lemon_juice

finally did my own research for a piston choice for us D15B guys. by using Civic GX pistons (PMS from 2001 models) i came up with 10.55:1 cr. using information from

http://www.knology.net/~jediklc/pistonnotes.htm <--here

anyone willing to check up on my work using the compression calculator

http://www.knology.net/~jediklc/D.htm <--here

and from what ive been reading up on, they should just bolt in directly. another good thing about the GX pistons are that they are forged=stronger.

lemon_juice

and now i read somewhere that the exhaust side of the gx (PMS) piston may cause some close calls?

lemon_juice

then i found out on the link up there is the dome=4cc, not the 5.05 which makes more sense to me, bringing down the cr to 10.3

but the dish of a 3mm piston =10.10cc and the dome of the gx piston is 1.5 which leads me to believe 5.05. but whatever the site says i guess is law.

lemon_juice

hmm, i guess no one is as interested in the d15b as me...

schardbody

i hate to burst your bubble, but the pms pistons in a D15b will not work. see the calculations you came up with were assuming you were using vx D15z1 rods, which will not work on the D15b crankshaft. keep up the research though.


Modified by schardbody at 7:58 PM 3/16/2006

lemon_juice

i did the research. i have a d15b and yes i know the crank is its own special design. but basically its a destroked d16z6 crank with the same size bearings, and this destroked version is the same as a vx crank. and the rods are the same length, 137mm. the only difference from the d15b and d16z6 is the crank, they share the same rods. and the difference in the crank is made up in the deck hieght.

so in turn, im using d15b rods with the pms pistons. the onli difference between d15b and vx rods are the bearing size on the crank end. theyre they same length and everything.

schardbody

ok, i see what your saying now, the link you attached talked about the vx rods, so i assumed thats what you were thinking of using.

lemon_juice

right, but have u ever heard of anyone using the pms pistons in the d15b? i read a post from bense in another forum mentioning sumtin bout the exhaust side of the piston causing clearance issues which id like to find out.

schardbody

i speak to bense quite often as he is the one that built my transmission, very bright guy. he infact agrees that the pms pistons will work in the D15b, but i am almost certain nobody has proof. i was wondering where you got the info about the pms pistons being forged???

lemon_juice

haha, i did my research. actualli alot of his research i read about, stating that the gx is running off some different kinda fuel i forget, but it has forged pistons to handle it, along with high compression stock, i think 12.5 i still havent seen a pic of the pistons but once this rain stops i will head to my dealership and maybe get them to let me check em out/purchase some. u wanna get him into this to see wat he thinks of using pms pistons in the d15b thanks

civicEXtreme

::COMBO-BREAKER::


WHat the craps a pms piston? Sounds like a sexual position.

schardbody

LEMON, i spoke to bense via YIM and he agrees that they work in the D15b, if we can get him to this thread and we all add it to our sigs maybe it can be another project research thread. i wont be the one cracking open my D15b. i will be using the z1 with pms pistons.

schardbody

pms pistons =01-03 civic gx

civicEXtreme

never heard of a gx... and isn't that a 7th gen?

schardbody

GOOGLE "civic gx"

The_Head

The civic GX runs on natural gas. That's why its not well known.

lemon_juice

which motor do you have?
if u have a jdm d15b use those rods.
if u have a vx d15z1 use the vx rods.

i found out all piston ends of the rods are 19mm.

http://www.knology.net/~jediklc/pistonnotes.htm <--this site has alot of info that im picking off from, including a d16z6 buildup if you want using integra ls rods.

lemon_juice

found pics on pistons, including our PMS GX's.

http://www.heeltoeauto.com/tec...shtml <--here

check out the pic on the piston, it has reliefs on the intake side but none on the exhaust side. will this cause troubles for us?

lemon_juice

ttt

Archidictus

Hmmm...spend a shitload of time and a clutch of cash making a D15B 10hp more powerful or spend the same amount of money and time slapping a homemade turbo on it and making 60 more hp.

Tough decisions.

lemon_juice

haha, having a turbo sohc with others expecting 12-13 E.T's or having an N/A 1.5 underdog sohc keeping up with and usualli owning B-series because people like you think so low of them. hmm, i dont mind "wasting" money.

and either way, if you look at it that way everyone is "wasting" money but towards what they enjoy. dont act like you havent had a week of passion towards your honda.

Bense

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bense &raquo;</TD></TR><TR><TD CLASS="quote">they work. here's sources. Ironically, I have been realizing why they used to always teach us that MLA stuff in english class. I used to hate making citations and all that nonsense. Now I understand, because people want to know if what you're saying is legit and want to see documented proof so they know that you're not talking out of your ***.

Nevertheless....don't flame me if it's not in MLA format:

Heel toe's d-series piston comparison.
http://heeltoeauto.com/tech/dseries/dseries1.shtml
P07-010 - 92-95 VX - D15Z1
total height: 57.65mm
compression height: 27.75mm
7.05mm dish

PMS-A00 - 01-03 GX - D17A?
total height: 47.42mm
compression height: 27.00mm
1.50mm dome

GOT PMS?!



"PMS 01-03 GX:
These pistons have the standard size D series wrist pins, but have a low 27mm compression height. Ironically this low compression height coupled with 137mm VX rods in a D15 make an interesting combo..." -http://www.knology.net/~jediklc/pistonnotes.htm

most accurate compression calculator
http://www.zealautowerks.com/dseries.html


remember, d15z1 has 137mm rods which are the same length as d16 rods!</TD></TR></TABLE>

lemon_juice

ok, i seen this pic of the pms, from the d17a7 haha, and i see that there are reliefs in the intake side for the valves, but there are none for the exhaust side. will this be a problem?

Bense

Allow me to clear up some confusion. Not trying to prove you guys wrong but this stuff gets tricky. Luckily I can cruise the web at work so I have sorted out all the good/bad info.


A JDM d15b is basically the same block as our d15z1
HOWEVER
the jdm d15b has enlarged journals so it uses d16 rods.
our d15z1 has a normal d15 crank with the smaller d15 journals with unique 137mm rods that are the same length as a d16 rod but the journal size is that of a d15.

The d17 gx has 12.5 compression but remember it draws in more air due to the longer 94.4mm stroke. The dome on the gx piston yields 12.5:1cr when in a 94.4mm stroke engine (D17) but not when it's in a 84.5mm stroke d15z1

schardbody

this research wasnt solely to find a way to better the D15b, but to also find a solution to not having pistons avail for them stateside. with the gx pistons in a D15b or VX with P28 head the CR is appr. 11.4:1. add that to a very happy R/S ratio and turn it as high as you want. with the proper tuning this combo will send home a gsr easily.