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denz88
05-23-2002, 04:51 AM
Hi guys, i'm going to rebuild the motor and to get higher compression ratio as well. Need little help finding information about combustion chamber volume, bore, stroke, the exact compression ratio of 88-89 A20. Thanx :pimp:

pric
05-23-2002, 08:06 AM
The A20A3 bore=3.26 in. or 82.7 mm stroke=3.58 in. or 91mm 9.3:1 comp ratio for the 88-89. Do not know the combustion camber volume sorry.

funkytuqe
10-20-2003, 03:39 PM
Check out this board
http://wsbf.net/phpBB/viewforum.php?f=28
There are guys there with ludes over the 200hp mark. That board has all the hard core 2g prelude guys. There is not a question that they don't know the answer to.

Also have you been to preludepower.com???

Oyvind Ryeng
07-25-2004, 05:55 PM
*What is the exact bore the Diamond pistons require? (Prefer smallest possible bore for maximum sylinder wall rigidity)

*What piston-cylinder wall clearance?

*Are they low- or high-silicon? (Low silicon= bigger clearances - expands more - takes more of a beating. High silicon= smaller clearances - expands less - takes less of a beating.)

*Asking about the 9.2-9.4 compression (whatever is easier to get) pistons with the 21mm wristpin for a FI buildup.

*What do they cost incl. wristpin and rings? I will preferably buy these from Sean to show my appreciation for all his efforts.

I want a piston that gives about 9.2-9.4 compression in my A20A4, and that will withstand 400 WHP @ nothing more than 7000 RPM. Also, they have to have the 21mm wristpins for use with the Eagle H-beam connecting rods.

So what clearances to they require? Also, low or high silicon content?

shepherd79: This engine will be built as a low-RPM torque monster, and that's why lower compression is out of the question. I will run a good intercooler, water injection, 10% toulene in the gastank, Haltech E6X direct fire /w 4 coils for DIS, J&S Safeguard /w knock sensor(s) and a TechEdge WBO2, so detonation and/or preignition is not something I will be all that worried about.

I realize that my A20A4 has a bore*stroke of 82.7mm*91mm, I was just wondering if Diamond builds clearances into the pistons so I'll know if I have to bore it to 83mm or like 83.1mm. Guess I have to email them, and ask them directly.

I would not overbore an (ANY!) engine for the sake of more displacement, I'd overbore it to get the old wear marks away and the new pistons in. More displacement is always the cowards way out, real men just up the boost, or even better; combine it with DIY-racefuel and/or other manly tricks.

Now I'm wondering about if, and how deep the wear-marks are; if possible I'd get a custom bore piston to use with a 82.8 mm bore. Guess I'll have to ask my machinist about the cyl-walls conditions @ 82.8 mm. Diamond _can_ make a custom bore piston, right?

The bottom-line moral of the day is: "Don't bore a FI-engine any more than what is absolutely neccesary (sp?)".

Justin86
07-30-2004, 04:48 PM
yea that sounds about right. Sometime I need to go and get my self a barrel of it for experiment. oh yea the bore is 82.7mm and stroke is 91mm.

smufguy
08-04-2004, 07:49 PM
I realize that my A20A4 has a bore*stroke of 82.7mm*91mm, I was just wondering if Diamond builds clearances into the pistons so I'll know if I have to bore it to 83mm or like 83.1mm. Guess I have to email them, and ask them directly.

The max overbore is about 83.01 mm - 83.02 mm. So forget about the 83.1.mm its just too much. Besides, if ur gonna go boost, dont over over. If ur gonna go na, then u might but its not worth ur money i tell you. That extra 0.1L of displacement is not gonna give u much.

the service limit is 82.73mm which is 0.03mm over the stock. So u will be good. ur not gonna be cutting any deep gash into the engine or the wear is gonna be that bad. Its a cast iron engine my man. Besides, thats why u have the piston rings to contact the walls. Besides, if u think that ur motor car wear 0.1mm, then u need to take a closer look at what "tolerance" actually means ;). Hope that helps.

Robs89LXi
08-05-2004, 03:14 AM
Yes. Talk to Ron Beaubien.
[email protected]

Contact Ron Beaubien at Diamond ([email protected]) and tell him you want pistons like they made for job # 18604. Be sure to specify what compression ratio you want though.


I have done extensive research on this board and everything i have read and re-read say's that stockers are 19mm...

They are 20mm.

AccordEpicenter
08-05-2004, 07:14 PM
yeah but going to maximum overbore somtimes invites cracks between the cyls... just get it honed to what you need... dont have bore it to have a nice ring seal

rjudgey
09-07-2004, 11:57 AM
you can get a few nice bits from K-mod racing, but you guy's you can't just drop forged pistons into standard bore block, the cylinder bore clearance on forged pistons is bigger than cast as forged ally expands more, you have to have the bores bored out slightly to allow for the expansion, p.s 83mm is probably the maximum safe size to have for FI and 83.5mm for N/A you can get 83.75 but your right on the limit then!! The extra increase in size is not going to make any real power difference just stick to stock size unless bores are worn or damaged or if you are fitting forged pistons.

maka_RTH
09-17-2004, 12:15 AM
they come with everything. all the rings and the wrist pins. i believe the wrist pins are 21mm..., so i don't think they'll fit the stock rods cuz i think stock is 19mm... i actually didn't even realize this till i was looking at everything just now. anyways, here's some links to pics, they're 1024x768, so kinda big. anyways:
http://www.maka-rth.com/pics/jepistonsbox.jpg
http://www.maka-rth.com/pics/jepistonsspecs.jpg
http://www.maka-rth.com/pics/jepistonsringseverything.jpg
http://www.maka-rth.com/pics/jepiston.jpg
i'm thinking $300 shipped ground and insured.

*edit: if you're looking to get new rods, you may as well go with some aftermarket ones that are 21mm anyways instead of the stock rods. i now both eagle and scat will make rods you could use. don't know part numbers for those tho...

4sillypwr
09-17-2004, 07:18 AM
stockers are 20mm.

89T
09-22-2004, 07:05 PM
stockers are 20mm.


I have done extensive research on this board and everything i have read and re-read say's that stockers are 19mm...

thanks to mr. maka_RTH i now have new pistons and ordered eagle 'h' beams with 21mm wrist pins.....

look look into the light a high compression boosted 3g ............
:uh: what was i thinkin!

oh i think it's going to work..

