rev limit for built f22 head

[nostringz]

i have an f22 head with bisimoto titanium valve springs and retainers. the camshaft is a level 2 with skunk2 cam gear. What rpm can i top off the limit safely at? or maximum? keep in the mind the bottom is stock. i was thinking 7200 or 8000. what do you guys think?

[deevergote]

Your best bet would be to ask Bisimoto what their springs are rated at.

However, with that valvespring setup... I would think that your bottom end (assuming that it's stock) would be in trouble long before your head is. If your bottom end is stock, I wouldn't rev higher than the stock redline. You definitely don't want to put a piston into that semi-built head of yours.

[Joey GT-R]

Correct. Your crank shaft has more to do with the redline of your motor than your camshafts do. If you try to spin it faster than what it is designed to do, you'll cause some serious damage. I know from talking to Julio at Bisimoto that he has an F22A stroker crank that may be able to be customized to your goals.

What intrigues me is why you went with a Skunk2 Cam Gear? Didn't even know they made such for an F22A. I imagine Bisi would have gotten you his for cheaper?

[PR CB7]

7.5k, block limited
so your head will be fine, some teflon rocker spacers would'nt hurt
at 7.5 your 95mm crankshaft with its shitty rod/stroke ratio will be around the max you can spin it daily
if you feel you need to spin to 8 to make power you're doing something wrong

[HondaFan81]

Have you done any research? The level 2 powerband is advertised to max out by 5900 RPM. Your statements are unrealistic.

In my experience, if you wish to obtain anything near 100K miles of engine durability, I would not aim more than 7000 RPM on stock block. Use a quality engine oil. The lower the mileage on the stock block the better and with proper maintenance history.

The camshaft is the major contributor in determining your RPM powerband, but the block geometry can be a limiting factor if your camshaft is capable of more RPM. The engine components should be designed or chosen to work together toward a common goal.

[dj_ender]

Correct. Your crank shaft has more to do with the redline of your motor than your camshafts do. If you try to spin it faster than what it is designed to do, you'll cause some serious damage. I know from talking to Julio at Bisimoto that he has an F22A stroker crank that may be able to be customized to your goals.

What intrigues me is why you went with a Skunk2 Cam Gear? Didn't even know they made such for an F22A. I imagine Bisi would have gotten you his for cheaper?

They only made the Tuner series of Cam gear, there wasnt a Pro version made, and from the looks of it, they dont even make the Tuner ones anymore. And if I remember right they were on par with Bisi's price.

[deevergote]

Joey, the head does play a role in rev limits. Valve float can occur when you rev too high. Of course, his upgraded valve springs make that a non-issue.

Have you done any research? The level 2 powerband is advertised to max out by 5900 RPM. Your statements are unrealistic.

That's the most important thing to consider, right there. How high do you NEED to rev? If 5900 is where the Stage 2 camshaft stops really making power, you don't need to rev much higher than that... and that is safely within the engine's limits (not that it isn't still a strain on the internal parts, but the engine was designed to rev that high, at least!)

What you really need to do is figure out where your engine's powerband is. Find where the power really begins, and then find where it drops off. Figure out where you need to shift up high so that the next gear will start in the powerband. That will determine your maximum necessary RPM. This can be done on a dyno, or by trial and error on a track. Start low, and work your way up. You don't need to rev to the moon... especially if you're not making any significant power up high anyway.

[Joey GT-R]

Joey, the head does play a role in rev limits. Valve float can occur when you rev too high. Of course, his upgraded valve springs make that a non-issue.

That's the most important thing to consider, right there. How high do you NEED to rev? If 5900 is where the Stage 2 camshaft stops really making power, you don't need to rev much higher than that... and that is safely within the engine's limits (not that it isn't still a strain on the internal parts, but the engine was designed to rev that high, at least!)

I was alluding to that, but guess I should have went further into detail with it. And now that you mention it, if he has Stage 2 cams, he should have dynoed the car anyway, and his tuner should have been able to tell him where he needs to shift and he should know his powerband. You don't do those kinds of mods without taking the proper precautions.....or he'll be back to an F22A in no time.

[wed3k]

with bisimoto's spring pressures, id rev it past 8k. hell ive done that on my stock valvetrain on accident.

[mjsstanley]

with bisimoto's spring pressures, id rev it past 8k. hell ive done that on my stock valvetrain on accident.

You have to remember that its not only about valvetrain but also the block as Deev stated . If he spends a lot of money on the valvetrain and then throw a rod because his block is stock and can't handle the power the head can , his head work will just be a waste after a piston goes through it .

[wed3k]

You have to remember that its not only about valvetrain but also the block as Deev stated . If he spends a lot of money on the valvetrain and then throw a rod because his block is stock and can't handle the power the head can , his head work will just be a waste after a piston goes through it .

thats not what the OP was asking.

[deevergote]

Well, since he said "keep in mind, the bottom end is stock", I assume that means he understands that the bottom end offers some limitations as well (and he clearly underestimates those limitations...)