a good deal to improve overall temps.  That's logical. Colder charge temp, ultimately, yields lower EGTs, I would think.  Colder oil, ultimately, will have a better impact on piston cooling, though not as good as squirters would, logically.
  
  
  I hope this ramble makes sense and doesn't turn the knowledgeable folks off. I just have a lot of "what if" questions about this setup, and I've been trying to register here for a while.  I finally was able to register successfully, so the flood of questions dumped out!
  
  
  Thanks to anyone that made it this far, and thanks to anyone who can set me clear on some of this information. 
  
  
  Pleasure to be here. 
  
  
  
  Last but not least-  Anyone here have a 1.6td long block ( fully dressed, ideally) or short block they are looking to sell?  I'll buy it!
• #1 by Tomoturbo55 on 06 Aug, 2022 17:44
• N/A pump can stay if u dont mind a little black smoke until turbo spools,
  
  Injectors are 130 bar vs 155 turbo- should give a little more top end
  
  Turbo: k24 is better for egt, but its laggier than k14.
  
  Td-s have oil cooler trough cooling systems
  
  Fmic helps aaaaa tonnn forr power and egts, bigger exhaust helps, bigger TD radiator helps.
  
  Dont roal coal i think it Will just be fine Like regular TD.
  
• #2 by ORCoaster on 06 Aug, 2022 18:39
• Welcome aboard Caja,  I will attempt to answer your Q's later tonight when the time is not so pressing for me. 
  
  
• #3 by fatmobile on 07 Aug, 2022 02:24
• First off thanks for separating your paragraphs and some bold type.
   Made it very easy to read.
   
   I hope you haven't paid for the stock TD parts.
  In my opinion the turbo should be a VNT-15.
  They are used on the MK4 TDI engines.
  The whole VNT-15 turbo and exhaust manifold can be found used for $250 or less.
  It's easier to install and remove a Vinny, because those 4 exhaust manifold to turbo bolts on the stock setup are a pain.
   It doesn't limit what intake you can use, because the VNT-15 sits low.
  And you can remove the intake without having to remove the turbo with Vinny15.
  The stock 1.6TD intake has to be a skinny thing and not easy to find for cheap.
   https://vwdiesel.cokenet.org/viewtopic.php?t=9515
   
  Turbo outpipe is easier to make since the turbo is farther to the right,
  away from the shifter linkage,.. and you won't find a stock TD downpipe for a MK1 Rabbit.
  OK maybe you will find one but they are very rare,.. and therefore spendy,
   like a stock MK1 airbox for a MK1.
  You'll need to use the stock MK2 TD airbox or go with some custom air filter setup.
  The stock turbo doesn't boost very high and doesn't come on early enough.
  The stock turbo won't make it feel very fast, a VNT-15 will make it feel very fast.
  
   I run an NA pump on my TD. The Load Dependent Assist/flying saucer doesn't add more fuel,
  it reduces fuel until there is boost.
  It doesn't run on vacuum, it is boost controlled.
  If you don't want smoke keep your foot out of it.
  And since the VNT-15 brings boost so early,..
  (the stock boost doesn't come on until 2000 RPM)
  it clears up the low RPM smoke pretty good.
  
   More boost makes it run cooler not hotter like a gasser.
  With the diesel; black smoke means it's burning hotter.
  Stuffing more air in cleans it up, cools it off.
  That's why a turbo on a diesel is a given.
  On a gasser you have to be careful not to add too much air or the pistons will burn.
  Worst thing with too much air on a diesel is it adds backpressure on the exhaust side and steals power.
  I suppose it could blow a headgasket if pushed too far but my little 1.5D, 11mm headstuds, VNT-15 held at 35psi.
  
   Running a turbo without the oil squirters should work just fine.
    My 1.5D with a VNT-15 did just fine with an NA pump and no piston squirters.
  I don't like going over 1200F. At least not for very long.
   No idea what kind of temps an NA diesel sees.
   I've never put an EGT gauge on an NA diesel.
  An intercooler would help, I want one on my 1.7TD/VNT daily driver because the EGTs get to 1350F if I keep it floored.
  
