Where to stop?

I'd be more than happy help log and give advice in Iowa

A little update to this...

Jeff re-tuned my RC5 and RC6 ECU's so the car does not cause a solar eclipse over ~75% throttle and does not smoke just climbing a hill with the cruise control on. RC6 still drives the best of all the tunes - lots of low RPM power and the cruise maintains +/- 1 MPH instead of +/- 3 MPH

Mileage before winter fuel has been right around 50, had a trip to detroit and back in October that netted 53 MPG at a 69 MPH average speed from key on to key off (was driving 78-80 most of the way).

I'm running all three BFI Stage 1 mounts and it still feels like there's a big rubber band holding the engine in place. Particularly on engine transition from powered to overrun, it feels like there's a huge amount of backlash/windup in the drivetrain

Vibration is still there (unchanged), and comes and goes when it feels like it...

I finally installed my oil temp/pressure gauge over thanksgiving...I need to replace the thermocouple since the one that shipped from McNally is too short (wires) to reach from the oil pressure switch area to the dash. I have it installed and working, but it's all ghetto, routed in a straight line just to make the wire reach. I have a new one with a longer wire coming ($43 my cost). I'm not sure how everyone else does it but this one is at least a foot short - McNally claims that they don't typically have any problems on ALH's.

The gauge works fine, oil temps are 30-40F below coolant temps per the scangauge - I thought they would be closer. Another minor thing is that the temperature does not read below 32F which I find a little disappointing. How hard is it to program a signed value in the digital display? It's not a big deal, but not what I expected I guess.

Timing is advanced to ~10% over the top line and with extended glow plug times it starts right off even at 15F temps the last few days. Has a little white smoke, but nothing as bad as shortly after the rebuild.

Added a lower intercooler pipe as described in this thread...

I have not looked in a while, but am coming up on ~15k miles on the rebuild. There's a very minor oil leak coming from somewhere up by the vacuum pump somewhere that I should fix sometime - does not even drip on the top of the skidplate, but there is some wetness up there running down the back of the head.

I'm planning on changing the thermostat - the 186 or whatever temp that IDParts sells is too low for my taste - especially since it only gets to that temp after 30 minutes of steady driving - If I'm lucky it will hit 175 on the way to work (17 miles/25 minutes) I'm replacing it with a NAPA (stant) one that runs ~195 and gets there quicker - at least it used to before the rebuild.

Fix_Until_Broke said:

I'm running all three BFI Stage 1 mounts and it still feels like there's a big rubber band holding the engine in place. Particularly on engine transition from powered to overrun, it feels like there's a huge amount of backlash/windup in the drivetrain

Vibration is still there (unchanged), and comes and goes when it feels like it...

Click to expand...

Did you notice any improvement in your shifter feel? I thought the BFI mounts tightened things up nicely. Especially now that it is getting colder in our part of the country, things seem pretty ridged...but maybe you were expecting more?

I've noticed that the engine in my wagon seems to move a bit more on tip-in then I remember. Chill replaced the front mount, the dogbone is about 6 months old. All stock. I think it's related to the fueling and torque that's delivered when I first press the accelerator. Not objectionable, but I did notice.

It's definately sloppier than stock (engine/driveline play)

I didn't notice any difference in shifter feel, and being cable operated, I wouldn't expect it I don't think?

For the slop you could try upgrading to the stage 2 dogbone inserts or the ECS Ultimate dogbone mount. http://www.ecstuning.com/Volkswagen-Jetta_IV--TDI/Drivetrain/ES5669/


Just something to consider. When I upgrade engine mounts I went with stage 1 for the engine mounts themselves and went with the stage 2 dogbone mount to lock things down.

Those mounts are fine with the PD's, but an ALH is really harsh with poly mounts unless you have your idle up around 1000-1100..

For reasons that I will explain in more detail later, I had the opportunity to pull the main and rod caps off on this engine and see how they've held up over the last ~80k miles.

