E30 Zone

Hi there guys, I have been doing some work on this and thought you m30 perverts would like to have a gander.

The head had been worked on, but the customer wanted a little improvement while it was apart. The course of action was some nice 3 angle valve seats and back cut valves as the stock valve cuts are a little agricultural, then a quick go over with the soda blaster to get rid of the carbon build up.

Chambers as I got them, not bad really.



Valves as I got them, again not bad. They had been ground in the old fashioned way with a stick and paste, never as good as two freshly machined surfaces.



Valves got cleaned up and the angles recut, the seating face at 45* and then a back cut at 30* this improves flow. By the way the machine doing the cutting is made by black and decker, and over 40 years old, a time when we where still making a few things to be proud of





The finished valves, given a bit of an extra polish to prevent carbon build up.



Next new seats, cutter pilot installed.



The first cut at 60* is the bottom cut.



Followed by a 30* top cut, then the seat cut, both are on a double sided cutter. The seat cut is at 46* the two faces will bed in together within the first moments of the engine being started.



This is what you end up with after it has been soda blasted, and all the cuts finished.



A before and after, not alot of difference really as the head had already been scrubbed, but the soda gives it a nice uniform look and doesn't damage the surface of the alloy.



The real difference will come from the seat, which will no doubt produce an extra 500bhp Ok not quite that much but a good step in the right direction, and its future proof in that it will compliment all other mods done afterwards.

There are a few other bits that could have been done to improve flow, but this is the design spec on this one and it will better the head as the seats on the m30 have room for improvment.

I hope you enjoyed you bunch of wrong'uns

thats a very nice job
Did you modify valve stem and the underhead of valve part (where it meets the valve head) in any way?
Again I'm not an expert but question out of interest cause I heard that top cut at 38*-39* is superior to traditional of 30* in the way that it lets air flow easier. Just wandering if you tried them angles in the past and they didn't realy work (or is it best angle for m30)?

pianist wrote:thats a very nice job
Did you modify valve stem and the underhead of valve part (where it meets the valve head) in any way?
Again I'm not an expert but question out of interest cause I heard that top cut at 38*-39* is superior to traditional of 30* in the way that it lets air flow easier. Just wandering if you tried them angles in the past and they didn't realy work (or is it best angle for m30)?

The only modification on the valve is an extra cut closer to the stem at 30*, you can see it best in the second pic of the valve in the machine (4th down).

As for a 38-39* seat, well I can't say I've tried it there is so much banded about, people trying to convince others that they have found a magic bullet, you will usually find you cant have your cake and eat it, a cut that may be good in one place may be cr4p everywhere else and vice versa. It would have to be cut using an adjustable cutter or a dressed stone, I only use fixed carbide cutters.

Like I said there are other things that could be done, but it is best to start where you can pick up the easy gains, and the m30 seat is just a 45* seat against a 90* angle. I do know one thing it will flow better now than it did before.

Nice work Byron, no doubt the customer will be hapy with work like that

What else could be done to the head to help it a bit more??

"Like the sign says: Speed is a question of money, how fast you wanna go?"

There is another cut that can be done on the valve, and the bit of the port behind the seat could be blended into the insert. That is about the limit of the simple stuff.

Next you are on to removing the sharp edges within the port, (not porting, although some would call it that, this can only be done properly with a flow bench) leaving the standard shape just finishing it by hand. To some this would be a full stage 3 port and polish BMW heads are usually very good as far as shape and flow are concerned, I'm not saying they cannot be improved upon, but you need to know what you are doing, and what you are aiming for.

Valve stems can be waisted, made thinner, but you are now at the point of diminishing returns, i.e alot of work for not alot of gain.

Looks good

How much would the above work cost roughly?

Bristol_Jer wrote:Looks good

How much would the above work cost roughly?

PMed

Me too

i gonna have m30 conversion soon could you tell me where about you are located and what prices you do
thanks in advance thats very interesting stuff

M30's respond well to head work, nice job.

maggspower wrote:"Like the sign says: Speed is a question of money, how fast you wanna go?"

There is another cut that can be done on the valve, and the bit of the port behind the seat could be blended into the insert. That is about the limit of the simple stuff.

.

I'm sure the customer wouldn't mind you doing that while you're at it

Any more updates on this byron