Bumping the IP timing one tooth

[Gizmoman]

Makes sense libby. I'll screw it to 18 psi - not hard to do. If that doesn't lower EGT's, I'm backing off the fuel.
I have many other projects waiting, and this one has been much too time and funds consuming to keep at it.

The goal was to build the engine for dependability with power a second priority. I believe I have achieved that as there is no blow-by, no leaks, starts and idles well, and has more poop than it used to. Having all the sensors to monitor things gives me the ability to adjust to it's needs before I cook it.

It's basically a mini motorhome that should provide decent milage, and hopefully many miles of "out of the madness" scenery. A good cleaning, a coat of wax, a new seal for the pop-top, and I'm good.

Speaking of poop, I need to get a porta-potti to put under the rear bench

Cheers to all of you. I'll be checking in daily. It's become part of my routine.
Jim

[theman53]

From my experience with the VNT 15 in the alh and from what I have read that libby posted about his I would say for this heavy unit it would be a great choice.

My thinking with the manifold is all the N/A diesels I drove had a good bit better pull off bottom than the first TD I built. After reading a ton of stuff and building my new longer runner intake I have snap off the bottom more so than the N/As do. I think your engine has a lack of runners and more of an open plenum so the air is not becoming like a sound wave or spring if you will. It is just bouncing all over the place until the engine gets wound up enough to get the velocity of the air more uniform. I really don't think it is the cores completely. They could be causing a restriction that wouldn't help, but if you had them attached to the end of 24" runners it may change it to the way you want it to run.
The "ideal" intake plenum volume is supposed to be 1/2 of the engine displacement. Less than half will allow faster spool, more up to 1.5:1 *IIRC* will allow for more flow in the high rpm at the cost of spool. 1/2 engine displacement is the general rule for the best all around performance as it doesn't sacrifice much of either low or high rpm performance. So a 1.9L would be .95L of plenum volume, which 1L would be fine same as .9L would be fine. At any rate that is what I read when building my intake. You can have 9 feet of IC tubing with much more volume, but where the plenum expands the piping and starts to direct the air, it makes a huge difference in how the car will drive. I say that to say, I don't know what adding a 3rd core would do as I don't know if it would be part of the plenum as it is where the air is being directed, or if it would be like the IC piping and normal air to air IC. That is why I suggested testing a manifold. If it changed the performance you would at least know it is one aspect of that manifold and you would just need to figure out which one

[Gizmoman]

From my experience with the VNT 15 in the alh and from what I have read that libby posted about his I would say for this heavy unit it would be a great choice.

My thinking with the manifold is all the N/A diesels I drove had a good bit better pull off bottom than the first TD I built. After reading a ton of stuff and building my new longer runner intake I have snap off the bottom more so than the N/As do. I think your engine has a lack of runners and more of an open plenum so the air is not becoming like a sound wave or spring if you will. It is just bouncing all over the place until the engine gets wound up enough to get the velocity of the air more uniform. I really don't think it is the cores completely. They could be causing a restriction that wouldn't help, but if you had them attached to the end of 24" runners it may change it to the way you want it to run.
The "ideal" intake plenum volume is supposed to be 1/2 of the engine displacement. Less than half will allow faster spool, more up to 1.5:1 *IIRC* will allow for more flow in the high rpm at the cost of spool. 1/2 engine displacement is the general rule for the best all around performance as it doesn't sacrifice much of either low or high rpm performance. So a 1.9L would be .95L of plenum volume, which 1L would be fine same as .9L would be fine. At any rate that is what I read when building my intake. You can have 9 feet of IC tubing with much more volume, but where the plenum expands the piping and starts to direct the air, it makes a huge difference in how the car will drive. I say that to say, I don't know what adding a 3rd core would do as I don't know if it would be part of the plenum as it is where the air is being directed, or if it would be like the IC piping and normal air to air IC. That is why I suggested testing a manifold. If it changed the performance you would at least know it is one aspect of that manifold and you would just need to figure out which one

Thank you for the detailed explanation. The only reason I suggested another core is that the implied 250 HP from Laminova is very likely based on a gasser. As was mentioned, a diesel needs quite a bit more air flow.
 I suppose I could try to find another intake (very tough so far) and use it as a new "base" to build to, using runners as you suggest. Heck, all I need is a new gasket, a chunk of aluminum and four sausage stuffers.

What you are saying makes sense and it does feel like the air is trying to figure out where to go off the line. Once the turbo comes on, the decision is made and woW. If I ran a VNT 17 I may have that "decision" made much sooner. The addition of the higher volume from the larger turbo may also lower EGT's as well.
However, libby's VNT set-up is certainly more than a weekend's worth of work - possibly several months of weekends .

