TheSamba.com :: View topic - U.S. Diesel common sense: 1.6TD vs 1.9TD?

Mon Feb 18, 2008 3:43 pm

went from a 1.6td to an AAZ and the difference is huge! even though on paper torque/bhp are not too different , they drive like totally different vans. (although i have put a 1.6 LDA pin in) - have not touched max fuelling screw at all.
1.6 engine was in good condition/tune, pump timing and cam timing were both perfectly set up but after replacing with the 1.9 i am getting an extra 100 miles from a tank of fuel!!!! go figure :shock:

Tue Feb 19, 2008 5:18 pm

How far are you getting to a tank of fuel? Poor fuel mileage is a symptom of a worn out engine. Low compression, in other words.
Al

Tue Feb 19, 2008 8:30 pm

Poor fuel economy is most often a sign of a worn or poorly calibrated pump. When worn, the timing advance goes to pot and the fuel economy and power go out the window at the same time. If a 1.9TD replacement got better fuel economy than the 1.6TD it replaced, then the 1.6TD had a significant problem. Adjusting pump internal pressure will often result in a 20% increase in fuel economy and HP with an older pump.

I've driven both an intercooled 1.6TD and 1.9TD in a vanagon the 1.6TD was a noticeably better performer. The 1.9TD was non-intercooled. It's LDA pin had, however, been ground to a significant taper. I'd have to say I was quite excited to get to drive a 1.9TD and significantly disappointed when it had nothing on my mildly modified 1.6TD.

Andrew

Tue Feb 19, 2008 8:37 pm

Oh, forgot to add, the 1.9TD was a new engine and my 1.6TD had 180,000 miles on it.

Obviously, if the same tuning is done to a 1.9TD as is done to a 1.6TD, the 1.9TD will be a better performer. But, to me, considering the cost of the 1.9TD where I am, it is not enough bang for the buck. If springing for the extra cash over a 1.6TD, I'd bypass the 1.9TD and get a TDI and enjoy increased power and 10%+ better fuel economy.

Andrew

Tue Feb 19, 2008 11:59 pm

Andrew A. Libby wrote: Oh, forgot to add, the 1.9TD was a new engine and my 1.6TD had 180,000 miles on it.

Obviously, if the same tuning is done to a 1.9TD as is done to a 1.6TD, the 1.9TD will be a better performer. But, to me, considering the cost of the 1.9TD where I am, it is not enough bang for the buck. If springing for the extra cash over a 1.6TD, I'd bypass the 1.9TD and get a TDI and enjoy increased power and 10%+ better fuel economy.

Andrew
I think if I had a dyno and a big budget, I could show you that both engines would make almost exactly the same horsepower. The 1.9 could do it at a few hundred rpm less speed. In other words, if the hp peak of the 1.6 was at 4400, the hp peak of the 1.9 might be at about 3900. The torque at that 3900 would be somewhat higher because hp is a product of torque times rpm.
This is because all internal combustion engines are basically air flow machines and the head and turbo is pretty much the limiting factor. and in this case, the head and turbo can be pretty much the same.
I've heard about dyno studies done on gasoline engines that showed this,and I think the small diesels might be similarly compared. There are practical limits to turbo boost and intercooling, but the turbo and intercooler are probably the limiting factor. Of course, you've got to get fueling to go with the air, but that's up to the guys that build the pumps.
Al

Wed Feb 20, 2008 7:18 am

As an interpretation, would that mean that the 1.6 might be more suited to use with an automatic transmission without re-gearing? (since normal cruising rpm is in the 4000-4200 range)

Wed Feb 20, 2008 7:57 am

dr. no wrote: As an interpretation, would that mean that the 1.6 might be more suited to use with an automatic transmission without re-gearing? (since normal cruising rpm is in the 4000-4200 range)
It seems like it to me. I recently got a 91 Vanagon with 2.1 WBX and automatic. This is the first Vanagon I've ever had with an automatic. It seems like it has an incredible amount of slippage. While accelerating briskly, the tach needle just seems to stay at 3000 rpm for a long time. Most of the time, thru 1st, second and some of third. It seems like the stall speed is too hihg for the diesel. I also think this wastes a lot of fuel in stop and go driving. Mileage seems to be around 12mpg, but it does great on the highway.
It seems like a diesel engine might be happier with a lower stall speed. Such a converter might exist . Perhaps the converter from earlier type 2's 73-75?
Al

