Help! What is a CVCC valve??

[kesmai]

Hey guys.. I've got a City Turbo 2, and the head is stuffed. It originally burnt out number 1 valve, so i had a new valve put it, a few months later its burnt out number 4 valve. Someone said it might be a CVCC valve?? Any information would be appreciated. Or any way to test to find out whats wrong.. Car runs standard boost etc etc no mods..

Thanks

Gaz

[city_cabriolet]

i've heard of a few people having trouble with their engines, i personally would fork out the $600 at your local jap importer for an ER turbo block, comes with the turbo still bolted on, so it's second-hand, but you could spend double that and still not have a working vehicle if someone doesn't do the job right...
just my 2c.
Cheers,
Luke

[Colza]

If it is valves that are causing problems I would say you dont need to buy a block and turbo! However i presume there is something CAUSING all your valves to die which would be the sort of thing you need to look into. It is, however, not something that i have ever had trouble with so i am probably not going to be much help here :-/

[kesmai]

Well really i'd just need the head.. I've done a bit of reading through this forum and on the web.. And i've seen that people have had problems with this CVCC valve thingo and the camshaft lobes. What i'm wanting to know is what is this CVCC valve exactly? And if it was broken, then could it cause serious engine problems? And finally , if it is worn, what needs to be replaced so it doesn't happen again. I've read there is a place in Sydney that rebuild the cam or something. Any help appreciated.

Cheers

Gaz

[75civict2]

Make sure you are runing the right spark plugs for the engine it sounds like your getting hot spots and killing the vavles.

[JohnT]

If you open up the rocker cover you should find that there are 12   inlet & exhaust valves (not the usual - 8 normal size on the manifold / firewall side, and four smaller ones at the front (away from the inlet manifold). These 4 valves - the cvcc inlet valves -  have their own rocker, and it rides on a third lobe on the cam (per cylinder) - so there is exhaust, mian inlet and CVCC inlet for every cylinder.

If your cvcc valves are stuffed, you may be getting a really lean mix - also get that if the mixture adjust is wrong. That can burn valves. There is description of cvcc elsewhere on this site.

If these cvcc valves are missing you've been sold a dud.

John

[Charles]

Burnt valves= not enough fuel/incorrect timing/bullshitting mechanic.

If they are truely burnt then check things like fuel pressure regulator and fuel pump. Check your timing and check injector flow. Your mech should have identified the problem first time around rather than just replacing the burnt valve.

[doggystyle]

the first thing i would say would be rounded cvcc cam lobes as burning a valve was exactly what mine did.. number four cvcc valve wasnt even opening.. i would take off your roker cover and crank the motor (with ignition disabled)and see if theyre opening or not.. a.. actually what is the lift of the cvcc v' anyway