If I were retired it would be a great project but I have several years to go yet. I received my new pulse unit to hook up to my timing light today. It's too dark to mess with and the holidays will put me to Friday before I can hook it up.

I'll keep you all posted.
Again, thanks for the detail - I think your'e on to something for sure.

[theman53]

BTW I think I was working too hard with the sausage stuffers. Although they turned out great I wouldn't do it again. I found that the aluminum I used *6160 I think* is really easy to bend when heated. If I were to do it again I would just get a billiard ball or something similar, heat the tubing well, put the billiard ball or whatever on the heated end of the tube, and push really hard. I think it would give a good enough shape for what I would need, and basically that shape is just trying to pack more air into that tube than the tube would want to have in it at its normal diameter.

Then again, I love saying sausage stuffer intake...

[745 turbogreasel]

maybe spin the starwheel back a little so you off boost fuel comes up a little faster?

[Gizmoman]

BTW. . .

Then again, I love saying sausage stuffer intake...

Ha ha, me too
Sauaawwsidgestufffers!

maybe spin the starwheel back a little so you off boost fuel comes up a little faster?

Ohh, scary stuff there! I paid Giles a large sum and he did his magic  - I'm even scared to touch the fuel screw

[Gizmoman]

After fixing the valve cover leak http://www.vwdiesel.net/forum/index.php?topic=34302.0 I finally hooked up the FERRET Diesel Injection Detector #765 for the first time.
Based on what I've heard from libby and a few others (OK, mostly libby), I wanted to try it and see if it made any difference over using the indicator method.

I don't have any dial numbers to relate to other than I was at .95 on the dial. With the gun set to fire @ 14* BTDC, I had to rotate the pump slightly away from the head to get the mark to line up with the pointer.

It seems to run a bit cooler (not sure why) and 1300 F (EGT) seems a bit tougher to hit than it was. It may also be a bit less laggy on the bottom end and boost seems to come on sooner. Not rock-sold sure about the improvements. Could just be my mind justifying the expense of the injector trigger chingus

One thing for sure - it's easier than diddling around with the dial, and I am checking a running engine which make more sense - at least to me it does.

[bbob203]

Mark did suggest a retarding the timing didnt he?

[Gizmoman]

Mark did suggest a retarding the timing didnt he?

Yes, yes he did.

Thanks Mark. I might even go a bit more now just for grins. It still starts way easy (almost too easy).

[dieseljunkie69]

I have got my mk2 1.6td time retarded enough where the cold start is most certainly required to get a steady idle, and even then it stumbles.. but this is good, because that is what the cold start is for.

I run a Synthetic 0w40 oil. Start the car, clear the windows and drive. After a few minutes of easy easy driving the cold start can be pushed in for smooth idling at 850-900rpm.

I backed it down from 1.16mm (summer running, good top end, bad low end) to 0.91mm. Much more low end, less top end.. but by that I mean 4250+.

[Gizmoman]

I have got my mk2 1.6td time retarded enough where the cold start is most certainly required to get a steady idle, and even then it stumbles.. but this is good, because that is what the cold start is for.

I run a Synthetic 0w40 oil. Start the car, clear the windows and drive. After a few minutes of easy easy driving the cold start can be pushed in for smooth idling at 850-900rpm.

I backed it down from 1.16mm (summer running, good top end, bad low end) to 0.91mm. Much more low end, less top end.. but by that I mean 4250+.

Any idea of your EGT temps?

[libbydiesel]

If retarding the static timing increases low-end but decreases high-end then the dynamic advance is not functioning as it should.  Most likely that's an issue with the internal pressure.

[RustyCaddy]

Wanted to post a quick question to this old and interesting thread.

Could you in effect skip a tooth at the camshaft by first setting the timing of the motor and IP with the camshaft slightly retarded and then readjusting the camshaft to TDC without loosening the timing belt (and not readjusting the IP from the original setting)?

This kind of relates to Tylers second to last post re. Dr. Diesel in this thread:

http://vwdiesel.net/forum/index.php/topic,37038.0.html

[ORCoaster]

But are there not three points to the timing alignment?  Cam, IP and Crank.  Setting the timing on the cam requires the plate in the back so that the #1 cylinder is TDC.  How would you propose retarding the cam?  The Crank needs to be TDC so when doing the belt I always pull it up tight on both sides and rock the crank a bit to be sure I have the belt in the pulley at the bottom good and sound then just play it from one side to the other till I get to TDC mark showing through the inspection hole.

The only thing one can change that I am aware of is the position of the pulley on the cam.  The IP has wiggle room and I have moved a tooth one side or the other to get more or less advance out of the setup when all is tight and slack is taken up.

That is the only way I have gained a tooth or lost one. 

[Gizmoman]

I'm not enough of an expert to comment.
ORCoaster  is.