[HAPPYHANDS]

How high can a stock head 2.0 rev and still be safe. Im reving to 7200rpm at the moment. Would 7,500 be ok? Or any more increase?

 

[Mike_Mac]

i wouldnt go past 7k rpm without a oil pump and internal upgrades but thats me.

 

[hEaT]

What mods do you have? Chances are unless you haven't done some serious breathing mods and more aggressive cams, you aren't making power that high and the car will be quicker shifting lower.

 

[HAPPYHANDS]

I make 162whp at 7200rpm right now...

 

[BlckZTS]

what mods u got? I wouldnt go to 7500 without cams, breathing mods and a built motor, the risk isnt worth the reward

 

[jetrinka]

I wouldn't go north of 7k. Above that you could risk getting valve float from the stock valve springs (main reason not to) and you start getting into strange vibration issues due from the stock rotating assembly not being perfectly balanced. Whats the point though. Unless you have modifications to support it, you won't make power north of it anyway.

 

[whynotthinkwhynot]

Apparently he does if he's making 162 hp at 7200.

For higher rpm you would want a few things. A new tach, for one, if you have the factory tach. Then once you start reaching over 7500 you'd need a different valve-train like titanium valves and higher lift cams. The lower weight of titanium valves would allow you to rev higher without having massive spring rates- increasing hp and reducing damage to the valve guides. That's an expensive proposition though. You might be better off power wise to making more power lower, but that won't increase your MM top speed where rpm is needed. From what I've read, the stock D20 crank is good for 8k rpm, but if you're going for the max- steel might be required for much more reaching.

 

[HAPPYHANDS]

Thanks "whynotthinkwhynot"...Im running into the problem where i will have to go to 5th gear to set the record im trying for. Ill keep it at 7200rpm. Thanks for all the advised guys.

 

[Buickboy]

i did some calcs for piston speed and accel a little while ago:

found a piston speed calc and even at 8000rpm the 2.0 has speeds that are less than the 2.3 at 7200 lol.

7200rpm: 4440.94feet per minute for the 2.3, 3925.98for the 2.0
7800rpm: 4877.02fpm 2.3, 4253.14fpm 2.0
8000rpm: 4934.38 2.3, 4362.20 2.0

I know the acceleration forces are important here so I tried some math and found this:
mean piston speed: [email protected]: 1793fps, [email protected]: 1872fps
max piston speed: [email protected]: 115374fps^2, [email protected]: 114200fps^2

 

[HAPPYHANDS]

Thats nice to know. Thanks for the info.