:lol: :lol: :kekeke:
i am just trying to be funny.

i am going to give it a go though..

i did order a bunch of goodies...

i ordered a turbonetics wastegate, blow off valve, fmic, je pistons (thanks greg), eagle rods, safc, msd fuel press. reg(boost dependant), msd btm, aspec 3" to 4.5" muffler
and a 255 lph fuel pump.......auh! i got it out in one breath...lol...
still thinking about the injectors, and whitch turbo to use..

any suggestions?

i am trying to keep it street leagle also... :uh:

by the way out of everyone i have delt with money wise on the net greg was the best...

mad props to greg!

89T
10-01-2004, 03:48 PM
10,1:1 is pretty high with boost. You wouldnt be able to boost much.

that was the thought....high compression low boost..
say you had a engine that had 8.5:1 comp. and runs 14psi of boost making say 250 hp. actual compression will be about 22:1 under boost..

now the same engine with 10:1 comp. running 9psi making the same 250 hp.with the same actual 22:1 comp. under boost...
you make the compressor more efficiant...not to mention the extra tourque when not under boost...

(those numbers are hypothetical)
to me this makes sense but if you have a diffrent opinion i want to hear it...


and if i have to i do have a standalone.. i want to see what the limmit on the stock is..

now the copper: http://www.importperformanceparts.net/
$88 to $120 from .031 to .125
copper gaskets are stackable...

on the other car i boosted i pulled 108.9hp per liter (2.3l)
that probably dont sound like much but when the stock hp is only 88 you'll see the big picture..

Accordtheory
11-12-2004, 05:38 PM
that was the thought....high compression low boost..
say you had a engine that had 8.5:1 comp. and runs 14psi of boost making say 250 hp. actual compression will be about 22:1 under boost..

now the same engine with 10:1 comp. running 9psi making the same 250 hp.with the same actual 22:1 comp. under boost...
you make the compressor more efficiant...not to mention the extra tourque when not under boost...

(those numbers are hypothetical)
to me this makes sense but if you have a diffrent opinion i want to hear it...


I have a slightly different opinion. Where do you get your numbers?? Atmosperic press is 14.7psi at sea level. Take a hypothetical engine with 8.5:1 dynamic compression, assuming 100% VE, running no boost at sea level. Running another 14.7 pounds will theoretically give you a "dynamic" compression of 17:1, assuming a doubling of your VE. Where do you come up with 22:1? And my way of looking at it doesn't exactly correspond with reality either, as the air is already partially compressed as it enters the cylinders..

Think about this scenario: 2 engines, one N/A with a displacement of 4 litres, and another boosted one bar with a displacement of 2 litres. Both engines have the same compressed chamber volume, in other words, the same static compression ratio. So both engines are taking approx the same amount of air and compressing it into the same volume, just 2 different ways. However, if the charge air is at the same temp as the N/A engine's intake air, the forced induction engine does not actually have the equivalent of double the N/A engines dynamic compression, (at least in one way of looking at it) because part of the heat of compression was taken out by the intercooler.

Intercooling has the ability then to increase the total VE of an engine, but damn, then are you looing at the dynamic compression as a function of mass vs compressed chamber volume..instead of initial volume vs compressed volume..whoa ok never mind I am making myself dizzy. What I am really trying to say is that shit is too complex, there are too many variables that go into to just look at it in those terms. I agree in general that a higher static CR engine will give you better response, and have a lower bsfc, but you probably still could run like 20psi with 10:1 if you have good enough intercooling and run rich enough, and take out enough timing. If you want to read some interesting articles about this shit, I know a good site, endynracingengines.com. L. W. runs 27lbs on his raised deck destroked d16z6 with 11.2:1 static compression. 1.55L, almost 500hp.

89T
11-18-2004, 08:02 PM
like i said those numbers are hypothetical....
here is a good site for you... http://www.turbofast.com.au/TFcompB.html or http://www.turbofast.com.au/javacalc.html
the #'s werent quite as dramatic as i posted....

I wasn't trying to do a write up or anything...

I was looking at a honda builders hand book by cartec they did a comparison on a civic...
8.5 vs 10.5...the 10.5 had better #'s on hp and tq..the only real differance was in cfm...the 8.5 had a slite advantage.

all i was saying was you can possibly make a turbo set up more efficant.

system-f
03-01-2005, 08:09 AM
that was the thought....high compression low boost..
say you had a engine that had 8.5:1 comp. and runs 14psi of boost making say 250 hp. actual compression will be about 22:1 under boost..

now the same engine with 10:1 comp. running 9psi making the same 250 hp.with the same actual 22:1 comp. under boost...
you make the compressor more efficiant...not to mention the extra tourque when not under boost...

(those numbers are hypothetical)
to me this makes sense but if you have a diffrent opinion i want to hear it.....


more compression doesn't get more oxygen in the engine to be burnt, more boost does. this is the big difference....now which provides more power? more O2 or less O2, but more highly charged ie. compressed more? As far as more torque off boost, just make sure you stay on boost :hs:

89T
03-27-2005, 07:39 AM
i agree, but when you are running a t3/t4 hybrid 62-1 with a stage 3 turbine it is a little harder to spool..especially when you don't belive in nitrous, and still running and automatic.

the car is alittle slow off the line but when she comes under boost she pulls pretty hard.(i also have a full interior and a big ass box with 4 orion 10's)
Thats why the high comp. pistons..

i am still playing with the fuel so i can run more than 10 psi.

dews89blkaccord
03-27-2005, 07:11 PM
i agree, but when you are running a t3/t4 hybrid 62-1 with a stage 3 turbine it is a little harder to spool..especially when you don't belive in nitrous, and still running and automatic.

the car is alittle slow off the line but when she comes under boost she pulls pretty hard.(i also have a full interior and a big ass box with 4 orion 10's)
Thats why the high comp. pistons..

i am still playing with the fuel so i can run more than 10 psi.

What rods are you running?

89T
03-30-2005, 04:34 PM
eagle H-beams

Slipknotcraig133
05-09-2005, 09:41 PM
So for rods all i would need to do is get a set of eagles or which ever brand i choose for a teg ls and get the small end milled to 21 millimeter. And then when i order the pistons say which compression i want, bore, and wrist pin size. I am hoping to get this done soon i have another motor that i would like to build.

