Ok so i have a jdm h22a with crowers stage 2 cams, crower valves and springs. I Have herd so many bad thing about turboed h22a4 but mine is just as i said a h22a. im just wondering if it will be safe to run only about 7lbs?

 

H22A, H22A4, same thing in regards to your question.

The weak point is the piston ringlands, check out the FAQs.

 

i tried but they weren't helping me any.

 

7 lbs would be fine if tuned properly..but i advise you to rebuild before you do any forced induction..

 

Also your n/a cams will hurt a trubo application, youd be better off with stock cams or turbo cams.

 

why would they hurt? higher compression?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by snobordboi &raquo;</TD></TR><TR><TD CLASS="quote">Also your n/a cams will hurt a trubo application, youd be better off with stock cams or turbo cams.</TD></TR></TABLE>

Actually, there are alot of B-series guys that like the Skunk2 Pro2 N/A cams, I have seen like 90whp gain when dialed in properly. I plan on experimenting with some N/A cams in the 700whp range soon in my prelude.

 

^yea i just watched a video of a LS (b18b) motor making 407whp on BIG all motor cams

 

sweet so im safe with them then?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ccssk8ter11 &raquo;</TD></TR><TR><TD CLASS="quote">why would they hurt? higher compression?</TD></TR></TABLE>

Cams do not change compression. Anything that changes combustion chamber volume changes compression....pistons, valves, head, etc..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 95greenlude &raquo;</TD></TR><TR><TD CLASS="quote">^yea i just watched a video of a LS (b18b) motor making 407whp on BIG all motor cams</TD></TR></TABLE>

To be fair nonVTEC cams, OEM or aftermarket, are pretty puny compared to VTEC cams. ie, B-series Crower 404s have pretty similar lift and duration specs to OEM CTR/ITR stuff (in VTEC obviously).


But the high HP turbo guys have definitely been experimenting and doing well with various "NA" cams. idk if people running more moderate manifold pressures have done it with success as well.

 

My understanding is that the overlap is much higher on the n/a cams that you run into issues, not the amount of lift they have. I know theres plenty of people making big power with stock cams, maybe the best thing to do is ask whoever will tune the car what they think about it.

 

cool i will do that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by snobordboi &raquo;</TD></TR><TR><TD CLASS="quote">My understanding is that the overlap is much higher on the n/a cams that you run into issues, not the amount of lift they have. I know theres plenty of people making big power with stock cams, maybe the best thing to do is ask whoever will tune the car what they think about it.</TD></TR></TABLE>

Yessir, too much overlap at the wrong time can let the boost blow right out of the chamber On the other hand, big lift with the right timing can help bring in more boost pressure

 

a sweet not it all makes sense!

 

Cams do have an effect on dynamic compresion

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rexbo &raquo;</TD></TR><TR><TD CLASS="quote">Cams do have an effect on dynamic compresion</TD></TR></TABLE>

Please do enlighten us.

Edit, nevermind, here we go:

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

The calculated compression ratio, as given above, presumes that the cylinder is sealed at the bottom of the stroke (bottom dead centre - BDC), and that the volume compressed is the actual volume.

However: intake valve closure (sealing the cylinder) always takes place after BDC, which causes some of the intake charge to be compressed backwards out of the cylinder by the rising piston at very low speeds; only the percentage of the stroke after intake valve closure is compressed. This "corrected" compression ratio is commonly called the "dynamic compression ratio".

This ratio is higher with more conservative (i.e., earlier, soon after BDC) intake cam timing, and lower with more radical (i.e., later, long after BDC) intake cam timing, but always lower than the static or "nominal" compression ratio.

The actual position of the piston can be determined by trigonometry, using the stroke length and the connecting rod length (measured between centers). The absolute cylinder pressure is the result of an exponent of the dynamic compression ratio. This exponent is a polytropic value for the ratio of variable heats for air and similar gases at the temperatures present. This compensates for the temperature rise caused by compression, as well as heat lost to the cylinder. Under ideal (adiabatic) conditions, the exponent would be 1.4, but a lower value, generally between 1.2 and 1.3 is used, since the amount of heat lost will vary among engines based on design, size and materials used, but provides useful results for purposes of comparison. For example, if the static compression ratio is 10:1, and the dynamic compression ratio is 7.5:1, a useful value for cylinder pressure would be (7.5)^1.3 × atmospheric pressure, or 13.7 bar. (× 14.7 psi at sea level = 201.8 psi. The pressure shown on a gauge would be the absolute pressure less atmospheric pressure, or 187.1 psi.)

The two corrections for dynamic compression ratio affect cylinder pressure in opposite directions, but not in equal strength. An engine with high static compression ratio and late intake valve closure will have a DCR similar to an engine with lower compression but earlier intake valve closure.

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

Interesting





Modified by Hawkze_2.3 at 8:04 PM 5/3/2008