How much boost and still hydraulic?
12-13-2010, 04:20 PM
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With that being said, Mark Kohler ran mid 7's with a hyd roller valvetrain, so it can be done at high boost. I would think you would ok in the mid 30lb area
12-13-2010, 06:37 PM
#5
absolutely there is. As intake pressure increases you need to run more spring pressure to make up for the boost pushing on the back side of the intake valve, more spring pressure requires heavier valvetrain components. the extra spring pressure and heavier components put a beating on those hyd lifters.
With that being said, Mark Kohler ran mid 7's with a hyd roller valvetrain, so it can be done at high boost. I would think you would ok in the mid 30lb area
With that being said, Mark Kohler ran mid 7's with a hyd roller valvetrain, so it can be done at high boost. I would think you would ok in the mid 30lb area
12-14-2010, 11:48 AM
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Attached is a couple pics showing the rockers in place. I believe the highest he ever spun the engine was 8100rpm, although his normal shift point is down in the low 7XXX range. I think he ran just over 30psi.
Kurt
Kurt
12-16-2010, 08:18 AM
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Most rocker problems seem to be connected to losing control of the valvetrain. When boosted I believe your best bet is safe lobes with proper springs and the strongest pushrod you can get into your combo. Keep everything in control and add boost, the power and durability will be the fun part!
Kurt
Kurt
12-17-2010, 09:45 AM
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Mark has decided to stay with the single turbo after considering all his options.
The cam lobes are something you need to work out between your engine builder and the cam company. In a boosted engine the ability to move air is a given, control is really the thing that is sometimes comprimised with aggressive lobe designs that get the valve open quicker, even though guys are running big heavy valves and hardware that can put that type of lobe into a bad place.
Kurt
The cam lobes are something you need to work out between your engine builder and the cam company. In a boosted engine the ability to move air is a given, control is really the thing that is sometimes comprimised with aggressive lobe designs that get the valve open quicker, even though guys are running big heavy valves and hardware that can put that type of lobe into a bad place.
Kurt