FyreDaug
06-12-2005, 12:03 PM
Has the price changed at all? Wiseco quoted me 780 cdn

military mase
06-12-2005, 04:19 PM
I got mine 2 months ago and they cost me about 380 bucks. The work is real nice and clean. Ron at Diamondracing is a good guy to work with when tring to figure out what you want.

bobafett
08-01-2005, 08:34 AM
what was the turnaround time for you getting your pistons? i may be in the market!

87preludeA20A3
03-04-2006, 03:28 PM
Does anyone know the part numbers for these or even if it ever happened... Get back i'm in need of forged pistons...

bobafett
03-04-2006, 03:48 PM
call them up and tell them chris and elijah just ordered pistons within the last couple months.... they DO still make them, but they are custom, but call them up www.diamondracing.net and ask for eric or ron tey are super nice guys. :)

btw these are not cheap! i paid over 600 for my piston/ring setup

AccordEpicenter
03-04-2006, 04:57 PM
i saw somebody had venolia forged pistons and they cost like $475... you guys might wanna look into that (venolia is a reputable company like diamond/wiseco/JE etc)

military mase
03-05-2006, 05:30 AM
If you want to get the right setup just mention my job # 20809(brian mason)which is set for compresion 9.4:1. when i asked for seans setup he didn't have the locking ring or the grooves plus no oil rings. I had to go back and forth to get it right but it was worth it. I really don't like the lady reseptionist but Ron is understanding and he's the man.This job # is setup for the Eagle H-beam rods. To make sure just ask them about the pins size. Damm bobafett!! why the high charge price for diamond. Mine were right about 380 bucks.

bobafett
03-05-2006, 10:41 AM
not sure... did you go with .050? they changed a lot of stuff on mine and i know i ended up bitching about the rings and getting different ones that were a LOT better. but i thought they were supposed to be cheaper.

either way, if its cheaper now for you guys then thats great! maybe more people will start doing real engine builds with a20's!

87preludeA20A3
03-05-2006, 11:14 AM
Ok that is cool... but what i still havent read about and got a good answer is the stock rod pin size... For my first build i just want to use the stock rods... Is it 21mm or 19mm those are both what i hear... and my compression is for turbo so maybe like the stock 9.4:1 will work...

bobafett
03-05-2006, 12:07 PM
but you cannot use LS rods with modification if you do not bump up to a piston with 21mm pin diameter

AccordEpicenter
03-05-2006, 12:18 PM
so mase you got .030 overbore or stock or what? 21mm wrist pins and rings for about 380? Stock C/R or bumped C/R? 9.4:1 sounds fine. What kind of rings?

87preludeA20A3
03-05-2006, 12:28 PM
What year Ls's are these rods from...? If that is a stupid question just hit me...lol Oh and when you say LS you do mean integra right...?

AccordEpicenter
03-05-2006, 01:33 PM
b18a/b rods kid

military mase
03-05-2006, 03:11 PM
i think it is .030 over. I have 21mm wrist pins and i'm sure 9.4:1 is stock but it's good for my turbo application. i think sean had a diffrent setup so i had lots of problems getting everything right but like i said just use my job # as above in my last post. bobafett what ring did you end up getting?? I just got the moly rings

bobafett
05-27-2006, 10:32 AM
Things to keep in mind about my next post:

I have .050 overbore so the bore numbers ARE NOT STOCK
I have custom copper Cometic head gasket, so the gasket number ARE NOT STOCK
My block has been decked so the number may not be accurate.
The head was probably shaved just to clean it up, that may effect the numbers.
I am not using stock pistons, so some of the numbers are things that WE CHOSE. :D
I am using eagle H-Beam rods from a non-vtec B18A/B (LS Integra)

All things considered this is probably really useful for those of you who are planning on boring/building. but do keep in mind these numbers are for my unique setup. feel free to use this info how you will, but don't come blaming me if you give people the wrong numbers and your shit doesn't work. ;-)

-Chris

bobafett
05-27-2006, 11:26 AM
Custom Piston Specs: Job # 22507
----------------------------------------
Bore: 3.307" (remember, this is +.050 overbore)
Compression Height: 1.167
Effective Volume: -11.9
Intake Valve Depth: .125
Exhaust Valve Depth: .077
----------------------------------------
Top Ring: 1.2M
2nd Ring: 1.2M
Oil Ring: 2.8M
----------------------------------------
Lock Ring Decription: SPIROLOX DBL
Lock Ring Part Number: #01-5000
Wrist Pin Diameter: .827"
Wrist Pin Length: 2.500"
----------------------------------------
Piston Weight: 328 Grams
----------------------------------------
Note: Install these pistons with .0040 clearance measured 90 degrees to the pin hole @ .850"

----------------------------------------
----------------------------------------
----------------------------------------
Custom Piston Information: (These are the numbers that were sent to Diamond for them to make my pistons)
----------------------------------------
Finished Bore Size: 3.307" (big)
Stroke: 3.583"
Rod Length: 5.394"
Compression Distance: 1.167"
Block Deck Height: 8.352"
Desired Piston to Deck: 0
Piston Type: Dish
Ring Groove Info:
Top: 1.2mm
2nd: 1.2mm
Oil: 2.8mm
Radial Widths:
Top: .125"
2nd: .144"
Oil: .105"
Support Rail: Yes - 019012276
Rings With Order: Yes
Part Number: CR-3794 (STD)
----------------------------------------
Wrist Pin Info:
Diameter: .827"
Length: 2.500"
Pins With Order: 4130 (std)
Wall Thickness of Pin: .145
----------------------------------------
Pin Lock Type:
Double Spiral: .042"
----------------------------------------
Other Order Info:
Quantity: 4
Engine Type: Honda
Application: Street/Strip
Desired Compression Ratio: 8.5:1
Cylinder Head: 12v A20A
Casting #: PJ0 / HF7
Chamber Volume: 47.6cc
Comp. Gasket: .050"
Gasket Bore Dia.: 3.340"
Known Gasket Volume: 7.1cc
Rod Info:
Material: Steel
Small End Width: .785"
Thickness Above Pin: .203"
Piston Material: 2618
Skirt Shape: Ribbed Side Relief
-----------------------------------------
Misc Engine Information:
Approx Engine Only HP: 150
Combined HP: 350
Power Adder Information:
Type: Turbo
Pressure Max: 20 psi
Fuel Type: Gasoline
Octane Rating: 91 Minimum
Notes: .180 Crown Min. Brushed Rod.
-----------------------------------------
-----------------------------------------
Shall I continue?
-----------------------------------------
-----------------------------------------
Compression Ratio Calculator Results:
Number of Cylinders: 4
Bore: 3.3070"
Stroke: 3.5830"
Rod Length: 5.3940"
Gasket Bore: 3.340"
Comp. Gasket: .050"
Block Deck Height: 8.3520"
Top Ring Down: 0.210" ------ 20PSI Boost
Chamber Volume: 47.6
Dome(-) Dish(+): 12.00"
Piston / Deck: 0.000"
Calculated Values:
Total Volume: 571.78
Cylinder Volume: 504.32
Clearance Volume: 67.45
Gasket Volume: 7.18
Top Ring Volume: 0.68
Deck Volume: 0.00
Piston Top Land: 3.269
1/2 Stroke: 1.792
Comp Height: 1.167
Cubic Inches (lol): 123.10
Compression Ratio: 8.48:1
-----------------------------------------
-----------------------------------------
Another page of crap I have from them:
Base Engine Inputs:
Bore: 3.3073"
Stroke: 3.583"
Cylinders: 4
Rod Length: 5.394"
Deck Height: 8.3582"

