Civic EG

hi im new at the building engine thing bu they im trying just in alil need of help trying to figure out what size pistons to get i understand i need to get forged pistons for a turbo build 400-500hp and i need to know to figure out the size of the rods

what crank and block are you using.

if youre using an ls crank in an ls block, get ls rods
if youre using a gsr crank in a gsr block, get gsr rods
if youre using a gsr crank in an ls block, get gsr rods
if youre using an ls crank in a gsr block, get ls rods.

Cant help on pistons, since you didnt list what block youre using.

I THOUGHT WITH THE POWER I WAS TRYING TO REACH I COULDN'T USE THE STOCK RODS OR PISTONS

No but aftermarket parts are made based off oe pieces.

So what block and crank are you using?
Does the block need bored? If so how much.

i was going to resleeve and use prolli stock crank

Then you'll need gsr length rods.
As for pistons buy them in whatever sized bore you'll be running. Drop the block off at a trusted machine shop and have them bore the block to match pistons and set p2w clearances.

Thats what im rryin to figure out what is a good bore size to run with turbo

daiquans wrote:Thats what im rryin to figure out what is a good bore size to run with turbo

Start small so if and when you have problems there is room to fix it.

I'd start at stock bore 81mm and go from there.

you should never use a stock bore when building it up, you can cross hone the cylinders but if the size is off by a bit your screwed, blow by.

over bore the cylinders from stock to .25 (technically its .20) any way, post up some pics of the block you have so we all have an idea of what you are trying to actually accomplish.

technically any bore size is good for turbo, if you are resleeving the block with something like aebs, or dart.

a good brand piston is cp

a good rod is eagle

yes rods are designed from the stock rod, length, journal bore, and wrist pin size.

but they have more than twice the tensile strength.

Dart re-sleeves blocks?

kylenjdm93 wrote:you should never use a stock bore when building it up, you can cross hone the cylinders but if the size is off by a bit your screwed, blow by.

If he's sleeving the block why wouldn't it be ok to start at 81? If he uses new pistons and has a good machine shop do the work required setting p2w etc...

I disagree on CP being a good piston choice. Seen a few failures on the smaller bore related to the valve reliefs and how they're cut into the piston on the outer edges.

^ your right, if he is actually going to re sleeve the block he can start with oe sized pistons. instead of over sizing them.

I was under the assumption he wasn't going to sleeve after he found out the costs for all of it.

you get sleeves installed ok, now what?

gotta bore/hone the sleeves anyway because after you press them in they are actually warped.

line hone the main journals because they get warped too, remember a Honda block is primarily made out of composite aluminum. each manufacturer has they're own recipe......

which is why they warp. now to installing all your goodies. make sure you check every individual ring gap in the cylinder wall to insure proper sealing. file them down to spec.

when you purchase your pistons make sure you buy the rings in a kit for that specific piston, aftermarket pistons primarly do not use oe rings, they use some sort of higher tensile strength ring than the steel style. nitrate coating if I remember right. plust they are thinner anyway

DEPENDS ON WERE YOU BUY YOUR PISTIONS

supertech makes a pretty damn good piston for the price. cant beat it

real street performance has a decent price list, and they are knowledgeable and helpful tell them what you got and they will help you get the right parts.

So... OP... did any of this help?

im tryin use 8.5 forged cp pistons and stock sized eagle rods darton sleeves bored to 81mm

8.5 is going to have some serious turbo lag
You'll be fine going with a ratio such as 10:1,etc and before the critics say otherwise I've personally seen ratios as high as 10.5:1 boosted (reliably) to great success.
If you are still a bit skeptical 9.5:1 would be ideal but in todays day and age ur original choice won't be sufficient in terms of hanging with the comp.
Wishing you the best of luck with ur build, research,research,research and you'll be ok.