recently there has been a couple of shares on facebook about an article on Import Tuner website entitled Piston Anatomy - Tech Knowledge
the link to the article is here : http://www.importtuner.com/tech/impp_1110_piston_anatomy_tech_knowledge/viewall.html
very good article... nice, long and detailed read.
as you may remember in my previous post, i blew my engine in SIC... so when i was rebuilding a B20 (which just went kapow again 4 days ago...sigh) i also did some research on what pistons to use and all that. these are my findings which i posted on a forum a long while ago... the recent shares of Import Tuner's article has reminded me of this post. so i decided to blog it to make it easier to find in the future for my own or others reference. basically summarizes what i discovered during my research which is also mentioned in the article linked above. im just gonna copy paste what i posted.
theres basically 3 types of pistons generally used for engines..
1/ cast iron
cast iron are basically stock pistons...the good thing about them is that they dont expand much when heated up and they take very little time to heat up. this allows for tighter piston to wall clearance which basically eliminates piston to wall slap. they are also the weakest type of the 3.
2/ forged with low silicone content using 2618 aluminium
Example of the brand is Wiseco. this type is the strongest of all....the downside is that both types of forged pistons will expand MORE than cast iron pistons so will require greater piston to wall clearance. another downside is that they take longer to heatup and expand. so during cold starts, piston to wall slap is pretty common...at least til the pistons warm up. wall slaps can scratch ur sleeve.
3/ forged with high silicone content using 4032 aluminum
Supertec and CP uses these... a common trait of forged pistons is that they expand MORE than cast iron pistons so will require MORE piston to wall clearance. the bad thing is, they take longer to heat up and expand.. so during cold starts, piston to wall slap is common. again, wall slaps can scratch ur sleeve. this type of piston however, expands less than the one above. so u can get tighter piston to wall clearance and minimize wall slap. they are also not as strong as the one above but still significantly stronger than cast iron pistons.
myself, i went with supertec 11.5 pistons for my rebuild. my mechanic wanted me to use wiseco, i refused as i didnt wanna take the chance of slapping.. though i know hes built a number of daily driven engines with wiseco with no issues...no slapping etc. but still i kiasu...so i dun wan
ive also seen a picture on hondatech of a wiseco piston suffering severe slapping... that the W on the side of the piston actually wore off and were badly scratched.
up to u which one u wanna use. talk to ur mechanic if need be. im not sure if u get 84mm forged do u still need to bore a little for the wall clearance or not..
as for the (Ford) TX3 pistons, it was pretty common to use it in B20 a long time ago.. nowadays, i rarely hear of anyone using them.
other options cast iron are RS Machine and YCP pistons. both only available on the internet and outside the country...mostly on ebay. both have the same exact design: B18C-R design but with different sizes. should give u around 10+ compression. the YCP is significantly cheaper than RS Machines (which has alot more good feedback, barely hear anything about the YCP either postive or negative)...but recently i found a set of used RS Machine pistons on mudah
another option for cast iron would be the stock F20B pistons... these however are 85mm and will require a rebore.. also, the pistons need to be worked on by the machine shop in order to be fitted into b series to ensure clearance and fitment.