Diamond Pistons Specs

[AccordEpicenter]

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]

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]

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]

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]

but you cannot use LS rods with modification if you do not bump up to a piston with 21mm pin diameter

[AccordEpicenter]

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]

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]

b18a/b rods kid

[military mase]

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]

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.
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]

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

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Custom Piston Information: (These are the numbers that were sent to Diamond for them to make my pistons)
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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)
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Wrist Pin Info:
Diameter: .827"
Length: 2.500"
Pins With Order: 4130 (std)
Wall Thickness of Pin: .145
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Pin Lock Type:
Double Spiral: .042"
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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
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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.
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Shall I continue?
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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
-----------------------------------------
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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]

you fucking rock dude, that is awsome.

[87preludeA20A3]

those are some sick specs... i might just use that.... thanks

[MessyHonda]

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]

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.

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

[Legend_master]

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

[Listen2myBASS]

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]

sounds like a deal to me, put me down for some turbo pistons, or should i do high CR with turbo

[ghettogeddy]

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]

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]

diamond pistons were cheaper and they are gorgeous

[gfrg88]

so whats the difference between these and Diamond's pistons??

[Legend_master]

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]

whats the quality this guy puts into his work, is he local where your at?

[MessyHonda]

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.