Sun Dec 09, 2012 7:35 pm

the caveman wrote: if you already have a 1.6 td in the truck i don't think just throwing in a 1.9 will make so much of a difference to be worth it. different story if you just had a regular 1.6 non-turbo. if you really want more power maybe install an intercooler and then get your pump modified for the extra power that will give you

There is a huge difference between the 1.6 and 1.9. The 1.6 has no power and the 1.9 has great power. All you need is to replace the bottom end with the 1.9. They are the same. All the parts interchange except the block and crank.
In basic terms the 1.9 is a stroked 1.6td. It has way more power and the gas mileage is the same if you drive it for gas mileage. However when you need the power it is there.

Here is my experience with both engines. I have had them both so I know exactly what they drive like. And yes I would be willing to bet I would woop your ass in a drag race with a stock n/a injection pump on my 1.9 n/a with a TDI replica turbo kit only running moderate boost and beat you pump to pump in gas mileage race.

The 1.9 has way way better bottom end power. So you are not needing to rev the engine up at all to get up to speed. Immediate boost above idle. (1.6 needed to spool up). Even without a turbo the 1.9 is more of a pleasure to drive than the 1.6td but you are loosing efficiency.

After having both I would never never ever run a 1.6 if I could at all afford a 1.9. You may see me at the drags when I put on my M-TDI custom Frankenstein pump running pretty impressive numbers. (working on the pump right now).

In short If you want to have great gas mileage and be able to pass somebody when you want to not when you spool up enough boost. Then go with the 1.9l VW diesel. I even forget I have my a/c on when I am climbing a hill at 80. I would recommend using the TDI turbo kit because the turbo is just better engineered than the ones that come on the early engines. Even though it is probably made in china.

Sun Dec 09, 2012 8:20 pm

Sun Dec 09, 2012 9:12 pm

Almost five years later...
1.6td with aircooled tranny, extremely driveable. It's worth the conversion, especially if you just get the JX vanagon version, the holes for the engine mount bars were already there.

But if I wanted to "woop" someone ass, I'd pick a different vehicle to do it in than a 30 year old camper...

Sun Dec 09, 2012 9:19 pm

Do any of these engines drop right in? Particularly the mythical 1.9 AAZ NA?

I fear turbos because of the added electronics, cooling (intercooler and otherwise), and EGT monitoring. I'd love to be able to take out the 1.6na and throw in a 1.9aaz NA in a single day, even if I had to pay more for the AAZ...

That said, I have a 5-speed which I just found out sits 2" further towards the back, so it might not even fit.

Sun Dec 09, 2012 10:04 pm

Oil cooling, intercooling, gearing, bigger tires, where do I put my new bigger spare...
I think diesels are bitchin' but...,
looks like a big ol' spiral to me, but give it a shot, maybe you'll get me brave! :)

Mon Dec 10, 2012 8:18 am

whafalia wrote: Oil cooling, intercooling, gearing, bigger tires, where do I put my new bigger spare...
I think diesels are bitchin' but...,
looks like a big ol' spiral to me, but give it a shot, maybe you'll get me brave! :)

Just think of your OE spare as a space saver. In the event of a flat, it will work just fine until you have an opportunity to get the larger tire repaired. Of course, the flat tire will have to be hauled inside the Van ,,,,,,,, good incentive to get it fixed. Maybe Go-westy, Van Cafe, etc., will make a modified clam shell to accommodate the larger wheels ... :D

The AZZ, AHU, ALH, etc., TDI engines already have oil cooling systems. As discussed, an Intercooler adds tremendously to power, efficiency, etc., of the engine. There is plenty of space in the engine bay to accommodate the necessary piping.

