blackEK2.0

Ok so i want to build a 2.0l gsr... I know i need to bore it out and use 84.5 mm pistons.... but i have a few questions... like how big should the sleeves be (darton sleeves were 84 mm... im assuming the sleeves are placed then overbored to 84.5 mm to house the pistons) and im shooting for a 9.0: 1 compression rating with a gsr crank any ideas on rods... and my last question.... running 18 psi what size fuel injectors would be the all around best... when not racing probably on 8-10 psi daily driven....

thumper64

First, I believe you're going to have to move to a LS crank to get 2.0 liters. The GSR crank will fit right in, you'll just have to plug the oil squirters or bend them. It's only a 2% difference, but if you insist on it being a true 2.0L...

I believe the sleeves will come a little undersized and then after being installed they will be bored and honed out to whatever size you like. This is to make sure it's all straight and perfectly round. When pricing sleeves I saw that 81mm were the same price as 84mm. Getting 81mm sleeves would allow you more piston choices since they'll have to be bored out for whatever pistons you get anyway.

Shop around and you can save a lot of money. I've seen people on here and craigslist selling sleeves for less than retail, like $400 instead of $500 or so. Then keep an eye out for pistons. If you're a little lenient on compression and size, or at least patient, you can find some good deals. 81mm turbo pistons usually sell pretty cheap. Or odd sizes, like 83mm. You're really not gaining much displacement by boring out another millimeter... Or check the for sale section here or the sponsor marketplace. Support the people on here!

You're going to want some aftermarket rods if you're going boost. Eagle is perfectly sufficient for almost anyone here. They're good quality, lots of people have used them. If you'd like to save some money, I got a set of LS and GSR Eagle rods, PM if interested.

blackEK2.0

so the piston head are where my compression ration comes from not the length of the rods or anything... hmm ive heard of people using LS cranks ... using an ls or gsr crank wouldnt make much of difference though would it... i was hoping to stick to a gsr crank... ive calculated the displacement and for it to be the same displacement as an overbored B20 i have to use 84.5 mm pistons.. and yes i really want it to be a true 2.0l... the only thing is do i HAVE to use an LS crank to get 2.0L and whats this about the oil squirters?

thumper64

The cylinder head, pistons, deck height of the block, and yes the crank will affect your compression ratio. You can manipulate it various ways. For example, an LS crank will up your compression about .2 points on a GSR. You're only adding 1.8mm stroke, but it all adds up.

You won't get the same displacement as a B20 without boring it to 84 and using a LS crank crank or boring it out to 85mm, but that's getting close to the limit of the sleeves. Like I said, you're not increasing the stroke very much.

The are disadvantages to boring and stroking. A larger bore will typically have the pistons rock more and a longer stroke will vibrate more. This is why Honda has typically made small bore, short stroke motors and why the B16 is actually a great motor since it's able to rev really high safely.