Chamber / Piston Inputs:
Chamber CC's In Head: 47.6
Piston Design: Flat Top w/valve relief (i have dished pistons, they probably don't need this for their calculations to work)
Valve Reliefs: 12cc's
Gasket Thickness: .050"
Gasket Bore Diameter: 3.340"
Deck Height Clearance: 0.00"
Piston Ring Depth: 0.21"
Piston Top OD: 3.236"
Compression Height: 1.173"

Calculated Results:
Cylinder Size: 30.78 cubic inches / 504.5 cc's / 0.505 liters
Engine Size: 123.12 cubic inches / 2018 cc's / 2.018 liters
Chamber Size: 4.15 cubic inches / 68 cc's / 0.068 liters
Compression Ratio: 8:41
Bore/Stroke Ratio: .923
Rod/Stroke Ratio: 1.505

Volume Contributions:
Head Chamber: 2.904 cubic inches / 47.6 cc's / 70% of total
Gasket: 0.438 cubic inches / 7.18 cc's / 10.6% of total
Deck: 0 / 0 / 0
Valve Reliefs: 0.732 cubic inches / 12 cc's / 17.6% of total
Piston OD: 0.077 cubic inches / 1.26 cc's / 1.9% of total

Legend_master
05-27-2006, 11:52 AM
you fucking rock dude, that is awsome.

87preludeA20A3
05-27-2006, 12:29 PM
those are some sick specs... i might just use that.... thanks

MessyHonda
05-27-2006, 12:54 PM
yeah those specs should be on a sticky since it might help out other 3geez members...i like the way you build your motor.

bobafett
05-28-2006, 09:18 AM
i would have to ask the shop. i havent compared any of these numbers to stock numbers, aside from the ones that i KNOW are different, like bore and gasket bore/volume. i assume the numbers on the head were after porting, since they did headwork way before they ever bored the motor. but i may call them up and ask.

it would be a reaaaally smart idea to nail down as many of these figures for a stock motor as possible, just to make sure on some of the differences.

also I can probably upload the EXCEL application they sent me for tweaking with shit. :D

here you go, have fun guys: http://a20turbo.com/3geez/CompRatioChart.xls

Legend_master
09-08-2006, 05:45 PM
Hey guys I have been working on a turbo a20 project as a DD and in my search I came across RSmachine on H-T. They make custom pistons and would be willing to make them for us. We could jsut use 83mm b18 rods and turbo pistons ($500.00 to purchase the pistons and have them remove all the valve relief from the piston) for the turbo application. He also said he can make High Compression pistons for us to, but that will require a set of rod, pistons, and a head (hitch I have all). The price for a group buy is

$595.00 a set for 5 sets
$550.00 a set for 10 sets

I asked him if we could mix and match turbo and NA, but I have not received any answers yet. I also asked him if he could join the board and give all you guys answers.

Here is his thread on H-T (http://honda-tech.com/zerothread?id=1569878)

Listen2myBASS
09-08-2006, 05:49 PM
dam man, i dont know what to do know...turbo or n/a...i would need to come up with that money 1st...put me as a big maybe...

gfrg88
09-08-2006, 05:55 PM
sounds like a deal to me, put me down for some turbo pistons, or should i do high CR with turbo :D

ghettogeddy
09-08-2006, 05:56 PM
man i wish it was jan aready my tax money is already burning a hole in my pocket id love a set for a n/a build but ill have to wait

2ndGenGuy
09-08-2006, 05:58 PM
I'm interested...

But it depends on the timeframe for when I need to pay, and when shipping occours. Then I could say for sure if I'm in or not.

AccordEpicenter
09-08-2006, 06:27 PM
diamond pistons were cheaper and they are gorgeous

gfrg88
09-08-2006, 07:19 PM
so whats the difference between these and Diamond's pistons??

Legend_master
09-08-2006, 08:45 PM
ok I talked to him, he said mix and match is not possible. That would cost more money, so if we need to figure out what kind we want and if they are better then diamond or not. What material are the diamond psitons made of? and are they better for Turbo or not?

ilikevtecs
09-08-2006, 09:08 PM
whats the quality this guy puts into his work, is he local where your at?

MessyHonda
09-08-2006, 09:52 PM
man i wish it was jan aready my tax money is already burning a hole in my pocket id love a set for a n/a build but ill have to wait

lol same here...cant wait for tax money....i might convert it to OBD 1...one step at a time tho.

2ndGenGuy
09-08-2006, 10:22 PM
I am looking for high-compression pistons. It sounds like you guys want the low CR for turbo. If we go that route, I'll probably be out. Yeah and how reputable is the machinist? Also, if we did go high compression, I would want to go pretty high too... I don't know how many people are going to want to go the same route as me...

bobafett
09-09-2006, 06:20 AM
dude i paid 565 for my diamond racing pistons, totally one off custom, with BADASS rings. :)

www.diamondracing.net

you could probably get them cheaper, but i got a really nice setup. i lowered the ring positions etc for stronger ringlands, and the machine shop suggested some other modifications too i think.

call them up and ask for eric. :)

bobafett
09-09-2006, 06:25 AM
http://a20turbo.com/features/chris/interior/IMG_0422.jpg

mmm mmm dish. we had to hammer them in there cause the rings were pretty tight. :)

1.2 1.2 2.8 rings, just like the badass boosted cars use! i had to go with .050 bore to use these rings, cuase they didnt have them available in .040 overbore, which is the minimum that my motor needed. i imagine they have the nice total seal rings in sizes that are closer to normal honda pistons. :)


Check out there order form to get an idea of what you will need to know before hand:
http://www.diamondracing.net/orderform.pdf

they can be made from different materials depending on your needs. sean went with diamond way back in the day too, he actually had some deals in the low 400 dollar range, but when i called them they didnt have any of those pistons still available at those prices.

