F23 SOCH VTEC to F20 DOCH VTEC

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RichieB9280

New Member
Hello. I'm a former Honda mechanic, I work on the other end of the business now writing collision estimates. It was time to hang the wrenches up and I wanted to learn how to do body work to make myself a well rounded car guy. ;)

I own a 2001 Accord EX-L with a SOHC F23 mated to an auto trans... The one I can change in 2 hours because I replaced one under warranty every day for the majority of the 5 years I fixed Honda's. I want to rip out the auto trans and install an F20 with what ever 5 speed it's mated to.

I found a swap kit that comes with the Motor, Trans, ECU, Harness, and axles.

What I need to know is the following:

1) Does the 5 speed manual trans on an Accord SIR II use the same shifter linkage as a standard 5 speed Accord?

I was thinking of raiding a bone yard to get the shifter, clutch pedal, shift linkage, and clutch master cylinder.

2) What is the difference between the F20 in the first generation S2000 and the F20 in the SIR II?

Is it something as simple as a set of cams, and pistons?
Is it the difference between a B18C1 and a B18C5? (Ported and polished head, blue printed and balanced lower rotating assembly)


I want to build the F20 up to rev and perform like an S2000 if the lower end will handle it without stretching a rod and it's not too costly. Unfortunately I live 5 hours from where I used to work and I don't have access to in.honda.com any more.

The reason I ask is a 9000 RPM 240 HP daily driver would suit my driving style. (I drive like an ass hole) :D

I got this Accord for next to nothing because my father didn't want creeps coming around his house looking at his car and my two little tween cousins that he adopted. If it wasn't for the great deal I got I would have never purchased an automatic trans but for what I paid and what it will cost to ship that puppy here there is a lot of room before the project becomes a bust.
 
PS this is going to happen soon weather or not I like it. I got that Accord with 165,000 miles on it... Original trans too (I flushed it every 30k)

With me behind the wheel I'd say it's got about 5-10k miles left on it before it's slipping like crazy.
 
H22a swap would go much cheaper than a Blue Top Accord Type R motor for sure... Probably reach your goals better too...

F20 out of the s2000 is...well for starters its rear wheel drive lol, and they are a completely different block from the one found in an Accord.

If your bent on doing the auto/mani swap, good luck, it sucks. Go online and buy a full h22a kit and enjoy some fun. Build it when ready.
 
I wanted to go H22 swap but it's much more expensive than an F20B swap. I know that an S2000 is RWD but the block is stamped F20C which means the block is the same but it's mounted as RWD so the only difference should be the motor mount brackets. What I'm referring to is the difference internally. If the F20B puts out 197 hp and the F20C puts out 240hp then there is some sort of difference. The motor either has a blue printed balanced bottom end, which would make sense with the 9000 RPM red line, a worked head (ports machined and polished to match the manifolds and possibly different pistons.
 
I've converted an auto to a manual before, it was a 79 Camaro but the idea is the same. The biggest problem we had was figuring out where to mount the clutch pedal.

If anyone knows where to get a cheap h23 or h22 swap send me the link please. Most of the swaps I found were in excess of $2500
 
The f20b sir motor is kind of a f/h hybrid motor. The f20c from the s2000 is more like a k series prototype than an f block. It shares the same bore spacing as a f/h motor but is runs a timing chain instead of a belt. Also I believe that the f20c rotates in a standard clockwise fashion like a k series rather than the counter clockwise of the d/b/h/f series engines.
 
The F20C and F22C blocks are not the same as the Accord/Prelude F motors. It's a very, very distant cousin of the other F-series motors, and it's essentially in a class by itself. If custom mounts were the only hold-up on swapping these engines in to Accords, Hasport or somebody else would have dealt with that a long time ago, and F20C-swapped FWD cars would be a lot more common. The S2000 has been out since 1999, but only just recently is the after-market starting to offer swap parts for Civics & Integras.

Trust me, you want to stick with the Accord/Prelude F-series or H-series...
 
The f20b sir motor is kind of a f/h hybrid motor. The f20c from the s2000 is more like a k series prototype than an f block. It shares the same bore spacing as a f/h motor but is runs a timing chain instead of a belt. Also I believe that the f20c rotates in a standard clockwise fashion like a k series rather than the counter clockwise of the d/b/h/f series engines.

