Who makes the best valves?

[gforce323i]

I purchased my beehive valve springs and stock diameter stainless valves from Metric Mechanic. Their valves are designed and shaped to take advantage of the M20's flow characteristics, many quality aftermarket race valves you find like Ferrea, Supertec, etc are not optimal for flow on an M20 due to their rather generic undercut stem and head design.

[structured]

I've heard that as well but i guess that you'd have a pretty low CR with that setup.


Does anybody know of a source for genuine BMW valves? Other than the dealer, of course.

[einstein57]

Word on the grapevine is you can get forged 2.8 pistons for the eta crank and i rods for $600. I have the order ref# somewhere. I was thinking of organizing a group buy to try and get them for $500 during tax season.

[fiftytakedowns]

I heard pig valves are pretty relevant

[nando]

Just out of curiousity, how would you set up a head to run the 284/272 cam, nando?

Sorry to thread jack.

well I did it with new BMW springs, Febi rockers, and BMW valves.. but ideally the springs should be stiffer, +1mm valves, and a port job focusing on the valve seats and bowls, and also the CC. Not much changes to the port inlets or outlets. It's working OK for what it is, though.

[structured]

how much did pistons run you?

I think that they were $500 with rings and dowels. If you are starting from scratch I'd recommend getting custom pistons, though. I only went with these because I had already commited to this setup when I found out that my block would need to be overbored to get straight walls. Simply honing them wasn't going to do it. As a result, the used seta pistons that I have would've been bouncing off the cylinder walls. By buying new pistons I was able to have the cylinders matched to the pistons and they are all essentially identical. It turned out for the better, albiet far more expensive.

If you want some used seta pistons, I have a set.

[Aptyp]

how much did pistons run you?

[whodwho]

I think maybe just the tip is sodium filled. and M20 valve stems aren't that small, try a newer BMW engine. I think the E90 M3 V8 has 5mm valve stems. :o

I've got a couple extras, maybe I'll cut one open to find out.

Inquiring minds need to know!!

If they are don't let any sweat drip on it when you get it cut open!!

[E-Thirty]

Just out of curiousity, how would you set up a head to run the 284/272 cam, nando?

Sorry to thread jack.

[nando]

I think maybe just the tip is sodium filled. and M20 valve stems aren't that small, try a newer BMW engine. I think the E90 M3 V8 has 5mm valve stems. :o

I've got a couple extras, maybe I'll cut one open to find out.

[whodwho]

Might have to cut one and see, I think the stems are a bit thin to be hollow.

[jlevie]

I don't know if the exhaust valves for an M20 are sodium filled or solid. The benefit from sodium filled valves is better heat flow from the valve lips (where they seal) to the head which reduces heat erosion of the seal area.

[structured]

well I have a 284/272, but realistically I'd like to build a whole new head specifically for that cam, and I'm not there yet.. but you might find others willing to trade.

If you change your mind about the cam I'd would be happy to trade.

I tried to find a buyer/trader for mine, but in typical r3v fashion all I got was ridiculous lowballers. I'd rather just let it sit on my shelf until I have a use for it.

Do you have any more info about the BMW valves? What is the benefit of the sodium?

Thanks

[nando]

well I have a 284/272, but realistically I'd like to build a whole new head specifically for that cam, and I'm not there yet.. but you might find others willing to trade.

[structured]

Thanks, gentlemen. This is just the kind of stuff that I was looking for.

the best quality are BMW valves - the exhaust valves for example are sodium filled which isn't cheap.

There's also schrick and a few other makes. I've been curious about IE's oversized valves, but they're cheaper than stock ones.. just makes you go hmmm.

whats your CR? I think that cam might be a bit poopy on anything less than 10:1. 11:1 is even more ideal. I've always wanted to try a 288 though..

Nando, I am aware that the cam is too big for my CR. I had a long discussion with Mr. Rowe about it. I have the cam already, though, and it was stupid cheap so I figure that I'll try it anyway. If you want it and have another to trade let me know.