Legend_master
09-09-2006, 06:45 AM
Holy shit, those pistons look beautifull. Are you using b18 rods or a20 rods?

EDIT: NM i just read your site. So did the psitons bolt onto the rod with no problems or did they have to be modified?

RamThis
09-09-2006, 11:32 AM
Damn, those prices are nearly what I paid for EIGHT slugs in my Mopar Magnum 360!!!!

I have Ross Racing Pistons Forged 12.3:1 CR in my 360, .030 over, with Speed-Pro Moly File Fit rings, Custom cut for my engine, all together was around $700.

I can't see paying nearly $600 for half the stuff in a Honda engine....

bobafett
09-09-2006, 04:29 PM
the pistons and rods bolted right together. i bought eagle h-beam rods for an LS intregra (b18)...

the trick is, when u get your pistons made, get them made with a 21mm wrist pin, NOT the stock 19/20mm pin.

as long as you have the 21mm pin you are good to go, cause the dimensions of the rods are perfectly compatible. :D

Legend_master
09-09-2006, 04:42 PM
the pistons and rods bolted right together. i bought eagle h-beam rods for an LS intregra (b18)...
the trick is, when u get your pistons made, get them made with a 21mm wrist pin, NOT the stock 19/20mm pin.
as long as you have the 21mm pin you are good to go, cause the dimensions of the rods are perfectly compatible. :D


Awsome dude, Great info.

EricW
09-09-2006, 04:45 PM
I'm going turbo also, so you've got my attention although the diamond pistons sound quite nice.

Legend_master
09-09-2006, 04:47 PM
I'm going turbo also, so you've got my attention although the diamond pistons sound quite nice.


I might just turn this into a diamond group buy thread. I will need to talk to them first.

bobafett
09-09-2006, 04:49 PM
yeah call them up and ask for eric. all the people at diamond were super friendly. the people at cometic are great too, just throwing that out there since it seems like we may have some more boosting brothers soon! :D

diamond made certain suggestions for me, such as going with a ring that wasnt gapless. they say that yes, it might be worth 5whp, but i would have to service the engine every 10,000-15,000 miles. so i opted for just normal chromoly total seal ring package, which will wear normally, so i wont have to tear apart my motor every few months. :)

bobafett
09-09-2006, 04:59 PM
http://www.3geez.com/forum/showthread.php?t=1243
http://a20turbo.com/3geez/CompRatioChart.xls

Job # 22507

u can probably use a lot of these specs, but you will not want the bore. i can check with my machine shop to see if every other number would work with your a20's or if there was a reason for doing the numbers just for my car.

Legend_master
09-09-2006, 05:05 PM
Now we need to find a steady way to get Turbo manifolds. Turboing the a20 should be simple for people that have good knowledge of cars. My setup will be simple a20 block, eagle(or something similer) rods, 83MM pistons, OBD1 conversion. I plan to keep AC, CC, and remove PS. There is a shop around here called turbo boss that i am going to speak with. I can't wait and thanks for all the info bobafett.

AccordEpicenter
09-09-2006, 05:33 PM
hmm ill find my job number. I talked to Ron at diamondracing, hes awesome! I used B18B rods and had the pistons made with a 21mm wrist pin so the rods were an exact match, i used crower I beam rods. My pistons were 9:1 .030 overbore pistons with full floating pins, they were absolutely fabulous looking! I also went with the tool steel top ring (boost tends to ruin the moly coating on moly rings)

bobafett
09-10-2006, 07:03 AM
yeah if you guys just use accord epicenters info, and choose the overbore diameter you should be safe!

i agree, all we need now is a good source on a few different manifolds. i would definetly throw some cash towards the f22parts.com guy, but i didnt really get the vibe that he was actually planning on building anything. but it was closer than we have been before.

gfrg88
09-11-2006, 10:43 AM
yeah if you guys just use accord epicenters info, and choose the overbore diameter you should be safe!
i agree, all we need now is a good source on a few different manifolds. i would definetly throw some cash towards the f22parts.com guy, but i didnt really get the vibe that he was actually planning on building anything. but it was closer than we have been before.
i talked to the guy and he said all he needs is a gasket so he can make them. but everyone just kinda backed off :thumbdn: oh well atleast i got the guy to come one here and talk to you guys :hs:

rjudgey
09-11-2006, 10:43 AM
Yo bobafett the springs in your signature picture are they doubles all round? If so what did you get them from?? Or was it something i recommended?
As for pistons i'd really like a flat top set with only three valve reliefs and the 21mm full floating titanium pin do you think diamond would do that?

bobafett
09-11-2006, 12:16 PM
the springs were purchased from another member who unfortunately doesn't know anything about them (and cant even remember where he bought them :( ) i wish i could give you more info cause i have a super nice valve train, but no idea how to duplicate it. but yes they are double springs all aroung. this setup (with the Ti retainers etc) is supposed to be good to 8500rpm. :) not that my bottom end would like that.

diamond 'might' be able to. but you would have to be specific about valve location. they are pretty good to work with so its worth giving them a call.

as for the turbo manifolds, i am probably just going to have a log made locally since i have a good portion of the materials, but i will be looking into ram horn style manifold as well for the future... and his f22 equal length manifolds look pretty impressive, so i think he would be a great person to go through.

AccordEpicenter
09-20-2006, 12:58 PM
si industries made all the stuff on my head, titanium retainers, race valves, dual springs all the way around, serious hardcore race stuff

Legend_master
09-20-2006, 01:17 PM
si industries made all the stuff on my head, titanium retainers, race valves, dual springs all the way around, serious hardcore race stuff


How much did that run you. I have been thinking of going through paeco

EricW
09-20-2006, 01:21 PM
si industries made all the stuff on my head, titanium retainers, race valves, dual springs all the way around, serious hardcore race stuff

Is this the company your talking about? http://www.sivalves.com/index.htm

You wouldn't happen to have an order number or something that could be used for them to refer to would you?