This is a little more like what I'm looking for. I've taken the head off of an F20C before when I worked at the Honda dealer. I'm aware that it has a timing chain, and when I was looking for info online I noticed that the oil filter was on the same side as the exhaust manifold which is exactly the opposite of the American Accord's motor.

The meat of what I'm looking for are the differences in the following

1) Cam shaft profile
2) Compression ratio
3) The Bottom end
a) Are both the F20B and F20C blue printed and balanced?
b) are either of the motors blue printed and balanced?
c) Do both motors use the same connecting rods?

The reason I'm asking is because I want to know if I can use a similar cam to what the S2000 has and if the bottom end of an accord F20B will be able to withstand 10,000 RPM. If I have to send the head out for a shaving and jack the compression up a bit I might do that before I put the motor in my Accord.
 
From what I see they took the bare short block of the F20B and bolted a RWD trans to it, sealed the timing cover and completely changed the head.
 
2) What is the difference between the F20 in the first generation S2000 and the F20 in the SIR II?

Is it something as simple as a set of cams, and pistons?
Is it the difference between a B18C1 and a B18C5? (Ported and polished head, blue printed and balanced lower rotating assembly)


I want to build the F20 up to rev and perform like an S2000 if the lower end will handle it without stretching a rod and it's not too costly. Unfortunately I live 5 hours from where I used to work and I don't have access to in.honda.com any more.

The quote above was my original question. I have no intention of trying to mate an F20C to my FWD Accord. LMAO
 
I wouldnt do it because it is hard to find parts for that head. camshaft and cam gears are the only things that are inter changeable between the H22 and F20B. i was on that route before i read everything on that motor with the same intentions you had of a S2000 motor type specs in my accord. All you can do is Higher Compression being that its 2.0, the displacement of that motor compared to a F20C. The F20B is off by 1 in displacement,Fuel ratio is off by 5, Camshaft specs are are more aggressive and the motor red lines are a high RPM which allows the motor to produce that much of power
 
So in order for you to rev that high you will need a Valve train High Performance upgrade which nobody makes...from what i searched and know.
Your Best Bet is to get high compression Piston ( 12:?.1 )
Do a 5 angle valve job
Port flow the Intake manifold
and call it a day
 
I hear that. I did some research about the motor since I posted this article some time ago. I was hoping that the bore and stroke were the same, unfortunately the f20b and f20c are very different.

f20b:

  • Bore: 85.0 mm
  • Stroke: 88.0 mm
  • Displacement: 1997 cc
  • Torque: 145 lb·ft (197 N·m) @ 5500 rpm
  • Horsepower: 197 hp (147 kW) @ 7000 rpm
  • Red Line: 7400 rpm
  • Compression: 11.0:1
f20c:


  • Displacement: 1,997 cc (121.9 cu in)
  • Compression: 11.7:1
  • Bore: 87 mm (3.4 in)
  • Stroke: 84 mm (3.3 in)
  • Torque: 153 lb·ft @ 7500 rpm
  • Horsepower: 240 hp @ 8300 rpm
  • Red line 9000 rpm
I am still purchasing the f20b despite the fact that I can't modify the motor as much as I could an H22. What I need out of my Accord is a daily driver. I have swapped enough auto transmissions out of that generation Accord to know that I don't want an automatic trans. I'm taking this Friday off to raid a similar Accord at the bone yard to get the m/t shifter, m/t shifter linkage (if it's not cut), clutch and brake pedals, clutch pedal position switch and pig tail, clutch master cylinder, and if they aren't cut the plumbing from the master to the slave.

I have a few concerns; first I don't know weather or not I will have to wire the clutch pedal position switch manually or if the harness supplied with the new motor or the harness already in my car will have the wiring present. Second I have no idea weather or not I will have to cut a hole in my firewall for the clutch pedal, if I will be able to bolt the pedal up or if I'll be welding it to the fire wall. Third if I remember correctly the immobilizer control unit is not attached to the ECU, if it is, I'm going to be towing my Accord to the dealer to program my keys. Fourth, to my surprise I have found the half shafts are the same part number for auto and manual trans'. I still have a hard time swallowing that but I guess I'll find out.
 
I could still change the cam to a more aggressive cam and upgrade the valve springs to dual valve springs and titanium keepers. The valve train stuff is available and not hard to change. I think I'll leave it alone for now because all I want is to get a few more years out of my car, I commute almost 100 miles per day. This motor and trans will be like a heart transplant for my old Accord with 171,000 miles. The motor I purchased has 30,000 on it.

