Who to go for SOHC Head Porting ??

[toysrus]

DD Dyno's measure 'tractive effort' which there is a Formula to then convert it to torque at the wheels

[mrb1]

nothing against barneys car, in fact i like how he managed 240hp on stock internals (craziness!!) but it did not make 1559Nm of torque

No problem except the stock pistons lack strength. Generally forged pistons will not make more power.
Stock things will usually hold together for a few dyno runs :D

[SpidersWeb]

Is it just the pistons, or do the rods need attention also?

[www.18u]

It depends on what your goal is.I used to to engine reconditioning and alot of port work and you can have a $100 port job or a $1000 port job but i would recomend you get your cylinder head reconditioned at the same time don't just pull it apart and put it back together.Also a good porter will give you a flow sheet so you can see the improvement and air speed so you can decide what camshaft to use. :D

[NXTIME]

LogiK is correct: convert the tractive effort ft/lb to Nm and then divide the figure by the diff ratio and also the gearbox ratio (if its not 1:1) to get the NM @wheels.

[flav]

Back to Topic....
Yes, we do head porting...
It was mainly for inhouse people but its been quite successful so its avail.
Clean up & mild start at $400 with port match.

[jdstaz]

whats the most amount of power someone has got from the sohc head?
if i want to achieve 220kw atw am i wasting my time spending money on it? or just do twin cam conversion?

[Junkers]

Thats around 360hp at the flywheel, perhaps a full performance port job, cam, turbo, multi point injection setup, large intercooler and new ecu would pull that off. With all those things mentioned there your looking at around $8000 but converting to a dohc head will cost above $10 000 alone. Personally I'd try with the sohc.

[SpidersWeb]

Although if you're getting new pistons, a new ECU, and going multipoint, and custom intake to flop on a big cooler, then slapping on a twin cam head wouldn't add that much to the cost.

I mean whats left? Custom thermostat, throttle cable, and the exhaust manifold (which should be replaced anyway), and wack the firewall with a hammer.

Then you get discounts/time savings - off-the-shelf pistons, off-the-shelf cams and cam wheels, bolt on aftermarket throttle bodies, the DOHC intake has the coilpacks attached to it so you could even just go and buy VR4/EVO spark leads.

220kW at the wheels is a lot for the SOHC. I have no doubts it will do it, but with the mods likely to be required, you should evaluate the extra costing involved in swapping the head, and if affordable, do it. Becuase its only 10,000 if you start with a standard Starion.

[flav]

I like the SOHC and stretching its limits...but the DOHC will produce more power, however this can become extremley expensive if you are chasing everything you can get out of it. Valves, K-lines, inserts, springs, retainers, porting, cams, gears and machine work.... There are critical measurements and steps in doing these heads up to withstand high HP so you need expert help here. We have seen them come through here done by someone else (hmm...no names) only to need to be redone again. Theres also some good studs to be added to that list and a cometic as well.

[WANTSOM]

Lets not forget the fuel. Different blends allow all sorts of things to be done with timing, compression , boost, detonation etc.

I remember Ron saying a while ago that when he dyno'd the Group A on Optimax out of the pump he got a LOT less power (and destroyed a HKS turbo in the process) than when he was running the Shell jungle juice that was being supplied to the Group A fraternity at the time.

[DD Phil]

Chris Collier told me that over 400RWHP was possible on the SOHC.

Does anyone know if it's been done?

I wrote to him "Can we get 500HP at the rear wheels for the odd drag race / dyno comp if we went stroker? Then turn the boost down for 300 on the street?"

He replied: "Youd get that from the 2Ltr, yes"

Phil

[Junkers]

Would it still be street driveable though?

[quest]

have a look over at starquestclub to see what guys are getting from the 2.6L sohc. These are not 'shop' cars. Built by enthusiasts just like yourself. Most of them tuned by novices.
Some make solid power on stock pistons, $25 head gasket, non-ported head and pump gas, with excellent 'street-friendly' torque curves.
I don't see why the 2L would be that far behind.
One thing they don't run is the baby turbos and weak boost that you see around here.

Highest seen so far is 475hp/500+ ft-lbs tq at the wheels. Magna intake

[Mr Ralliart]

Ofcourse you can get 400rwhp from the SOHC 4G63 , it's bloody expensive though . I know of a few in Japan that have . Not to mention the last of the 2L Starion Evolutions (Group B ) , they had that much (so they tell me..) . Also the Pajero Paris-Dakar Evolutions did , although they were actually 2.4L so maybe that doesn't count . . . but would be scary in the sand