I picked up a car with a JDM "F22B" SOHC VTEC (Silver valve cover) already swapped in. I am trying to verify the compression ratio. The JDM DOHC F22B is 9.3:1, higher than USDM. I would think that the SOHC would also be higher than the US. However, all the listings I see are the same 8.8:1 for the SOHC VTEC, JDM or not. I wonder if this spec is true or it are just an assumption that it is 8.8?

If you have experience with this particular motor please let me know.


FWIW I found some videos of JDM places doing a compression check on these engines for sale. They are in the range of 200-210PSI. I will be running a compression check on my engine soon.

 

I don't believe the ratios are any different between the USDM/JDM engines

 

I pulled some specs from the JDM VTE/VTI accord and so far I just find 8.8. However, if that is true and the DOHC non vtec F22B is 9.3:1, wouldn't that mean that adding the DOHC head would increase the compression to 9.3?

*hmmmm*

 

Hmmm. There are variables, like piston type, deck, and head gasket thickness.

I have no idea what those specs are..

 

I am not intimately familiar with the DOHC F22B but the difference is likely in the piston compression height and/or dome, not the head. You would have to check the combustion chamber volumes between the engines to confirm. Half a point of static compression is hardly worth going through all the trouble to mate that head to a SOHC block anyway.

 

No difference with the B1. It's the same engine USDM or JDM, there are slight differences in ancillaries but that's about it. Replaced my original B1 when the piston slap and oil blow by became a bit much. JDM unit with all the funky JDM stuff on it was made here in the USA.

F22B(DOHC) was never here in the US, it is closely related to the H23(USDM) but again, different bore and iron vs FRM cylinders.

The only similar engines that have different CRs are the various H22(VTEC) engines found across the Accord/Prelude lines.

 

just put a set of 11:1 forged pistons in it, it was awesome when I had my accord