Cylinder Head Porting & Polishing

[_Monkey 0]

I went for the big valve option and it made a huge difference to mine...so yes! :D

[Crasher 3]

Standard 40-mm inlet valves and 2-mm larger 35-mm exhaust valves, worth every penny.

[Shaggy 0]

i will 3rd that! defo worth it!

[Crasher 3]

Very difficult to put figures to but the change is dramatic and the most important change you can make to the head.

[Neil VR6 0]

It's the torque that will increase massively. I'd imagine something like 220bhp & 270ft/lbs with a big valve head. You'll need to watch your clutch with that! ;)

[Blue_Joe 0]

It's the torque that will increase massively. I'd imagine something like 220bhp & 270ft/lbs with a big valve head. You'll need to watch your clutch with that! ;)

 

I think your dreaming with that sort of torque figure Neil!!!!!!

 

Bearing in mind the extreme of my spec car I am running on the Stealth RR day today I hit 234lbs/ft of torqu and at last map at chipwizards 247lbs/ft although I am getting much higher bhp than you quoted.

 

But if you compare the spec that xtremg60 quoted mine is quite a bit beyond that spec. The closest any one else got to that torqu figure was mikeg60 with a 1.9 bottom end and CNC machined head at 216lbs/ft of torque.

 

The 220 mark of torque is the oh so difficult barrier to break on any G60 unless you go to very expensive lengths like i did!!!

[Neil VR6 0]

There's a guy selling a Pitstop built G60 putting out that power. Can't remember where I saw it now but I think it was on ebay, perhaps e38 too?

 

EDIT: Found it :)

 

http://www.edition38.com/forums/index.p ... opic=65751

[Blue_Joe 0]

Very much doubt it was 270lbs/ft of torque!

[Neil VR6 0]

Either it's true or he's a fibber ;)

[Blue_Joe 0]

Just looked at the thread on e38 neil - It's hardly the same sort of Spec that was talked about above. It's as I suspected a much more played with car, same tyoe of thing that I've done but wilder cam etc. I've done more to the bottom end but he's also done alot. And he's got his methanol working which I have yet to do so.

 

So you need to put it into perspective - as I said earlier to get near that sort of figure you need to do alot more work and spend alot more money than just a big valve head and such!

[junkie 0]

As monkey has got 240lb/ft with the big head and an IHI turbo set up and i got 300lb/ft of torque with same and 1.9l bottom end the 220lb/ft barrier can be broken.

 

Still not strictly a G60 but still the same engine just forced dirrerently.

[Blue_Joe 0]

As monkey has got 240lb/ft with the big head and an IHI turbo set up and i got 300lb/ft of torque with same and 1.9l bottom end the 220lb/ft barrier can be broken.

 

Still not strictly a G60 but still the same engine just forced dirrerently.

 

I'm not saying it can't - I'm just saying it isn't easy!!!! And just a big valve head and a few other bits won't break it - Only Major mods will!!!!

[W3RKD 0]

It's the torque that will increase massively. I'd imagine something like 220bhp & 270ft/lbs with a big valve head. You'll need to watch your clutch with that! ;)

 

I think your dreaming with that sort of torque figure Neil!!!!!!

 

The closest any one else got to that torqu figure was mikeg60 with a 1.9 bottom end and CNC machined head at 216lbs/ft of torque.

 

The 220 mark of torque is the oh so difficult barrier to break on any G60 unless you go to very expensive lengths like i did!!![/quote:9c8f9]

 

Mikes on a std bottom end sam and not one of our heads (YET) :lol:

 

G3WKS also made over 230lbs with very small mods also. Its not hard when you concentrate on efficentcy.

[junkie 0]

Yes i know mate i totally agree with you.

 

Was not meant to come across like i was disagreeing more like it is possible but with other ways and money and lots of grief, and believe me i know all about that.

[mondy 0]

Hi,

 

I went to the rolling road day yesterday and made 245bhp and 270lb/ft!

