Who makes the best valves?

[structured]

So, with the exception of those pesky intermediate shaft bearings the bottom end of my engine is built. Before I go on, if you or anybody that you know has the proper bits to size the intermediate shaft bearings please contact me.

I am ready to start on the head which has been decked, cleaned, and had new valve guides installed. Next on the list is to get some new valves and have them back-cut, along with grinding the valve seats on the head.

I have the option of Osvat, TRW, or an aftermarket oversized valve.

What have you guys used? Have you had any problems? Who makes the highest quality?



And just so that this thread isn't too boring, here are the build specs and some pictures so far:

M20 block, over-bored, cleaned, resurfaced
new 0.5mm oversized seta pistons
eta rods and new rod bolts
eta crank
new main and rod bearings

"i" head, decked, cleaned
schrick 288 cam (if anybody wants to trade me their 274 or 272 let me know)







Believe it or not, this cam is used:




Tom

[Danny]

Before you finish your build, might I suggest an M52 crank/eta rods/i pistons combo?

I say this because you declined to state which pistons you are using.

[structured]

Before you finish your build, might I suggest an M52 crank/eta rods/i pistons combo?

I say this because you declined to state which pistons you are using.

I most certainly did not, but just so you don't have to read my post again they are brand new 0.5mm oversized "super-eta" pistons. They are the ones in the second picture.

http://www.maxsilpistons.com/piston_kits.html

According to Bavauto:

"Not only are they lighter and stronger than original BMW pistons...silicon content allows for tighter clearance (0.0015'). Precision casting and CNC machining provides consistent quality and matched weight. ...Teflon coating on the skirt for better performance and longevity. Includes rings and pins. 5-year, unlimited mileage warranty."



Your suggested setup would have yielded a higher displacement (and higher comp ratio?) due to the longer stroke, but I don't have the capability of machining a crank adapter and I couldn't find one anywhere. Plus I had two eta cranks and no m52 cranks at the time.

[Danny]

Ah yes, I stand corrected. If you are interested in the M52 crank though: PM der affe, he's working on something.

[structured]

Ah yes, I stand corrected. If you are interested in the M52 crank though: PM der affe, he's working on something.

I would've been interested three months ago. The bottom end is assembled already.

[Danny]

Well then, best of luck to you sir!

[nando]

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..

[whodwho]

I don't think they are sodium filled, usually the stems would be thicker. It would be good if they were, have you seen it stated that they are somewhere?

[nando]

the exhaust valves are, I'd have to look for that again - maybe I got it from MM?

they are definitely expensive enough for it..

[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.

[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]

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

[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.

[whodwho]

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

[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.