F23 into a F20B

Information to understand My cousins thoughts to get a opinion or **FACT** to see if this will work or if its even possible....... If you familiar with the F20B and F23 Internal Specs then read at the bottom.

Deck Height :
F20B - 219.5mm/8.643
F23A - 219.5mm/8.643

F20B - open deck
F23A - open deck

Bore :
F20B block - 85mm/3.346
F23A block - 86mm/3.385

Rod Length :
F20B - 145.0mm/5.709
F23A - 141.0mm/5.551

Rod Width :
F20B - 23.75mm/.935
F23A - 19.81mm/.780

Main Bore :
F20B - 48.00mm/1.890
F23A - 48.00mm/1.890

Pin Bore :
F20B - 21.97-21.98mm/.8649-.8654
F23A - 21.97-21.98mm/.8649-.8654

Piston Bore :
F20B - 85mm/3.346
F23A - 86mm/3.385

Compression Height :
F20B - 31.0mm/1.221
F23A - 30.0mm/1.181

Piston Volume :
F20B - +8.0 cc
F23A - -18.0 cc


Wrist Pin Diameter :
F20B - 22.0mm/.866
F23A - 22.0mm/.866

Crankshafts :
F20B - 88mm/3.464
F23A - 97mm/3.818

Main Journal Diameter :
F20B - 55mm
F23A - 55mm

Rod Journal Diameter :
F20B - 44.98mm/1.771
F23A - 44.98mm/1.771

Intake Valve Diameter :
F20B - 34mm/1.34
F23A - 34mm/1.34

Exhaust Valve Diameter :
F20B - 29mm/1.14
F23A - 29mm/1.14

Combustion Chamber Volume :
F20B - 53.80cc
F23A - 50.00cc

Head Gasket Bore :
F20B - 85.5mm/3.37
F23A - 86.5mm/3.41

Head Gasket Thickness :
F20B - 0.66mm/.026
F23A - 0.66mm/.026

Main Bearing Width :
F20B - 19.9mm/.784
F23A - 19.9mm/.784

Based off this information is it safe to use a F23 Crank and Rods(which will really be a Eagle Light rod to be on the safe side) with F20B pistons in a F20B DOHC Vtec block

Creating a
Rod/To Stroke Ratio 1.45:1
Mean Piston Speed 2147fps
Displacement 2201.71
Compression 12:53.1

Using a .030MM Headgasket.
What do you guys think? This is my cousins thoughts and he doesnt know english.

yes, the crank and rods can both go into an f20b block. its going to come down to the main journals (55mm) of both cranks/block and the rod pe/be widths, being the same. f20b/f23ax internals are (crank/rods) are interchangeable, not to confuse the h22a4 crankshaft though having the 55mm mains cant go in cuz the rods width isnt the same.

ive also heard something about b series rods, sharing the same specs for width as the f23/f20b. crower makes rods for the f23, would those eagle rods be custom?

wiseco sells 85 and 85.5 on raceeng under f22 i think, which will all work. or bisi sells 85.5 and 86 i believe for the f20b guys. not sure what ur actual plan is overall. but ya stated stock pistons. i was just throwing some options.

bagoon316 said:

yes, the crank and rods can both go into an f20b block. its going to come down to the main journals (55mm) of both cranks/block and the rod pe/be widths, being the same. f20b/f23ax internals are (crank/rods) are interchangeable, not to confuse the h22a4 crankshaft though having the 55mm mains cant go in cuz the rods width isnt the same.

ive also heard something about b series rods, sharing the same specs for width as the f23/f20b. crower makes rods for the f23, would those eagle rods be custom?

wiseco sells 85 and 85.5 on raceeng under f22 i think, which will all work. or bisi sells 85.5 and 86 i believe for the f20b guys. not sure what ur actual plan is overall. but ya stated stock pistons. i was just throwing some options.

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F23 Crank is the biggest being 97MM Stroke
H22 crank is 90.7mm stroke
F20B is 85MM stroke

I dont know about that bseries rods being interchangeable but you can find rods for F23 at Horsepowerfreaks.com or call eagle and have them custom(is what my cousin will be doing)
I know if he can bore it to 86mm, he will but for now(budget in effect) he will stick to the type r piston it came with.

A F20B and H22A Head Flow the Same being that they both produce the same amount of volume in the CC.(*i would think*) prove me wrong cuz i do know the H22A Euro R has a port Flow Head.
so the setup should be :
F20B SKunk2 Stage 2 Camshaft
F20B SKunk2 Pro Series Valve Spring
F20B Skunk2 Steel Spring Base
F20B Manley Valves
SuperTech Valve Guides
Improved Lost Motion assembly
3 Angle Valve Job
Skunk2 K series Manifold Conversion H2K Plate(for more room space)

Block :
85MM Bore
97MM Stroke
11.0.1 Compresssion
Light Rods
8LB Flywheel

You're going to need custom length rods since you're changing the stroke 9mm.

BlkCurrantKord said:

You're going to need custom length rods since you're changing the stroke 9mm.

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Yeah we plan on calling eagle for that but in a worst case scenario, wouldnt the rods from the F23 fit? Cuz if he cant get the eagle , he's going with the crower that are made for a F23 bottom end.

Depends on what piston you're using but essentially yes you could.

BlkCurrantKord said:

Depends on what piston you're using but essentially yes you could.

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well if the labor is too much for him, he plans on using the pistons the F20B came with
i personally told him its better if he bored the block to 86mm, he can use the K20 or custom pistons to increase the torque much better. But it is what it is. People here charge like 1200-1400 to assemble a short block which is a rob:
hot tank,balance,assemble,...crazy

BlkCurrantKord said:

Depends on what piston you're using but essentially yes you could.

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if i knew how to give you rep points i would....... BLKCURRANTKORD is very knowledgable and is highly informative. Big ups to you. I respect u

i would check those valves also, last i read, no one made valves for the f20b, and they arent the same as the h22 valves. ive read people having issues with them falling out.

bagoon316 said:

i would check those valves also, last i read, no one made valves for the f20b, and they arent the same as the h22 valves. ive read people having issues with them falling out.

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u mean manley valves or oversizing to use a h22 standard size valve??