DOHC JDM F22B + H22A head, ecu and loom = VTEC engine?? - Honda Prelude Forum

NeilSkinner · 09-09-2003, 02:31 PM

Hi, i currently have a jap F22B (2.2 DOHC 16v NON VTEC) Prelude Si (4G), a mate of mine has just broken his JDM VTEC prelude, however the Head, ECU and all the wiring are fine and could be mine for a very decent price!

I really cant think of any reason why i cant put this head onto my F22B's bottom end (fit and wire ECU) and get VTEC'ness?

The rest of the car is the same (i think), the compression is very similar so I really dont see why this shouldnt work, so im posting here awaiting a slap in the face and brought back to reality

Neil

Zimmlude · 09-09-2003, 03:42 PM

I am pretty sure the JDM F22 doesn't have the same stroke as the H22. The loss of the 0.1 displacement from the H23 is from narrower bores. This create a problem as the rod to stroke ratio of the F22/H23 is pretty poor for high revs. I would imagine the swap would be just like the H23/VTEC swap people do here in the states.

I am sure others on here will chime in and help you more,

HTH,

Satan_SRV · 09-09-2003, 06:24 PM

It's like an H23 VTEC hybrid but the piston bore is 85mm and the head bore is 87mm..I don't know if that works...anybody?

jsmooney · 09-09-2003, 07:16 PM

the f22 bore is.........let me find it

Satan_SRV · 09-09-2003, 08:02 PM

I know what the bore is...it's 85mm. That' what I'm saying....there will be a 1mm gap between the deck/head gasket and combustion chamber....so I don't know how that works..

SikRedRX-8 · 09-09-2003, 08:09 PM

I would think this would create a problem because of the different bore sizes. But I have seen a F22 (S motor) with a vtec head on it, so I can get some info from him to see what he did.

jsmooney · 09-09-2003, 09:01 PM

vtec bore is 85, is it not? h23 is 87, right?

Zimmlude · 09-10-2003, 02:17 AM

The H22 and the H23 have exactly the same bore size, 87mm. The extra 0.1L on the H23 comes from a longer stroke, i.e. the H23 is a stroked H22.

Satan_SRV · 09-10-2003, 03:07 PM

Quote:

Originally posted by UBetterBelieveIt
vtec bore is 85, is it not? h23 is 87, right?

H22 and 23 are 87....the F22B DOHC is a 85mm H23 hence the less displacement.

Paluce · 09-10-2003, 08:44 PM

bore your block to 87mm. you'd have a F23B VTEC

marcucci · 09-10-2003, 08:57 PM

The bore wouldn't be a problem, I would worry about everything else. Are the gaskets and oil/coolant passages the same? The head bolt pattern?

Satan_SRV · 09-10-2003, 09:27 PM

Quote:

Originally posted by Paluce
bore your block to 87mm. you'd have a F23B VTEC

You can't do that. The reason the H-Series was able to get out to 87mm was with FRM technology. The 85mm is just a steel bore and won't handle being bored out.

That's whay H and F series blocks are largely the same it's an F block with FRM sleeves..

Paluce · 09-11-2003, 06:25 AM

Quote:

Originally posted by Satan_SRV

You can't do that. The reason the H-Series was able to get out to 87mm was with FRM technology. The 85mm is just a steel bore and won't handle being bored out.

That's whay H and F series blocks are largely the same it's an F block with FRM sleeves..

Wow, just learned something new!

Thanks!

jsmooney · 09-11-2003, 06:34 AM

WTF are FRM sleeves?

Satan_SRV · 09-11-2003, 09:10 AM

Quote:

Originally posted by UBetterBelieveIt
WTF are FRM sleeves?

Best post ever.

Satan_SRV · 09-11-2003, 09:12 AM

FRM, Forged Pistons, and Resleeving