I need to know the cc of a std bore h22 type s piston. Can anyone help? I need to calculate my compression. Thanks

 

a simple number will do....

 

i wish i could help ya. we put some TYPE S pistons in my friends buildup but i didnt know the dome height. ill give ya a bump just so hopefully someone will answer. if not, buy some custom 12.5 slugs.

 

The thing is I already have the engine together and Im running stock sleeves. Im also using a h23 crank and just by increasing the stroke Im upping the compression even more. I think Ive figured my compression to 12.1:1. h22 head milled .020". Deck height of .003 (not sure about this number either), stroke 95mm, piston bore 87.25. 54cc combustion chamber. Stock .030" head gasket. I figured the 12.1:1 number on c-speed's comp calc. Im running stoke cams and and getting kind of worried about detonating, looks like it will be 100 octane low lead for me until I get hondata.


Modified by civicsitek GanGsTa at 2:59 AM 12/26/2003


Modified by civicsitek GanGsTa at 3:00 AM 12/26/2003

 

can anyone verify the numbers in my above post?

 

I'm not at work, so I can't tell you for sure, but I believe that we measured the stock type S piston dome volume at either 6.8 or possibly 7.0cc.

 

what happened to the H22 that was sleeved??? with the 8.8 pistons???

 

sold that block. the pistons came out lookin like crap so I junked them, reconned the rods, honed the block and sold what I could. The crank was broken some valves were bent and the head gasket was blown. All in all it was the biggest mess Ive ever seen that still ran great. Ryan told me he squeezed after 500 miles and I believe that to be true. All those great parts were doomed from the very start. I have since done it all over myself using a new block, crank, rods, pistons, and even a new head. It will finally be done this spring after a 10 month lay over all motor 12.1:1, ported head, stroked, and tuned on slicks. I can't wait. In the mean time I hope to be able to start it with stock timing and 100 octane. I hope everything that I do goes well cause everthing he did has sucked *****.

 

When I do the calculations again with those domes I get 12.5:1 for a 6.8cc dome and 12.6:1 for 7.0cc. That sounds high but is it accurate?

 

I fugured the dome by using stock jdm engine specs and adding piston dome cc's to increase compression. I know it was a crude method but figured it would get me close to the number I was looking for. Using the calculations I described above, I got a 2.6cc dome for a jdm h22 to achieve a 10.6:1 compression ratio. Can anyone verify or deny what I have said for everyone to learn form?

 

to my knowledge, ryan did squeeze but he didnt squeeze much cause the car didnt run fast. but then i heard he sold the car not long after that.

i dunno how the H22s react with 12:1 compression on pump gas, but my B series ran fine. i had some generic skunk2 program and some bigger injectors. so i doubt u will have any problems. in fact, on initial startup i ran it on a stock P72 ECU. i still run pump gas in the ****** thing.

 

eh what rods are you using on the h22 block w/ h23 crank decl is a bit taller on h23, I could bw=e wrong

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicsitek GanGsTa &raquo;</TD></TR><TR><TD CLASS="quote">I need to know the cc of a std bore h22 type s piston</TD></TR></TABLE>

Did you ever find out what it cc volume of the dome is?

 

i would guess that it would have to be 6.5cc. Because the Wiseco 11-11.5:1 compression is based on a 6.5cc dome. The 11.5:1 is with a cut deck of 0.015" (dont ask me on this one....maybe its with a head gasket..)

 

What's the piston-to-deck height on a Type S piston? If it's also .015", then you can start to make a comparison on them being of similar displacement.

You also don't know if the valve relief pockets are bigger or smaller on the Wiseco's. That is also figured into the dome volume.

I'd be inclined to simply use Endyn's number that they gave. It'll give you a pretty close approximate figure. You can only get so far without measuring everything yourself and then crunching the volumes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IN VTEC &raquo;</TD></TR><TR><TD CLASS="quote">What's the piston-to-deck height on a Type S piston? If it's also .015", then you can start to make a comparison on them being of similar displacement.

You also don't know if the valve relief pockets are bigger or smaller on the Wiseco's. That is also figured into the dome volume.

I'd be inclined to simply use Endyn's number that they gave. It'll give you a pretty close approximate figure. You can only get so far without measuring everything yourself and then crunching the volumes.</TD></TR></TABLE>

i dont know how wiseco got the 0.015" piston to deck, but i know without the head gasket it is less than 0.003". As for the valve relief, i'm sure the valve relief pockets are larger than stock OEM Type S pistons. I'll double check though....but usually they are larger.

 

Most aftermarket forged pistons are spec'd with a compression height to give them around .015" to .030" of deck height clearance. Supposedly, it's to accomodate blocks that have been decked any number of times.

However, when most people run those pistons, they'll deck the block to give it close to a 0 deck height clearance (maybe minus a thou or so depending on their application and build preference).

Are you using the Wiseco's?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IN VTEC &raquo;</TD></TR><TR><TD CLASS="quote">Most aftermarket forged pistons are spec'd with a compression height to give them around .015" to .030" of deck height clearance. Supposedly, it's to accomodate blocks that have been decked any number of times.

However, when most people run those pistons, they'll deck the block to give it close to a 0 deck height clearance (maybe minus a thou or so depending on their application and build preference).

Are you using the Wiseco's?</TD></TR></TABLE>

Yes I'm using the wiseco pistons. So you're saying that the the pistons are made to sit in the hole 0.015" even thought the stock piston to deck clearance is close to 0.003"?

That would answer my question/confustion then

 

If you look in the Wiseco catalog they have deck clearance lsited as .015 - .38 and no thats not a typo on my part... In the catalog it actually says .38

Ive just always assumed they ment .038

Ive heard so many different claims of actual deck height, some say as much as .030, some say as little as .011

Does anyone know for sure?

 

unless they designed it be "In the hole" by 0.015" - .38" then it probably is correct. All I know is that the stock H22A4 pistons and stock H22A4's deck is almost pretty flushed with each other.

This means that it is pretty close to 0.000" unless the previous owner decked the block and I didnt know about it.

 

I remember a friend of mine telling me he had around .030 +/- when he built his H22 with Type S pistons...

Grrrr... This is getting frustrating

Ive been trying to calculate the ACTUAL CR of H23 VTEC motors with various OEM pistons for quite a while now... With very little available in the form of ACTUAL specs its a little hard to do

 

well....stock H22 piston is 1.222 in height and the Wiseco piston is 1.219. So that throws out my ASSumption

 

i dont know about everyone's h22/h23 but mine is pretty flush. now with your buddy, was it at TDC?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93H22ACX &raquo;</TD></TR><TR><TD CLASS="quote">i dont know about everyone's h22/h23 but mine is pretty flush. now with your buddy, was it at TDC?</TD></TR></TABLE>

yes, TDC...

The thing I dont understand is... Why does Wiseco have such a wide variant of compression listings and deck clearances...

11.0-11.5 and clearances from .015 - .38

If you look at the B series aplications they list the specs are listed with almost no variance... The compression ratios are listed with out a X - X but with a X... no variance in compression calculations...

Why such a wide spread for the H motor?

 

i dont know but good idea on bringing these questions up... it'll clear alot of things up