The F 23A1 engine installed in the 1998-2002 Accord LX, EX and SE models was manufactured in both Japan and the US. The heads, valve guides and valve keepers were identical. However, the Honda parts lists recommends different (and much more expensive) intake and exhaust valves for the Japan made engine than the US made engine.
00514711-P0A-000VALVE, IN. (TMSS Japan made) $18.51Qty:
00514711-P0H-A00VALVE, IN. (U.S. ENGINE VALVE) $10.45:
00614721-P0A-000VALVE, EX. (TMSS Japan made) $ 28.74
00614721-P0H-A00VALVE, EX. (U.S. ENGINE VALVE) $15.33

Dokuro, a Japanese manufacturer of valves, also lists different parts for the Japanese and US made engines.

But Beck Arnley and Federal Mogul lists the same valves for both US and Japan made engines.
My question:
1) Are the valves for the US and Japan made engines interchangeable? If not, what are the differences between those parts?
2) Has anyone installed valves for the US engine in a Japan made engine and encountered any problems.
Your advice would be appreciated.

Dennis Waller

 

Both engines (those installed in the U.S. and Japan) are built to the same specifications correct? You would think then that the parts should be interchangeable. Perhaps they could be made differently (material makeup, etc.) but I don't think that's very likely. It's very possible that the price difference merely comes from where and who they are purchased from.

Just my thoughts. Obviously that could be a bit of a naive statement, but it makes sense to me right now (as long as my base facts are correct). Feel free to elaborate on any other details you have found.

 

I suspect the valves have the same dimensions but probably have different metallurgy or treatment e.g. are the valves for the Japanese engine nitrided? My real questions are A) Do the more expensive valves perform better in service and b) in what ways are they different? The only people who could answer a) are experienced Honda techs and b) the engineers at Honda & Dokuro. I have struck out on the Honda techs and I don't know how to reach the engineers to answer b).