CA18 -> CA19

[DjLiquid]

I know this has been covered before but I have a specific question to ask. I don't know the exact diameter of the cylinders of the ca18 but I heard that we can't really bore out the block more than 1mm on each cylinder because the walls are very thin. With that being said. If I bore out the block 1mm on each cylinder, what will that make the overall total displacement and will I be safe to go with oversized rings boosting 1bar, or will you suggest a new set of pistons (oversized or non?)

please share your wealth of knowlegde with me. My engine is pulled for the duration of the winter so I can mod it =). If you have any other suggestions please let me know.

[Swedish Mike]

I know this has been covered before but I have a specific question to ask. I don't know the exact diameter of the cylinders of the ca18 but I heard that we can't really bore out the block more than 1mm on each cylinder because the walls are very thin. With that being said. If I bore out the block 1mm on each cylinder, what will that make the overall total displacement and will I be safe to go with oversized rings boosting 1bar, or will you suggest a new set of pistons (oversized or non?)

please share your wealth of knowlegde with me. My engine is pulled for the duration of the winter so I can mod it =). If you have any other suggestions please let me know.

You need 1 mm bigger pistons to match the cylinders, if I remember correctly you will get 1.9 litres from that mod.

Edit: 1852 cc if the stroke is 83.6 mm, I think that´s correct for the CA.

[float_6969]

Yes, 1mm is the limit. You can bore it more, but I wouldn't do it on a boosted motor. Maybe a high revving NA motor, you could go farther, but with boost, I wouldn't.

And as Mike posted, a 1mm overbore will put you at 1852cc, which rounds to a 1.9L

[DjLiquid]

any suggestions on a good set of pistons?I see a bunch online all the time but im kinda weary about purchasing $600 worth of goods online. Also, what about brand name? Who have you found to be the best?

[sideways danny]

1853cc

[themadscientist]

Overboring is not necessary. There are tons of high-power CAs running the stock bore.

[nocwage]

the gain is 0.04L

[float_6969]

CP makes CA pistons. You can get them from http://www.raceeng.com, but they only keep stock and .5mm diameter pistons on hand.

[Swedish Mike]

any suggestions on a good set of pistons?I see a bunch online all the time but im kinda weary about purchasing $600 worth of goods online. Also, what about brand name? Who have you found to be the best?

I´ve use 83 mm (or OD) Volvo pistons a few times. The S60R ones are crazy, 700 hp on a 5-cyl so far and probably good for 500 hp+ in a 4-cyl.Often cheap to buy as well, only one problem. You need rods with thick walls around the wrist pin and drill it up to 23 mm.

[pnblight]

1mm oversize is not a problem as the tomei ca20 kit runs 84mm pistons with 88mm stroke(1950cc) (std 83mm bore 83.6mm stroke)

And it's not the bore wall thickness that is the limiting factor but more the bore spacing, meaning there only a small amount of material between each bore which makes them prone to head gasket leaks etc. So you cant bore them out much because the bore spacing isn't there to accomodate it. The na ca20 motor ran a 84.5mm bore but i wouldn't think wise to go beyond this size on a heavily boosted motor.

pete