16v WBX heads

[toomanytoys]

Mmm.. I am confused.. the 16v head isn't vw, but you want to use vw parts..

Surely the engineering solution is to look at any quality item that could do the job.. even if it comes from elsewhere..

Motorcycle valves are high quality, light weight (very necessary weight reduction needed) and readily available too.. Worth a look..

[silverbullet]

Bike stuff is tiny!

I am thinking about ease of servicing. Admittedly if this thing comes off, the heads should last 100k before needing a rebuild but I will hopefully still be around to answer for them, keeping it all VAG means that the valves will be a LOT cheaper and this is all good for the purchaser.
G&S Valves do lovely work, but at a price.

Anyway, I now think that the SBF rocker solution is about the only one that will work for the unusual pushrod/port relationship, but not at that angle.
The exhaust ports will be an unusual shape but no worse than the non-symmetrical side of a twin-port quad-cam EJ25, but I may be ahead of myself again

[silverbullet]

Hang on... your'e thinking GS 1150 and the like...

[silverbullet]

101mm bore!!!!

Hmm...



Oops! Plenty of metal between the exh valves though...

[silverbullet]

These engines' redline starts at 7.5k so the valvegear is up to the task for its 70mm stroke, even if it is a chaindrive high cam/short pushrod design with solid cam followers.
I wonder how long they last?

...a quick look at some adventure bike forums shows that 100k is considered "just about run in" for an R1150GS , found an owner who has 155k in USA on a 2004 bike so I guess they last quite well!

End of bike talk, I dont even do motobikes...

[adyjoad]

KR valves (vw 1.8 gti 16v) are 29 and 32 mm diameter and approx 99mm long. 7mm stems. Loads of space in a 94mm bore but a bit tiny maybe

[silverbullet]

Thanks. Good for torque but maybe a bit small as you say...

I did a quick "balance some valves in the hole" mock up and new exhaust headers would be the way to go, the idea of one exhaust valve discharging across another one to match up with the old exhaust port is just a no-no:



Looking at a dead EJ quad cam head shows a similar snaky port on one end:





F..d Motorsport 302 valvegear it is then!

[silverbullet]

Or to put it another way, this may have moved into the realms of the possible.