HDi Question Please?

falling-out-with-my-car · Post by **falling-out-with-my-car** » 05 Jul 2011, 14:01

Hi, would it be possible to remove the HDi pump and injectors On an HDi engine and replace with a non HDi system ie standard pump an injectors?

or is there something different about the engine ie compression ratios etc

that wouldnt allow it to run properly.

thanks in advance.

Nigel.

DickieG · Post by **DickieG** » 05 Jul 2011, 14:52

Not entirely sure about this but wasn't the DW8 as fitted to C15's and ZX's an HDi with an old pump/system?

citroenxm · Post by **citroenxm** » 05 Jul 2011, 15:16

In a word NO

The injectors on an HDi do NOT screw in, they just "Sit" there but theres a Clamp that holds them in place...

HDi injectors are twice the length of ordinary injectors..

So really you would have to junk the head aswell and fit a DW8 Head, which does use a normal Roatry Pump and injectors screwed into the head.

When PSA designed the HDi engine the block is normal XUD block, but the pistons and head are completely new..

Anyway, why would you do that!!?? The HDi is smoother, better, faster, more economical and chipable!

Paul

wheeler · Post by **wheeler** » 05 Jul 2011, 15:18

The DW8 is just a normal indirect injection, never seen one fitted to a ZX, bit to early for that.
To answer the original question, i can see that you would be able to get that idea to work for quite a few different reasons.

Post by **CitroJim** » 05 Jul 2011, 15:23

not least because ther HDi is a DI (Direct Injection) and the XUD is an IDI (InDirect Injection)

Pump, combustion chamber and injectror requirements are totally and utterly different for the two methods and are not at all compatible...

If you are intersted in the techicalities Nigel, I'll be more than happy to expand...

falling-out-with-my-car · Post by **falling-out-with-my-car** » 05 Jul 2011, 15:47

Jim, I didnt realise that the HDi was a Di engine, that has scuppered any thoughts of adapting a C5 to run on Filterted Waste veg oil then and I wouldnt want to twin tank it.

would it be permissable in these modern days to fit an indirect engine to a C5 a donor engine from an Xantia for example??

thanks for the comments thus far.

regards Nigel.

Deanxm · Post by **Deanxm** » 05 Jul 2011, 16:27

you would be far better off just selling the C5 and buying a Xantia surely?

D

falling-out-with-my-car · Post by **falling-out-with-my-car** » 05 Jul 2011, 16:47

I would like a C5 if I could run it on veg oil.

sometimes its nice to have a new car even if it means a little work to get it right.

DickieG · Post by **DickieG** » 05 Jul 2011, 17:35

It'd be worth thinking over the question of emissions if fitting an engine of an older era.

citroenxm · Post by **citroenxm** » 05 Jul 2011, 20:10

CitroJim wrote:
Pump, combustion chamber and injectror requirements are totally and utterly different for the two methods and are not at all compatible...

.

Pretty much what I said I THINK...

Thats all in the head design, however, due to being DI, the piston tops are "Holed" out with a solid centre... um, like a hollow channel... so weither a DW8 head would fit I dont know...

Paul

falling-out-with-my-car · Post by **falling-out-with-my-car** » 06 Jul 2011, 09:08

I know some insurance companies won't insure a vechicle if it has had an engine change , esspecially an engine that wasnt specifically designed for that model, if your replacing a standard engine with a new engine this is allowed, I was only wondering if it was possible to upgrade the body at some point thats all, just exploring the possibility.

I know for a fact Di engines hate the veg and you get what we call ring gumming. whereas indirect engines dont suffer with this.

High pressure diesel injection systems are a no-no with running veg oil apparently it mucks up the injectors pretty quickly that was my reason for asking.

regards Nigel.