1.6/1.9 Franken engine fires up

[malone]

I'm curious as to know what your compression #s are now.

I've no idea what my compression is, but 935racer has the compression tester.. for some reason we haven't found time to do it.

I don't have a choice at the moment.  The engine misses too much to be driveable.  The miss firing seems to be directly related to the smoking, as soon as it idles smoothly when it has fully warmed up and there's no more misfiring, also no more smoke.

After you start the engine, hold the accelerator at WOT until the RPM finally climbs (this may take a few seconds).. avoid overrevving as it's hard on the engine. While you're able to rev above idle RPM, let out the clutch to begin moving the car and you may need to put the accelerator back to WOT.. putting load on the engine will reduce the misfire.

Once you're moving continue holding the accelerator at or near WOT during low RPM (keep shifting & lugging).. you won't accelerate quickly and your engine will run smoother from the start. The misfire time will cut down much more quickly. I use just enough fuel in this case not to exceed 800 degrees F pre-turbo EGT. I also don't rev higher than 2,800 RPM during cold start.

[malone]

Perhaps it's possible to install smaller volume prechamber cups in the 1.9L head.. if it will make a difference for compression.

Note that andy2 installed larger GM precups in his 1.9L IDI head to lower compression (1.9L block, big boost). I'm not aware of a smaller precup that will fit a 1.9L IDI head though.

FWIW I'm currently running a 1.6 camshaft in my 1.9 IDI head. We initially tested a customized cam and the compression was horrible... low 320's cold. The custom cam has more lift and IIRC stock duration. If I recall correctly the stock 1.9 cam has more lift than a stock 1.6 cam. That said, a leak-down test for your engine might be a good idea as well, in addition to a compression test. We found leaks through my valves with the custom cam (NOT the same cam that Passenger is selling, by the way). I haven't tested a fully stock 1.9 cam unfortunately. The one that came with my 1.9 IDI head was badly damaged by previous owner.

[fatmobile]

Have you played with the injection pump timing to see if that helps with the cold start smoke?
 Maybe advancing it a little might help.
 What's it set at now?

[deepmud]

1.9td video with turbo sound - 2" straight pipe.
http://www.supermotors.org/getfile/173947//dieselzukbump3.wmv

[addautomotive]

This is a great read. I'm following it very colsely, as I have a good 1.9 head sitting on my workbench. A 1.6 TD block won't be hard to find.

As for the misfire and smoke, I ricosuave might have a point... what about putting in a set of Duraterm plugs like the 96-on 1.9s use. I know the glow plugs in my 96 1.9 stay on for 3 minutes when I first start. If I turn them off manually, the car runs like crap and smokes.

[chrissev]

This is a great read. I'm following it very colsely, as I have a good 1.9 head sitting on my workbench. A 1.6 TD block won't be hard to find.

As for the misfire and smoke, I ricosuave might have a point... what about putting in a set of Duraterm plugs like the 96-on 1.9s use. I know the glow plugs in my 96 1.9 stay on for 3 minutes when I first start. If I turn them off manually, the car runs like crap and smokes.

The pump timing is set at 0.039 which is the limit I've been told.  I would advance it further, but I am afraid of damaging the pistons.  I wonder if the glow plug idea would work?  It takes about 10 minutes right now to warm up.  But after 3-4 minutes it would probably be driveable.  If I put the plugs on a manual switch and just kept them on for the first 5 minutes it would probably be fine.  Might just be the big prechambers and extra air from the big intake ports that makes the engine have poor combustion and missing when it is cold.

[malone]

I use a manual switch for glow plugs as well. It doesn't solve the cold-start smoke and misfire problem, but it does mildly reduce white/blue smoke while driving (especially idling or during low load) until optimal temp is reached.

Have you played with the injection pump timing to see if that helps with the cold start smoke?
 Maybe advancing it a little might help.
 What's it set at now?

Not to say that it won't help chrissev, but I've been through that many times: Timing was adjusted from .80mm to 1.20mm (a very extreme range) with no positive results. Using OEM spec timing or reasonably max. advance (i.e. 1.05mm) and using the cold-start pull seems to be sufficient.

