Does anyone know for actual fact if the crossflow is a more capable head than the traditional design?
I've tried them both on very similar engines, (both gas flowed on 2E blocks) and the x-flow seemed to pull better up the rev range. Only my opinion mind you, never seen a graph for either engine...
There's flow bench figures, valve sizes, etc on Vortex. Standard crossflow head outflows a ported counterflow head according to the details there.
Ok. Are the exhaust port geomerties the same for both heads? If the crossflow is better then why is the 2.0L engine considered to be so crappy? Is it due to bad manifold design, bad cam, bad fuelling, etc? So a stock crossflow head with a cam should flow more than 150HP. Has anyone done a crossflow conversion on a G60?
One of the main reasons the x-flow is better is due to the fact that it has smaller valve stems. x-flow heads are available from US mk3's or UK mk4's, the new beetle etc have x-flow heads.
Paul Horrocks built a crossflow G60 turbo with his mate Lee Ross. 1800 Rallye block, Beetle head, Garret T3 turbo. It's running about 300bhp I think.
Thanks for the info Presumably there are some shenanigans with the manifolds / injection system? Is the inlet side at the front? I'll think about one for the next engine version, but as I dropped my PB head off with Bill Blydenstein on Friday (lots of porting, reprofiled seats, bigger exh valves) I'm sticking with that for now (...and what a lovely bloke he is - It's not every day you meet a LEGEND!)
don't forget with a x-flow you'll reduce charge heating effects as well as the intake is no longer smack bang next to the exhaust tt
the inlet is at the front. the injectors go into the inlet manifold, rather than into the head like the counterflow. The mk4's use air shrouded injectors, so the size maybe different to the digi ones. the standard inlet valve is 0.5 mm less dia than the digi.
my x-flow should be finished soon! had it converted to solid lifters, enlarged exhaust and inlet valves, gas flowed and ported with schrick 304 cam
Back from the dead. I am getting a 2L ABA crossflow engine in a few months and would be interested to know the flow bench figures. Maybe a link????
The best way forward, although expensive, is to run the cross flow head on ITBs, as oakgreen 88 is doing.. He will have some figures from Stealth before long, so should give a decent comparison to some of the 16v cars..
