Is 495+vat a good price for folowing headwork

[projectgtir]

Just agreed to have the folowing done to my head seeing as its off .

Open up and flow inlet and exhaust ports
Open valve throats
cut valve seats
clean valves + cap
valve stem oil seals
machine head face
degrease and rebuild.

Also can port inlet and exhaust manifolds at extra cost

 

[Makaveli_se7en]

Does the guy have a flow bench? Personally I wouldn't let anyone touch a cylinder head with out being able to give me flow figures before and after and show that all 4 cylinders still flow equally. Its very easy to screw up the port shape e.g. sacrafice velocity for flow with the wrong shape and loose torque etc.. Also I see little point in what I refer to as spit and polish head work as I believe the gains from it are negilable.

 

[projectgtir]

I see what your saying ,the head needed a skim plus I wanted it degreased and pressure tested .
I'll find out if he has sccess to a flow bench

 

[stumo]

The ports are massive and don't need any work.

I forget the exact figures but the ex flows something like 66% of the inlet, you want to get this to approx 80% and that will come from working on the exhaust valve pocket. The inlet pocket also improves with work.


This was just an experiment to see how much smaller the ex port could be without dropping ANY CFM.... putty was added to the bottom of the port

The same was done with the inlet and a similar amount of putty could be added to that port, so it shows that the ports themselves are massive.

 

[projectgtir]

Interesting so is this pocket below the face of the valve itself.

Also Andy did say that the valves on the pulsar head are already quite large as I enquired about bigger valves etc.

So it seems the gtir head already flows near enough to its capacity anyway.

 

[stumo]

The head flows shite compared to the theortical amount for the valve sizes LOL especially the exhaust!!! (compared to a skyline head the GTiR head flows great LOLz)

The pocket is the area around the seat to where it then opens out into the port (so approx from the seat to 90 degrees to the seat.)

That area and getting the seats done well is where you want to be spending money.

The ports can be shaped slightly differently in certain areas but the gains aren't worth it for the amount of time involved (they are pretty minimal)

 

[projectgtir]

lol ok so what about exhaust manifold and inlet manifold .
Are they worth porting or should I just buy an after market exhaust manifold although they always crack so I hear.
Its just while its all off might as well treat the her lol.

I intend to upgrade from standard turbo as well ,to what I dont know yet . Either 2871 or 2860 ,havnt decided yet.

 

[stumo]

keep the standard ex manifold , you can clean it up (internally) if you want

unless you get a well built (expensive) manifold , don't bother as they're all shite.

 

[skiddusmarkus]

I did my own exhaust but its more a case of deburring it really and to give me something to do.I just used a dremmel and got it all nice and shiny inside.I wouldn't bother with any other manifold unless I was going for ridiculous power from a massive turbo.You can always add a remote wastegate to the standard mani.

 

[pulsarboby]

Does the guy have a flow bench? Personally I wouldn't let anyone touch a cylinder head with out being able to give me flow figures before and after and show that all 4 cylinders still flow equally. Its very easy to screw up the port shape e.g. sacrafice velocity for flow with the wrong shape and loose torque etc.. Also I see little point in what I refer to as spit and polish head work as I believe the gains from it are negilable.

100% agree with what the man said above!
inlet ports do not need opening at all, only a slight clean up and deburr, you will have a very lumpy and slow engine if that work to the head is not carried out to a good standard.

as for manifold...like stumo said, (funnily enough i was gonna do a thread about these as ive discovered that they are better flowing than a hell of a lot of so called uprated manifolds)
heres one i did yesterday for our car

all ports have been matched and opened to head (5 hours work)
if you look at the standard manifold also you will notice that it has a gate on the neck to turbo, this is there for very good reason and something you dont find on aftermarket jobbies

 

[nimhbk]

Pardon my stupidty Bob did you polish the outer of the manifold as well or paint it silver. looks really good

 

[pulsarboby]

no was just sandblasted nick, no paint