I smell secretions

what other Honda engines share the same valve size?
just installed a engine for a friend with upgraded ecu with 9000rpm limit. Would like to swap valve and valve springs but keep the stock retainers. Would h23 valves work? F23a Maybe?
of course aftermarket in either variant

I smell secretions

my Friend already did a peelout to 9000rpms and hurt the engine.... Come on friends,ACL main and rods bearing in as well as new rod bolts.as well as as skunk springs with stock retainers, looking for at least 15,000 miles before inspection. Looking for aftermarket valves at standard sizes outside OEM......?

hondasdohc

F20b shares the same intake valves as h23a1 and f22a1 and exhaust valves are also h23a1 or f22a1 that motor should last a long time if done correctly with heavy abuse i know i had one for 3yrs beating the life out of the 9000 rpms almost every day.

I smell secretions

thanks for the help!

JDogg

springs and retainers are the same as h22. I would not use aftermarket springs with stock retainers.. the stock retainers will break.

I smell secretions

any good set of snap fit retainers

Z-freak

I want to set the record straight here because the incorrect information in this thread (and a few others that seemed to use this information) cost me a significant amount of money.


F22A1 and H23 VALVES DO NOT FIT THE F20B. H22A4 valves will fit as a 1mm oversize for the F20B, but NONE of them directly drop in.

Pictures:

snobordboy

If you are going to the expense of rebuilding the whole engine, and want it done right to last at 9K, call up Ferrea and see if they have valves to meet the F20B spec.

Or call up 4Piston and see if they have dealt with some of those heads, and what they would recommend. That may be your best option actually.

Z-freak

I have manley making me a custom set for $350. FAR cheaper than OEM, and will be much more durable.


VALVE SPECS (measured by me):
NOTE: H23A is the NON-VTEC, US-Spec 92-96 Prelude engine, not the Torneo/JDM H23 VTEC engine.

INTAKE VALVES (Face) (Length) (Stem Diameter) (OEM Honda Part Number):
F20B: 34mm (1.338"), 107.00mm (4.212"), 5.5mm (0.215"), 14711-PCB-000
H23A: 34mm (1.338"), 104.00mm (4.095"), 6.5mm (0.256"), 14711-PT2-000
H22A4:35mm (1.380"), 107.00mm (4.212"), 5.5mm (0.215"), 14711-P13-000
F22A1:34mm (1.338"), 112.00mm (4.410"), 5.5mm (0.215"), 14711-PT3-A00

EXHAUST VALVES (Face) (Length) (Stem Diameter):
F20B: ****HAVE YET TO MEASURE*** 14721-PCB-000
H23A: 29mm (1.142"), 104.00mm (4.095"), 6.5mm (0.256"), 14721-PT2-000
H22A4:30mm (1.182"), 107.00mm (4.212"), 5.5mm (0.215"), 14721-P13-000
F22A1:29mm (1.142"), 124.000mm (4.882"), 5.5mm (0.215"), 14721-P0J-A00

hybrid_KJ

Can the h22a int valves (+1mm) be installed on the f20b valve seats with a new valve job or does the seat need to be changed as well? Is there a difference in the intake throat diameters between the h22a and f20b head castings?

CTCD5

I believe you can run H22 valves without modification. I'm ordering a blox H22 valve train and asked them about valve to piston clearances when being used in an F20b, and they had no clue. I didn't even think about seating issues

Z-freak

The H22 intake valves are NOT drop in...they are identical other than being 1mm oversize to the F20B. Exhaust valves for the H22 are the same as F20B.

98vtec

just in case people were wondering, there is not an aftermarket valve on the shelf for the f20b. I just ordered h22 ferrea valves and they offer the service at 7 dollars a valve to turn the heads down to the 34mm head diameter.

f22/h23 valves are NOT the same even if they shared the same head diameter. The lengths are different. f20b exhaust and intake valves are indentical in length and size to the h22 other than the intake valve being 1mm smaller in diameter.