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+--- Thread: Boost Valve Float (/showthread.php?tid=1627)
Boost Valve Float - winmutt - 08-16-2010
Forced, IIRC was told by someone that the valve springs would have to be replaced for running higher than 20psi. I hereby challenge somebody here to pressurize their intake system with the engine off and see what these springs (in average wear and condition) can really hold up to. Checking for valve float from RPM is probably impossible to check but boost should be easily enough, especially on the 617 as the rockers are easily removed without removing the cam.
RE: Boost Valve Float - ForcedInduction - 08-17-2010
When I eventually swap the GT23v on the 300D I'll see about making a test plug for #5.
Static opening pressure doesn't mean much. When the engine is running there is always positive pressure in the cylinder working against the intake valve head (Compression, power, exhaust backpressure).
The exhaust side is what I'd be much more worried about. Its got a 1:1 to 3:1 (VNT) ratio over boost and during the intake stroke there can be vacuum on the valve head from the 617's low VE.
The figure in the FSM for the OM602/3 is no more than 30psi backpressure. Now remember thats the spec for the stock turbo and fueling, not a safety limit.
RE: Boost Valve Float - winmutt - 08-17-2010
Very interesting items. On the 617 its easy enough to replace the springs. I think on the om60x the cam has to be removed along with the tappet buckets.
RE: Boost Valve Float - winmutt - 03-09-2011
Some good vids : http://www.youtube.com/results?search_query=valve+float&aq=f
RE: Boost Valve Float - dieselboy - 03-09-2011
I ran 30-35+ for a few months with no problems. brabus has a friend in the 40+ zone. I bet he has stiffer springs on that one.
I have a few heads in the garage I'll make a plate and pressurize it till it leaks out.
Lol the 6th video down the 242 Volvo one is a friend.
RE: Boost Valve Float - George3soccer - 03-09-2011
Yea I think its no problem, but if you run it for awhile it could cause severe problems I suppose.