  A TD will need an oil cooler or
  stock "oil warmer" which initially warms the oil up with coolant
   then uses the coolant to keep the oil cooler than the 300F+ it would be without it.
  
  Injectors just need a good spray pattern,
   to all pop around the same/proper psi
  and to not leak after pressure is off.
  
   2.25" exhaust is minimum, fits a Rabbit pretty good.
• #4 by cajafiesta on 07 Aug, 2022 06:12
• Quote from: fatmobile on 07 Aug, 2022 02:24

  First off thanks for separating your paragraphs and some bold type.
   Made it very easy to read.
  

  
  Yeah, sure thing.  Thanks for the detailed response.
  
  VNT The stock stuff came with the car.  I've considered the variable geometry turbo stuff ( it's variable geometry, as I understand it, yeah?  I gather that's how they manage boost.) off the MK4, but I don't know that I want to be bothered with controlling the turbo. I'm gonna read into the link you posted. I assume that the 1.6td and the 1.9TDI share the same exhaust manifold pattern?  Direct bolt on?
   I had a friend some years back with a pretty gnarly mk4.  I believe that engine code would have been ALH.  I'm still figuring out the nonsensical VW engine codes.  I'll read into how controlling the turbo is accomplished and sort of go from there. As I've said, I'm intimately familiar with forced induction spark ignition engines.
  
  With the idea of this VNT turbo making low rev boost- Is it safe to assume that diesels make peak cyl pressure at peak tq as a gas engine would? If that's the case, are there physical characteristics of this motor that I should be aware of if it starts getting fed boost ( and fuel to make the boost effective, naturally) at low revs?  Will these motors knock the rods out of themselves if peak tq happens at really low revs, like a gas engine would be inclined to do?  For example: If you've got a spark engine that's had an early-lighting turbo added, all things being assumed equal, and you let the turbo light, give it the spark advance it wants to make max power at a given rpm and the gasoline it wants to make it to the desired air/fuel---inevitably you're going to make high cyl pressure ( which correlates to high tq) at low rpms.  This will knock the rods out of the engines I'm used to dealing with ( honda 4 bangers, turbo LS v8s etc.).   Is that a concern on these idi engines or do they just suffer the abuse, since they're essentially detonating under high cyl pressure all of the time?
  
  
    Packaging, in general, doesn't concern me all that much.  Although I suppose easier/better fitting is always a benefit.  I've also got brand new billet wheel 61-61 T3(.63 back housing) in the shed.  That's way overkill, but it does actually have a very small hot side housing. It was spec'd for a 1.6L gas motor making in the area of 400hp.  WAY overkill for this application, but it may actually spool with the tiny hot side housing.  Anyhow, noted.
  
  Intake/Exhaust This area doesn't concern me too much either.  I'm frugal and I can see "stuff" in 3d.  I don't have much issue looking at the car and mentally coming up with a piping configuration that will work. I'm not scared to cut up the intake manifold to get the flange locations where I want them to be, id it comes to that.  Don't get me wrong.  I have no desire to put the turbo in the spare tire well, but if it came down to it, you know...   I'd never seek out and buy a downpipe, for example, unless they were $50 or less. I have no issue making a downpipe.
  
  pump Good info.  Makes perfect sense.  I knew it was doing something, but I didn't know what/how.  Totally logical.  So, presumably then, the LDA diaphragm is physically lifting up on something ( like a needle and seat perhaps, or just an actuator..whatever?) when positive pressure is applied and that adds fuel.  Cool, got it. Logical.  More air will take more fuel and make more power. I guess the base logic here is to allow the pump the ability to meet fuel demands while the system is seeing synthetic aspiration and then reduce fuel when it isn't so that EGTs are managed and a rich,hot fuel mix isn't clobbering pistons under slow engine speed and low load. I think I'm grasping that idea.  Noted on managing rich fuel mix out of boost by driving with the throttle.  Makes sense.  I can accomplish that.
  
