Todd,

I'm not one for looks, however they look great. Now how many cfm do they flow at 25 inches?

 

We also used Ferrea titanium valves for one set, however Forrea at the time did not make big enough valves for the other set. I appears you also are using different manufacturer for the other set.

I used Manley ...... who makes the ones you are using or are they your own? It appears they may be stainless .... are they? We didn't use stainless because of weight.

Again, fantastic stuff, you guys are on the leading edge.

 

Ferrea makes both now, we sent a cylinder head down to them for R&D I just don't know that it's been formally released (although I'd expect them to be in the near future).

 

Todd thanks for answering, it's nice to learn new things. This answer really also shows how much R & D you are doing and how ground breaking this stuff that you're doing really is. Congratulations and thanks for being one of the few Tuners that are willing to push the envelope. Some things may do well, others may fail, but either way, you learn from both. Though your "do well" seems to be a much higher ratio than the "fails" lol Keep it up!

 

Thank you Chad. The flow numbers are greatly impacted by the valve lift. Lets just say that they are optimized for the valve diameter and the lift of the cam

 

Thank you! Both the intake and exhaust are Ferrea and they are both titanium. The whole valvetrain is now 52% lighter than the stock 997TT valvetrain With the reduction of weight on these components, spinning this engine to 10K will not be a problem.

Another component that is changed but looks stock are the springs. We are using a titanium valve spring set that is not only light, but has higher and more consistent spring pressure than the stock valve springs.

 

No problem Scott, thank you for following. These projects are both mental and financial challenging. I am sure Chad can attest to this. Pushing the envelope is the reason I and the whole EVOMS team exists. None of us would be satisfied working on the same routine stuff every day. The problem with this is: 1) it is hard to be satisfied because there is always a better way to develop more power efficiently and reliably 2) sometimes pushing the limits gets out of hand financially and there is no way to recoup the investment.

Finding the balance has been difficult, however we feel fortunate that we are able to undertake projects like these because it really enables our whole team to push the limits and continue to gain valuable knowledge that helps all other aspects of our business.

 

Yes, you are 100% correct. I was just trying to get a feeling as to where you were going with the 10,000 rpm's along with getting some type of comparison.

Here is our flows, our cams are designed to be just a hair under a .550 lift.


Flowed at 25” water. Inlet bell and Exhaust outlet used.

lift 0.050”, intake 52.3 cfm, exhaust 40.9 cfm
lift 0.100", intake 97.5 cfm, exhaust 92.2 cfm
lift 0.150", intake 144.0 cfm, exhaust 144.7 cfm
lift 0.200", intake 194.0 cfm, exhaust 179.2 cfm
lift 0.250", intake 237.6 cfm, exhaust 204.8 cfm
lift 0.300", intake 272.8 cfm, exhaust 225.3 cfm
lift 0.350", intake 297.3 cfm, exhaust 238.7 cfm
lift 0.400", intake 310.7 cfm, exhaust 250.9 cfm
lift 0.450", intake 320.9 cfm, exhaust 259.2 cfm
lift 0.500", intake 324.5 cfm, exhaust 266.2 cfm
lift 0.550", intake 327.2 cfm, exhaust 272.0 cfm

Duration is also a very important issue with the turbo motor. Less is required than a NA motor.

 

I believe Todd's above statement is an understatement. That is why I am a real fan of the efforts the EVOMS Team is making. To be very honest we built our drivetrain with 12K rpm's in mind only to have our best minds tell us not to exceed 9600 rpm's. Their reason was the boxer design is extremely smooth at 6800, however because of design the opposing push/pull gradually becomes more unstable as it goes up from there. If TDC and BDC on opposing banks is off in the slightest it will cause the motor to become unstable and it will destroy itself. Imagine the preciseness required on each bank. Trust me when I say at these rpm's there is no margin of error allowed for the precisely syncronized timing and position of the two opposed pistons.

I really want to see EVOMS succeed here. With this they will raise the bar again.

Here is an older pic of our reverse side of the heads. They are extremely light and balanced. Note the bottom of the springs. The bases were machined and shins were added. Each spring has the exact (no variance) spring pressure. All individual spring pressures have been blueprinted.

 

One word stunning .

 

avh128996tt,

I'm sure this is nothing new to EVOMS, but we made a significant discovery a couple of years ago while we were designing our cams. We found that all the Porsche cams that we tested had harmonic distortion. We found that if we designed and manufacturered our cams in such a way as to eliminate harmonic distortion that we were able to drastically reduce the spring pressure required. It was reduced so much that more than one tuner told us they would not work and the motor would not survive.

The bonus of being able to run with lower spring pressure is you are not slamming and beating up the valve seats.

 

[quote=cjv;2571740]i believe todd's above statement is an understatement. That is why i am a real fan of the efforts the evoms team is making. To be very honest we built our drivetrain with 12k rpm's in mind only to have our best minds tell us not to exceed 9600 rpm's. Their reason was the boxer design is extremely smooth at 6800, however because of design the opposing push/pull gradually becomes more unstable as it goes up from there. If tdc and bdc on opposing banks is off in the slightest it will cause the motor to become unstable and it will destroy itself. Imagine the preciseness required on each bank. Trust me when i say at these rpm's there is no margin of error allowed for the precisely syncronized timing and position of the two opposed pistons.

I really want to see evoms succeed here. with this they will raise the bar again.

Here is an older pic of our reverse side of the heads. They are extreme light.




agree 100 %

 

Todd,

I have a question regarding your pistons on this stroker. If my question is privy, I respect your keeping the information private.

The question is, did you offset the wrist pin location (off center) in order to take advantage of a better centering of the pistons? If you did I won't ask you how much the off set was.

PS .... Sorry I get carried away when I see such a great thread as your's. I'll retrain from any more questions as I see I am getting off topic. Again, thanks for sharing as well as raising the bar again.

 

thats one hell of a project

 

Todd,

Please keep the progress coming! I really can't wait to hear more about this ground break project from EVOMS.