How do Type S cams compare to usdm ones in the midrange?

What might be the maximum compression that these cams might be able to feed?

 

The midrange will be the same until VTEC. Then you'll get a bit more torque. Not much. With the aftermarket being so cheap for H22s nowadays why run Type-S? A more aggressive low cam will fill in the gaping hole in torque that Type-S cams won't fill.

The only thing that limits the compression on any camshaft is the detonation threshold of your fuel. If you ran E85 you could safely use 12.5. If you tune it really well you could probably go up to 13.5-14:1 (NOx emissions notwithstanding). If you're in Denver you might be able to push it to 15:1 on E85 if you know what you're doing.

Read up on ottocycle thermodymanics. More compression = more efficient (more torque = more power)

 

Pirate, he's going to try and build a midrange monster like yours with a vtec head for a little top end. As far as I can see he's mainly concerned with midrange though.

High comp and pro2s?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">Pirate, he's going to try and build a midrange monster like yours with a vtec head for a little top end.</TD></TR></TABLE>

So I don't have any top end? At least my less-than-VTEC cams got me 200whp and gobs of midrange. lol.

I think Pro2's are too big personally. Even if you run up the compression you'll still bleed off a lot of dynamic compression in the midrange until the VE matches the high duration profile. If the block and valvetrain are up to the task then sure. Use S2Pro2s. Otherwise find a high lift cam that is better suited to the rpm capabilities of the block. But then again I have never tested it. Six Sigma did real well with them on only 11:1 CR range.

Pirate

 

Sorry Pirate, my e-sarcasm goes easily undetected these days

I compared the specs of the h23 crower3s vs h22 crower3s last night, the h23 ones are much much smaller all over the board, advertised duration is about 255 versus over 310 with h22 cams. The gross lift number is about 20 less with the h23 cams also, they make nothing comparable to them for an h22. I suppose this is because they want to make better top end with those cams, it would be nice if they made some more like yours, that kind of powerband is what we're looking for

Maybe pro1s then, the skunk cams seem to me, over all others, to be high lift, low duration, and as far as I have been able to think about it, that should mean better midrange, as lower duration will leak less dynamic compression...correct?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">Sorry Pirate, my e-sarcasm goes easily undetected these days </TD></TR></TABLE>

Apparently mine does too.

I'd pay more attention to duration numbers at .050" than advertised numbers. The advertised numbers are highly affected by the "length" of the ramp.

From reading Skunk2's published info the ProSeries cams have pretty agressive low cam profiles and if you want midrange than that's probably your best bet. Unfortunately they don't publish the low cam specs. They do however make it sound like the idle is a little rough which probably means that it's around 205˚-210˚ at .050"

With an H22-based engine that's limited to around 7000 rpm (If Vig is looking to emulate an H22 version of my build with the same rpm paranoia I have) and you upgrade cams that have the VTEC switchover at 5500 rpm then you only have 1500 rpm of use out of the VTEC profile. Until VTEC you're relying on 5000+rpm of low cam profile to get you moving. Also when you shift at 7000 then you're back down below VTEC stuck waiting again. With most H-series gearing your upshifts will drop you into the 4500rpm range on the first 2 gears.

You'll need a cam that emphasises peak torque at around 4500-5000rpm if you're limited to 7000 rpm with stock H-series gearing. Sounds custom to me.

Pirate

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">Read up on ottocycle thermodymanics.</TD></TR></TABLE>

The Day I see someone from HT go out and read about thermodynamics based off a post, I will crap my pants.

http://en.wikipedia.org/wiki/T...cycle

 

I agree Pirate, but do you not think that with upgraded hardware and properly-sized bearings that you can rev the f23 crank to 8k?

**** the K guys rev those 99mm cranks to 9000+

 

Yeah if you build it to handle the revs then use whatever cams you want and wind it out.

Pirate