93supercoupe

Sup honda-tech. i got my hands on some custom made arias pistons and im terrible with math, so i was wondering if one of you gurus can help me out real quick.

CTR block
LS crank
LS rods

CTR head, stock HG

Displacement: 111.95
Bore: 3.189
Stroke: 3.504
Rod Length: 5.430
Comp. Height: 1.153
Compression: 12.00


Pin Diameter: .827
Top Groove: .040
2nd Groove: .048
Oil Groove: .110
Piston Weight: 272.0


as you can see, its all in inches.

LMK if you need more info.

Thanks guys

cibao2ner

ctr block is the same as a gsr/itr block as far as deck height...the most important part is how many cc is the dome of the piston...

93supercoupe

5.3cc dome

93supercoupe

common fellers

DDTECH

LOL..go to zeal autoworks and enter in your info..

You'll be around 12.9CR roughly.. if you run a 3 layer HG.

93supercoupe

well the wrist pin height is not stock, and i cant find a calculator that has that option.

93supercoupe

I got 12.9 the first time- using the Zeal B series calc, which asks deck height. But no wrist pin location

then i got 10.3 w/o inputting the deck height or wrist pin location.

93supercoupe

and what does NaN mean in the compression value location?

93supercoupe

help

PyroProblem

If you look to the right of where you input your values, you'll see an option for "mm/in" highlighted in blue.
Click "in" for inches and then put your numbers in...
I get around 12ish to 1 with a 43cc head, .026" HG thickness, and nothing off the head or block...
(This is using the universal compression calculator)

93supercoupe

is compression height the same as wrist pin height?

00Red_SiR

No, but as long as you know your compression height and dome cc's, wrist pin height is irrelevant to the calculation.

93supercoupe

the way it was explained to me from arias is- for the pistons to hit the target 12-1CR, they were designed to be used with a LS crank and GSR rod (not possible).

So because the GSR rod length is longer, they moved the pin height in the piston.

So does it still make the pin hieght irrelevant?

GhostAccord

Compression height is the measurement from the center line of the wrist pin to the deck/face of the piston. So if you more the pin height it will change your compression height accordingly.



Compression height and dome CC is all you need.

Pin height and compression height go hand in hand. you can't have one without the other.... so if you have your compression height you basically know your wrist pin height/location

93supercoupe

got it.

So it really doesnt matter what the pin height its aslong as i know the dome cc and the compression hieght.

Is there anything else i need to take into consideration when calculating my cr?

GhostAccord

Have the head or block mating surfaces ever been machined?

93supercoupe

not to my knowledge, and im pretty sure the motor has never been apart