swap F20B piston on f22b jdm

[92smokeaccord]

Well this is the thing i will be useing the f20b crank and its 55mm unlike the 50mm my f22 crank is. So i cant use my f22 rods with this f20b crank. Now my big snag is the pistons will stick out of the hole by 0.20in so will the pistons hit my valves? ? Im useing a h22a4 jhead on a f22a block

i honestly dont kno..you would have to do some math...to make this much easyer u can get the sohc f20a crank and rods and just use the f20b pistons....

[gloryaccordy]

Well this is the thing i will be useing the f20b crank and its 55mm unlike the 50mm my f22 crank is. So i cant use my f22 rods with this f20b crank. Now my big snag is the pistons will stick out of the hole by 0.20in so will the pistons hit my valves? ? Im useing a h22a4 jhead on a f22a block

.2" is a lot man, that will smash into the head most likely

What's wrong with your buddy's F20B? Might as well get his whole motor and use everything from it that you can. If his head is bad snag his whole bottom end + the F20B cams (if the F20B came from a 5spd car, u will know if it was or wasn't by the TB size). Mixing and matching is a gamble, and like u said since the journals are different sizes there's not a lot that will swap over anyway.

At best, maybe u can get his rotating assembly and have a machine shop take down the 55mm journals to 50mm to fit in the F22 block. But I'm pretty sure the F20B block has shit like oil squirters and all that. The whole F20B engine was literally created for revving and racing.

[PR CB7]

you can use a f22 headgasket on a f20b
the f20b block is sealed on the last 2 drain holes, so a f22 HG will fit no problems

for the op, f20b crank is very hard to swap on a f22 block, the pistons will come out

the rods are too long, and the journals on the rods= b series size

[Darkcloud]

you can use a f22 headgasket on a f20b
the f20b block is sealed on the last 2 drain holes, so a f22 HG will fit no problems

for the op, f20b crank is very hard to swap on a f22 block, the pistons will come out

the rods are too long, and the journals on the rods= b series size

I want to see proof of that PR.

But the journals are b series size

[flcb7]

well I think I'm gonna snag the f20b block from my friend even know the shipping is gonna kill me. But by the time I do all the work I will prob. break even if not be on top. But anyways...by using that calculator just for kicks .....
f20b - everything crank rods pistons ect. and the math still came up with -0.020 sticking out of the head?? So I'm really confused b/c that was the same numbers I was coming up with when I did the h22 head with f20b guts. So can anyone explain this to me plz?? So from the factory the f20b pistons stick out of the head by -0.020????

[flcb7]

...by using that calculator just for kicks .....
f20b - everything crank rods pistons ect. and the math still came up with -0.020 sticking out of the BLOCK?? So I'm really confused b/c that was the same numbers I was coming up with when I did the h22 head with f20b guts. So can anyone explain this to me plz?? So from the factory the f20b pistons stick out of the BLOCK by -0.020????

anyone? anyone at ALLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLl? ?????

[92smokeaccord]

cant be...the only thing that changes in the f20b is the rods and crank...the pistons are the same as the f22a/b just more of a dome hence the compression change.trust me i already did this...but u want to destroke the f22b right..so in order for u to do this is u need the f20a crank and rods and mount them to the f20b pistons.this way its a direct fit no modification required.

[flcb7]

cant be...the only thing that changes in the f20b is the rods and crank...the pistons are the same as the f22a/b just more of a dome hence the compression change.trust me i already did this...but u want to destroke the f22b right..so in order for u to do this is u need the f20a crank and rods and mount them to the f20b pistons.this way its a direct fit no modification required.

take the calculator and do the math and it says the pistons sits out of the hole by -0.020in.

Ok ok let me get this right. I can take the f20b rods/pistons and crank and set them in my f22 block and the pistons won’t sit out of the hole by -0.020in?

I'm totally confused. As stated be4 it can't be done without taking the mains down to 50mm? Right??

Why I'm asking is I'm getting a f20b block with f20b crank/rods/pistons and I'm using my h22 head (with the 2 oil ports welded shut) So at this point the pistons WON'T sit out of the hole by -0.020??? Please break this down for me. I know you guys know TON's more than me. I'm just trying to understand.

[92smokeaccord]

ok heres the numbers. if u look at the differences between the f20b and f22a/b there the same..only differences is the main journal bore,diamiter,rod length and crank...the pistons are the same just different dome/more compression..


http://www.cb7tuner.com/vbb/showthread.php?t=41915

edit...what math equation are u useing...can u write it out for me so i can see if something is wrong....

[almostJDM]

one thing you guys are overlooking is the combustion chamber, the f22a has 50.5cc of room while the f20b has 54cc, it's going to get kinda cramped in the head, going from a -14.5cc to a +8.0cc piston

flcb7: you wont have any issues at all

[flcb7]

I use the calculator that was posted on the 1st page. ok this is what I got from the calculator...

http://www.zealautowerks.com/hfseries.html

85mm bore
88mm stroke
53.80 Combustion Chamber Volume (cc)
4.70 dome (cc)
31.00mm Comp Height (mm)
145.00 Rod Length (mm)
3 layer HG 0.026 Thickness (in)
_______________________________________________

10.99:1 Static Comp Ratio
1.56:1 Rod / Stroke Ratio
10.99:1 Effective Comp Ratio
-0.020in Piston-to-Deck Height
1997.42cc Displacement

EDIT: I'm using a h22a4 head not a f20b head. Not sure if that matters. I also tried using the f22 block and the f20b block. Came out with the same EXCACT numbers.

[flcb7]

anyone?

[flcb7]

bump!