Mains look brand new, however the rods look pretty much exactly like the below pictures from the original teardown.

Any suggestions for replacements that might perform better?

I'm putting in a girdle and smaller oil pump sprocket so there will be more oil flow available in the future.

Maybe I need to add rod bearings to the 100k mile timing belt service

Fix_Until_Broke said:

...

The top half of the big end of the rod bearings are showing signs of wear - The bearings are "tired"

#1

...

Click to expand...

I've been kind of curious about mine, with bigger nozzles (and an untouched and therefore much higher low rev torque limit), more advance and better head flow, the beating they get at very low RPMs where oil pressure's the lowest has to be a multitude of what it would be in a stock motor.

I've heard talk of "sputter bearings" when I was putting mine together but dismissed it before reading further. People since then have told me they make a difference.

Sputter bearings would probably be a good option, its what I'm running in my Passat if I remember correctly, wouldn't hurt.

Where do I get some of these?

What oil are you using? The bearings in my 300K miles ALH didn't look nearly as bad and that engine was run on the wrong oil most of its life. Also, how are the crank journals? Something isn't right.

Crank is perfect and so is the lower half of the rod bearing along with the mains. I'm using a full synthetic 5w40 diesel oil from champion. I'll get specs on it at the shop this morning.

Most likely Europe, I don't think we got them over here
http://www.darksidedevelopments.co....rnal-rod-bearing-kit-sputter-bearing-kit.html

turbocharged798 said:

What oil are you using? The bearings in my 300K miles ALH didn't look nearly as bad and that engine was run on the wrong oil most of its life. Also, how are the crank journals? Something isn't right.

Click to expand...

fub's look pretty normal in my experience for rod bearings

be interesting to see what's up with the sputter bearings. Reading up they just put them on the loaded side, save some money and just buy the upper shells overseas and reuse your lowers.

The oil I'm using in on page 3 of the below link - Part Number 4173

http://www.championbrands.com/Commercial-Industrial Product Catalog 9-14-r-s.pdf

Fix_Until_Broke said:

Crank is perfect and so is the lower half of the rod bearing along with the mains. I'm using a full synthetic 5w40 diesel oil from champion. I'll get specs on it at the shop this morning.

Click to expand...

You would never expect issues on the lower half bearings unless running at sustained extremely high RPMs, where the mass forces of the reciprocating group dominate.

Evidently, the worn out upper shells are symptomatic of any of a combination of too high compressive loads (i.e. PCP), insufficient bearing velocity or insufficient oil viscosity (waiting for somebody to jump on me for making this statement lol) in relation to the previous two factors - simple review of the Stribeck curve.

Better bearings would help, as would larger journal diameters, lower PCP @ low RPM, etc.

I'd love to go with larger journal diameters, however this involves some significant changes - may as well swap in a common rail engine at that point and reap all the rest of those advantages at the same time.

The thing that is a bit frustrating is that I have all the stuff to get PCP's and have even done a little bit of it.

Just wish I was able to spend the time on this to do it the justice it deserves. Getting data is easy, analyzing it efficiently and productively is another challenge, and then changing things, hopefully one variable at a time, and repeating the process takes more time than I'm currently willing to put into it . My curiosity exceeds my skills.

Ya, 240 bar is too much man. But I strongly suspect that ~200 bar @1600 RPM is more damaging to the bearings than 240 bar @3000.

You can know exactly where combustion starts on your pressure trace by plotting your pressure trace as a log-log graph. Your abscissa is in units of time, which is problematic to have the desired volume for a P-V indicator diagram, but it's no big deal; recursively find a suitable exponent constant for compression phase of the curve so that it will become an essentially straight line; it should be close to gamma=1.4. I have some literature that I can share with you if you'd email me.

I can feel this becoming a deep hole What is a generally acceptable value?

