Hi every one.
I found an F20B laying aroun last week,
I didnt knew about the geometrie of that motor so iv not been interested at first,

But now that i get informed about it.
it become a verry interesting project,
Using the H22 big valves head
Means that IM from H22 will also go on,

I dont even know where this motor will be install yet,

I dont want to make a big Thread on this project,
but i want to put my hand on this beauty to see how can i make it performe stock and bring the information here.

Here is the spec.

F20B
This engine series was used in the CF4, CF5, CF9, CL3 Honda Accord and Honda Torneo from Japan.
It uses a DOHC VTEC cylinder head similar to the H22A found in the Prelude but was designed to comply with many countries' sub-2.0 liter tax.
The automatic transmission versions received the lower hp version (180 hp), as it was tuned for more mid-range torque than its manual transmission counterpart.
The F20B (depending on auto or manual versions) also utilizied stronger cams from the H22 type S.

Specifications
Accord SiR wagon, SiR-T F20B 97-01 2.0L
Valve train: 4 Cylinder, DOHC VTEC, 16 Valve
Bore: 85.0 mm
Stroke: 88.0 mm
Displacement: 1997 cc
Torque: 145 ft·lbf (197 N·m) @ 5500 rpm
Horsepower: 180 hp (130 kW) @ 7000 rpm (Auto)
Red Line: 7600 rpm
Compression: 11.0:1
Fuel Control: OBD-2


DOHC VTEC Manual Version:

198 HP @ 7200RPM
145 TQ @ 6600RPM
147.10 kW
11.0:1 CR
85mm bore
88mm stroke
23mm wrist pin
145.5mm rods (f20b rod length = 145.425)
1.65 r/s ratio
55mm mains like h22a4 block


Good Starting point.

I am at porting the head a Lill bit.
New seals and valve job.
H22 IM is Ported and ready to go on. (W/H throttle)
62mm throttle will go on.
New berings from Honda
Arias rings
bla bla bla...

I dont know much about this motor,
But in my book, this géometrie is able of 200Whp/160Tq on the S cams that i dont have.
Motor's head was found empty.


See you nex for more.

 

This is the same Intake job that i did to the H22 IM

 

The F20B is a GREAT engine. Honda must have purposely under rated the SiR-T version. My completely stock engine put down 185/147!!! These engines have LOTS of potential with an 88-90mm bore (2141-2239cc), long rods, headwork, stage three cams, RRC IM, 4-1 header, etc....

Kudos on going with a GREAT alternative engine platform and good luck....

 

honda fitted 1mm smaller valves for a reason..... the 85mm bore.

the larger valves will be in effect shrouded on one side slightly, unless you plan on boring it out.

i'm running a stock f20b with supertech ti valvesprings, ks balance shaft kit, 52mm itb's, 3" single box exhaust with megan () header and standalone ecu, 229bhp at fly and 164 ftlb, limited to 8100 rpm

 

229hp at the flywheel not at the wheels??

why did you upgrade the valve springs and utilize 52mm itbs with out going with stage two cams? or did u mean supertech titanium retainers? either way, if you have itbs, a header and a standalone then you may as well upgrade the cams. if you have an SiR-T version from a car with a 5 speed then you dont even need to upgrade the valve springs because they already have Type S springs. all you would have to do is change to titanium retainers

 

Hi. thanks every one. I can maybe get a H22 bloc and install the short stroke crank from F20 and the long rods and run it 88mm stroke 87mm Bore
But there i will have to spend for 11.5:1 CR pistons.
1mm smaller valves ??? i do have both head. i will verefy that.

About the balancer shaft. some recomand to remoove them.
Honda put them there... they must have a raison for this...

 

I think about it now and... il just bore .5mm the sleeve around Intake valve then

 

hone the block out to 87mm and use some h22a type s pistons and call it a day. The balancing shafts can be taken out and wouldn't matter at all cause of the stroke being 88mm between a ls and gsr stroke.