Even if you go with a Zetec, Subie, etc., gearing should be a consideration to maximize use of the additional torque and HP of those engines (and, extend useful life)... Also, the vast majority of Vanagon trannys are in need of a rebuild anyway.... add the necessary 3rd and 4th gears while in there is a no brainer.

Right now, diesel fuel is about 33% more expensive that gasoline (widest gap I've seen in 31 years driving VW diesels). However, I consistantly get over 32 mpg with my ALH TDI. That's better than a 50% improvement............. dependability is a whole new topic!

Mon Dec 10, 2012 10:04 am

I don't know what it is about The Samba, but I've never encountered all this hand-wringing about concepts like turbos and five cylinders anywhere else on the whole wide intertubes. If it makes it any easier, just think of a turbo as a fancy muffler added to your exhaust--install and then forget about it.

Fri Feb 15, 2013 9:41 pm

dr. no wrote: Almost five years later...
1.6td with aircooled tranny, extremely driveable. It's worth the conversion, especially if you just get the JX vanagon version, the holes for the engine mount bars were already there.

But if I wanted to "woop" someone ass, I'd pick a different vehicle to do it in than a 30 year old camper...

Well my 1.9 is in a Rabbit pickup so yes it does go really fast.I can easily keep up with a 1.7 litre Na gas engine. But I am absolutely sure the 1.9 would pull a camper better without a turbo than a 1.6 td. With a turbo it has so much more torque you can be in 3rd gear at 35 and ease on the gas and accelerate like a gas engine. There is no extra work or fabrication in putting in the 1.9 either. Has all the same bolt holes as the 1.6 if you get the right one. The only difference is the fuel lines are longer but you can bend a set from a 1.6 when they crack and the block is about 1/2 in taller. And it has the same pistons as a 1.6td. So you can run a turbo with fairly low boost like the 1.6.

Changing to the Turbo kit from a tdi is an improvement as well. In the early turbo diesel VW, They put way to large of a turbo on the engine. The smaller turbo of the tdi and 2.0t spool up faster and are capable of enough boost to over boost the engine. So why did they put a larger turbo on the 1.6 with the adenoid pump. Technology an testing of today is much better than when they made these engines.

I also own a 06 jetta TDI. Now talk about efficient. That is a whole different subject.

Fri Feb 15, 2013 10:16 pm

-Rogue5- wrote: Do any of these engines drop right in? Particularly the mythical 1.9 AAZ NA?

I fear turbos because of the added electronics, cooling (intercooler and otherwise), and EGT monitoring. I'd love to be able to take out the 1.6na and throw in a 1.9aaz NA in a single day, even if I had to pay more for the AAZ...

That said, I have a 5-speed which I just found out sits 2" further towards the back, so it might not even fit.

I believe you are referring to the engine I have in my rabbit pickup. The 1.9 NA which I believe is the AAZ. (I would need to confirm it with Quality German Auto parts in Ontario CA.) has all the same bolt holes in it as the 1.6 TD or NA. In fact the 1.6 TD and 1.9 NA are virtually the same with the only exception. The block is 1/2 inch taller. The 1.9 is just a stroked 1.6. The pistons have the oil holes that the 1.6td have. You can get a bolt on trubo kit or also they have a factory turbo 1.9 that is not a TDI. TDI is a direct injection system and these are indirect. Still pretty efficient.
I have ran both the 1.6 and the 1.9 in the same vehicle with the same boost. The 1.9 hands down outperforms the 1.6 in every way shape and form. The 1.9 with the longer stroke has the ability to punch out boost at just above idle. Giving it much more torque than the 1.6. If you M-TDI your stock injection pump from a 1.6 td high output model aka Adenoid pump, you can enhance the torque by changing fuel timing. There is just a upgraded timer piston that you need to put in the stock pump. Putting the timer piston in the 1.6 would be pointless because the 1.6 doesnt gain significant boost until about 2500rpms.
The funny thing is that the gas mileage on both engines is very close to the same. The 1.6 had to work harder than the 1.9. The drivabilty of the 1.9 is very similar to a gas engine but more torque and you dont need to rev it like a 1.6. I find myself shifting way earlier and still pulling hard.