Might just be the big prechambers and extra air from the big intake ports that makes the engine have poor combustion and missing when it is cold.

Been through that.. I temporarily tested it by partially blocking the intake inlet to restrict the amount of air going in. It did not make a difference. I also tried blasting warm & hot air directly into the intake via a high-powered heat gun with a 3cm dia. nozzle. It didn't seem to make a difference either.

Just stating my experience...

[chrissev]

I use a manual switch for glow plugs as well. It doesn't solve the cold-start smoke and misfire problem, but it does mildly reduce white/blue smoke while driving (especially idling or during low load) until optimal temp is reached.

Have you played with the injection pump timing to see if that helps with the cold start smoke?
 Maybe advancing it a little might help.
 What's it set at now?

Not to say that it won't help chrissev, but I've been through that many times: Timing was adjusted from .80mm to 1.20mm (a very extreme range) with no positive results. Using OEM spec timing or reasonably max. advance (i.e. 1.05mm) and using the cold-start pull seems to be sufficient.

Might just be the big prechambers and extra air from the big intake ports that makes the engine have poor combustion and missing when it is cold.

Been through that.. I temporarily tested it by partially blocking the intake inlet to restrict the amount of air going in. It did not make a difference. I also tried blasting warm & hot air directly into the intake via a high-powered heat gun with a 3cm dia. nozzle. It didn't seem to make a difference either.

Just stating my experience...

well I did some research on the 1.6 and 1.9 engines.  I think I know what the problem is and unfortunately I don't think I can solve it.  The 1.6 engine has pistons which come all the way up to the valves, into the head gasket, and the air is compressed in the prechambers, where the fuel is injected.  Combustion starts there.  This would be the partial combustion that I am experiencing when the engine is cold.  The combustion then expands through the precup hole and into the cylinder, where it finds a small space on the indented area in the piston, and the force of this continuing combustion pushes the piston down and completes the power stroke cycle.  The problem with the 1.9 head being used on the 1.6 block is that there is an additional area where the combustion can go when it comes out of the pre-chamber, that being the space around the piston, and also the pre-chamber exit on the 1.9 head is not exactly aligned for the indented area on the 1.6 piston, meaning the combustion will be searching for a place to go when it exits the pre-cup in the 1.9 head.  When the engine is cold, the space around the piston where there is extra air is cold, and the engine misses.  When it is warm, the space in this area is warm so the cylinder will fire, but there will be reduced torque because the combustion isn't centred in the middle of the piston but rather spaced around the cylinder.  That is my theory.  It is all I can see that is different.  So to make this combination work I would have to get rid of the space around the piston, and modify the piston crown so that the indented area was directly below the exit of the pre-cup.  

I'm not going to do that.   So I will now proceed with my original plan and rebuild my 1.6 head (it's in sorry condition, has like 450,000k on it and needs total refurbishing) and install that instead.  This was an interesting experiment.  

What has probably happened on Malone's car is the space around the piston has been gradually filled up with carbon, so his engine now smokes less, but it still misses and smokes when it is cold because the pre-cup exit isn't perfectly aligned with the indentation on the piston.  That would explain why it took 6000km to reduce the smoke problem.  If malone and other people who have this 1.9/1.6 combination want to fix their cars so they run nice, what they have to do is change the location of the pre-cup exit so that it is directly on top of the indentation in the piston, and they also need to get rid of the space around the piston caused by the bigger 1.9 head gasket piston hole.  I unfortunately don't have the facilities to do this, but vw935racer seems to have a machine shop at his disposal so maybe this could be done on one of his 1.9 heads to test my theory?

On the upside of it all, I now have a really nice 1.9 head for sale, it is a turbo head and it works great (still on the car so I can verify that for anyone who wants to buy it, come and hear it run, then I'll take it off and you can have it.)  

Chris

[malone]

What has probably happened on Malone's car is the space around the piston has been gradually filled up with carbon, so his engine now smokes less.  That would explain why it took 6000km to reduce the smoke problem.

