has anyone installed bigger valves on a 1.6na? Is it possible?
if anyone has done this i would really like some info on sizes that were installed and if there was any big gains in power.
I did some research and found some valves that will work with some slight modifications. SBI valves intakes are part# 10746 and exhaust is 10060S. News seats will have to be installed, guides reamed out slightly, new valves have to be cut down slightly and different keepers need to be installed. My machine shop tells me this won't be a problem to do. We'll see what happens!!!
1.7, 1.9, 2.0 five cylinder and 2,4 intake valves are 36mm. Itīs 2mm larger than 1,6 valve. For exhaust, there is no direct fit.
What about using a valve with a smaller stem?
Achieves the same goal, no?
I think your best bet might be to check out Heron 1.6L (110hp gas GTI engine used in early European GTI's) valves. The Heron uses a flat-bottom head with no combustion chamber like the diesel so you'd think the stem length would be the same. I know it has larger valves than the regular gas 1.6 so I'm pretty sure it should be a decent upgrade for the diesel.