moving the oil pressure relief valve downstream?

[Hemi Joel]

This could apply to any engine not just in the FE. For my Drag Week effort, I want to send a lot of oil to the valve train for maximum durability with high lift and hefty valve springs. But I often hear concerns about bleeding too much oil away from the main bearings when sending a lot of oil to the top end. When the pressure relief valve is  installed at or near the oil pump (normal), is any tap into the main galley really bleeding off pressure from  bearings that are downstream from it? If so, what would be wrong with moving the pressure relief valve to the opposite end of the main oil galley as the oil pump? Would there then not be full pressure at every point along the main galley, regardless of sending extra oil to the top end? (assuming that the oil pump has sufficient capacity.)
Thanks for any input.
Cordially,
The Artist formerly known as Trunkumus Munkumus

[machoneman]

This could apply to any engine not just in the FE. For my Drag Week effort, I want to send a lot of oil to the valve train for maximum durability with high lift and hefty valve springs. But I often hear concerns about bleeding too much oil away from the main bearings when sending a lot of oil to the top end. When the pressure relief valve is  installed at or near the oil pump (normal), is any tap into the main galley really bleeding off pressure from  bearings that are downstream from it? If so, what would be wrong with moving the pressure relief valve to the opposite end of the main oil galley as the oil pump? Would there then not be full pressure at every point along the main galley, regardless of sending extra oil to the top end? (assuming that the oil pump has sufficient capacity.)
Thanks for any input.
Cordially,

So Trunkus....LOL! Perhaps a better way to ensure valve train oiling is to adopt what NASCAR racers used (and still do) long ago before the modern purpose built spec. engines came into vogue. Spring oilers in the valve covers.

 
The Artist formerly known as Trunkumus Munkumus

[jayb]

Dear Artist formerly known as Trunkumus Munkumus,

If you look in my book you will see that I did that test on the FE by monitoring the oil pressure at various points in the system (I believe you have a copy, but if you don't, I will sell you one for $500).  Yes, there is some pressure bleed-off, maybe 20 psi at the back of the block.  I see no reason why you couldn't put an oil pressure relief valve at the end of the oiling system to address this.  In fact, Ford did that with the factory 427s; they were built with an oil pressure relief valve at the back of the block.

I think you should change your name from "The Artist..."  to "The Artiste ..." .  It will give you a little more panache.

[machoneman]

This could apply to any engine not just in the FE. For my Drag Week effort, I want to send a lot of oil to the valve train for maximum durability with high lift and hefty valve springs. But I often hear concerns about bleeding too much oil away from the main bearings when sending a lot of oil to the top end. When the pressure relief valve is  installed at or near the oil pump (normal), is any tap into the main galley really bleeding off pressure from  bearings that are downstream from it? If so, what would be wrong with moving the pressure relief valve to the opposite end of the main oil galley as the oil pump? Would there then not be full pressure at every point along the main galley, regardless of sending extra oil to the top end? (assuming that the oil pump has sufficient capacity.)
Thanks for any input.
Cordially,

So Trunkus....LOL! Perhaps a better way to ensure valve train oiling is to adopt what NASCAR racers used (and still do) long ago before the modern purpose built spec. engines came into vogue. Spring oilers in the valve covers. Many ways to do so and here's just one idea.

http://www.cpperformance.com/c-356-valve-spring-oilers.aspx

Today's Ford NASCAR engines use the same idea but said oilers are essentially built-in to these high dollar engines that share zero parts with any OEM 351C or 351W design. That said, their must be a reason all these high zoot teams could have done what you suggest...and by their actions strongly reject said idea.

I think I know why. Merely diverting more oil to the top end through the factory designed oiling passages offer little additional benefit in cooling the valve springs , providing better contact area lubrication, etc. Ah, but a directional spring oiler points that oil spray exactly where one wants it and, through tube sizing or actual removable (hence adjustable) jets controls the exact volume required by the builder.     

[Hemi Joel]

I like that spray bar oiling from a valve cover spacer idea, because I need valve cover spacers any way. I shall have to look into that.
I am running some aftermarket rockers that spray the springs and the roller tips pretty well. This engine (an early Chrysler Hemi) sends timed squirts of oil to the valve gear thru a port in the # 2 and #4 cam journals, which line up twice per cam revolution. I cut 360 degree grooves in these 2 cam journals to provide full time oiling to the rocker gear, but I'm concerned about starving the crank for oil.

Jay I do have your book and have read it cover to cover at least a dozen times. I don't know how I failed to remember the oil pressure test. Perhaps old age is affecting my brain cells. But I do seem to remember paying significantly less than $500 for it...

[WConley]

Joel -

Just be sure to provide PLENTY of drainback capability if you're going to be spraying oil up there.  It's truly amazing how fast those valve covers can fill up.

On my SOHC spintron machine, I put a recirculating oil system on for the head, with an adjustable pressure regulator.  I figured 5 or 10 psi would be just fine to keep the cam bearings happy and lubricate the rockers.  WRONG!!  At that pressure the 6 QT pan pumped dry in seconds and the head was drowning.  I had to dial the oil way down to just a little bit of positive pressure.  Despite less than 1 psi pressure at the cylinder head oil inlet, I still saw plenty of oil flowing out the sides of the cam bearings, and the rockers were slinging oil from the tips.  This was perfect, though I still had to provide a 1 inch drainback line to collect the stuff and get it back to the pan.

We had a lot of troubles like this at Ford.  The first 4.6L Mod engines would pump the pans dry and explode on the dyno.  Everybody was worried about keeping enough oil pressure up in the valvetrain to feed the roller finger follower adjusters.   It took a lot of work to improve the drainback system and arrive at the right pressure / flowrate to the heads.

Just a "heads-up" 

[Hemi Joel]

That is some great info, thank you. I was planning to add an external drain to the rear corner of each  head, with a hose going down to the oil pan. maybe I need something about three quarter inch? also, it sounds like maybe I need to restrict the amount of oil going to the valve gear, rather than let it get full pressure from the oiling system. To be honest, that restricting has been suggested to me before, but my thinking was why restrict it? It seemed to me that more oil equals better. But if I can't get it all back to the pan quick enough, then obviously that would not be true.

[Drew Pojedinec]

In fact, Ford did that with the factory 427s; they were built with an oil pressure relief valve at the back of the block.

Clearly, you need to just run a Ford 427 in your dodge......   It'd be worth it just to annoy the diehard types.