Will 0,5mm oversized Ferrea valves,be un-damaged when the engine turns up to 10.000rpm,instead of 1mm valves and if yes why do you think will be damaged??

 

There is alot that can be damaged. If you dont have the supporting mods its not even worth fixing the car every time you rev it up.

And just spend the extra money and get the head fully ported and go with the 1mm oversize values if you dont later on you will regret it.

 

If i understood correctly,you recommend to use 1mm valves?Note that the hole engine is modified including the head,i just had from the begining the 0,5mm valves.

 

Its not the size of the valve that matters but how fast it can close which matters at high rpms. On that note performance springs are going to be the limiting factor of how many rpm's you can turn a valve train. For example cosworth has 1mm oversized heads which support 10k rpm operation.

I feel the limit of your engine speed is going to be the relative max piston speed you can safely obtain. I'm quite certain vendors have left their 2.0L built blocks for drag applications at the 9500 rpm limit for a good reason.

I'm sure a quick call to any of the drag racing gods out here would give you some idea how much engine speed you can safely run on some said rod piston combo.

Borrowing the EvoM engine tech guides words
https://www.evolutionm.net/features/article/evomtech/77

Mean piston speed (ft/min) = (stroke(mm)* 2 * RPM)/(25.4*12)

88mm mean piston speed = (88mm * 2 * 10,000rpm)/(25.4*12) = 5774 feet/min
100mm mean piston speed = (100mm * 2 * 10,000rpm)/(25.4*12) = 6561 feet/min

 

Thanks,but i have seen a 'god',as you say,video with an evo viii turn up to 10.000rpm and in dyno and if i am not mistaken,is AMS.

 

So maybe they did but was it safe?

Call Eric at AMS and just talk to him You'll get alot better answers from someone that has done it rather than the geek like me which has seen it.

 

I asked someone at AMS days ago,i do not remember his name,but his answer was"I can not help,just recomend to buy all parts from us...or then we can help..."

 

I also agree that rpm is relative to rod/piston ratio. BUT you have to have some damn decent valve springs (dual) just to help with valve float, And your going to need some very aggresive cams to even make it worth your time up there. It is possible but Its just not ideal for anything other than a drag car.

 

Well that sucks..

AMS isn't the only vendor that drag races though. There is probably at least 1 vendor on this planet willing to give you some advice on that area..

 

Thanks anyway,i totaly agree that sucks to speak like you ARE the one and only in the world and do not give a damn to anyone that needs some advice...We did not want to learn any secret....

The only think i admit is that he has one of the most powerful evos.

 

I have Manley Dual valve springs and Tomei 280 11,5 lift in/out cams.I am thinking to change the cams into Jun 272 10,8 lift in/out.What do say??

 

I have manley dual springs in my talon, and I wouldnt feel comfortable taking my talon to 10k Just my .02 But my talon does see 9k maybe a tad more just at the traps

 

Why feeling uncomfortable?You tried,you have the wright compo?>

 

I have a built and balanced 2.1 liter I guess I just don't see the benefit in it. Might I ask why you so desperatley want this number? I personally don't want to walk that close to the edge.

 

I have passed threw a LOT to design and modify this car,at first it was like an argue with a competitor of mine,but in the end(after i saw the time,money etc that was spented) i realised that i can develop a 1000hp race/street car.Since i started i couldn't stop.