Replacement engine? Hardened valves needed?

[mickael]

Just got a CNG off eBay and it turns out I need a new engine!

It is a 1999 Chevy Cavalier. I found a reasonable replacement but I heard I may need a special engine with hardened valves and intake. Has anyone else heard anything about this? Any advice is appreciated.

[neongreen]

Re: Replacement engine? Hardened valves needed?

I don't know what is required, but as I have said before, you can't go wrong with good stainless valves, hardened seats and good valve guides.

[Yroc]

Re: Replacement engine? Hardened valves needed?

I have a converted 2000 Escalade and have been reading about hardened valves and seats. Am I going to have problems with the valves in my engine? I try to run as little regular gas as possible, but do let it get some now and then. Also, it starts up on regular gas, does this help anything?? Has anyone thought about this or found any information about it?

Thanks all

[Idarusskie]

Re: Replacement engine? Hardened valves needed?

check out this engine design. They are building a bunch of engines for a natural gas company in Canada.

http://www.coatesengine.com/technology.html

[CNGvw]

Re: Replacement engine? Hardened valves needed?

All car makers went to harded seats an valves when lead was pulled from gasoline 1969?? I have been doing cyl head work for over 40 year from racing to stock on gasoline engine and CNG engines. It is just a way to charge more money when they say you need to change something.
Bob Mann