06-11-2010, 08:33 PM #1
Lightweight valves and ECU question
I have an '05 RXP which of course has the weaker exhaust valves. I am going to replace them with Ferrea Lightweight Valves before I drop a valve and was wondering if that alone will be enough to run an 8650 ECU or if I'll still need retainers or a valvetrain upgrade kit? I'm not trying to cut any corners and know that if I did valves and upgraded the springs and retainers I would not have anything to worry about, but if I only need retainers, or just the valves by themself will safice, I wouldn't mind saving the extra money. I won't ever be revving past 8650 and don't plan on changing my S3 charger.
06-11-2010, 09:02 PM #2
From reading Jerry's post about people wanting to mod their skis, it says with the lightwieght valves, you can just run the retainers, but just curious as to others experience/recommendations with that set up.
06-11-2010, 09:11 PM #3
The Springs in the upgrade kit are a whole lot better for higher RPM's.
We had them put all the way through a spring manufacturers lab in Aus, and they reported a far better metal, and coiling was good for the application. Basically he said the OEM ones were good, but as you start to put pressure on them, the Riva ones would be more stable.
I know there are major tuners who change only the retainers, and you can do some engineering to lighten the OEM ones, and shim the bottom of the coil to get pressure back.
Remember the Major tuners always have the top off the engines to make sure all is good!!
I know that not all the "Earlier" valves were bad, or at least don't appear to be. I have a friend running 8500 on 04 OEM valves, and no problems encountered yet. Mind you, he is particular with his ski, and really looks after it after a ride.
If you are taking the head off, it probably is good practice to go the whole hog, and eliminate any % of problems piece by piece.
07 Valves were good as reputation has it, and not seen many, or heard of many going to self destruct. I ran them in mine at the 8650 limit before I went Ferrea without trouble.
I think peace of mind is always a good plan, and draw from information from GH users also.
06-11-2010, 09:24 PM #4
I had looked at just replacing the exhaust valves with the 07 or newer ones, but when I priced it out, ordering the OEM valves ($464.94 not including tax or shipping for just the exhaust valves ) were much more expensive then the Ferrea once ($525 for both intake and exhaust), so that decision was easy. Maybe if I find someone parting their ski out I could get them cheaper (depending on why they are parting it out). I like to things right the first time, and not have to worry about it. I have just heard stories of 04-06 skis dropping an exhaust valve and causing a tremendous amount of damage. If this is much less common than I am thinking it is, I may not worry about it and keep everything as is. Just trying to make sure my ski continues to perform well and without issues.
06-11-2010, 09:34 PM #5
I think it sometimes depends on how much of a flogging the ski gets, and how well it is looked after is a major factor in all this.
I have seen Ferreas in bits inside cylinders too. One thing was the owner gave it a beating everytime it was out, nothing is bullet proof.
It's always a way to get peace of mind, but at what price.
Remember lifting the head to change the valves can get expensive.
You may figure to change the cam chain guides too. So you will have to replace the stretch bolts on the valve gear anyway, maybe the head bolts, gasket, possibly manifold seals as good practice, The head may need a touch of flat, so upgrade the oil jet on it. Before you know it... $$'s.
AND.. you may not stop there. See a bargain cam, then consider flowing the head...!!
The tuning bug may bite you!
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