Originally Posted by 351ClevoCorty
I've been thinking the last couple of days about a dry sump system for the corty. I pretty much know the very basic fundamentals of this setup ie: Kind of like a remote sump so to speak. I was wondering if anybody has had experience with this type of setup and is there any advantage of having this setup over the norm. Would appreciate accurate technical information on this please. As detailed in previous posts this car will be street driven but not everyday, Mainly Friday or Saturday nights and the occasional Sunday run.
The most immediately notable thing about dry sumps is that there is more complete oil scavenging and much less windage. Dry sumps were popularized by the ability to have multi-stage pumps that supply various pressures to various areas of an engine thus giving more finite oil system control and responsiveness. Traditional cylinder block oil passages were no longer an issue with "direct feed" oiling made possible by multi-stage pumps. There is really no practical way to make a multi-stage wet sump pump.
If a wet sump system is doing well for your needs, a dry sump may be an expensive add-on that doesn't do much for your power or engine life. There is some talk that more total oil flow can be maintained in a dry sump system due to the amount of power than can be applied to an external pump over the internal wet sump pump through the distributor/cam gear/oil pump drive shaft.
Another aspect of it that pertains solely to racing is that an oil pump failure may not cost you the race when running a dry sump. It is reasonable to understand that a seizure of a wet sump pump is going to stop the distributor right quick, whereas the external pump may just burn up the belt and/or pulley, but will likely not affect the engine ignition for that last remaining tenth...even if at the expense of a totally hosed engine. That extra measure of "racing finishline" insurance is what it takes to be competitive at the highest professional levels...not that I'd know first hand or anything.
Most dry sump oil pumps take more power to turn than a regular wet sump pump due to the multiple stages. It is not impossible that the same engine running a wet sump can make more power than the one with a dry sump. Usually, the added pan scavenging and reduced windage make up for the differences in pump drag when comparing a 3-stage pump to a HV wet sump pump. However, 4 and 5-stage pumps are going to kick up the power consumption in addition to the price tag. One thing to keep in mind is that there are quite a few parts inside of a street/strip Cleveland that *need* oil splash through windage means. Pro Stockers regularly plumbed oil feed lines to the cylinder bores, camshaft bearings and definitely direct feed to the mains. Timing chain sets where a few seconds are all it sees at a time won't mind a reduced oil flow over them, especially when the engine is torn down between rounds and lube is generously applied to all frictional surfaces on the reassembly/rebuild...or, in the case of a lot of Pro Stockers in Cleveland's hey-day...a totally new engine was replaced. A street engine has a groove in the front cam bearing that feeds oil to the timing chain/gears and the distributor/cam gears. Reducing oil flow in this area can be a critical mistake for a street-driven engine.
Anybody who has built a Cleveland knows that the front cam bearing is a rather "huge" oil leak that is designed to make substandard cast iron gears and whimpy chains run upwards of 100,000mi. Reducing the oil flow keeps more oil in the pan/fed to the mains, but at the expense of something else? Modern billet gear sets and nice double roller chains are fairly tough beasts compared to factory gear. Oil restriction to these areas can be applied to better control oil in a wet sump environment. I don't recommend dry sump for any street engine unless ground clearance is an absolute must/problem area.