AccordEpicenter
09-21-2006, 05:40 PM
yes i believe that is them. Sry, i have no ordering or part number info on anything i have (came on a race head that was already put together). For Diamond Racing, My job number is 24582 and it cost me $490.56 with rings and wrist pins, shipping was an additional $16 but they came in a nice big box and packaged well. Basically they are .030" over stock bore pistons (stock compression or very close) with tool steel top rings and regular second and oil rings, and 21mm full floating wrist pins.

Tomisimo
09-29-2006, 09:00 PM
dude i paid 565 for my diamond racing pistons, totally one off custom, with BADASS rings

Do you stil have the "order form"? if you ordered custoum...
Can you help me up?

azazel_18_2
10-31-2006, 01:31 PM
There are forged pistons everywhere for the b18c1 with an 83mm bore so you would have to have your engine bored a little bit. Use a set of b18c1 pistons on a set of b18 rods and it should work?? I don't see why not then again the best way to tell is have a piston in each hand.

9:1 Comp in B18c1

http://cgi.ebay.com/ebaymotors/CP-Pistons-83mm-9-1-Acura-Integra-B18C1-B18-GSR-VTEC_W0QQitemZ8041508857QQihZ019QQcategoryZ33623QQ rdZ1QQssPageNameZWD1VQQcmdZViewItem

11:1 Comp in b18c1

http://cgi.ebay.com/ebaymotors/CP-Pistons-83mm-11-1-Acura-Integra-B18C1-B18-GSR-VTEC_W0QQitemZ8041509711QQihZ019QQcategoryZ33623QQ rdZ1QQssPageNameZWD1VQQcmdZViewItem

Am I wrong? I know you would also have to use b18c1 rings but shouldn't this work? Just trying to make things a little easier on us.

bobafett
10-31-2006, 01:36 PM
it would depend on the distance from the center of the pin hole to the face of the piston, but it might be possible. although for that price you could get totally custom pistons from diamond racing, and they would work with you to build EXACTLY what you need. :)

you might call them up and ask how similar a20 pistons are to b18 pistons. we know the rods are pretty much compatible.

azazel_18_2
10-31-2006, 01:48 PM
JE Pistons are about $400. What these are is B18C1 bored .080. These pistons are redily available through that company and JE both in low and high compression. Does anybody out there have a B18C1 Piston? We need to know how far up the pin is in the piston. I put a set of diamond pistons in my car not to long ago BEFORE i knew I could put forged b18 rods in her and paid an arm and a leg for forged a20a3 pistons. I just need the dimensions on a b18c1 piston.

ChaseR
10-31-2006, 01:49 PM
Yeah plus the valve clearance is totally different on the tops of those, thats for a 16 valve, where we have that one Huge exhuast valve

azazel_18_2
10-31-2006, 02:23 PM
Have you seen the top of your OEM pistons? They have a place for a fourth valve. The b18C1 has a stroke of 3.433 and the A20A3 has a 3.582 stroke. I really need the dimensions of a b18c1 piston

Legend_master
10-31-2006, 02:48 PM
Have you seen the top of your OEM pistons? They have a place for a fourth valve. The b18C1 has a stroke of 3.433 and the A20A3 has a 3.582 stroke. I really need the dimensions of a b18c1 piston


This is true, but I believe the valves are closer together on the b18 heads. This would lead to the valves tapping the pistons.

AccordB20A
10-31-2006, 02:57 PM
you mean the pistons tapping the valves ahaha hey i heard b16 pistons fit a b20a and up the compression lots is this correcT?

azazel_18_2
10-31-2006, 03:15 PM
I may just buy a cheap piston from Bumper to Bumper and compare it to my old A20A3 piston. I think they told me like $21. Worth a shot I guess.

guaynabo89
10-31-2006, 04:18 PM
send a piston in and ave them made. no hassles and you get exactly what you need fo the same price

AccordEpicenter
11-01-2006, 12:56 PM
my forged diamond pistons cost like $500 with rings. Thats about what it costs for good B series pistons, maybe slightly more.

bobafett
11-01-2006, 01:10 PM
adam had pics of (way too small) stock b16 pistons in an a20. height SEEMED to be ok, but i dont think he ever put a head on the block and tested clearances. :)

if this is the case then we could possibly get package deals on pistons/rods. or maybe open up some more used aftermarket. :) either way it can't hurt. :)

snoopyloopy
11-01-2006, 02:24 PM
adam had pics of (way too small) stock b16 pistons in an a20. height SEEMED to be ok, but i dont think he ever put a head on the block and tested clearances. :)

if this is the case then we could possibly get package deals on pistons/rods. or maybe open up some more used aftermarket. :) either way it can't hurt. :)
and he said the reason the pistons were too small was because he was test-fitting stock pistons in his bored block. in a stock block, they should work out better. and they were b18 pistons, if that makes any difference. here's the thread:
http://3geez.com/forum/showthread.php?t=52447
http://i34.photobucket.com/albums/d144/b20accord/DSCF0362.jpg
http://i34.photobucket.com/albums/d144/b20accord/DSCF0361.jpg

bobafett
11-01-2006, 02:44 PM
basically we could use any series pistons as long as the diameters were between 82.7mm (stock) and 84mm (.050" overbore)

assuming the height is ok, and there is not any valve interference. :)

rjudgey
11-02-2006, 06:33 AM
Your best bet would be to order them at 83 or 83.5mm with blank crowns and have the valve reliefs done at a machine shop and have only three put in instead of 4. The stock pistons valve reliefs are way off on both inlet and exhuast, also the depth of the dish looks bigger too so would lower the CR ratio. All that grief might as well have them custom made.

smufguy
11-09-2006, 12:14 PM
the quench area depends on the type of combustion chamber you have. not always corresponding to the number of valves per cylinder. (CORRECTED: The quench area i was talking about was for the Head, the valve relief should normally correspond to the number and placement of the exhaust and intake valves.) Stock overbore is set to 0.03 which lets u run a 82.99 mm piston, 83.00mm piston would be acceptable.

