WTB hotrod valves & springs for M30

[Robin-535im]

And is it worth it?

I don't plan on racing, just spirited city driving up to 6500 RPM or so.

I've read about sodium-filled, stellite-tipped, stainless valves, super-duper race springs, titanium retainers, 57-angle valve jobs, etc.

Does this give more power over stock or just more RPM range?

Any thoughts / insight / experience is very much appreciated. Looks like I'm in for a whole head rebuild at this point and am considering my options.

- Robin

[Rus]

The higher RPM range is warranted by stronger valve springs and lighter valve train. It is also impacted by cam timing. Basically, the biggest issue that an engine experiences at high rpm is called valve float. It happens because the valvetrain is moving beyond its design specification and the valves do not get a chance to close. Lighter valves and stronger springs remedy this problem. Valve grinds (2, 3, etc angle), and titanium retainers aim to improve valve sealing and component strength and weight. Just my $.02

[Jeff N.]

Hey Robin,

Unless you're going to get regularly into that range and stay there (ie racing, etc) I don't think specialty valves and valve train parts are what you want.

If I was to do my planning all over, I'd start by working it this way.

- determine the powerband you want for your motor
- find a camshaft that will deliver that - options are short really. Schrick, MM, Korman, or have a custom cam ground via someone like webcamshafts.com
- determine what you need to drive that valve train - improved springs..fancy valves, you name it.

If you want a free revving engine, it might be more productive to look at the following:

- reduce your piston mass via lighter weight pistons and wrist pins. Custom piston can save a lot of weight.
- lighten up the flyhwheel to maybe 14lbs, see if you can get a lighter weight pressure plate too.
- consider knife edging your crank
- see if there are lightweight crank hubs around (I never found any but didn't look too hard)
- get a good balance job done during assembly

Just a couple thoughts.

Jeff

[Robin-535im]

Hey Robin,

Unless you're going to get regularly into that range and stay there (ie racing, etc) I don't think specialty valves and valve train parts are what you want.

If I was to do my planning all over, I'd start by working it this way.

- determine the powerband you want for your motor
- find a camshaft that will deliver that - options are short really. Schrick, MM, Korman, or have a custom cam ground via someone like webcamshafts.com
- determine what you need to drive that valve train - improved springs..fancy valves, you name it.

If you want a free revving engine, it might be more productive to look at the following:

- reduce your piston mass via lighter weight pistons and wrist pins. Custom piston can save a lot of weight.
- lighten up the flyhwheel to maybe 14lbs, see if you can get a lighter weight pressure plate too.
- consider knife edging your crank
- see if there are lightweight crank hubs around (I never found any but didn't look too hard)
- get a good balance job done during assembly

Just a couple thoughts.

Jeff
Thanks Guys.

How does one choose a cam / power band?

My plan is to build up the head I want now, and do the bottom end separately as time allows. Trying to save the most expensive parts until last, I'll sort out the head, intake and exhaust first and build up a bottom end if/when I still have the car and my wife hasn't thrown me out. :)

[Paul in NZ]

well for instance MM have a "power" and a "Tourque" cam.I think i would go for tourque,run a higher compression and a chip.I think trying to run higher rpms on this engine is the wrong way to go...Get a S38 for that ;)