that is a nice result i guess the JE pistons are lighter weight, allowing it to rev slightly higher? i know they are stronger as i have a set i was going to use for a 16v turbo. the setup you have sounds similar to mine. think ill invest in the same cams. maybe because i have had quite a bit of weight taken out of my bottom end (crank lightend and knife edged, flywheel also) i might be able to make the same. whats standard compression on a 9A with a KR head? is it possible to skim the KR head slightly to bring compression ratio up a bit. by increasing comression ratio, will it put strain on pistons etc...? it obviously seems worthwhile thing to do... im running DHLA side draughts too. apparently they use a wider range of jets to the webber DCOE so can be tuned much more accuratley.... how much are schrick 276's and where can i get a set? is it worth getting a vernier pulley too?
Tell that to Essthree who used a single 268 inlet stock exhaust cam and came up with very impressive numbers nd gains on remapped ABF management.
Deffo. Bore size is a limiting factor to valve size on the 16v, hence you don't see many big valve heads. Standard CR is 10:1 I think. There is an optimum working compression ratio for any given cam profile, so decide on cams first and go from there.
dont think i could bring myself to shell out for another set of JE's when i have a set brand new that im just using as paper weights cus i put the turbo engine of the back burner. was wondering. if i ever wanted to turbo my 9A, will my 83mm pistons that where ment for a KR engine still fit into the 9A? does the 9A run the same size rods, and gudgeon pins as the KR? would be handy if they do fit. thanks for the info. its all gold
Sorry to go slightly off-piste here but... Am I the only person whose struggling to put down the power with these modded mk2s?? I mean I'm only running 172bhp/140lbft in mine and the other day I was wheel-spinning it in 3rd! I mean I'd love to get the power up to 200bhp but at the moment I can't see the point when I can't seem to get any traction as it is... I guess it'll be much better in the summer, probably just the weather at the moment but it's really putting me off any further mods to the engine
Thanks for the replies to my question - don't take it as dissing anyones results from TB's though, as i'm not. I understand the big gains from TB's is the area under the peak figure - but i always expected to see big peak power figure gains too. On zetec's, vauxhall 16v's etc you often see 30bhp gains at peak with the rest of the mid-range too... just couldn't understand why VW engines seldom seemed to get this kind of gain <and breathe...>
well the vw inlet must already be better than the XE and zetec one thinking about it the XE inlet must have been shyte as it strangled even that great engine design down to 150bhp
the tiny vw bore size has a fair bit to do with the poor breathing, isn't an XE 86mm? even 1400cc vaux engines can run 83mm pistons, even our 2.0s aren't that big. which ultimately limits valve size
The XE head & engine combo is very very good. N/A XE engines easily get 240+bhp. The latest generation of Zetec engines (ST170 and the like) as even better than the XE showing even better power & torque development for similar . The VW engine has been neglected because of how expensive they were when 1st produced. They never really got the development they deserved. Guys in germany worked with them further but its small scale compared to the number of products available for Vauxhaul/Ford engines.
If you look at a Zetec inlet / ex ports , they're 1/2 the size of a VW 16v head, makes you wonder why people bother with them in kit cars etc. ST170 and the new Duratec HE Ford engines are better though, SBD are selling bits for the new Duratec for instance. Edited by: G_V_K
Im not sure about other manufacturers but VW offered a motorpsort cylinder head for the 16v which apparantly was ALOT better. Probally why they never bothered to make the road goin heads any better ? I'd like to know why people think the VW head is so bad, and why it seems to be a common opinion that the exhaust side is pooe, yet you dont get alot of gains from modifying it. At the end of the day the vaux engines you see producing mega power are very, very limited milage lifetime engines that have been extremely heavily developed. Theres also the pub bhp figure exxageration to take into acount.. How many VW tuning companys are there out there, like SBD for vauxhal that really do alot of motorsport engines and really develop engines on a higher level ? Not alot. maybe thats why you don't see as big numbers for vw engines..
