the f20b of 2016
 

hey guys, im a young and upcoming engine builder, my current project is a 96 integra with a h2b swap, i overheated the h22 and swelled my stock pistons in the bore and ended up scaring the cylinder walls resulting in a nasty knock, ive determined its piston slap when i disassembled the enigne, it was an unfortunate event, i did some research and found the f20b to be a cheep alternative and great for some boost, well i bought a prelude that had one swapped in it for the same price i could of got the engine for, so a gained a couple parts and a junk car, well when i pulled the engine and did a compression test i found two cylinders low on compression, upon disassembly i discovered i had purchased a pile of #### anyways. the engine looked like they poored sand in it and ran it, probly ran it without the airfilter since it didnt have one when i got it , anywAYS THE CRANK is on the verge of its service limits,and the cylinders were scared, so im going to reuse the crank and i ordered new bearings and everything to rebuild it, plastigauged the crank its going to live, only thing is the f20b is a pile of junk when it comes to aftermarket parts, i did some research and found a couple of people saying ya f22 pistons! and some saying k20 pistons, well i decided to order the k20 pistons , since they are already full flooting rod type pistons, and i was going to get the block bored to 86 mm, well ebay sent me k20a3 with the negative cc dome, when i ordered the k20a1 pistons, which isnt a big deal becuase i planed on boosting it with my calculated 11 to 1 c/r well i ended up with 10.1 to 1 with the other pistons anyhow everything seemed to be going great besides the offset of the k20 is a little bit less but should be fine, but im worried about piston to valve clearance, siince i have to turn the pistons 180 for them to work becuse the k20 is a cw motor and h22 /f20b is ccw , the valve cutouts are slightly off, i just wanted to know if anyone has ever successfully installed any other piston besides the stock or bisimoto forged piston into a f20b , i was going to use the f22 pistons but they dont have circlips and the c/r was to low for me 7.8 to 1, ide love to get it bored and install them and clay the motor for p2v clearance but i dont want to waist my money if it wont work, either way i could just remove some of the dome of the piston if it doesnt have enough clearance , seeing how im already miling the rod ends 1mm to fit the pistons, block is gonna be sent of monday to get bored , would appreciate some hard core facts on these f20b,s though :hugs:

Re: the f20b of 2016
 

Too loooong post and a lot of mixed things and ideas. If you really plan to become an engine builder/tunner first organize in what you want to do. Then research, then buy parts and look for a good shop manual

1. h22 rotates cw and k20's ccw. Look engine at the flywheel.
2. If you have f20b blue top, those are FRP like the h22, then you can't bore to 86mm like other iron lined motors. Also honing is not the same either.
3. If h22 internals are good, you can take block to a machine shop and have cylinders repaired with new iron liners. Shoul be $50-80 per cylinder. The u can use forged pistons or whatever you want...

Let us know how it goes with the boring

Re: the f20b of 2016
 

he mentioned flipping the pistons 180° which takes care of the offset difference (from the piston's point of view they are going the right direction)

OP, I clayed for P2V clearance in my F23A block/F22A head/K20A3 piston build and had plenty of clearance on intake and exhaust. I am only suggesting that it's plausible that it will work fine with your combo. As always, check for yourself during dry fit to verify your clearances.

Re: the f20b of 2016
 

No.

F20b are iron cylinders and you can do 86mm fine on stock sleeves. I've even seen 87mm done.

Re: the f20b of 2016
 

Good to know

Re: the f20b of 2016
 

I understand why to turn pistons 180°. But, piston point of view?
Definitely this guy should search more...

Re: the f20b of 2016
 

from the perspective of the piston. ignoring all forces and motion that do not directly act on the piston it "sees" the same kinematic inputs when installed normally in a K20 as it does 180° in an F20. i was trying to be concise initially. :P

Re: the f20b of 2016
 

Maybe I should rephrase this, I am a mechanic , and a competent engine builder , I have a shop in az and this is what I do for a living , if you have ever owned the f20b and tryed to find any hardcore info and any parts for u u probly found that it's extremly hard, that's why I made this post to ask people who have hardcore facts , not people with incorrect facts , like I see far to often on here, so if your not 100% sure about what your telling me then IDE rather not , I know the cylinders are steel, because I have the block siting right in front of me , and nobody around here bored or homes the h22 frm liner , anyways I got the block back from the machine shop this weekend , had them set the piston to wall clearance at to 1.5 thousands , I plan on running boost is why I didn't put them any tighter , I'm going to build the engine next weekend , I will let u know how it goes, I'm pretty sure everything will work out fine , just worried about the piston to valve clearance , but we'll see when I clay it

Re: the f20b of 2016
 

Just wanted to update , it's august 2nd 2017 , the f20b with k20 pistons, still lives , it has a little over 10k hard hard miles, tons of 150+ mph pulls , trips all around California an Arizona , i had the head rebuilt around 8k miles an installed rc1000 cc injectors an hondata s300 , the car dyno tuned at 189 whp And 145tq when I first put it together , since then I have worked all of he bugs out, an we now have our own dyno at our shop mnr racing in Parker Az, so the tune is dialed in now, the original 189 whp was on a dyno in kingman Az, our dyno read the same , I have not had it back on the dyno to see what it's making now, since I have fine tuned it on the street , An also found some things causing lose of power, so I do expect bigger numbers, which is crazy considering that's wheel horse power An the engine has lower static compression numbers then stock, other wise , the car is going to be turboed soon, I will update again soon

Re: the f20b of 2016
 

Re: the f20b of 2016
 

Those stock rods WILL give up around the 300ft/lb range. Save yourself from a catastrophic mess and keep it under that or put some H beams in it. Kaizenspeed sells F20B H beam rods off the shelf now.

Re: the f20b of 2016
 

Hey guys! I just found this post and i think you can help me with this. I live in dominican republic and here its very hard to found aftermarket parts of F or H engines, there's a lot of K's and B's engines parts and they are really easy to find.

Few weeks ago i disarmed my F20B because a low compression issue, and i found my 4th piston sleeve with a few deep scratches... I was looking for F20B 86mm pistons (1mm oversized) and it was just wasted time. Now i want to put K20 pistons and i want to know if all stuff are going to work well... Please if you can, give me a brief guide to instal K20 pistons...

I hope you can help me...

Re: the f20b of 2016
 

Re: the f20b of 2016
 

very interesting read actually. I have a similar setup but for some reason they call it a G22 or something to that nature. I am currently running F20B sub-assembly with K20 pistons... H22 cylinder head with F20 intake manifold. D-series Gearbox and Stock B-series loom and ECU... all this in a SO4 Honda 4 door Ballade. South African version. Yes this is a little Frankenstein monster and I love it but motor is apart for a few adjustments or modifications on the sub-assembly and Flywheel. But very nice read bud