Wish me luck, I'll post pics when I'm done. I should start the swap in the next two weeks if the weather stays as mild as it's been (no garage yet:(, coming summer 2012 :D)
 
I hear that. I did some research about the motor since I posted this article some time ago. I was hoping that the bore and stroke were the same, unfortunately the f20b and f20c are very different.

f20b:

  • Bore: 85.0 mm
  • Stroke: 88.0 mm
  • Displacement: 1997 cc
  • Torque: 145 lb·ft (197 N·m) @ 5500 rpm
  • Horsepower: 197 hp (147 kW) @ 7000 rpm
  • Red Line: 7400 rpm
  • Compression: 11.0:1
f20c:


  • Displacement: 1,997 cc (121.9 cu in)
  • Compression: 11.7:1
  • Bore: 87 mm (3.4 in)
  • Stroke: 84 mm (3.3 in)
  • Torque: 153 lb·ft @ 7500 rpm
  • Horsepower: 240 hp @ 8300 rpm
  • Red line 9000 rpm
I am still purchasing the f20b despite the fact that I can't modify the motor as much as I could an H22. What I need out of my Accord is a daily driver. I have swapped enough auto transmissions out of that generation Accord to know that I don't want an automatic trans. I'm taking this Friday off to raid a similar Accord at the bone yard to get the m/t shifter, m/t shifter linkage (if it's not cut), clutch and brake pedals, clutch pedal position switch and pig tail, clutch master cylinder, and if they aren't cut the plumbing from the master to the slave.

I have a few concerns; first I don't know weather or not I will have to wire the clutch pedal position switch manually or if the harness supplied with the new motor or the harness already in my car will have the wiring present. Second I have no idea weather or not I will have to cut a hole in my firewall for the clutch pedal, if I will be able to bolt the pedal up or if I'll be welding it to the fire wall. Third if I remember correctly the immobilizer control unit is not attached to the ECU, if it is, I'm going to be towing my Accord to the dealer to program my keys. Fourth, to my surprise I have found the half shafts are the same part number for auto and manual trans'. I still have a hard time swallowing that but I guess I'll find out.

Ok..the reason a S2000 makes so much power is because the Bore is bigger and the crank is smaller. Thus, allowing it to rev higher.
The intake valves and exhaust valves of a F20B and H22 are the same( not all ) but the stem aren't.
You will need to some how find a vin tag of a Accord S.I.R-T CF4 and call in for them valves,springs etc etc. All you can do is use aggressive cams but without the proper valvetrain you will just stress the whole head that before you know it...Bo0OM!..and what happen?......
There are a few people who did use a H22 head on a F20B but im not sure on how it was done and if its even reliable since this is your commute car.
As far as ecu, you will have to take off the immobilizer because im not sure if the dealer will do it but if they do it; it will be EXXXXPENSIVE.
You wouldn't find after market rods but Pistons can be made since CP will do it.
Try these website to see if they can help :
Bisimoto.com <<< Valvetrains
Order OEM Parts <<< OEM MOTOR PARTS

I could still change the cam to a more aggressive cam and upgrade the valve springs to dual valve springs and titanium keepers. The valve train stuff is available and not hard to change. I think I'll leave it alone for now because all I want is to get a few more years out of my car, I commute almost 100 miles per day. This motor and trans will be like a heart transplant for my old Accord with 171,000 miles. The motor I purchased has 30,000 on it.

Wish me luck, I'll post pics when I'm done. I should start the swap in the next two weeks if the weather stays as mild as it's been (no garage yet:(, coming summer 2012 :D)
Good luck bro......
you're better using the H23 DOCH VTEC BLUE TOP since EVERYTHING!! is interchangeable with a H22 except Short Block Internals
 
And being that the pistons are 11:0.1 compression.... what ever you do, DO NOT MILL the head over .009 because it will mess up your timing a bit and tuning will be a lil harder.
You should get 12:0.1 - 12:5.1 compression pistons since your rods can hold 50 hp more after crank power.
So go to a machine shop and let them know your specs and how much compression you want out of it.
Dont take a chance and go with 12:5.1, you should go with the 12:1.1 since your rods can snap once you over the hp limit that those stock rods can hold
 
Got the motor and trans, found the right shift linkage, to the bone yard.
 
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