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valves are now ready for installation. I sent them out to be coated for better heat dissipation and less friction. Look like black chrome now. Coating will disappear around seating furface once valves are lapped/ground to the seat.

Also you can see the Titanium retainers in this pic. Everything on left is new and right side is old (cleaned) parts. The titanium retainers ended up weighing less than half of the stock retainers. If I would've duplicated the stock design/mass I would've only been about 35% lighter. But due to the lightened valve train and the Ti I chose I could make the retainers of less mass and cross-section lightening them further. They were then sent out with the valves and surface hardened.

I went with a new set of stock Audi valve springs. Sent them out and had them shot-peened/stress relieved. Rate increased about 5% from 94lbs at .500" to 98.5lbs at same compressed height and service life will increase anywhere from 400-1200%. I then polished their upper/lower seats so they don't gaul into the lower seats or the Ti retainers. I had to buy 3 complete sets of Audi valve springs in order to end up with a perfectly balanced and matched set of inner/outer springs. Other people were waiting in line to gobble up the remaining 2 sets. I may still take the springs back and have a surface treatment added as I was impressed with the advantages.

You can see the valves are smaller stemmed and under-cut compared to stock. Little harder to see each valve also has a 1mm larger diameter head. Valves also feature a thinner profile head for additional weight savings. I'll break out the drug dealer paraphenalia (Ohaus triple beam) in the next day or two and let everyone know the weight differences for each individual part as well as the overall percentages on each stacked assembly. I'm anticipating +/- 30% weight-savings on each valve, retainer/keeper and lifter assembly.

Still awaiting the lightweight, 8,500 RPM lifters but they had to come from England. Hey I know I'll never see 8.5k but have you ever tried ordering lightweight 6,300 RPM hydraulic lifters!?!

My new nickel alloy valve seats should be here later this week and my silicon bronze guide material I'll use to turn up my own guides.

Everything is right on schedule so far with this project tho any single item could go south in a banana boat at any moment. Still looking like a mid-August/early September installation date.

More updates as they occur.

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Are you just trying to open and close them that bit faster?

more grunt out of the turns on a road course, faster speeds down the straights, faster 0-whatever times.

Same reason any of us does any engine modification.

I can't wait to see how this turns out for you. Probably be a while before I can get to it.

I think I am going to order the HF die grinder, speed control, and burrs soon so I can get started on the IM workshop and this project. :-)

Thanks for all the time and research into this stuff. Kudos.

And as you've probably guessed there's not much within this thats cheap or inexpensive. I'm guessing valves with coating at/near $40 each. Ti retainers at +/- $20 each. Springs are $150 for all 12 inner/outer. Then add $8 each for shot-peening. Polishing spring tops/bottoms would add another $4 each and if coated could run another $6 each. Lightweight lifters at $28 each including Int'l shipping. Nickel alloy seats at $18 ea and custom bronze silicon guides machined for PC Teflon seals +/- $24 ea. I'll go out on a limb and 'guesstimate' $1500 just in parts, another $1k for labor services, ie; valve job, seat/guide installation, machining for correct installed heights etc. Porting/polishing could easily run well over $1k additional if farmed out.

But for the most part it's just too early to quantify a price at this stage. And then someone will inevitably come along and say; "How much is everything except nickel-alloy seats?" and everything changes.

<img src="http://audi12v.home.comcast.net/pix/headguesstimates.gif">

in quantity. Some things by as much as 40% and others by as little as 25% if I do orders of 10 and they'll allow my initial production run to count as part of the 10. Some things I did order multiple sets of initially as I wanted spares/extras in case of screw-ups. If I were to order 25 sets of anything there would be additional discounts tho not as dramatic as the original 10 quantity.

Problem is as you can see from the prices this stuff adds up in a hurry. Would take upwards of $15k out-of-pocket to just do the first 10 qty order. I don't think there's 10 among us that'll ever be a candidate for this extensively modified heads in spite of dramatic power gains. And of course all this is aggrivated by the fact we can't get any of this stuff off-the-shelf anywhere for the 2.8 12V engine. All we can get are an oversize intake valve thats not under-cut. Everything else available to us is simply a tit-for-tat duplicate from an OEM supplier of what we already have. And "one-up" or short-order custom production runs are spendy to do.

But I'm gonna need that header if I have any chance of 300+HP. These AAH/AFC exhaust manifolds will only flow 292CFM of air and that will limit me to +/- 275HP. Extrude honing will only yield 2% better or +5.45HP. But a well designed header could easily give me 20-25 additional ponies with these heads. Which if doesn't put me over 300HP at least has me seriously flirting with it.

(no pun intended) :-)

Is your plan that we will be able to buy these bits and pieces (ready to install) through you?

to be enough interest I'll step up and place an initial order of 10. It's just $15,470 is a rather lofty &amp; long limb for me to be climbing out on. Especially without some idea as to recovery time and ROI.

So far I'm at the "definate maybe" stage.

to accomplish which design goals. Cause I haven't found evidence to explain power gain directly from the lighter valve trains... From what I can find in the Google library, eliminating valve float at higher RPMs is the chief benifit of a lighter valve train.

Most articles associate lighter valve trains with higher RPMs (if the pistons and thier supporting components can take it). This is one of the better articles I found so far...

http://www.canadiandriver.com/articles/jk/021002.htm

Just lightening valve train and holding stock red line seems a waste of serious dollars. Please explain the mechanics of benifit at stock RPMs.

Are our valves floating as we near redline now?

I can understand that larger valves weigh more, and could need some kind of offsetting weight reduction to prevent float. But given your valve undercutting and hollow stems, I bet the valve mass is reduced not increased, in spite of the larger size.

Another aspect is that lighter valve train would prevent float with more agressive cam- i.e. steeper lobes which could introduce additional valve train acceleration?

And I think you have said you plan more agressive cam?

The biggest distinction when doing modifications is understanding the difference between needs &amp; wants.

Lighter valve train requires less parasitic power to operate. Lighter reciprocating/rotating assemblies put more power to the ground and less power to rotational needs and associated frictional losses.

Doesnt matter how much or to what degree when you're going for maximums. I'm building up to a HP goal based on "wants" rather than down to a budget motivated by "needs." Would be very frustrating to be short of the mark by .4 HP and know I scrimped on something/anything whereas being short by the same number and know I did everything I possibly could have.

Besides, if you're gonna be a dog, why "choose" Chihuahua!?!

If the flow bench, dyno, and/or time sheets show gains, more than just the few "insane" persons will buy in.

perhaps he would feel willing to get flow numbers before he installs?

Michael, care to chime in on that idea? I cannot do it, because I already have installed mine.

I already know they flow in excess of 290CFM and likely closer to double that and maybe even more. They'd have to have a roll of nickels welded inside each runner to flow less. Tho I'm not enamored with their design there's no arguing it's far better than anything I have presently. And I'd run em in a heartbeat over stock manifolds and damn well like em to boot!