Wow some serious engineering getting mentioned here, and serious chemistry as well.

How about an exhaust scavenging improvement using a tuned exhaust system. Or just drop in a John Barret big block 8.6 litre V8 crate motor.

I do fear for Jason's sanity if he's already so close to what the Touring Car boys are able to achieve from a (slightly) bigger 16v engine, and he's still looking to continue... :(

I'm not sure scavenge effects will make it upstream past the turbo, but I think that rallying and some of the J-tuners working with things like Skylines and Supra 4s, Imprezas and Mitsu Evos have experimented with tuned length manifolds into the turbo.

you wont be able to easily fit bigger valve seats in a pd head jason, there is an internal water jacket that cools the part between the valve seats, plus it would run fairly close to the glow plug, if anybody has a spare pd cylinder head knocking about that you dont mind me experimenting on and can send it to me i will give it a go for you

What about twin turbocharging it?

I mean a turbo for the low end so there isn't much lag then a big turbo for the top end.

That should help compress more air in there and when combined with a high flow exhaust and injectors with a good spray pattern you should see something.

sequential turbo-ing is too much balls ache mark, you need too many non-return valves and bypass chambers etc

sequential turbo-ing is too much balls ache mark, you need too many non-return valves and bypass chambers etc

I knew it was a pain, but figured he was running out of other options.

I guess a rebore of the engine to increase capacity, keeping the stroke length the same and then a nice turbo and what have you could be an option.

Is there space to rebore a 1.9 out to 2.1L?

no chance, you'd be lucky to get an extra 50cc by overboring, and that is IF you can find suitable pistons, also if you overbore too much you risk breaking through to the water jacket, there isn't much 'meat' to play with on most vw blocks, in some places it will be less than 2mm and that's not taking into consideration any possible core shift when the block was cast. it might be possible to overbore then sleeve the cylinders with cast iron liners, but bear in mind you will again need to find suitable oversize pistons and also you'd need to find a cylinder head gasket with larger bore holes

As I said before, this thread (third post from bottom) seems to suggest that the 2.0L block was a rebore of the 1.9L anyway, and that even that is pushing the limits of what's achievable... :ne_nau:

Ahh I didn't know how much room VW left in their blocks.

Time to go the XUD route to get from 1.9 to 2.1 and increase the stroke then start playing wildly.

I assume the head from a 2.0 16v is incompatible with the 1.9 block.

dont know enough about the diesels to comment on that mark, but i would say no because the piston crowns are the wrong shape

That last page was getting too much like a chemistry lesson!

Getting back to valves and yet more power, I wonder if a 16v head would fit? I have wondered maybe not a twin turbo, but adding a supercharger as they run best at low revs. I have never seen one for a 4 stroke deisel, only seen on two stroke marine engines.

The other alternative is to remove the engine and drop a 1.8T (petrol) in it.

dont know enough about the diesels to comment on that mark, but i would say no because the piston crowns are the wrong shape

New pistons, and a longer throw in the cylinders too to increase capacity while you're at it if it was to fit some how then

If we're going to these lengths, a taller block and lower-decked pistons so we can fit longer conrods and reduce side-loading...

SO basically we think Jason needs a different engine to go much further.

SO basically we think Jason needs a different engine to go much further.

Start off with the twincharged BMW 2.0 liter than.

Start off with the twincharged BMW 2.0 liter than.

I'm not so sure Amanda will be happy if Jason starts hanging around her car, but yes that is a sweet engine.

I'd rather their twincharged 3L straight 6 derv mind