how high can the stock h22a block rev to??? searched but results were nil, assuming rebuilt head and cams that would still produce power above 7600, whats the limit for the crank and internals....

 

about 8500ish is the max i would take a stock block. assuming a built head like ya said.

btw i am not talking out my ***, i do push a stock block to 8500 daily, :thumbsup:

 

Most built (NA) H22's don't make power past 7400 rpms, Especially not a stock block.

Power peaks around 7000 rpms, shift there.

 

peak power yes but u should shift at redline

 

If you shift at redline on your stock tach are actuall shifting at about 7000 rpms

When i had my vafc if i shifted at redline on the stock tach i was actually shifting at about 7000 or 7100 rpms.

 

i shift at about 7400-7500 on the vafc =D

 

you dont want to shift at your highest peak point. you would want to shift a little higher (redline for a reason) so that u land in a higher torque band.

er. only a dyno can determine which would be the best rpm to shift at. most of the time a little higher than 7400 is fine on a h22.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Eddiebx &raquo;</TD></TR><TR><TD CLASS="quote">about 8500ish is the max i would take a stock block. assuming a built head like ya said.

btw i am not talking out my ***, i do push a stock block to 8500 daily, :thumbsup:</TD></TR></TABLE>

eddie understood, everyone else didn't, with aftermarket cams, most times you will still make power above stock redline, so with a built head that can withstand higher reving PAST stock redline, how high can the stock block rev to before problems occur since the head has already been rebuilt to withstand the high reving

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by twistedbydezign &raquo;</TD></TR><TR><TD CLASS="quote">eddie understood, everyone else didn't, with aftermarket cams, most times you will still make power above stock redline, so with a built head that can withstand higher reving PAST stock redline, how high can the stock block rev to . . . .</TD></TR></TABLE>
Most engines, yes. H22's . . . I have yet to see one that did anything beyond it's stock redline, no matter what cam was being used or headwork was done. **shrug**

But to answer your question, 8,000 on the stock bottom end should be okay on a regular basis. Maybe 8,500 if you're only doing it occasionally - but again, chances of making it being worth your while to go that high are slim to none.

 

eddiebx's skunk2 stage 2's are making power after the stock redline, then again they are not stock cams nor does he have a stock ecu either.

i shift at 7800 rpm usually though i have fuel cut at 8200 which i have hit once or twice. with a little bit of tuning i am able to extend my power upwards enough that its worthwhile to shift that high.

 

I would think you'd be ok up towards 8000, except for the auto tensioner. That will be your weak point.

 

sometimes its benificial to shift past peak power, so you land on the fatter powerband. I tend to shift upwards of 8200, but the engine has hit my 8500 limiter often, not that it makes sence to hit it, but I do w/o issues. So thats how I come up with my 8500 max rpm to push a stock block theory. Till the day she blows up I wil believe my stock block is happy at 8.5k,

and for the record I make power till 7700-7800 and the power barely drops by 8k.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">eddiebx's skunk2 stage 2's are making power after the stock redline, then again they are not stock cams nor does he have a stock ecu either.</TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Eddiebx &raquo;</TD></TR><TR><TD CLASS="quote">and for the record I make power till 7700-7800 and the power barely drops by 8k</TD></TR></TABLE>

Dyno of said power? Searching, but can't find anything.

 

you guys, its not all about peak power, and power under the curve when it comes to the best shift point.. you have to take into account the gear ratio's and torque multipication..

 

I tend to go past redline and shift at 8k with no problems. This is with stock internals and basically a stock motor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Russbus &raquo;</TD></TR><TR><TD CLASS="quote">I tend to go past redline and shift at 8k with no problems. This is with stock internals and basically a stock motor.</TD></TR></TABLE>

i am hoping ur using the stock tach and its actually 7600ish ur shifting at when the tach reads 8000, cuz shifting at 8k on stock head is not smart...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GaRn &raquo;</TD></TR><TR><TD CLASS="quote">you guys, its not all about peak power, and power under the curve when it comes to the best shift point.. you have to take into account the gear ratio's and torque multipication..

