1.9L block information

Some years ago, I did a 1Z/AHU swap into my Toyota truck. It's worked great until a few days ago, when It may have blown a piston, ring or something; I'm not sure yet.

I was looking at replacement options when the thought that "this could be an opportunity" came to my evil mind.

I can't think of a better group of folks to ask this question:

What are the differences between the 1Z/AHU and newer blocks, like the ALH or maybe even the BEW?

Would the motor mounts be the same?
Would the tranny bolt up to the block with the same pattern?
Would the flywheel bolt on the same?

I've done a LOT of mods to my AHU - so if a newer block would bolt in similarly, swapping to a newer style of engine may be possible.

Does anyone have any info/links about the block details for the 1.9L VW diesel engines?

Thanks a bunch,

E*clipse

What are the differences between the 1Z/AHU and newer blocks, like the ALH or maybe even the BEW?

The newer blocks are a very different design with an integral water pump driven by the cam belt. They have completely different accessories to the early style blocks so you would need to swap almost everything to suit the new block. The ALH is a VE-pump motor like the AHU but thats where the similarity ends - again different bracketry and a different pump too. The others are PD type so completely different fuel system as well as everything else. You're pretty much starting again if you want to swap to a new block.

Would the motor mounts be the same?

Depends which ones you used. The four bosses on the back of the block at the belt end (used for the mk2/mk3 mount) I believe are the same, but none of the rest are. The front of the block (or left in a longitudinal setup) is completely different.

Would the tranny bolt up to the block with the same pattern?

Yes. Thats about the only part of the new motors which stayed the same as the old ones.

Would the flywheel bolt on the same?

Yes

Yea, it would almost be like starting over. I'd build another AHU maybe with some stronger internals and some head work.

I will never do an other 1Z / AHU / AFN swap again in my personal vehicles. They are decent engines, but the electronics are very limited for tuning options and these engines are 20 years old and mega miles on most of them now.

My engine of choice for swaps at this moment is the BEW "Pumpe Düse". Visually very clean as there is no external pump. Modern vane style turbo - 1749VB is available everywhere. Injectors that can flow a lot. Electronics that you can modify and simplify. Making 150hp / 250ft.lbs of power is pretty much bolting on a new turbo and flashing the ECU. Doesn't have the cam issues the BRM PD does. CAN bus for simple integration with your dash using CAN2SDASH yet not as complicated as the 2009+ engine that needs CAN to communicate back to the ECU in order for it to work correctly. The BEW is that middle ground that gives the most amount of benefits with the least amount of fussing, while having and engine that shouldn't have too many miles on it if you choose not to do a rebuild.

You logic of wanting to upgrade is sound and well worth re-engineering one motor mount and some minor coolant hose re-routing. Go for it!

?beefing up the bottom end?

Thank you, everyone, for the info.

First, I would have no problem changing plumbing or motor mounts for a better solution - especially cooling plumbing...

The motor uses the transmission for the "rear" motor mounts. I have a motor mount towards the middle of the injection pump side of the block and another one toward the pulley side of the inlet/exhaust side. It sounds like I would need to re-design the mount on the injection pump side, but the other mounts would still work.

I just finished talking with Thomas at Quality German Auto Parts. The big question for me is that given the mods I've done to my 1.9L engine, would there be much advantage to a PD?

His feeling was that I'm already pushing the 1.9L block as hard as it can handle. In fact, he suggested dialing back the boost a bit from 18psi to 15psi to protect the rings. It does appear that I've been pushing it too hard - as evidenced by the long term failure of the rings.

To review: (it's in my sig line)
11mm injection pump
.216 injectors
GTA2056 VNT turbo
BIG FMIC
BIG aluminum radiator for a Chevy V8 to cool things
A bunch of intake and exhaust flow improvements
RC3+ to tie it together

This really isn't to brag; it's more to say Thomas is probably right.

Were the newer generation 1.9's, like the PD made with sturdier internals than the AHU, or could one build a sturdier 1Z/AHU with the right parts? Does anyone have links to a maxed out 1Z/AHU build thread?

Thanks again for the help & suggestions,
E*clipse

I don't think you're pushing it at all at 18psi - I was running an AFN at 28psi and only stopped because it shredded its SB Endurance clutch!

Spec is:
11m pump
.260 injectors
GT2052v turbo
OE FMIC
PD130 inlet
Ported head
Newman cam
Malone custom tune

Output was >200bhp (flywheel) and that was lugging around 4000lbs of C5 A6q so it didn't have an easy life! There are a bunch of us in the UK and across Europe pushing the AFNs pretty hard.

The AFN has the same bottom end as the AHU and 1Z, just with VNT, bigger injectors and a slightly different pump. Rods, pistons and crank are the same as the AHU. The early 1Z has different pistons and it seems to be consensus that they are weaker than the AHU, but I've never pushed a 1Z hard enough to break it.

You could easily build a sturdier AHU with Rosten Rods and possibly PD pistons, but by then you may well be in to the same or more cost as swapping to a PD, and those engines are definitely built tougher than the AHU generation since they were designed to make more power from the outset. It depends how much re-engineering you want to do really and where you want to spend the money.

Much as I like the old VE-pump motors (because they are cheap and I have plenty of them to play with) Hasenwerk makes a very good point about the BEW

That might be the core issue!

