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OEM Stainless Valves???

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In a valve reply on another thread the poster stated that he was aware that Honda is now providing OEM stainless steel valves. Anyone else hear about this???

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In a valve reply on another thread the poster stated that he was aware that Honda is now providing OEM stainless steel valves. Anyone else hear about this???

They are referring to the valves for the Honda 450 quad actually, it has SS valves stock. :banghead:

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Are they completely interchangeable with CRF's 31mm exhaust, 36mm intake? Already have the KW's coming but this would have been an interesting option.

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I spoke with my mechanic this morning and said that the OEM SS for the CRF450 are the ones that they put in the TRX450. It is a direct replacement, you do need to use TRX450 vlave spring and a few other things. This was actually the first I have heard of this but it sounds like Honda understood the problem and designed a OEM SS valve to make the TRX450 have more longevity. While I am getting these valves installed they are also installing an 04 Piston. I am very anxious to get the bike back.

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Do a search!!! I think RHC has talked about this some time ago. I believe the quad's valve stems are slightly larger around then the CRF's. This may only require the quad's guides but I don't know. You dont weant to force a tight fit on the stem as the valve will break and then you've got BIG problems.

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I just finished measuring both valves. Here's what I came up with:

Intake valves- Both CRF and TRX intake valves are the same.

Exhaust Valves-

The CRF exhaust valves measure 31mm head diameter and 5mm stem diameter.

The TRX exhaust valves measure 30mm head diameter and 5.5mm stem diameter.

The verdict is in. The intakes will interchange but the exhuast will not. Hope this helps.

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Do a search!!! I think RHC has talked about this some time ago. I believe the quad's valve stems are slightly larger around then the CRF's. This may only require the quad's guides but I don't know. You dont weant to force a tight fit on the stem as the valve will break and then you've got BIG problems.

Why is there always some JA that says, "do a search". Why can't they just answer the questions or STFU? Give it a rest, go for a ride. :banghead:

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So you guys are saying that You can order the quads Valves for the Intake and they will Fit in the Bikes Motor? Do we know if that will fix the problem the same as if we bought the valves from kibblewhite?

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Regardless if they will fit or not, the KW stuff works and is cheaper. No need to get OEM.

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You can get the OEM stuff pretty cheap from ServiceHonda.com. Just an FYI they are only changing my Intakes with the OEM SS valves.

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Well I did the search myself for you. The thread was from Rich Rohrich about the TRX valves. As you've probably now realized, they will fit but you still need quality springs to control the heavier valve. The TRX spring is the same as the CRF and won't work on the CRF. That's because the TRX cam is less radical than the CRF's. You're right, the aftermarket valves are far superior at a slightly higher price. I would go ride if I didn't have to work. Sheesh.

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I spoke with my mechanic this morning and said that the OEM SS for the CRF450 are the ones that they put in the TRX450. It is a direct replacement, you do need to use TRX450 vlave spring and a few other things.

If you do a little research you’ll find that the TRX and CRF run the same intake valve spring in spite of the fact that the TRX intake valve is a much heavier steel piece. The reason Honda can do this is the TRX runs at much lower peak rpm and has a much milder cam with significantly lower valve acceleration rates than the CRF. This allows Honda to run a light spring in the TRX even with with heavy steel valve

Bottom line is, anyone using the stock CRF valve springs with steel valves has a high risk of failure.

Another thing you’ll find with a bit of research is the OEM TRX intake valve isn't stainless and it was designed to be built at a much lower unit cost than the good aftermarket Stainless Steel valves. In other words it's just a cheap valve. Material spec and valve head shape is far superior on the Kibblewhite and Ferrea valves.

If you are hell-bent on using the TRX valves at least make sure you use good springs like the Kibblewhite kit or the springs RHC is selling. You can really run into some serious issues and breakage if you increase the weight of the valve without a corresponding increase in spring pressure at both the seat and open positions. The basic laws of physics can't be trifled with if you expect an engine to be reliable. The physics involved in controlling a valve with a spring can't be denied my friends no matter how much we'd like to ignore them for the sake of economy and the lure of a $3.00 valve spring.

One last point for what it's worth. Not cutting the seats after you've hammered the crap out of the valves is an incredibly bad decision. You'll never get a proper seal between the seats and the new valves so cooling, flow and valve longevity will be seriously compromised. Lapping valves is what you do when you are rebuilding lawnmower engines, no 11,000 rpm race engines.

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By "cutting the seats" do you mean replacing or just actually have them cut ie: end-mill?

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Any Engine reconditioning shop can cut the seats for you. You should not have to replace anything. A good shop will have a specilized head machine (maybe a SERDI)that is used just for cutting seats. Your honda manual even has a few pages on this.

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Just got the bike together this morning after installing the KW's. Went to the track and after a few "EZ" laps proceeded to flog the beast as best I could. Ran AWESOME! And starts the first kick. Lytle Racing on ebay will get you set up for a tad over $300. $20 for a head gasket and you're good to go. Look forward to not having to remove the head for a L O N G time!

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Hey Adam, my 02 was eating ti valves every couple of weekends. I bought some stainless valves from Honda for the 450 quad and have had no problems. They fit right in and I used the same springs. Good Luck!

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