  Pump tuning So this is starting to sound more like maybe a giles pump isn't necessarily always the answer.  It sorta sounds like I can use my NA pump, dont drive like a dick at low revs, and then tune the pump via online tutorials to meet my goals, within reason.  The gist of tuning these things sorta sounds like " asses the situation.  Understand what's going on.  Give it fuel until it smokes in whatever rpm range it's going to "work hard" in and then back it off just until the black smoke stops, or is minimal, while using the EGT gauge as a tuning tool along with your eyes and ears.      I've been reading some about what does what on these pumps.  I gather there's a "master" fuel adjustment.  I see people add fuel until the motors rev hangs slightly and then back it off.  Then address idle speed, as overall fuel impacts that when turned up/down. Then there's err.. a governor in there doing something, presuming tapering off fuel slowly as the pump nears the max engine rpm.  I gather that can be adjusted, too, to provide more fuel up to max revs.  I need to dive into that more.
  
  EGT good details, thanks.  So now I've got some kind of insight on what sort of EGTs occur under XYZ scenario.  That gives me something to go off.   I'm starting to see here that, perhaps, a lot of what the internet says " must be done" is, as it often times is, sort of not true.  At least not in a situation where the person playing around with things has an understanding of what is actually happening.  I'm pretty used to this in the honda world. People say " oh you can't do that or itll break the rods"  " the most that engine will handle is 250hp." wellllllllll.. not really. It's more like that's what common convention has decided, but we're not taking into account that this "common convention" may have been established by people that were ignorant and guessing rather than people that really understood how to correctly tune a small displacement turbo engine.   Cool.  Good info, again. Thanks!
  
  Cooling a front mount ( or a side mount) depending on space has been on the table from the beginning.  I see no reason to ever have a non-cooled intake charge, if you can fit an intercooler.  There is no downside in spark and/or compression ignitions engines. So that's a definite.  Oil cooling makes total sense to me, as well.  Where are y'all sourcing your oil feed ( and where is it returning to) when a large oil cooler gets installed? Do people generally pull off of some sort of aftermarket oil filter sandwich plate deal, or is something like the oil pressure port on the block getting tapped into?  Is the return from the cooler typically dumped into the valve cover?  Oil pan?  Y into the turbo drain line? 
  
  
  Thanks so much for all the details.  I really appreciate it! 
  
• #5 by ORCoaster on 07 Aug, 2022 22:00
• I forgot to pick this up.  Thanks to Fatmobile I don't have to.  Nice.
  
• #6 by fatmobile on 08 Aug, 2022 01:49
• The VNT-15 does provide quite a load on the engine down at low RPMs.
   I think the longer stroke helps protect the diesel engine from the torque load.
   I did have a problem with a small amount of wear on the rod bearings but it was in an engine with low oil pressure,..
  due to clevite I-shaft bearings.
   I now use sealed power brand and have had great oil pressure.
   I am running the VNT-15 in a 1.7 diesel engine.
   It's a 1.6 hydro-block with 80mm pistons from a KY block (2mm bigger than the largest stock bore)
  and it still seems to handle it.
   No broken rods yet.
  
   In the pump there is a vertical lever.
   The LDA reaches down and keeps it from moving and adding more fuel until the boost comes on.
  A giles pump might not be necessary but he sets them up to provide more fuel at higher RPMs and he does a few other tricks.
  The EGT is my main way of setting the pump.
  I like it at or just under 8psi boost at 800F for a midrange.
  It can run up to 18psi for a short while, but at the top 15psi @1200F and holding is the plan.
  That is probably the max for one of these IDI engines when it's floored so the VNT-15 is matched pretty good for it.
  I wouldn't want a bigger turbo on one of these IDI engines because there isn't enough fuel left at high RPMs to use it.
  Give it too much more and the prechambers can blow out.
   I have a hard time getting over 10psi with the stock turbo.
  
   I stuck a starion conquest intercooler on the grey GTI, in front of the radiator and it fit pretty good.
  
   I like the sandwich plate for the air/oil cooler.
   The whole setup from an old volvo works great but any old sandwich plate will work.
  You just have to get the lines up over the alternator.