probably a ben r question

[Ben j]

whats the differences between the 16v head, willy head and megane 2.0 head?

 

[adiclio16v]

willy an megane have 32mm valves 1800 has 30mm, megane has diff cams to willy i think

 

[Colin_S]

Yea i think that is what it is too,

 

[Leigh]

They best configuration is a 16v head on a 2.0l bottom end !!

Phone hill power he reckons that its ultimately a better set up !!

Dont use the megane head !! Use either the 1.8 16v head or the willy head !

 

[haitch]

il just use me girlfriends head thanx, he he.

 

[Colin_S]

Cheers Leigh, Im maybe trying to sell a Megane head here. lol only kidding

I might be selling a Megane head but if you put after market cams into the Megane head i am under the impression that it will be the same as the willy head with the same after market cams.

 

[Red16]

megane head only has inlet ports about 50-70% the size of the williams and 1.8 16v heads

 

[RobFenn]

Quote: Originally posted by Colin_S on 10 March 2003


Yea i think that is what it is too,

Yeah i blatanty thought that too..erm..maybe

 

[BenR]

Having not had a Willy head in my hands (oooer) i have not had the chance to take measurements and volumes. BUT, if the were identicle, i would go with the willy purely as inport velocity will be the same and low lift flow will be higer due to a larger crosssectional area.

However, swirl and tumble might be better in the 7P head, but again, i would need both to compare.

 

[Ben j]

so you recommend??

 

[BUTRE]

I thought the megane F7R had the 30mm inlet valves like the valver... :/

I think its really hard to guess Ben j.

Theory says that bigger valves will deliver more peak power. Power band will go up. But also theory says that the more an head flows, the more power will be delivered, and this is not 100% true.

btw, the only 100% good use for a flowbench is to know if the head is flowing equal on all inlets. This is what I presume by reading and listening alot about head flow and head work. Never done none of this.

 

[haitch]

never given head eh? he he

 

[BenR]

BIgger valves do NOT move the power band, thats more to do with cam profile as your choosing where to make peak power and you cant have lots of peak power and lots of 1000rpm tractability, VVT systems are still trying to get this perfect.

And a head that flows more will ALWAYS make more power....where that power is ade is not the point, peak power is a result of max volume of air process per unit of time....hence more flow = more go.

And a flow bench is a highly valuable tool for measuring flow....not for jsut balancing ports, if your a good head specialist, you should get that right before it goes ont eh flow bench!

its a far better tool for testing different port shapes and the amount of flow at diff valve lifts. Its great for checking everything from valve back cuts, vale seat geometry, port shapes, short side radius besnds, tapers...so on and so forth.

You need to buy some new books mate!!!

What i recommend? i wouldnt bother worrying about valve sizes until you really looking for serious power i.e. 200 and above. the 30mm inlets are fine for most applications.

 

[BUTRE]

what took you so long???

head flow and its theory... but I cant keep away the idea that the engine is not only about head flow... damn thing uh? when you get the head back on the engine the damn thing never flows like it did on the flowbench. aint life a b$#ch.
dont get me wrong! flowbench is a very good for develepment but remember what Ive stated above... dont just go after benched engine parts gains. Take a look at it as a global upgrade.

power band.. eheh my bad. the idea was peak power at a higher rpm. At least this is shown on some CVH and Pinto. ya ya 8v engines I know. :/

books keep on saying diferent things. Its the tunners dilema! everyone is against the technics used by the other. Cant say if its a ego thing or just a markting trick.

The only guy that questioned the flowbench (besides me, but Im a nobody in this tuning world) was Graham from IES. Nissan Primera engine for BTCC 300bhp.

at least everyone is ok with this: "TBs is the only way to go..."

 

[Matty]

David from Ktec told me that the 2l head was better than the 1.8 and they seem to have done a lot of testing for their gasflowing.

 

[BenR]

i took so long as i have been away for a week wehere i only have a 56K connection which i cant be botered using, but im back on BB now.

Theory.......its all about head flow, and of course it wont flow the same, the simple design of the poppet valve means that they are opening and closeing and different flows at diferent lift occur......which is why to test at diff lifts to account for this!

 

[BUTRE]

ok.. Now you won!!! just because I didnt understand what you are saying now. eheheh

I had my share of car electronics today... Im sick of cars right now. Tomorrow will get back at them again.

btw, cars on ice... beautiful the way they can dance!!! that its art. art: tubular chassi, AWD (...) and 400bhp!