DW8 vs XUD

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20th Century Pug
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DW8 vs XUD

Post by 20th Century Pug »

Been searching the forum posts for info about the DW8. I am interested to learn what tech advances Peugeot made when they superseded the XUD with the DW8? As far as I can tell, they are similar. Change to dry liners and repositioned glow plugs and the addition of EGR & cat. The basic architecture appears to be the same. However, in my experience the DW8 has very noticeable increase in performance, and wondering how I could apply that to my XUD. Is there a change in the swirl chamber shape for improved combustion? Or is it to do with the manifolds and injection pump?

My 305 estate will return approx 45mpg around town, 48 - 52mpg on a run. I ran a 99model 206 for six months. A similar size car, albeit more streamlined shape. That had the DW8 engine. Performance was more lively and it returned 55 - 60 mpg. I was expecting the EGR to decrease performance! However, I am not certain the EGR was actually working as the valve had a load of black gunk inside. Some earlier posts suggest it can be troublesome.

Thanks
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Re: DW8 vs XUD

Post by Huskyxantia »

The dw engines are more refined less noise but a little bit more pipe work than thd xud, egr stuff and so on, dw feel like a larger petrol the xud feel like real old diesel
Husky. :?
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Huskyxantia
Donor 2023
Posts: 1949
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Location: Surrey Kent sussex border
My Cars: Past cars
Xsara Picasso 2019 to 2022 r.i.p
Xantia mk1&2 1.9D & 2.0Hdi
Peugeot 206 sw 1.4hdi
Other models
Skoda fabia,escort van,ford ka,Vauxhall astra g car & estate, Vauxhall corsa b, Suzuki swift
Escorts mk 1,2,3,4,5 fiestas mk 1,2, Sierra diesel mk1 Mondeo mk1 diesel .
Peugeot 207 , 307sw

Now cars
Picasso 2.0Hdi now gone to scrappie
Citroen zx estate 1.9D the cherished one
Peugeot 206cc raised from the dead & saved from the crusher traded up to a 308cc
307sw traded for the 207 .

Wish list.
Peugeot 405 diesel
106 or 206
Mondeo Mk1 diesel once owned 1.8tdi was real nice.
x 398

Re: DW8 vs XUD

Post by Huskyxantia »

Husky. :?
20th Century Pug
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Re: DW8 vs XUD

Post by 20th Century Pug »

Thanks for the useful links. I note that the inlet manifold and intake system are different, also that the head has 'Advanced Comet Ricardo latest technology precombustion chamber'. So is this 'latest' design of swirl chamber the main improvement over the XUD? Does this mean that the injection pump has revised metering and advancement characteristics? What about the valve timing?

Does anyone know if a DW8 head will fit an XUD block? Just thinking this could be a relatively simple way to get a worthwhile improvement in economy with an XUD engine car without the wiring and ECU issues of a full HDi.

Anyway, just a thought. :idea:
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Huskyxantia
Donor 2023
Posts: 1949
Joined: 30 Jul 2018, 22:11
Location: Surrey Kent sussex border
My Cars: Past cars
Xsara Picasso 2019 to 2022 r.i.p
Xantia mk1&2 1.9D & 2.0Hdi
Peugeot 206 sw 1.4hdi
Other models
Skoda fabia,escort van,ford ka,Vauxhall astra g car & estate, Vauxhall corsa b, Suzuki swift
Escorts mk 1,2,3,4,5 fiestas mk 1,2, Sierra diesel mk1 Mondeo mk1 diesel .
Peugeot 207 , 307sw

Now cars
Picasso 2.0Hdi now gone to scrappie
Citroen zx estate 1.9D the cherished one
Peugeot 206cc raised from the dead & saved from the crusher traded up to a 308cc
307sw traded for the 207 .

Wish list.
Peugeot 405 diesel
106 or 206
Mondeo Mk1 diesel once owned 1.8tdi was real nice.
x 398

Re: DW8 vs XUD

Post by Huskyxantia »

Would the new engine be like a frankenstien moment ! lol
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20th Century Pug
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Re: DW8 vs XUD

Post by 20th Century Pug »

Maybe. Just trying to find out if it's possible - like are the hole centres the same?
puddlethumper
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Re: DW8 vs XUD

Post by puddlethumper »

I put a DW8 head on my 305 van and it works ok apart from idle being a bit odd.
puddlethumper
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Re: DW8 vs XUD

Post by puddlethumper »

I put a DW8 head on, couldn't find an Xud one, and it works ok.
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Re: DW8 vs XUD

Post by MattBLancs »

Sorry to be asking what may be a daft question, but isn't the obvious "how to improve XUD performance?" Answer not to swap it complete for an XUD9T ? IE the turbocharged version giving 92 Vs non turbo's 68? (DW8 - 71?) Would be best with intercooler but isn't there a non intercooled version (possibly XUD7T - i.e. the 1.8 as fitted to 205 STDT amongst others) think they were about 80bhp? Would simplify the intake pipework at cost of some performance.

Matt
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