Anyone tried AAZ pistons in a Franken engine? (1.6TD with AAZ head)

[Alcaid]

Hi,

The cold-start issue one gets with the Franken engines (1.6TD with AAZ head) due to the lower compression kills that option for me as I live in a cold country (Norway). Using AAZ pistons would increase displacement and compression somewhat, but would it be enough?

Are the cylinders thick enough for 79.5mm pistons? (76.5mm stock) Or even bigger oversized AAZ pistons?

The 1.6TD is running 76.5mm bore and 86.4mm stroke (1588cc total displacement)
The 1.9TD is running 79.5mm bore and 95.5mm stroke (1896cc total displacement)
The 1.6TD with AAZ pistons would then have a total displacement of 1716cc

How much would it effect compression, anyone got numbers for the volume "above" the piston stroke? (piston bowl, squish gap, pre-chamber)

Are the pistons even interchangeable with regards to wrist pin, piston height and so on?

Love to hear you opinions

Best Regards
Petter

[Rabbit on Roids]

the pin height and diameter are not the same. you would have to make special rods probably. and i doubt you can bore the engine 3mm without hitting the water jacket. even if you didnt hit the jacket, i still wouldnt do it unless you threw liners in it also.

why even do this? it would be 1000 times easier to just run a straight AAZ. than to build a complete custom engine. if aaz pistons and crap fit in a 1.6 EASY, there would be more people doing it.

ok, that sounded a little rude. i know why you want to do it, cause nobody else has. but it just doesnt seem feasible. Aki-76 was running some sort of HUGE piston in his high boost engine.

[burn_your_money]

Isn't that how the 1.7L engines are made? 1.6 stroke but 1.9 bore?

[Alcaid]

The reason I wanted to do it was because I like the response of the shorter stroke engine and I don't want a crank pulley failure. Just putting in a bone stock AAZ sound so boring

Is it possible to run the 1.6TD pre-chambers in the AAZ head?

Anyone know of pre-chambers sized in between that can be used?

[burn_your_money]

I think there is a thread in the FAQ covering the different precup sizes, although it may only be their volume...

[Alcaid]

Found it, thanks:

CC's above piston and compression ratio / pre cup cc volume

[Aki-76]

Aki-76 was running some sort of HUGE piston in his high boost engine.

Noup.i use 1Y piston,6mm lower compression height as aaz and 1Y rods,6mm longer than aaz orginal parts.Piston size is orginal 79.5mm.Engine is not ready yet 

[Rabbit on Roids]

Aki-76 was running some sort of HUGE piston in his high boost engine.

Noup.i use 1Y piston,6mm lower compression height as aaz and 1Y rods,6mm longer than aaz orginal parts.Piston size is orginal 79.5mm.Engine is not ready yet 

for some reason i thought you built a 2.1 stroker with some sort of huge oversize piston.

[Rabbit on Roids]

The reason I wanted to do it was because I like the response of the shorter stroke engine and I don't want a crank pulley failure. Just putting in a bone stock AAZ sound so boring

Is it possible to run the 1.6TD pre-chambers in the AAZ head?

Anyone know of pre-chambers sized in between that can be used?

i hear you about the quickness of the short stroke engine, thats most of the reason im partial to my 1.5's

and about the precups, i know TD's and 1.5's use the same diameter pre cup. thats it tho, i dont think any others interchange.

[the4ork]

you could always talk to a company like JE pistons and get a custom set made...

maybe something like the 1.6 bore to stuff in the 1.5? sounds boring at first but what if you copy like an aaz piston?

[RabbitJockey]

1.6 and 1.5 have the same bore

[Alcaid]

you could always talk to a company like JE pistons and get a custom set made...

maybe something like the 1.6 bore to stuff in the 1.5? sounds boring at first but what if you copy like an aaz piston?

JE custom pistons = expensive

I was more thinking in the direction of using used AAZ pistons or cheap a$$ prothe pistons. But if it doesn't fit, it doesn't fit

[truckinwagen]

I had for a while pondered the idea of boring a 1.6 block and using AAZ pistons and rods on a 1.5 crank(which would come to proper deck height) but realized that the 1.5 used smaller rod journals, which ruins it.

if it did work it would be 1.6L but shorter stroke.

[NintendoKD]

I have my thread updated and if you are patient then you can watch the lemming make the leap for you  I will be doing some heavy modification though.  Although you won't have to do all that I am "dry sump pan, oil res., vnt setup, meth injection, custom block heater of the 1,000 watt variety, etc." it will still be a pretty nice build.  I understand your concern for cold starts but if you sit back and relax maybe I can give you some good news.  My thread newly updated with pictures can be found here:
http://www.vwdiesel.net/forum/index.php?topic=22148.195

Good luck and don't give up on your dream,

Kevin

[Alcaid]

We have 10degF/-12degC today, so the Franken combo wouldn't exactly be ideal to say the least (Good thing I have my PD150 4Motion Golf for winter fun  )