Head work?

[MIKE-FORD]

What sort of head work can be done to a hdi like updated cams or port and polished cylinder head? Not really seen any threads on this?

[Oil-burner]

Not worth it on a diesel unless you are going for mega power.




Also you live at butlins in skeg?? Lol

[MIKE-FORD]

Don't be like that lol

But for people who wanna, would port and polishing a head make a difference? Even for a stage 1 or so on?

[Oil-burner]

Possibly but it wouldnt be worth the money.
Darrenjlobb went into different cams etc but said it wouldnt be worth it unless pushing stage 3 +

[Piggy]

same money and time could be spent on other things and get much bigger gains

[Poodle]

Don't take this the wrong way, but you're approaching tuning this as if it's a na petrol - it's not. All these mods are generally done before serious headwork on a boosted cr diesel:

Mapping
Exhaust
Intercooler
Turbo

Also, often:
HP pump
Injectors

Not including required supporting mods, such as:
Clutch
Fuel pressure sensor
MAP sensor
Manifolds

Every one of the above will get you more bang for your buck than cams and a polished cylinder head.

[MIKE-FORD]

Never seen a thread bout it so thought ill ask for future users

[Ruan]

The stock cylinder head is of no markable restriction until past 170hp. And the ports of the cylinder head aren't the issue, you'll have greater issues to overcome at around 170-180hp.

At 200hp I'd be looking at longer duration cams and opening up the ports for a bit extra flow, but seemingly nowhere really knows what they're doing with DI Diesel cylinder heads in the UK, there's not many places I'd trust taking a head to and be sure that it's going to be an improvement. Same with cams.

[Dum-Dum]

You dont want head work on a stage 1 as larger ports give lower gas velocity, as ruan says the head is probably fine till at least twice stock power.

There is a reasonable bit that can be ported out of them, have a look at how much bigger the hole in the gasket is compared to the holes in the head/manifolds. If you get the head ported youll need the manifolds done to match. Polishing is a contentious matter due to the useful effects of a certain amount of turbulence.

There is no space to fit larger valves on the 8v HDi

Piper can re profile your cam however weather this makes any gains is the subject of much debate and ive not seen proof either way.

[Ruan]

With regards to porting even to match the gasket - I seriously wouldn't bother.

A DI Diesel PURELY uses the port to swirl air - i.e. if you change the geometry even slightly you're MORE than likely to completely cock the swirling up at the sort of engine speeds a HDi runs at causing poor mixing of the Diesel and shit combustion - i.e. lack of power, smoke, worse economy.

Leave DI Diesel heads well alone unless you seriously know what you're doing. As I've pointed out, pretty much nowhere in the UK I'd trust to *improve* a DI head...

There's so much to be had out of these engines from simpler mods - most of the time people are struggling to fit suitably sized turbos let alone port out heads.

[Dum-Dum]

yeah thats kinda what i was trying to get at but as per usual ive not explained well..

There is loads that can come out but you need the port velocity and the swirl so dont mess if you dont wanna f*ck it ip.