Why no 1.6l tdi?

[ShoulderMan]

Ive serched far and wide, but have not found anyone who has put anything togeather and took a picture of it.
Just lots of talk and speculation.
   Is it the pistons that keep anyone from trying this?   As it seems that everything else is taken care of.  Mdti pump, 1z head, 1.6l block,... so the pistons are the limiting factor?
or is there more to it? 
I hear of pistons pricing from 150-250 each,  which scares people away, but a $1200-2000 mtdi pump seems to be, not so bad.
   I also know that they now have a 1.6l tdi with comon rail, but, im sure its a lot more expensive and harder to come by.

 Thanks
-Ron

[OM617]

Pistons, rods, crank, block.

[ryanp]

the 1.2 tdi pistons are said to fit a 1.6 idi block and rods.

[ShoulderMan]

why cant you just make custom pistons to fit the 1.6l block?
 then you can use the rest of the assy.
   Is custom making a diesel piston that much more diffucult than making a gasser?
 

[8v-of-fury]

I think it would take a quite a skilled machinist to make TDI pistons.. (??)

They have caverns in them, as opposed to the flat top gasser pistons and even divets in a idi piston. I would think this would be more cost then it is worth essentially.. having a 1.6 TDI will have no benefits over a 1.9 except maybe a slightly quicker revving engine, with less torque and power? lol

I dunno, just my view on things lol

[blackdogvan]

Seems to me a good way to keep the massive fleet 1.6 diesel's in north america going forever. Since Prothe's pistons are possibly the best quality parts available on his site maybe he can source the 1.2L pistons.? Back when Pete was posting here (well at least under his own name) he was looking at a 1.6 tdi conversion but I never heard if it made it all the way. IF there was a cheap piston available its just about finding a head & I guess a mechanical pump would be the best way to go. With the amount of mtdi pump tribal knowledge out there I can see more & more guys being willing to tear into their pump & install a tdi cam plate.

But like Andrew says, with unobtanium pistons its a bit of a non starter.

[ShoulderMan]

Well, Ive done a little homework a year or so ago,
 I had found the 1.2l pistons, the only problem, was that they did not make any that were oversized. so, if your 1.6 needed the next size up piston, good luck. they were also around 150-250 each.

 The main goal would be for the mpg. right now i can get 55mpg out of my 300K mile block, and that was with the crappy exhaust manifold and 1" pipe out the back. 
I now have a 3" out the back with the better exhaust casting from a later block, just waiting to have to refuel again to compare.

 And the fact that I have already invested lots into the block and rods. the only thig I need is the oversized pistons to make this work.

Ive seen and read Prothes' site and posts,  I would not mine getting the door handle latches, and some cosmetic pecies. I prefer overkill on engine conponets, like 2 OT battery cables 

I dont know if it would work or fail early, but what about machining the tdi pistons to fit in the idi hole?   then chill harden them and coat them or something?

[JRD]

Hy,

I'm comming from French forum, so keep gently with my english!  


I've got the same idea from long time!
I've look at information from different vw engine to know the better pat to use in this project.

Link to the french topic: http://www.vwdiesel.net/forum/index.php?topic=25040.0

My idea is to make a "downsize" Mtdi engine to optimize comsuption and keep power and torque of a standard 1.6TD engine (80hp)
This engine will be used in a VW caddy, my daily car.

The parts I want to use:
- 1.6TD engine RA (just for the block, crankshaft and connecting-rod)
- Engine head from 1Z engine
- Pistons from 1.2L TDI engine (if it's ok for the block!) The other solutions consist to use 1Z pistons and modified the bore of the block. But the capacity growed up to 1715cc...

To optimize this engine, I've fixed a Garrett VNT15 to increase torque at lower RPM.
The Waste-gate have been modified to work without electronic control.


Is the pistons from 1.2L TDI engine realy ok to fit in 1.6TD engine block?

What are the modification to do to the fuel pump?
I've thinking about camplate and high pressure head from TDI engine, but what about the other parts? (I don't really know about optimisation of a fuel injection pump...  )

[ChopSauce]

Hi!

Is the pistons from 1.2L TDI engine realy ok to fit in 1.6TD engine block?

The 1.2L TDI pistons are a direct bolt-in swap [...]  It just seems to me like more bang for buck considering how available the 1.9TDI parts and engines are.

An answer to your question was already there. The advice sounds much like the ones you got in the french section. Just build your pump like any mTDI one and everything should be fine - I guess Just read on.

One more comment : if you really want to optimise consumption, then you definitely need an eTDI!

[ShoulderMan]

unfortunately,  I have found out why there are no "on the road" 1.6l tdi's
 
 we can not use the 1.2l pistons from the 1.2l block because of how different everything is.  the connections at the Rod end and the Piston connection are trapazoidal.
 
 end of rod connection looks like  / \   instead of normal  ||     they say the extra material at the piston connection allows for a more robust design and can take more beating.  

 the other end of the spectrum is,  yes you can have forged pistons made, but they dont have a mix of material to take the constant beating and detonation that our high 18:5.1 - 22:5.1 compression ratio engines dish out.   they are OK for Drag Race, but not for putting around town getting good fuel milage.


With out having a 1.2l piston to compair to our 1.6l piston we are just guessing on what we could do.  If we bought one new for around $200 each, and found that it was an exact match and drop in to our block,...
First they only come in 1 flavor, Stock  no over sized pistons avi. if you need a fresh bore, your SOL

Second, even if they would drop in,  they wont bolt up to our connecting rods because of the unique shape at the end of the rod.
so at this point you have a very expensive paper weight.

and Third, if you can get one and pay for it, there is a chance that it just wont work
 
NOW, if someone had access to a good used or new piston, and it does by chance fit and work every which way,  there is the possibility of having the piston blueprinted and adjusted to fit our stock connecting rods, then alls we would need to do is get enough people togeather to buy 10 or 20 sets at I would guess maybe 1000 per set and have the piston re cast to fit our needs.

since a cast piston will take the beating that a forged piston will not.

[ShoulderMan]

[JRD]

So is it possible to use the 1.2L tdi connecting rod?

What is the length and the head diameter (to fit on the crankshaft) of these connecting rod?

I've found your topic about rod length
http://www.vwdiesel.net/forum/index.php?topic=24920.0

Do you have more information now?

[TDIMeister]

http://forums.tdiclub.com/showpost.php?p=3038171&postcount=51

[TDIMeister]

I suggest a different track.  Start with a 1.9 TDI long block and install a short-stroke crank.  The 1.6 IDI has an 80mm stroke, which yields 1588 cc.  All else being equal, compression ratio will drop from 19.5 to 16.5.  The pistons, block and crank remain VW parts bin components.  Only the rods need to be custom.  Much cheaper (and available) than pistons.

[ShoulderMan]

Before that, I had even thought of going down the newer road and using the new 2010 1.6l common rail engine pistons, but it seems as if they are also of the 1.9l specs, with, like you said, a 1.9l bore and a shorter stroke.  So, out of all of this, seems the new generation is going with the larger piston bore as well.

 In order to keep the shorter stroke, will I beable to use the 1.6l crank?  its just a drop in part?

Another Question I had, Can I use the rods from a 1.6l Block, and just Mill the Deck of the 1.9l block? to get an acceptable c/r?

and are all 1.9l blocks interchangable with the 1.9l AAZ head? from 2000-2010?