I should find a stock TDI and see if I can get some similar traces. In an attempt to be expedient with this, I could just measure cylinder pressure only and calculate RPM off time between pulses and re-create the below data to get a rough feel for it.

I don't think different bearing's would help, unless they can't hold the oil to keep the bearing off the journal. Sounds like TDIMeister hit the nail on the head, too much boost/torque at too few rpm where there isn't enough oil pressure to keep the bearing off the crank.

Agreed.. looks like classic lugging to me..

Seems you've been down this road before...

If there wasn't an oil pressure/engine concern then I wouldn't be too bothered with just replacing the bearings.I havn't used any special main or rod bearings on any of my builds.I ran the BHW oil pump sprocket but found the pressure to be to high when used on the ALH.

I'm not sure if the darkside bearings have the lock tab or not.Rosten offers the bearing with or without the lock tab,

http://rosten-performance.com/produ...s-rotating-assy-and-block-engineparts-diesel/

andy2 said:

I'm not sure if the darkside bearings have the lock tab or not.Rosten offers the bearing with or without the lock tab,

Click to expand...

for "cracked cap" rods like in the CR motors

Hmm - hopefully the rod bearings I have coming from Darkside have the lock tab.

Oil pressure ran right around 20 psi when warm (160F) at highway speeds (1600-1900 RPM) with a 5w40 oil and stock ALH pump/gear. I do have a bypass filter which steels some oil and may reduce pressures a bit when warm, but I've not taken the time to block/unbock the bypass to check it's effects on oil pressure.

Andy - can you explain why you thought the oil pressure was too high with the BHW Oil Pump Sprocket?

I agree that my "quest" for low RPM power/transient response has likely led to this damage. In regard to lugging - Let's have that discussion over here...

Fix_Until_Broke said:

Hmm - hopefully the rod bearings I have coming from Darkside have the lock tab.

Oil pressure ran right around 20 psi when warm (160F) at highway speeds (1600-1900 RPM) with a 5w40 oil and stock ALH pump/gear. I do have a bypass filter which steels some oil and may reduce pressures a bit when warm, but I've not taken the time to block/unbock the bypass to check it's effects on oil pressure.

Andy - can you explain why you thought the oil pressure was too high with the BHW Oil Pump Sprocket?

Click to expand...

I can tell you that I had the EOT up to operating temperature and didn't like the pressure that I saw at any given engine rpm.I had determined that it was simply overkill.

I have ran the BEW rod's and bearings on my ALH based daily driver with compound turbo's,

http://pics.tdiclub.com/showphoto.php?photo=101640&title=dyno-2&cat=500

The cylinder head is the first weak link with PCP's.I've yet to destroy or really damage the ALH style rod bearing.I run a synthetic 20w50 on the drag car and a synthetic 5w40 on the daily driver.

If you don't have any black stains in the coolant bottle then I wouldn't worry about rod bearings.

As said before, that's always how rod bearings seem to look. Same with the mains, the one at the belt end wears in the direction that the belts pull it.

Way I see it, on startup there is not any oil pressure (ditch the engineer babble about flow and pressure, it is like saying HP is a made up number), so the bearings are doing their slidey thing rather than their floaty thing. Metal to metal contact makes for wear, it isn't all galled and spun so you know it isn't happening at any great speed.

@F_U_B, I look forward to seeing the fruits of your newly acquired knowledge and enlightenment you have in your possession.

Fix_Until_Broke said:

I can feel this becoming a deep hole What is a generally acceptable value?

Click to expand...

155 bar for a stock ALH. The R-TDI engine from 1997 had PCP of 185 bar to produce 190 HP but peak torque was "only" 350 Nm, and this at 3500 RPM.

I've been mulling an "efficiency" build using a camshaft that achieves a Miller/Atkinson cycle, keeping the stock 19.5 geometric CR but reducing the effective CR. This will need more boost provided by a 2-stage turbo system to operate optimally. If interested, we can start a new thread to discuss...

So, to answer your original question, it *NEVER* stops.