i just bought a F20B the other day. ive been doing alot of research and i found out that i have the weaker camshafts and small tb because its a auto version. I wanted the auto version for it being less beat on that a manual version. But anyway i will be doing the EURO R intake manifold swap with a JDM H23VTEC TB. H23VTEC tb is 3in in diameter. So heres my question can i install JDM Prelude Type-S camshafts WITHOUT them chewing up my valvetrain or i should be fine cuz its a F20B?

 

I'm fairly certain that teh valvetrain on the heads are the same, therefore you should be able to just straight swap in type-s cameshafts.

It sometimes is hard to find out solid information on these motors, but keep researching and learn as much as you can. Good luck.

 

i have never heard of 3 in tb

 

the outside of the throttle body

 

thanks man. ive been searching alot on this motor. its a very good motor. i ve found out that the type s head is the same as this head (f20b) so i should be ok with the cam swap.

 

Good stuff. I figured you would be.

Good luck.

 

it took some time but i got info. a guy i know has this motor in a cb7 so he told me a few things about it. when im ready to do this swap ill post up pics in the F20B thread.

 

I did lots of F20B research 3 years ago and as far as the valvetrain goes the manual and automatics do not share the same valve springs (different OEM part numbers) so i would advise you to at the least to use Type S springs. In fact to say that the F20b and Prelude Type S heads are the same is incorrect. They are similar (as in you can put the cams into the F20B head just like how the manual version has the S cams and be able to mount any H22 intake/exhaust manifold) but have different casting numbers (PCB versus P13). they have the same cc volume yet the F20B has an entirely different head gasket to accomodate its 85mm bore. F20B has smaller 34mm intake valves versus the 35mm in the H series variant. All of this was done and verified while building my all motor F20B (now 2.2 liters).

Like why does Skunk2 even suggest that their valves are for the H22 and F20B makes no sense. You'd have to open up the intake valve seat to accomodate them but they'd drop right into an h22ax motor.

Whats the inlet bore on that TB (Most likely its 62mm)? my aftermarket blox TB is 76mm, or 3inches at its inlet....

 

It was difficult to find info about the motor but if you know someone that has actually taken one apart or rebuilt one, or even has a built one where they have measured it up (like i did) it makes things a whole lot easier.

In the early going alot of fellas decided to assume that more things were similar between them than the truth. They have alot in common and alot of differences.

 

good stuff, thanks for the info.

 

Fo sho bro anytime