Cylinder head porting

[Rally205]

Has anyone had their heads ported or thought about doing it?

[Adam.Findlay]

Yeah a bit of advice would be good here im thinking about getting the heads ported and polished with larger valves being ground in, as I have a spare set of heads lying around (due to old motor throwing a rod at the race track). Just like to know is porting worth doing on a turbo engine? I know it helps a good amount on N/A engines but im really unsure about turbo engines, i definatly know the valves would be a major but worth it in the long run. and does anyone have a clue how much it would roughly cost for this kind of work to be done professionally.

[foxdie]

Wow, you dug up a 4 year old thread, should hopefully be someone around who can help

[elnevio]

Wow, you dug up a 4 year old thread, should hopefully be someone around who can help

At least the Search was used!!

I don't think there's been much porting done on the 6A13TT - but maybe the likes of Gowf, Kevin AP, valmes or zentac could contribute, as it could well be something they've considered/done.

[Mark 4]

I am definitely "thinking" about it. I would want to do it as a a standalone mod so that the car can be dyno'd before and after which would (hopefully) prove whether it is beneficial or not.

[Wodjno]

I would suggest a set of Cam Pulleys fitted and tuned 1st would give better overall performance increase for your buck..

The valves themselves would be the best place to start

[Turbo_Steve]

On it's own it's not likely to achieve much unless you've already reached the limit of the turbos efficiency with a big intercooler, exhaust and high boost and a standalone ECU. IF you've got all this, porting the heads will potentially allow an improvement in turbo efficiency (less pressure for same flow) and therefore some improvements can be made in the map. You'll be changing the torque curve, though, so timing pulleys will be, as Wodj says, essential, and you should be considering Cams.

For the effort and expense, I'd be more inclined to go for bigger turbos first.
Bear in mind we're talking new headgaskets and timing belts as soon as you take the head off. Cheaper if you strip it and reassemble the head yourself, but not by much. What is it you're actually trying to achieve.

[Fully]

The manifolds on the heads are a very good match, so there is no real need to match port.
However there is a bit of work to do if you want to match port to the gaskets.
A lot of hassle for bugger all gain, unless you had other mods in mind.

I was thinking about adding some thread to the intake side of the heads, going from a harsh thread at the injectors and a finner thread at the valve.
All this will do is make the car more fuel efficient and turn the mist of gas into a fog.

[Adam.Findlay]

Wicked sounds helpful so far. My plan is to flow heads that I have in my yard, valves, port polish, cam gears and cam shafts. I plan to have the heads done first as they are the only useable parts of the motor that threw a rod. Then once the heads and the plenum are done they will sit aside until i can afford to build a forged short block. Once all the parts are paid for and bolted together I plan to engine swap the fully rebuilt engine into the car. I want to build the engine on the side as my car is a daily driver and i don’t want to be pulling the engine in and out of the car every time i want to do something to it. I figure do it once do it right. Big plans but long term plans

[Turbo_Steve]

In that case, yes: get them flowed, ported and the sides roughened. Make sure the inlet shape gradually reduces in size from the plenum right the way to the bore: If this means porting the plenum or making another, do so. The power increase will be surprising: it will get you on boost a lot quicker.

Couple it with some high lift cams, and you don't need silly duration: this allows you to retain some low end torque, but run a bloody silly turbo (or pair of turbos).

Pair of GT30Rs?

[pitslayer]

Hasnt Nick had his heads ported and polished, I think it was done before he bought the car though, so couldnt compare

[Nick Mann]

Yes.

I don't have adjustable cams and AFAIK they are standard. I do know that I get very good torque figures though, and the only mod that seems to be different to other peoples is the port and polish.

[Mark 4]

That's it - tell everyone