</TD></TR></TABLE>

explain more please about taking into account the ratios and torque....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Daemione &raquo;</TD></TR><TR><TD CLASS="quote">


Dyno of said power? Searching, but can't find anything.</TD></TR></TABLE>

yeah i never got dyno plots from my shop, i was too happy about the power i made i forgot and left, , sorry.

as for taking into account power under the curve that is true too, but the way i figure it out is at the track, too lazy to sit down and do all the theoretical ****,

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by twistedbydezign &raquo;</TD></TR><TR><TD CLASS="quote">explain more please about taking into account the ratios and torque....</TD></TR></TABLE>
Well, every gear multiplies the torque of the engine by X amount. So for example, 1st gear multiplies it by a factor of roughly 14 (assuming a 5th gen tranny & stock 24" diameter tires). 2nd gear multiplies it by roughly 8.3, 3rd gear multiplies it by 5.7, etc.

So a stock H22's dyno plot looks something like this:

(dyno courtesy of joel aka satan_srv)

With stock H22 gearing, this engine at 7,600 rpms in 1st gear would be putting down roughly 1,330 ft/lbs. of torque (95 x 14). Shifting to 2nd gear (at about 39mph) drops your engine to roughly to 4,500 rpms - which given 2nd gear's torque multiplication grants you 996 ft/lbs. of torque.

If you could run the engine to 8,000 rpms in 1st gear, you'd still be making 1,120 ft/lbs. of torque (extrapolating & guessing that we'd be somewhere around 80 ft/lbs. from the engine). And when you shift into 2nd @ 41 mph, you'd land around 4,760 rpms, resulting in another ~996 ft/lbs. of torque there (because of the flat spot just before you hit VTEC).

So in 1st gear, shifting at a higher than stock redline would result in faster acceleration. But doing the same math for 2nd --&gt; 3rd gear, the results aren't as good. Since shifting from 7,600 rpms in 2nd gear lands you right on the torque peak in 3rd gear, you'd be actually be going from 788.5 ft/lbs. of torque to 813.7 ft/lbs. -- MORE torque in the higher gear. If you did the same maneuver shifting @ 8,000 rpms you'd be all the way down to 667 ft/lbs., going up to around 810 ft/lbs. in 3rd gear. So plainly not worthwhile waiting to shift any higher than the stock redline from 2nd to 3rd.

You can play around with the numbers yourself if you'd like to see what other gears and shift points do. Just find an online gearing/mph/rpm calculator & have a torque plot & list of gear ratios on hand.

These are all rough numbers, of course, since I'm just eyeballing how much torque is being made at specific rpms. And it is also a stock engine - so if you're able to maintain torque higher up instead of it dropping like a rock past 7,500 rpms on the stock engine, a higher shift would become advantageous. But like I said earlier, even on H22's with highly modified valvetrains, I've never seen one that makes any respectable torque much past the stock redline. Certainly not past 8k.

Here's the same engine as was dynoed above after a boatload of modifications, including custom Crower stage 2ish cams, JUN valvetrain, and some headwork:


Notice that the torque curve still doesn't maintain itself past 7,000 rpms, and drops by more than 20% by the time it reaches 8,000. Dyno's I've seen out there using S2S2's do about the same.

Hope this helps . . . .

 

awesome post, you explained it much better then i could or would have.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Behan &raquo;</TD></TR><TR><TD CLASS="quote">awesome post, you explained it much better then i could or would have. </TD></TR></TABLE>

amazing post, great info

 

nice dynos hehe

 

wurd, dyno's don't lie. Even with valvetrain upgrades,
i still see no reason to rev past 7600.

 

yeah i take my H to da max just about everyday

 

so you say that an H22 will not make any torque up on the high end. what if you take an engine that has had some bottom end, valve train, and tranny upgrades like let say the crank has been knifed-edged, rifle drilled, bearings clearence blueprinted and rebalanced and maybe 11:1 compression or turboed. the valvetrain has titanium valves and retainers and high rpm cams. and lets say a Quafie is put in. Do you think that that engine could not make any power at higer rpms? Cause what about F1 cars they make alot of power and rev to 12k or more.