DHX engines etc....

[Lwilliams]

Looking at a DHX engine in local breakers...

If I am correct I think the xantia engines are DHX with some electronic fuel pump that can be swapped with a Bosch?

And I think before when I was going though jamma's thread he was using a DHX because they were rumored to have stronger bottom ends... I assume this was to do with having the stronger of the rods?

Are there any differences with other parts of the engine..... as I know they have better inlet manifolds?

Also I have read about people going on about the D8A engine etc... Wondered why, is it really just the rods?

I really don't understand the engine codes, I've seen DHY codes and loads of other different ones but no one seems to give an answer on the differences...

I have found this but doesn't seem very good?

http://www.peugeotlogic.com/workshop/wsh...code1d.htm


PLEASE HELP

[Tom]

Yeah you can take off the ecu pump and put a proper fully mechanical one on. IMO the differences between the engine codes is minimal. If your running enough power to break a D8A your just as likely to break the rest.

[Lwilliams]

Yeah you can take off the ecu pump and put a proper fully mechanical one on. IMO the differences between the engine codes is minimal. If your running enough power to break a D8A your just as likely to break the rest.

and from what im gathering the only difference with the d8a is rods?

thanks mate for getting back to me on this

[Tom]

Apparently one of the DH's has a coating on the pistons, not sure exactly sorry.

[Chris_90]

It's all a myth just luck of the draw people have thrown rods on standard engines others haven't in highly modified engines.

Just hope for best with any of them, just fitted hdi rods to mine and it's still possible to throw a rod so just either live with the risk or have a back up engine, or if your pockets are deep go fordged

[Jenkosowls]

30k on a t25 dhy engine on average running around the 150bhp mark. No problems what so ever

[Lwilliams]

Yeah I am looking into forged but was just thinking about any other bonuses; better made block etc... I guess they are all pretty much the same just with extra's like egr and different inlet manifolds and different exhaust manifolds... any one got any ideas on this?

[Tom]

Theres only two types of exhaust manifold for the 4 different turbos. Inlet manifolds are all the same in the 306 except egr and non egr.

[Lwilliams]

Theres only two types of exhaust manifold for the 4 different turbos. Inlet manifolds are all the same in the 306 except egr and non egr.

Which of the 2 flows better? and I dont mind looking for an engine thats not in a 306 standard if they have better parts.... Like xantia inlet

[ozonehostile]

Dhx block has ceramic coated piston tops and some other bits in the head apparently. I haven't had the head off the Dhx in my car to confirm this yet though.

I'm sure Darren will know

[Tom]

Personally i like the K14 manifold. The differences in flow are minimal i imagine.

[Piggy]

non egr inlet flows better imo too, as even with egr blanked, the inlet is full of egr crap

[Tom]

non egr inlet flows better imo too, as even with egr blanked, the inlet is full of egr crap

Thats what blow torchs and brake cleaner is for

[Lwilliams]

Hope darren comes along soon

I think I can remeber some one saying the T2 mani flows better... not 100% sure thanks for input though

[Ruan]

I've heard of DHXs having 8v HDi sized rods, but I think this is one of those incremental changes, so you can't attribute them to one engine. I think probably the DHYs did at some very late points, the DHX and DHY are two totally different engines in terms of control and features but produced in the same era.

Both DHX and DHY have a coating on the piston crowns to prevent heat transfer and on the skirts for friction reduction and the heads will have the steel inserts between valve seats to prevent cracking.

D8As seemingly threw less rods than DHYs, but I've seen both throw in stock and tuned applications, I've also seen DHXs pop rods as I've also seen 8v HDis pop rods - none are infallible. DHXs seem to do it less, but the chance is always there - but on the same token I've seen DHYs put up with incredible amounts of abuse, yet D8As barely spool the turbo then pop.

K14/T2 exhaust manifold does seem to flow better, but a GT15 one will spool turbos faster - higher gas velocity, closer to the head etc. Go look at Antos dyno result with a TD04 on a GT15 manifold - one of the higher powered TD04 engines, still on a GT15 mani - a T2 would eventually produce higher figures.

"Xantia" inlets i.e. front mount IC inlet manifolds - there is NO such thing as a non-egr Xantia inlet - some do have a cap over the EGR inlet port, but have all the stuff inside ready. At least, to this day I've never seen one.

Basically:

D8A - Two types - old style with old lucas pump or for a time, Bosch VE, no EGR, no cat and old design cylinder head, no piston coatings. Newer style had updated Lucas pump, early EGR and a Cat - they're rare though.
D8B - Newer engine design for 406/Xantia - Bosch VE only with shield over solenoid, FMIC "Xantia" inlet, has updated design of the later D8A which included a Cat, early EGR and coatings inside the engine.
DHY - Newer design to replace D8A, has a coded, newer design Lucas pump (shield over solenoid), EGR, Cat, coatings inside.
DHX - New design for later 406s and Xantias and various vans - Only a Bosch VP21 pump (ECU Controlled advance system), variable EGR, Cat, coatings on internals.

From what I understand, the DHX and DHY were to conform to new emissions standards, they are simply lightly updated designs of the D8* engines. The D8* engines really are a mish mash of bits, from DH* things conform a bit better.

[zx_volcane]

^ Great info there Ruan all in one nice post, someone should make that a sticky

[Lwilliams]

Thanks Ruan for taking the time to clear things up for me...