port and flowed the 1.9td head and manifolds?

Twiss · Unread post by **Twiss** » 30 Jul 2008, 14:21

As any one on her heard of or even done port and polishing to the 1.9td head and manifolds?

I ask not Cos i want more horses but more MPG. Wandered if it would benefit in any way.

Thanks Vaughn

MikeT · Unread post by **MikeT** » 30 Jul 2008, 16:43

I think there is at least one forum member that has done some re-work but it was to a 2.1 head, if that makes any difference?

But looking at the head I have on the bench, I don't think there's much that can be done to improve it.

The inlet manifold on mine incorporates the EGR passage which I suspect is detrimental to even flow through the runners and could have been designed better IMO. The induction is a tortuous route of multiple bends while the exhaust manifold also has some nasty 90-degree bends before the turbo and then has a further restricting catalytic converter.

I think best results would be had from a free-er flowing exhaust and a tweak or two to the fuel pump and turbo.

XantiaMan · Unread post by **XantiaMan** » 30 Jul 2008, 16:53

I dont think it will make much difference TBH. It would definatly improve bhp but what you need is more torque. Optimising the fuelling settings to improve low down torque and thus elss frequent gear changes makes a difference, as does increasing boost slightly. Regular changes of air and fuel filters and on every other tankful a bottle of diesel injector cleaner will also help keep your engine as economical as can be, and dont forget driving style is one of the major factors of increasing or decreasing your mpg!

KP · Unread post by KP » 30 Jul 2008, 17:36

You can get rid of the mid cat by just buying the pipe designed for the 1.9tds that didn't have it fitted.
Better would be re-thinking the inlet tract but all this will just lower the level at which the turbo picks up.

As said above, tweaking the injector pump and turbo is your best bet, a batch or two of say BP Ultimate or V power diesel will help as well(doesnt need to be a full tank but say 1/4 tank on a low tank twice should do it, and stick some veg oil in there to to clear it out.
Then stick to 5k for oil and filter changes.

A good way to save money is to buy a K&N type replacement filter, also make sure the ducting to the air box is clear as this will help a nice clean, semi forced induction into the system.

Also go thru the car and remove all the junk you dont need on a daily basis from the cubby's, under seats, and give it a hoover as well, most cars i've seen while look clean still hold a lot of dirt! and then junk the spare wheel and jack and the rear wiper to improve airflow

Under trays are good but there aren't many left out there although citroen still sell and stock the front and rear ones(even the spanish police special front undertray!)

handyman · Unread post by **handyman** » 30 Jul 2008, 17:46

Not done any tuning or porting on the diesel heads but I do know that the petrol heads are usually in a good state of tuning to start with.

I have found that an increase in the inlet valve size and recutting the seats to three angles, along with matching the manifolds, gaskets, etc has made a difference to my 1.6 petrol engined ZX, but it is a non-catalysed, so breathes easier to start with.

I am doing some research on the 2.0 twin cam head, which also shows a good state of manufacture. Seems like PSA got it right to start with.

As commented before, a removal of the cat and lighter shoes on your right foot will certainly help.

Handyman

Unread post by **Peter.N.** » 30 Jul 2008, 18:22

Port polishing is designed to improve the gas flow but when you have a turbocharger forcing the air in and a control system that regulates the fuel input accordingly, you won't gain a lot. Fitting a 2.1 head, if you could, would make a tremendous difference to low down torque but you would need to go some with a 1.9 head to get the same performance

citronut · Unread post by **citronut** » 30 Jul 2008, 19:34

a few years ago i had the head off on my 1.9D (not TD) BX, whilst it was off my X workshop landloed (GAINSPEED) gas flowed and ported the head, the diferants is amazing, i found it gave it a lot more get up and go all the way through the gears but not any more top end, also were citroens dont like driving round at 30 in top gear this BX did after it had been worked
regards malcolm

ps.
GAINSPEED do a lot of work for raceing people all over the country, he is in st leonards on sea
east sussex

Unread post by **CitroJim** » 31 Jul 2008, 19:10

Hi Vaughn,

Have a word with the Doc (docchevron1472) over on the BX Club Forum

He has done a lot of XUD tuning and tuned them to the point of grenading them

Have a look on the BX Forum at his posts.

Just don't take the Doc too seriously. He enjoys an extremely well developed sense of humour

Of course, what you really want is a 2.1TD

It will give you all what you want out of the box as it were. I believe the Doc has discussed 2.1TD heads on a 1.9 block in the past.