Fri Feb 15, 2013 10:44 pm

69doublecab wrote: Andrew A. Libby wrote: Oh, forgot to add, the 1.9TD was a new engine and my 1.6TD had 180,000 miles on it.

Obviously, if the same tuning is done to a 1.9TD as is done to a 1.6TD, the 1.9TD will be a better performer. But, to me, considering the cost of the 1.9TD where I am, it is not enough bang for the buck. If springing for the extra cash over a 1.6TD, I'd bypass the 1.9TD and get a TDI and enjoy increased power and 10%+ better fuel economy.

Andrew
I think if I had a dyno and a big budget, I could show you that both engines would make almost exactly the same horsepower. The 1.9 could do it at a few hundred rpm less speed. In other words, if the hp peak of the 1.6 was at 4400, the hp peak of the 1.9 might be at about 3900. The torque at that 3900 would be somewhat higher because hp is a product of torque times rpm.
This is because all internal combustion engines are basically air flow machines and the head and turbo is pretty much the limiting factor. and in this case, the head and turbo can be pretty much the same.
I've heard about dyno studies done on gasoline engines that showed this,and I think the small diesels might be similarly compared. There are practical limits to turbo boost and intercooling, but the turbo and intercooler are probably the limiting factor. Of course, you've got to get fueling to go with the air, but that's up to the guys that build the pumps.
Al

Well I would beg to differ with that. Having run both engines. A rebuilt 1.6 and a used 1.9 with fairly low miles. There wasnt a comparison. The 1.9 running the same max boost and turbo as the 1.6 is much stronger. I DK what the dyno says. I am without a doubt sure in a race the 1.9 would be the winner. In a uphill drag again the winner. I am going 80 afraid to floor it up hills with my AC on my other engine would barely do 65.
Same timing and everything. but here is the kicker. I was running the adenoid pump on the 1.6 fueled up about a 1/2 turn. I am only running a stock 1.9 Na pump on the 1.9 not even fueled up. I am sure when I put the other pump on it will be even better.

After all the comparison I have done I would never run a 1.6 especially in a bus.

Sat Feb 16, 2013 7:16 am

Most of this thread is from 5 years ago and things have changed a bit since then. The cost of used/core AAZ and 1z/AHU engines has gone down considerably in that time. The parts availability for the AAZ has actually increased in that time with many vendors selling parts for them and Worldpac picking up the AAZ parts as well. With the greater availability of parts and lower cost of 1.9 engines they are a decent way to go.

There are quite a few variables to the various stock installations with minor differences in max hp/tq, but the following is a decent guideline.

1.6TD -----------------------------68 hp - 98 ft-lbs
1.6TD GTD (intercooled)--------80 hp - 113 ft-lbs
1.9 non turbo (1Y)---------------67 hp - 97 ft-lbs
1.9 AAZ (non-intercooled)------74 hp - 111 ft-lbs

As you can see, the 1.9 non-turbo has very close to the stock power and tq of a non-intercooled stock 1.6TD. The 1.9 displacement would give more torque off-the-line. The 1.6TD has far more tuning potential. There is very little bang for buck in tuning a non-turbo diesel. Adding an intercooler to a 1.6TD and delivering appropriate fuel for it will allow it to deliver considerably better performance than a 1.9 non-turbo and actually better performance than a stock AAZ. The AAZ was considerably detuned from the factory and so stock form is quite anemic. The stock AAZ injection pump is quite sad. With adding an intercooler and appropriate boost enrichment, it is quite easy to get 100+hp and 130+tq still maintaining stock or close to stock boost.
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Sat Feb 16, 2013 8:31 am

Sat Feb 16, 2013 9:01 am

Andy, I hope you don't think I find the electronics 'scary or hand wringing'. I certainly don't feel that way. As I've mentioned before I own and work on both eTDI and mTDI. There are advantages with either. Regardless, any comments about TDIs in this thread are off-topic.