the never ending AAZ vs TDI debate

[Blaizefed]

Gentlemen, I need a bit of input from those of you who have a bit of experience here. I have recently bought an 86 JX powered westfalia. Now, the last one I had a couple of years ago threw its cam belt on the M3, and I replaced it with an AAZ. My plan with this one was to do the same. The JX in there now runs fine (though it could do with a valve adjustment I think, and it will get one in a couple of weeks once I have time), but having owned one with an AAZ I know they just run better. That extra torque makes all the difference. I was up to Scotland a couple of times in the last one and it just hammered along at 65 in a way the JX doesn't.

However, I can't help but wonder if I should just cut to the chase and go for a TDI. If of no other reason they are a damn sight cheaper these days as the breakers have all clued in about the AAZ conversion. Seems silly to spend £700 on an AAZ when I can get a TDI with all the leads and ECU's for £500.

But then there is the gearbox. I really don't want to get into all that crap, but I suppose I'm going to have to. I have very little interest in using a flipped non VW box, and I am only marginally more excited about re-gearing the box that is in there. in either case, it would have to be staged, that is to say the engine first, then the gearbox a few weeks/months later. I appreciate the TDI power is down lower, but is it just inefficient with the JX gearbox (5 speed, dogleg) or is it so bad that its not usable on the motorway that way?

I should mention, I am an ex VW dealer Mechanic. (house husband now raising my son) so none of the mechanics of this scare me. I can handle the wiring, and the bolting together. I can rebuild the gearbox myself. I don't want to but I could even weld together the left engine mount for the TDI.

So who has been down this road? am I going to bolt in the TDI and hate driving it until the gearbox is changed? Are the parts available to re-gear the transmission? do I even need to? can I just bolt in a petrol box? is that any cheaper, or the same cost, so I may as well rebuild and have a fresh setup?

All of this is compounded by the fact I will be moving into London (Blackheath) later this week, so while I will have a driveway and a garage to work in, I can by no means buy a donor car and strip down the engine myself. So I have no choice but to buy an engine on a pallet (and therefore pay a breakers yard who knows what I am doing and will charge accordingly).

Though I did notice a couple of TDI's pop up in the classifieds today and I am damned tempted.

I know this is well trodden ground, but everything I find is bit and pieces of info and mostly years old so I am hoping to hear what the state of play is these days on all this.

[Aidan]

if moving to the smoke wouldn't a petrol upograde be worth considering AGG or similar inline 4's with a standard petrol box, cheaper than TDi on a diesel van

[lloydy]

if i was moving to london, i would future proof the conversion a bit by fitting a in line petrol. Either 1.8T or just the 1.8 20v or 2.0 20v. or if your on a budget the 2.0 gti AGG engine.

Some time in the not distant future it will be very hard to own a diesel in a city

[Blaizefed]

OK, thats 2 of you. Not to totally derail what I was asking about, but what are you on about? I have been hearing rumblings about this for a while, but not paying any attention as I am down in Winchester at the moment. Is there some sort of actual legislation coming that I didn't hear about? Or is this fear mongering that "they" are going to tax us to death.

What have I missed?

[Blaizefed]

A 1.8t could be A LOT of fun though........Wonder what the MPG would be like.......

[lloydy]

don't get me wrong, i have a tdi and live in london.. they are great, but if you live in the london emission zone and your van isn't registered as a motorhome you can't have a diesel. If it is registered as a motorhome, your ok for now. it will change at some stage though...
A 1.8T does low 20mpg's

[Blaizefed]

Yeah, stuff that at low 20's. The beauty of these things for me has always been the fuel economy. I have been looking for a good reason to swap a 1.8t into something and I even have a spare mega squirt lying around, but as much fun as the power would be, I'd miss the economy. It's a factory Westy so I shouldn't have any trouble for the time being, I think I'll stick with diesel.

So back to the larger debate.

[lloydy]

if your not re gearing the box, you won't get the best out of it. you might even end up hating it. Presume your 2wd? if so larger rear tyres may help a bit until you fix the box. Have a play round on a gear ratio calculator, input final drive and gears ratios and play with the tyre size. 60@3000rpm will be livable for now
http://westfield-world.com/gtc.html" onclick="window.open(this.href);return false;

if you know your gearbox code, you can get ratios from here
http://www.brick-yard.co.uk/VehicleSpec ... fo/gbx.htm" onclick="window.open(this.href);return false;

Obviously a AAZ will negate all that, and they are a good engine. oil cooler, charge cooler, a bit more boost and fuel and it'll be nice!

[Blaizefed]

So looking for parts to re gear, all I have found is brickwork doing a ring and pinion for £600. While I realize that is not THAT absurd given that we have a rather involved shaft for the pinion gear, it damn sure isn't cheap either. I have heard mention of German companies selling gears for these boxes, they any better? or just the same thing in euro's?

I am going to have to look into these damned flipped boxes aren't I......

[Blaizefed]

So having spent the night reading up on what's involved, I am going to say nevermind. Think I'll go AAZ with a fiddles fuel setting and a better boost pin again. Tempting though all the cheap TDI's may be, it's going to still rattle up to being a more expensive (and more time consuming) project to go that way, and this bus is going to be our daily driver very soon. So simply don't have the down time to spare.

[axeman]

Having just installed a 1.8 20v and only had 2 fill ups i have now hit the 30mpg the first was 28mpg but i was enjoying myself. all be it a rough calculation and in a doka . I think lloyd may be be quoting figures from the samba where the american mile and gallon are different from the uk mesurements. Roughly calculating usa to uk the 20v T mpg figure is about 25/6 mpg.
The main difference you will find is the refinement with petrol engines. And there ability to rev and rev some more which makes them so much fun to drive and more than keep up with modern traffic.

Neil

[ajsimmo]

If it were my choice, I'd go for the AGG on LPG. Best economy, best power, nicest driving experience, no gearbox ratio problems, straightforward to do if starting from a JX, and probably no future LEZ worries in that London.