Valve question

[hendrix]

Are all small block nova engine valves the same?? I.e. will valves out a 1.2carb fit a 1.6mpi??
Cheers :thumb:

[Stuart]

no

the 1.4sri and 1.6mpi valves are the same, they are bigger than the 1.2-1.4 non mpi items. i also belive that they are a little longer too.

Ive never measured the valves so dont know the exact numbers. BUT 20xe inlet valves are the same head/stem size as std 1.2-1.4 valves... not sure on length or if the 20xe collets fit into the spring retainers for the 8v springs.

[hendrix]

Thanks stuart, most helpfull. As I am at work (and cant just nip and have a look at the head/car) can you tell me if the smaller diameter valves are inlet or exhaust so I can order some new ones.
Is this a good option considering there are two with small cracks in near the top of the stem?? Obv it got very hot at some point

[Stuart]

the smaller diameter valves of an engine set are the exhausts.

[hendrix]

excellent. thanks!

[hendrix]

right, been looking at the valves tonight and they all seem to be scored quite badly where the colletts have been, some actually have deep cracks in them, any ideas why this is?
also where is best place to get cheap valves from?
ta

[Stuart]

would be cheaper to get a 2nd hand head....

[hendrix]

what would cause the cracking though stuart?? Engine getting very hot is my best guess.
Ive just had headwork done so another head isn't an option and they are getting hard to find around here.
Guess I'll get some new valves, ho hum!
Can anyone suggest the best place?? Auto-vaux perhaps?

[garyc]

try www.allittmotosport.co.uk (http://www.allittmotosport.co.uk)

[Stuart]

Id get the valve guides checked out too.

cracked exhaust valves that high up sounds like it got bastid hot... maybe a fuel/timing issue + crappy oil supply to the head... lots of things i guess.