ZackieDarko
02-25-2007, 02:22 PM
so if im reading this right

get an a20 block punched to 84mm
get a set of ls rods/blank flat top 84mm pistons
take said pistons to a machine shop and have our valve reliefs cut in and it would work

right?

rjudgey
02-25-2007, 02:33 PM
Yes but not 84mm bore thats pushing it a little and you'd need a custom head gasket. Stick with the 83mm pistons and have the bores re done to suit the piston makers clearance specs. 83.5mm would be the absolute max you could have with a Felpro or Ajusa Head Gasket anything bigger looking at custom right Bobafet? what gasket did you use on your 84mm pistons? Oh also were looking at the LS 83mm pistons because they seem readily available from the manufacturer.

bobafett
02-25-2007, 03:39 PM
i used a custom cometic head gasket. cost wasn't bad. $65 shipped for a .050 (crushed) gasket. i just sent them a stock one and they sent the stock gasket and the copper gasket back to me. :)

was pretty simple really... but its trickier to get a copper gasket to seal. takes a little bit more effort, but it's doable. :D

bobafett
02-25-2007, 03:42 PM
so if im reading this right
get an a20 block punched to 84mm
get a set of ls rods/blank flat top 84mm pistons
take said pistons to a machine shop and have our valve reliefs cut in and it would work
right?

84mm IS a bit extreme. i went with this (taking diamond racing's suggestions) in order to allow myself to use a really badass set of chrome steel rings. i could have gone 85 mm, but i didnt want to risk it, and the block had to have at least 83.5mm to get rid of the scarring that was there from before.

i would suggest not boring any more than you have to. order some custom pistons from diamond racing, and then buy a nice set of off the shelf LS rods. :) when you get the pistons made make sure they have 21mm wrist pin diameter, and you are set.

ZackieDarko
02-25-2007, 05:38 PM
why get custom pistsons if you can just get your block bored out a smidge and use stock oem rods/blank top pistons with our valve refliefs cut in from an integra?

or do you think it really would be cheaper to drop $500 on 21mm wrist pin pistons?

bobafett
02-25-2007, 06:35 PM
what honda motor has pistons that will be between 82.7mm and 84mm?
http://www.teirney.net/civic/B16AReference.htm
http://en.wikipedia.org/wiki/Honda_B_engine#B20

dont know if these are accurate, but it shows them as significantly smaller bore than what we would need at a bare minimum.

what oem pistons are you looking at buying? if you are planning a boosted application more than likely oem pistons won't cut it, which is the reason to go aftermarket in the first place. unless u can find a stock 83-84mm honda piston, with the same pin height, and approriate ring location, which will generate a compression ratio you actually desire (we don't know the affect of a B series piston on our CR), i would seriously just suggest a custom piston setup. it will be cheaper in the longrun imho

B18 - 81.0 x 87.2mm
B16 - 81.0mm x 77.4mm
B20 - 84.0mm x 89mm

EDIT: so its possible that an oem size b20 piston will work assuming its other characteristics lend itself to boost. :D

rjudgey
02-26-2007, 02:49 AM
You can't get oem pistons with a blank crown they ahve to be aftermarket but you can get JE and Wiseco pistons for B18 that are 83mm and with a quick word to the manufacturer should be able to supply with blank crown but technically would be a custom piston. It's easier for the manufacturer they can use the same pattern as what they have but just not bother machining the crown.

SQ is the SQUAD
02-26-2007, 07:26 AM
if i have time before our builds are started ill have my buddy measure his stock b18c pistons/rods in our blocks

smufguy
02-26-2007, 04:28 PM
You have to use the same motor combo as in B18 rods+pistons or A20 rods+pistons. The reason is, sometimes the bearings are in the piston and sometimes they are in the rods and sometimes both. you dont want to mix and match because once you order your parts, you dont want to end up with parts where there is no bearings for either.

rjudgey
03-04-2007, 02:41 AM
If i remember correctly the ACL bearings are listed for B18, B16, B17, and ET, ET1, ET2, A18, A20 so they should all be the same. I'll try and double check next tiem i'm in my workshop.

MessyHonda
03-04-2007, 02:51 AM
If i remember correctly the ACL bearings are listed for B18, B16, B17, and ET, ET1, ET2, A18, A20 so they should all be the same. I'll try and double check next tiem i'm in my workshop.


well we have a member that had A20 bearings...here is the link

http://www.3geez.com/forum/showthread.php?t=56757

hondaman1986
09-07-2007, 06:00 PM
does anyone know if b18c1 83mm je pistons would work with b18a/b rods on our blocks? the only thing that could mess this up is the compression height which the b18c is i think .010'' higher at 1.176 how bad could this screw up my plans??? btw the je part # is 242879

MessyHonda
09-08-2007, 12:08 AM
does anyone know if b18c1 83mm je pistons would work with b18a/b rods on our blocks? the only thing that could mess this up is the compression height which the b18c is i think .010'' higher at 1.176 how bad could this screw up my plans??? btw the je part # is 242879



i dont think any one had ran b-series pistons....and the pistons have to be from a b18a/non vtec engine. but the pistons and rods will fit our crank. only a machine shop would tell.

bobafett
09-08-2007, 08:07 AM
adam put in some super small b16 pistons and it appeared to fit, but we were not sure about the height and we couldnt run them, because they were far far too small. nobody has actually taken the time to bolt a head on and see... however, for the cost of B-pistons (new ones anyway) you might as well get custom pistons made. :)

hondaman1986
09-08-2007, 12:47 PM
adam put in some super small b16 pistons and it appeared to fit, but we were not sure about the height and we couldnt run them, because they were far far too small. nobody has actually taken the time to bolt a head on and see... however, for the cost of B-pistons (new ones anyway) you might as well get custom pistons made. :)

ok jw thanks boba

edit: boba how much did your pistons cost?

bobafett
09-08-2007, 07:22 PM
i think it was about $550 from diamond racing with pins, rings, locks, etc.... everything :)
I believe I dealt with eric or ron.. they were both super helpful if I get their names right both of those guys would be good to help you out!

hondaman1986
09-08-2007, 09:09 PM
i think it was about $550 from diamond racing with pins, rings, locks, etc.... everything :)
I believe I dealt with eric or ron.. they were both super helpful if I get their names right both of those guys would be good to help you out!

awesome!!! ill hit tem up and see what they will give me on a price. ":toilet:goes my money lol"

MessyHonda
09-08-2007, 09:28 PM
i think it was about $550 from diamond racing with pins, rings, locks, etc.... everything :)
I believe I dealt with eric or ron.. they were both super helpful if I get their names right both of those guys would be good to help you out!



what kind of rods are you using?

bobafett
09-09-2007, 08:43 AM
eagle h-beam rods for an ls integra.

something like this:
http://cgi.ebay.com/ebaymotors/Honda-Acura-Integra-Eagle-H-Beam-Rods-B18A-B-ARP_W0QQitemZ200150752251QQihZ010QQcategoryZ33623Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem

hondaman1986
09-09-2007, 02:37 PM
eagle h-beam rods for an ls integra.

something like this:
http://cgi.ebay.com/ebaymotors/Honda-Acura-Integra-Eagle-H-Beam-Rods-B18A-B-ARP_W0QQitemZ200150752251QQihZ010QQcategoryZ33623Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem

how well did the whole thing turn out?

bobafett
09-09-2007, 04:30 PM
needs engine management at the moment. it runs, but not too well. its WAY too rich and throws EGR codes.

but if you look at the setup i am running its not suprising... these pistons and rods are definitely fine to run.

