i am trying to find some missing hp in my h22. i think i am missing about 20hp. well i think i want to raise my compresion. supposedly my comp is at 13.1:1. i really doubt this because i was only putting out 220-230 psi

and to guys that really care about cams, i have skunk2 stage 2.

i do have one thing to add to the cam stuff when it comes to compression, if you argue that the cams bleed compression, i really doubt that it drops psi that much especially b/c that they are vtec. i doubt the low lobes are hugely different.

please let me know what your octane and cranking pressure. and supposed cr.

 

http://www.rbracing-rsr.com/comprAdvHD.htm

Too high is going past about 25% increase in cranking pressure. Bigger cams you go, you'll notice the huge decrease in cranking pressure. Anything below 5% below stock and your engine's hurting.

 

yea BIGGER CAMS but vtec is what so bigger. so when you do a compression test vtec is not activated, so i really shouldnt see that low witha a supposed 13:1 motor.

what i want to know is what are people running on pump gas. i mean when you do a compression test.

 

Hmm. I have a B18C1 with 12.5.1 JE pistons SK2 Stg 2 cams.. im getting 240 across the board. Makes me wonder if I have a problem

 

WELL I SEE YOUR CLOSE. I WONDER WHAT OTHERS ARE AT.

 

I am also running skunk2 stage II cams on my H22 with a measured compression of 12.9:1
I get a cranking pressure of over 300 PSI across the board.

After a trip to the dyno, my compression was WAY to high for the primary (non-vtec) lobes (running 98 RON fuel) . The car would not take timing at all without pinking its merry little head off

I have since ordered a 0.057" Cometic gasket to reduce it to around 12:1. Hope that will sort my problem.

I have a similar problem understanding VTECs running such high compressions when the primary lobe duration and overlap is not sufficient to reduce the dynamic compression ratio to an acceptable level. This seems to be a limiting factor in choosing the correct compression for your VTEC motor.

Someone please help me out to understand this

 

the vtec lobes have a higher ABDC valve closing degree than the primary lobes. Meaning, there is more pressure/compression bled away than the primary lobes.

13:1 is pretty much not streetable b/c of this. thats why they have VTEC killer cams along with other reasons.

the low lobes are hugely different from the VTEC lobe..it has way less lift and duration(which as a result has less compression bleed)

Your compression numbers do seem low though. are you burning oil at all? what kind of clearances did you run?

 

YEA SO I WONDER WHAT IS THE DYNAMIC COMPRESSION RATIO FOR OPTIMUM TIMING WITH 94 OCTANE> THIS IS WHAT I AM TRYING TO FIGURE OUT.

ANID TO THE GUY BELOW, YOUR AND I ARE SAYING THE SAME THING I GHUESS. THERE SHOULDNT BE SUCH A DROP AND PRIMARY LOBE WHEN CHECKING COMPRESSION.

I THINK KTHAT THE PISTONS I HAVE ARENT WHAT THEY ARE SUPPOSED TO BE

 

My old H22 was stock block, .020 milled head, Crower Stage 2 cams, and I was around 270 psi. I think it was close to 11:1. When I re-built it with higher compression and tested it I pegged the gauge and don't know for sure. 290 at least.

 

your running 93-94 right?

 

Year? 1995 JDM H22

 

no octane

 

OH! LOL. I was confused. I ran 93 octane in it all the time. I still ran 93 later on when I put the Type-S pistons in. Those made it around 11.6:1. Now that I'm 13.5:1 I'll be running 100.