Forged B16a2?

**jd m** · 02-11-2011 08:24 PM

Hey guys, I am thinking about forging my B16a2 with CP pistons and eagle rods because one of my pistons are cracked. As my mechanic told me I have to hone my block down to fit the forged pistons which is the exact same sizes to the OEM pistons(81 mm) is that true? is it better to go oversized bore? and if I were to get the pistons compression ratio 10.5:1 would I need to retune my car cause the standard one is 10.2:1 which is not much of a difference so I'm guessing I do not need to retune it. I'm not planning to turbo the car or anything though so yeah can you guys give me suggestions of what I should do?

Thankss

**jdm18c** · 02-11-2011 08:51 PM

are you doing anything else ? or just wanna put forgies in? if the case dont really see the point

**Glocker** · 02-11-2011 08:54 PM

Higher compression = higher chance of pinging detonation. But your stock ECU should adapt to it with the right timing. To get the most out of it though better get it tuned.

**jd m** · 02-11-2011 09:17 PM

Yeah just putting forgies in. Cause I checked OEM pistons and they cost roughly about $250 per each piston from Honda and forged pistons cost about 800 for a set including eagle rods which made me think that if I were to rebuild might as well do it good unless if someone knows another place which sells OEM pistons for cheap =/

**hmetro24** · 02-11-2011 09:36 PM

A mechanic told me when ever I wanna change pistons to new pistons, I may have problems with cylinders, due to the heat the sleeves and pistons will not be oval.So i have to take the Bottom and machine the cylinders. Anybody can confirm if it's possible to change to new piston with out taking bottom end out.

**jd m** · 02-11-2011 09:48 PM

Well yeah depending how bad it is I guess but my mechanic said if its forged pistons then the bottom end must be honed and if its just standard OEM pistons its alright. Not sure if its true can anyone clarify this?

**Bludger** · 02-11-2011 09:48 PM

if you didn't machine it, you're doing a half arsed job.

building a motor to fail.

**Bludger** · 02-11-2011 09:49 PM

Originally Posted by jd m

Well yeah depending how bad it is I guess but my mechanic said if its forged pistons then the bottom end must be honed and if its just standard OEM pistons its alright. Not sure if its true can anyone clarify this?

but yes, you can put new rings in. it will work.

**mocchi** · 02-11-2011 09:56 PM

Originally Posted by hmetro24

A mechanic told me when ever I wanna change pistons to new pistons, I may have problems with cylinders, due to the heat the sleeves and pistons will not be oval.So i have to take the Bottom and machine the cylinders. Anybody can confirm if it's possible to change to new piston with out taking bottom end out.

without taking bottom end out of the car?
yes possible but 10x the effort.

so much easier when engine is on stand and you can turn it around to fit conrod cap, measure end gap, let engine oil drip on drain pan etc.

not to mention oil drip gonna be a real pain.