A20A1
02-03-2008, 02:11 PM
Custom Piston Specs: Job # 22507
----------------------------------------
Bore: 3.307" (remember, this is +.050 overbore)
Compression Height: 1.167
Effective Volume: -11.9
Intake Valve Depth: .125
Exhaust Valve Depth: .077
----------------------------------------
Top Ring: 1.2M
2nd Ring: 1.2M
Oil Ring: 2.8M
----------------------------------------
Lock Ring Decription: SPIROLOX DBL
Lock Ring Part Number: #01-5000
Wrist Pin Diameter: .827"
Wrist Pin Length: 2.500"
----------------------------------------
Piston Weight: 328 Grams
----------------------------------------
Note: Install these pistons with .0040 clearance measured 90 degrees to the pin hole @ .850"

----------------------------------------
----------------------------------------
----------------------------------------
Custom Piston Information: (These are the numbers that were sent to Diamond for them to make my pistons)
----------------------------------------
Finished Bore Size: 3.307" (big)
Stroke: 3.583"
Rod Length: 5.394"
Compression Distance: 1.167"
Block Deck Height: 8.352"
Desired Piston to Deck: 0
Piston Type: Dish
Ring Groove Info:
Top: 1.2mm
2nd: 1.2mm
Oil: 2.8mm
Radial Widths:
Top: .125"
2nd: .144"
Oil: .105"
Support Rail: Yes - 019012276
Rings With Order: Yes
Part Number: CR-3794 (STD)
----------------------------------------
Wrist Pin Info:
Diameter: .827"
Length: 2.500"
Pins With Order: 4130 (std)
Wall Thickness of Pin: .145
----------------------------------------
Pin Lock Type:
Double Spiral: .042"
----------------------------------------
Other Order Info:
Quantity: 4
Engine Type: Honda
Application: Street/Strip
Desired Compression Ratio: 8.5:1
Cylinder Head: 12v A20A
Casting #: PJ0 / HF7
Chamber Volume: 47.6cc
Comp. Gasket: .050"
Gasket Bore Dia.: 3.340"
Known Gasket Volume: 7.1cc
Rod Info:
Material: Steel
Small End Width: .785"
Thickness Above Pin: .203"
Piston Material: 2618
Skirt Shape: Ribbed Side Relief
-----------------------------------------
Misc Engine Information:
Approx Engine Only HP: 150
Combined HP: 350
Power Adder Information:
Type: Turbo
Pressure Max: 20 psi
Fuel Type: Gasoline
Octane Rating: 91 Minimum
Notes: .180 Crown Min. Brushed Rod.
-----------------------------------------
-----------------------------------------
Shall I continue?
-----------------------------------------
-----------------------------------------
Compression Ratio Calculator Results:
Number of Cylinders: 4
Bore: 3.3070"
Stroke: 3.5830"
Rod Length: 5.3940"
Gasket Bore: 3.340"
Comp. Gasket: .050"
Block Deck Height: 8.3520"
Top Ring Down: 0.210" ------ 20PSI Boost
Chamber Volume: 47.6
Dome(-) Dish(+): 12.00"
Piston / Deck: 0.000"
Calculated Values:
Total Volume: 571.78
Cylinder Volume: 504.32
Clearance Volume: 67.45
Gasket Volume: 7.18
Top Ring Volume: 0.68
Deck Volume: 0.00
Piston Top Land: 3.269
1/2 Stroke: 1.792
Comp Height: 1.167
Cubic Inches (lol): 123.10
Compression Ratio: 8.48:1
-----------------------------------------
-----------------------------------------
Another page of crap I have from them:
Base Engine Inputs:
Bore: 3.3073"
Stroke: 3.583"
Cylinders: 4
Rod Length: 5.394"
Deck Height: 8.3582"

Chamber / Piston Inputs:
Chamber CC's In Head: 47.6
Piston Design: Flat Top w/valve relief (i have dished pistons, they probably don't need this for their calculations to work)
Valve Reliefs: 12cc's
Gasket Thickness: .050"
Gasket Bore Diameter: 3.340"
Deck Height Clearance: 0.00"
Piston Ring Depth: 0.21"
Piston Top OD: 3.236"
Compression Height: 1.173"

Calculated Results:
Cylinder Size: 30.78 cubic inches / 504.5 cc's / 0.505 liters
Engine Size: 123.12 cubic inches / 2018 cc's / 2.018 liters
Chamber Size: 4.15 cubic inches / 68 cc's / 0.068 liters
Compression Ratio: 8:41
Bore/Stroke Ratio: .923
Rod/Stroke Ratio: 1.505

Volume Contributions:
Head Chamber: 2.904 cubic inches / 47.6 cc's / 70% of total
Gasket: 0.438 cubic inches / 7.18 cc's / 10.6% of total
Deck: 0 / 0 / 0
Valve Reliefs: 0.732 cubic inches / 12 cc's / 17.6% of total
Piston OD: 0.077 cubic inches / 1.26 cc's / 1.9% of total

so you have a 83.9978mm - 84mm bore? I thought somewhere else you said you had a 83.5mm bore. Maybe that was someone else.

bobafett
02-03-2008, 08:13 PM
84mm bore... :)

hondaman1986
02-04-2008, 02:59 AM
cant you just send in a stock piston and have them make a forged piston set off of it?

bobafett
02-04-2008, 08:05 AM
Yeah they will need a stock piston regardless of what you do. But since you are then getting a 'custom' piston it is worth it to do the little tweaks that make it better.

such as 21mm pin so you can take your pick of LS rods, changing the position of the rings (help prevent blowing up ringlands - not sure on the details of this one, but I know it happened on my set) etc etc...

But yes I'm sure they could just clone a stock piston, though I am not sure why you would want to do that.

Seriously I would just call them up and pick their brain, they are super helpful and will probably have ideas for you if you just ask them what are some of the common tweaks or upgrades.