 

As far as I know all that is on it is a flowed head/cam/FMIC. It's also got an off-the-shelf chip so could do with a re-map as the torque graph isn't very smooth and it looses all it's power after 5000rpm.

 

David.

[W3RKD 0]

Hi,

 

I went to the rolling road day yesterday and made 245bhp and 270lb/ft!

 

As far as I know all that is on it is a flowed head/cam/FMIC. It's also got an off-the-shelf chip so could do with a re-map as the torque graph isn't very smooth and it looses all it's power after 5000rpm.

 

David.

 

Is this the Nugget yellow car with our exhaust system/cam etc etc fitted ?.

[mondy 0]

Yeah that's the one - forgot about the exhaust! Just remembered it's got a flowed throttle body and toothed belt kit as well!

[GazzaG60 0]

the glader is the limiting factor here. only the very best will make 270lbsft.

 

yes the turbo boys will make more but they are using a far more efficient type of compressor. 1.2bar on a G60 is a lot less than the same on a vfxx

 

im with Blue_Joe those who think a big valve head will make them 270lbs ft most will be dissapointed. removing restriction in the head doesn't mean it flows more air especially with a belt driven device and no map controlled boost device.

 

why not go the ihi route on and run 1.5 bar? less money, probly more power and reliability.

[Walesy 0]

Hi,

 

I went to the rolling road day yesterday and made 245bhp and 270lb/ft!

 

As far as I know all that is on it is a flowed head/cam/FMIC. It's also got an off-the-shelf chip so could do with a re-map as the torque graph isn't very smooth and it looses all it's power after 5000rpm.

 

David.

 

Sweet, it made just under 200bhp on a very hot day when I had it, Mods were :

 

Jabba Ported head/throttle body

68mm Pulley and SNS Chip

Standard Rebuilt G-Werks Charger

G-Werks Exhaust

Mocal Oil Cooler

 

So the cam/FMIC and toothed belt kit seem to have added a good few extra BHP!

 

My next G60 will be having a ported head without doubt.

[Henny 0]

Just swapping the head off my engine (standard valve sizes, but with RacePower having ported/polished it) for a G-Werks CNC top of the range (big valve, mega ported and polished) and matching cam, I gained over 30BHP...

 

That's a real world figure as it was the only changes that I did at that time to go from 217bhp to 252bhp... There may be even more to come as I've now got a fuel pump which is giving decent pressure :oops: and an exhaust which isn't as restrictive and isn't going to melt like the miltek one I had before did... :|

[Blue_Joe 0]

But my point still really stands though Henny as your car is FAR from standard - ALOT of work has been done to the rest of the internals of the engine and other ancillaries. It's not just a head that has increased the power but the combination of a whole host of mods!

[g60bv 0]

i have a head for sale. std inlets 35mm exh. p&p by keith at rpm. but its down at g-werks some where, i'm SURE darren can locate it for me if your intersted. pm me for price. needs to sell. xmas money etc. ian

[Henny 0]

Blue_Joe, no, you totally missed the point in my last post...

 

I went from a standard valve head to a big valve CNC head and gained the extra 30+bhp... Ignore the rest of the mods that have been done to my engine as they didn't change, the ONLY changes were the head and matching G-werks cam to gain that 30+bhp...

 

I'm not saying that if you bolt on one of daz's heads, you'll gain 30bhp, but you will definately see gains over a standard valve sized ported/polished head... 8)

[GazzaG60 0]

i see both your points and both are valid. proven horsepower gains but was that built engine on a standard head holding back the power?

 

having said that you wont get the full benifit from big valves and cam on standard engine anyway.

[Henny 0]

but was that built engine on a standard head holding back the power?

That's exactly the point I was getting at, but based on a standard engine... 8) The standard engine benefits from a flowed head (I know, the head I swapped off for the CNC one was bought for my standard engine before the crank bolt snapped and sent me spiralling into the depths of a silly power rebuild!) but, as per the original point of this thread, a bigger valved head releases MORE power than just a ported polished one AND provides a better basis for extra future modifications... ;)