what does everyone make of Gas Flowed Heads?

[dangle172]

Iv heard good things from a few friends (VW owners) on gas flowed heads. Has anyone ever had this done on here and whats the real gains?

http://www.cncheads.co.uk/Renault_clio172.html

 

[fearless]

I believe that the standard heads are infact pretty damn good because they're cnc'd in the factory. Think there are very marginal gains to be had from further work.

I could be wrong though.

 

[sideways danny]

biggest gain you'll see from headwork is torque really. Had a look over CNCheads stand at autosport and there was some nice work.....though i personally hated their F4R head design

 

[dangle172]

Iv never really looked into it much. iv just not seen of heard of anyone on here doing it before. The VW guys seem to rave about it.

 

[Henry]

bit of a black art

 

[Andyman]

I'd highly recommend it. As Danny said torque is the main gain. I managed to get TB levels of peak torque (175lb/ft) running just Piper cams and the usual bolt on's.

There are decent gains to be had.

 

[dangle172]

Iv read that's its a good mod on other sites. And i thought £750 was a good price too. Added with some lower profile cams that is.

 

[sideways danny]

Iv never really looked into it much. iv just not seen of heard of anyone on here doing it before. The VW guys seem to rave about it.

I've done lots of head for customers. Normally as part of complete engine builds in honesty, but it's not that unusual. The thing is, the F4R is pretty decent to start with so it's a bit harder to find the gains. Peak numbers often dont change much, but if you look at the midrange you see a nice chunk of extra, which is what makes the car quicker

 

[Andyman]

Cams headwork and map isnt good VFM. For that price youve better off jumping straight to TB's or saving for a charger.

I only got headwork and cams as roughly 6 years ago there wasnt many modding options available for these.

 

[dangle172]

I would be curious to see how there machined. Whether they use a five axis miller or just a 3 axis. If i knew how/ what to do id attempt it myself at work. My boss seems to think there is a lot too it tho and says it would take a lot of programming!! Out of my league i think

 

[SkidMarx]

Its something im looking into ATM, a fully worked head, 3 angle'd seats, skim, new valves and stem seals is about £800 - £1000 from the quotes ive had.

On a limited budget theres probably better ways to spend that money, or as previously said put it towards TB's or a charger.

 

[stan*]

There are plenty of gains from the F4 head, it's way too biased towards swirl in my opinion, and in doing so cfm really is reduced. There are ALOT of areas of sheer in the intake, which disrupts flow and causes a poor velocity gradient...takes a fair bit of work to iron this out.

Should have some reliable before and after results from the dyno very soon.

 

[sideways danny]

There are plenty of gains from the F4 head, it's way too biased towards swirl in my opinion, and in doing so cfm really is reduced. There are ALOT of areas of sheer in the intake, which disrupts flow and causes a poor velocity gradient...takes a fair bit of work to iron this out.

Should have some reliable before and after results from the dyno very soon.

I did mean a bit harder than an old 8v or the like where much bigger gains ar normally more obviously found from poor castings. I know there's plenty you can do, just a bit less obvious to the un-trained eye

 

[stan*]

Sorry wasn't specifically aiming at you matey, was just my take on it

I can't remember the last time I worked an 8v head...prehistoric or what
I can actually, it was an rs turbo about 5yrs ago!!!

 

[Gumby]

I've done lots of head for customers.

That made me giggle in a child-like manner

 

[stan*]

LMAO!

"deepthroat danny"

 

[2 live]

u 2 get on so well.....lol......whos the giver??

 

[stan*]

Bend over and I'll show you

 

[2 live]

i think u have me mistaken for someone else.....my initials are jb not rb

 

[sideways danny]

Sorry wasn't specifically aiming at you matey, was just my take on it

I can't remember the last time I worked an 8v head...prehistoric or what
I can actually, it was an rs turbo about 5yrs ago!!!

ewww, nasty head. Not quite as bad as a nissan silvia though :dead: Truely terrible. Last one i did was for my own 205 gti

 

[Fred@BTM]

danny any idea who did the head on fmp's old engine? i hope it wasn't you! its f**king shocking, not 1 port the same!