By extra space around the pistons, I'm assuming you mean the larger bore in the 1.9L headgasket.

I failed my first Aircare (emissions) last Fall with a 49% exhaust opacity result. That was during the first 1,000km of the 1.6/1.9 setup IIRC.

My 1.9 head was pulled in the middle of December (after roughly 4,000km of non-stop idle smoke.. still guaranteed Aircare fail) with a headgasket replacement and it was under 2,000 km later when I went to Aircare and passed almost flawlessly with a 2.69% diesel smoke opacity, below the average 6.90% reading. Maximum allowable reading is 30%.

Although we switched from a 3 hole to 1 hole headgasket and ceramic coated the inside of the prechamber cups, the smoke problem was still just as bad when we started it up. 1 week later it's still the same, much to our disappointment. However, another week or two passed by and the smoke level was reduced amazingly. At that point I did the aforementioned 2.69% Aircare. To this day the smoke is still nice and low, aside from the first 30 seconds of cold start. Why didn't this happen in 4,000km from October to December? I think my block was still breaking in and the compression went up a bit.

That said, I'm not sure about the carbon build-up around pistons being a significant contributor to my smoke reduction. Seeing as a few people have run 1.9 headgaskets in complete 1.6TD longblocks, I have yet to see any of them report difference in smoke. Misfire isn't happening either.

Not forgetting that the deck of my 1.9 head was grinded down in 4 places each cylinder, resulting in more cylinder volume.. if they weren't grinded down I bet my cold smoke would be reduced even more, making it more practical for anyone.

the pre-chamber exit on the 1.9 head is not exactly aligned for the indented area on the 1.6 piston, meaning the combustion will be searching for a place to go when it exits the pre-cup in the 1.9 head.

This does make sense. Haven't thought of that myself. This somewhat encourages me to perform the piston crown mod that can also supposedly improve top end HP. There is a large thread covering this in this forum. Besides that it also makes the 1.7L project more appealing. It consists of a AAZ longblock with a 1.6 crank and custom rods.

935racer did note that my pistons have a very nice even burn over them after approx 4,000km. I'd like him to elaborate more on that.

There will be reduced torque because the combustion isn't centred in the middle of the piston but rather spaced around the cylinder.  That is my theory.  It is all I can see that is different.

In theory, the reduced torque makes sense, but from practical experience the low RPM torque is mind-blowing.

These are Gtech results with my old 90bhp 1.8L 8v gasser and the 1.6/1.9 with LDA disabled (ecodiesel or NA style).. both using exact same transmission, and in the exact same car:
http://dieselinside.com/1.6td/gtech/8v_vs_16td_eco.jpg

Also compared my old stock 1.6TD to my power enhanced 1.6/1.9:
http://dieselinside.com/1.6td/gtech/16tdstock_vs_16tdmod.jpg
The above Gtech plot is a better example - the torque gain during low RPM is very noticable. The wheelspin on wet roads is silly. I never had much wheelspin when my car (same car, same tires, same transmission) had the standard 1.6TD longblock with Giles pump.

I wish I recorded from 1,500 RPM instead of 2,400 RPM onwards.. will do that next time.

I also drove the 1.6/1.9 with the intercooler piping removed (no boost into the intake) and it still moved nice *shrug*

My deck mods may have something to do with the torque, contrary to your findings.. boy, in addition to prechamber cups and piston identations that sure complicates the combustion process even more. :lol:

If I were to do it all over again I'd have the 1.9 head ceramic coated more thoroughly. I think I'd keep the deck mod as it seems to have positive results. The ceramic coating should reduce the size of my cold start smoke during the first 30 seconds... 45 minutes or so of driving afterwards is pure bliss :twisted:

It looks as if the 1.6/1.9 combination is only for those who are serious about performance. More people may be better off modifying the 1.6 head that could possibly be ported to match the stock 1.9 head's flow. A modified 1.6 head may be more economical than a 1.9 head, but for bleeding edge performance, a modified 1.9 head is the way to go.