 

I guess on the valve job its possible to remoove a lill of valve Dia..
We are talking about 15 tow here...
And its possible to port the cylinder. just a lill (20 tow) At Intake valve opening and not to deep in the sleeve. Stoping before the piston ring
But i just dont know what ill be using yet.
$$ have to first fall from the sky so i could go on... lol

 

if you'd where to rock the type-S pistons you won't loose any cr as far as i know.

p5p = 3.9cc with 87mm diam
pcb = 4.7cc with 85mm diam

both seem to have the same cr-height so the increased displacement (2.0l->2.1l) should make up for the .8cc difference

so.....
h22block + f20b crank/rods + h22 type-S pistons = 2.1l with a 1.65R/S ratio @ ~11cr
coupled to a ported h22 head/intake mani and some header/cams, make it a H2B and your golden

the lack of stroke (versus the h22) can be fixed by choosing a light chassis

 

hi mate, the itb's were 2nd hand and too cheap to miss, it was an auto engine so i fitted my type s cams from my old h22 engine, the springs and retainers were installed just for peace of mind as its in my oval racer and very often running around the 8k rpm mark, my intentions are to upgrade the cams and header over the winter break for next season.
229 was at the flywheel, 50 more than what the engine was ment to have stock, hoping to get 250bhp (210+ whp) with cams and header,

 

get the balance shafts out mate, great oil pressure and no noticable vibration issues.

 

i;am current rebuilding my f20b hopeing to hit around 220-240whp. heres my setup

arias forged pistons stock cr
fully built head
port match intake and exhaust
3 angle valve job
skunk2 pro series IM portmatch to 75mm TB
skunk2 stage 2 tuner cam
springs retainer
440cc injectors, aem fuel rail and regulator
2.5" race header with 2.5 full catback
t2w4 tranny
will be tuned on hondatas200

current in the shop should be done in about a week or two. I have this in a 5th gen prelude.

 

fully agree but i was talking about something else

i said if your down on stroke/torque you can make up for it by running a lighter chassis was a joke

think h22 EM1 vs F20B CRX

 

Sounds like a nice project. Maybe some of the big H/F series guys will chime in with some more tips. Looks like you have it under control. Love the hand porting on the manifold...I'm not into all those fancy expensive machines.

 

have you completed your buil? sounds like a build i would like to run with as i have qsd h2b kit on my stock f20b making only 178whp at 138wtq on skunk2 IM... i was depressed. please let us kno how that turned out. thanks

 

Funny both my stock f20bs made the same thing or right at it 185/147. Both ran 13.5 in a stock heavy *** si eg hatch back and will run forever taking alot of abuse. If the springs are still in the head thats what im running on my pro 2 cams for years (type s valve train). These are great motors and id love to see what one would do with big cams on stock bottom end. The bottom end will take 9,000 rpm reeves for years stock trust me ive done it . The motor is very stout.

 

dude that f20b block is no joke its the best high revving h/f block they made period.
I had one also and it took so much abuse for 3years revving it to 9k not every day but mostly. It never gave up on me when it was on my 92 prelude and on my 92 civic sedan until a puddle killed it. that motor has ***** keep it do a bigger bore high compression pistons and you will be set 240whp just from that with cams.

im about to build a high compression f22a1 block with the f20b head looking for more torque and i can rev that baby high im already doing it with no problems both the f20b anb f22 blocks dont have oil squirters so its all good. G22a1 vtec baby!!
thats my current setup runs hard but with high compression even harder

 

a kind of off-topic newbie query; would a pcb-004 (F20B sir-t/manual version's) ecu do on a h22 type-s? if it would, how different could it handle the motor than the p5p?

Actually, neither a p5m nor a p5p is available here at my part of the world!

 

If you do the math, 187 is around 210-215 at the flywheel. Of course this is higher than the 200 Honda claims the manual F20B produces. I cant work on mine till I move, so no mods for mine until sometime in 2013.

 

The PCB is completely different than the PDE, so it shouldnt work at all.

 

Sorry i do not have lot of time.. but im still in mecanick lolol

For me your set up sound good. exept for the ( arias forged pistons stock cr )
If you want to use big cams stage II you will need the CR to work with it...
i would say a nice 12.2:1 on 94Octane Gaz

But i will try to find type S cams as i know the power band... they are lovely torque on Nonvtec lobe and can pull till 8200rpm on vtec 11.5:1CR well tuned.
And my personal throttle body is 62mm to acheave 240Whp.

I did an H22@233Whp on 60mm throttle body and ported H22 IM.
Dont slow down your Vélocity

 

Hi,
I recently purchase a sir-t 2.0l f20b .
brought it for my first drive the other day and the timing skipped and burst the block and valves.
I was fortunate enough to find another f20b bear engine with big end bearing gone in cylinder 4.
I'm going to attempt the rebuild myself.
i was wondering if anyone knows what should be checked and or replaced on a budget build.
I would like to raise compression ratio slightly without breaking the bank or building a bomb.
any help would be much appreciated .