So the early 1Z had weaker pistons - that might be exactly what caused my problem! Yeah, compared to the numbers some of the folks around here are posting, my numbers seem fairly modest. However, with a weak design in the pistons some sort of long term fatigue failure would make sense. Looking into the issues involved with towing might be the reason for the issue. The truck is an aerodynamic brick with large tires, and yes I use it to tow semi-heavy trailers (horse trailer & smaller airstream camper).

So it sounds like moving to an AFN would get the sturdy enough block to run the upgrades I have. This would improve future reliability, but limit future upgrades.

Moving to a BEW would improve the bottom end strength but require changes in just about everything, except the flywheel/clutch, transmission mount and one of the motor mounts. The similarity with the flywheel and transmission make this look feasible.

Can you tell me a bit about your cam upgrade, the ported head and the interchangability of the inlet and exhaust manifolds? I'd assume that this will require a new computer.

Thank you VERY much for the info! I couldn't imagine more relevant info!

- E*clipse

Mikkijayne said:

I don't think you're pushing it at all at 18psi - I was running an AFN at 28psi and only stopped because it shredded its SB Endurance clutch!

Spec is:
11m pump
.260 injectors
GT2052v turbo
OE FMIC
PD130 inlet
Ported head
Newman cam
Malone custom tune

Output was >200bhp (flywheel) and that was lugging around 4000lbs of C5 A6q so it didn't have an easy life! There are a bunch of us in the UK and across Europe pushing the AFNs pretty hard.

The AFN has the same bottom end as the AHU and 1Z, just with VNT, bigger injectors and a slightly different pump. Rods, pistons and crank are the same as the AHU. The early 1Z has different pistons and it seems to be consensus that they are weaker than the AHU, but I've never pushed a 1Z hard enough to break it.

You could easily build a sturdier AHU with Rosten Rods and possibly PD pistons, but by then you may well be in to the same or more cost as swapping to a PD, and those engines are definitely built tougher than the AHU generation since they were designed to make more power from the outset. It depends how much re-engineering you want to do really and where you want to spend the money.

Much as I like the old VE-pump motors (because they are cheap and I have plenty of them to play with) Hasenwerk makes a very good point about the BEW

Click to expand...

If you want to stick with the early style block then its worth noting that the longitudinal versions of those engines have a much stronger block than the transverse versions. They have a very thick web around the sump flange, almost like a block girdle, and have more webbing on the other side too. These blocks will be stiffer than the transverse versions and so is likely why we can push them so hard.



So, if you want the ultimate early-style bottom end you'd need one of these blocks from Europe, either complete and use it as-is, or bare and add your choice of rods and pistons. One day I may build one up with Rostens and BHW pistons to get 2.0 litre, but at the moment the AFNs are plentiful enough that I can push it 'til it explodes and then throw in another one. I haven't exploded one yet though!

The cam I have is a Newman regrind of the stock one. They reduce the base-circle of the lobes which then gives the ability to re-profile them and increase lift. It goes from 9mm stock to 10mm iirc and makes a decent difference to the top end breathing. Its a very usable and cost-effective road setup which doesn't need any other mods although I did put 16V gas dual valve springs in for peace of mind. Some TDIs have dual springs as standard but I've never worked out the pattern for which.

My head work is very mild compared to some since its a road engine and I'm no expert. Basically port-matching with the gaskets and removing casting flash and sharp edges. I used a later head with 7mm valve stems rather than the early 8mm version which your 1Z may be.

The PD130 manifold bolts straight to the VE heads and again provides a useful improvement in flow. It needs an adapter creating to fit the original pipework but thats simple enough.



I did all these mods separately and could feel a difference from all of them. The countryside is very lumpy where I live so performance up long inclines shows up any changes. Once I'd done all the mechanical stuff Mark Malone did a custom 28psi tune to suit

Personally I would just pull the head and see what's going on. The time you are going to spend hunting around for another motor you can have the pistons out and a new set of ASV pistons in. ASV pistons with PD100 rods and ARL head bolts will make that motor handle 20PSI all day long. Also not really the boost that causes issues, its fuel and timing. Lots of fuel and timing will blow a diesel engine quickly.

I second turbocharged comments

long slow stress....

In my situation, the truck has a front axle underneath the oil pan. It's an independent suspension setup, and dropping the front axle or pulling the engine is a similar amount of work. I don't have clear access to the bottom of the motor.

I will be pulling the head to see what happened, but I'm still pretty stuck with either replacing the engine or pulling it and doing a proper rebuild. (which would include sending the block out for boring the cylinders)

I would have to agree that the fuel & timing are key issues - demanding lots of torque for long periods of time would be tough on an engine. Maybe a bit like long hills.... However, I live on top of a long hill, and the way home can be pretty hard on things.

Would you have any detail about how fuel and timing will kill a diesel? I have a sneaking feeling that I put that combo together along with long high-torque demands. Tow a load of hay up a long hill...

Because of the amount of work - and cost balance, It's looking like going with a newer PD would be the way to go. Not much more work than a AHU swap and it would only cost a few hundred $$ more. It seems like a good opportunity to get a more robust base for my future upgrades.

- E*clipse