[andy2]

For what its worth chris It would still be nice to compare compression results now with the 1.9 head on then when you put the 1.6 head back on we can test it again(just one or two cyl's).I have the tool's and don't mind doing so just so that everyone can see the results,and It will help for others still questioning this combo!

[chrissev]

For what its worth chris It would still be nice to compare compression results now with the 1.9 head on then when you put the 1.6 head back on we can test it again(just one or two cyl's).I have the tool's and don't mind doing so just so that everyone can see the results,and It will help for others still questioning this combo!

I might be able to bring it by your shop this Friday afternoon if I can get an issue with the water pump worked out.  If not then next Friday.  How late are you there on Fridays?  

Chris

[935racer]

Yep, just like I said before, the 1.9 head is for performance! No point unless ultimate IDI power is required.

[chrissev]

Yep, just like I said before, the 1.9 head is for performance! No point unless ultimate IDI power is required.

This is very true.  Nothing else going for the 1.6/1.9 engine/head combination at all.  It basically takes a good running 1.6TD engine and turns it into a smoking, misfiring engine, in the name of increasing horsepower and torque.  It is a little unpractical.  I go out in the morning to start my car, and I have to sit and wait for ten minutes while it bucks and misses, and pours out smoke like I've never seen before in all my years of driving IDI diesels.  It is incredible.  The smoke fills up my whole front yard.  It covers the neighbour's house so I can't see it.  I have never seen so much smoke come out of a car before.  The first time I started it I just stood there watching the thing and shaking my head, like who in their right mind would want to do this sort of thing to a car?  At any rate I've arranged to swap the 1.9 stuff for a good rebuilt 1.6 head so I will soon be back on the road again without having to choke to death on the fumes pouring out the back of my poor car.  The situation is almost funny really.  Man that is a lot of smoke.  I feel like someone has played a practical joke on me.  I just sit there like, holy sh*t am I supposed to deal with this every day I start this thing?  Anyway enough ranting.

Chris

[chrissev]

For what its worth chris It would still be nice to compare compression results now with the 1.9 head on then when you put the 1.6 head back on we can test it again(just one or two cyl's).I have the tool's and don't mind doing so just so that everyone can see the results,and It will help for others still questioning this combo!

anyone who's questioning this combo, you gotta tell them about the smoke.  It is a huge issue.  I'm not talking about a few puffs here and there.  I'm talking about like if your neighbour's house was on fire.  It is thick, dense, pluming smoke.  It goes everywhere.  Sometimes I can't see the car.  People need to know about that if they are going to try this.  I think compression would be a secondary thing to worry about.

[malone]

Since October 2005 and about 10,000km later I have yet to receive a single complaint from my co-workers or my neighbors (I live in a dense neighborhood) regarding my cold smoke. Hell, I work in the Vancouver RCMP (police) headquarters! Outside of work I got pulled over at a roadblock once.. they just gave me a warning for no front license plate. No they didn't know I work for the RCMP as I was in casual clothes.

During the next 50,000km or so I'm expecting the cold smoke to continue dropping a little. Honestly I'd be quite discouraged off if I received a complaint, but so far so good.

I fully disagree with your "completely impractical" statement. A little impractical, yes, but only during 30 seconds of cold start in my case. After that it has better low RPM torque than a stock 1.9 TD and is great for city driving. Smoke is neglible or non-existent after cold-start. Completely impractical? I don't think so. I love it.

It's not unlikely to have to sacrifice something in daily driveability when you want bleeding edge performance. i.e. road noise after vehicle weight reduction, grabby clutch, low compression, etc.

I guess we've learned that if you just want to slap a stock 1.9 head on a 1.6 block without making other improvements or without concern of having a fast little IDI, then you've probably wasted your time. Ceramic coating and perhaps modding the piston crowns should be considered. A thorough ceramic coat may be more than enough for me for a daily driver.. 45 minute commute in heavy traffic each way. It's not that bad like you described :lol: I think there might be other issues in your setup.