dry sump questions

[gt350hr]

    gt350hr is the license plate number on my '66 GT 350 H and a screen name I commonly use. My PRI badge has always said Randy Gillis . I stop by Chris's booth every year. Last year he was out and about but I still said hi to you.

[mbrunson427]

    gt350hr is the license plate number on my '66 GT 350 H and a screen name I commonly use. My PRI badge has always said Randy Gillis . I stop by Chris's booth every year. Last year he was out and about but I still said hi to you.

I couldn't help myself. I looked you up. Nice car, Randy!
https://www.youtube.com/watch?v=v9vYDK5-AyU

[scott foxwell]

    gt350hr is the license plate number on my '66 GT 350 H and a screen name I commonly use. My PRI badge has always said Randy Gillis . I stop by Chris's booth every year. Last year he was out and about but I still said hi to you.

Sorry Randy, I meant no disrespect. Just didn't know who you were. Unfortunately PRI is mostly a blur for me with all the different people I talked to. I spent most of the time at the Rottler booth this year with our new 5 axis machine. Thanks for clearing that up for me. I'll know to be a little more attentive next year.
Edit to add; just watched the vid that mbrunsen posted...beautiful car and now I do remember seeing you.

[wowens]

Dang Randy, that is a fantastic story and a "bitchin ride".

[gt350hr]

   44 years of drag strip abuse by me and no end in sight. There is also a video of a run at Fontana Dragway as well.

[mike7570]

Surprised I don't remember that car, I was at all of the same tracks you mentioned with various mustangs I owned.
I sold a '67 GT500 in 1979, did you look at it in '79?
About '84 or so I was racing a red '67 coupe in super street at all the west coast tracks.  Were you running mostly bracket races with it? 
Very nice car!

[TomP]

Cool Shelby, Randy. I've seen H's at shows around here but never noticed if they have that master cylinder, that is very different.

[Joe-JDC]

   44 years of drag strip abuse by me and no end in sight. There is also a video of a run at Fontana Dragway as well.
[/quote
]Randy, you might appreciate this picture since I bought this GT-500 new, and still own it.  I need to get it back on the road for some of these FE reunions.  At least now I can show it and not worry about being judged for originality.  I quit the car shows because of all the bickering about originality.  It is hard to bite your tongue when you know your car from day 1.  Joe-JDC

[gt350hr]

   Waaaay off topic but I have bracket raced this car since I bought it in '74 . Very little street driving has kept the actual mileage under 87,000. It was painted metallic blue for 27 of those years when I ran the Boss 302 in it.

[blykins]

I've been running a six stage on the SOHC in my Shelby clone for the last several years.  Three pickups in the pan, one at the back of each head, plus the pressure stage.  I was told by the dry sump folks (Peterson Fluid Systems) that this would give me plenty of crankcase vacuum.  That turned out to be BS, it will deliver some vacuum at idle but not when the engine starts running at higher engine speeds.  I was always able to get 15 inches of vacuum with my GZ Motorsports vacuum pump.  For the cost, weight, and complexity of the dry sump system, and no crankcase vacuum to speak of, I'm very disappointed in it.  I'm going back to a normal FE oil pump and pan, a vacuum pump, and an accumulator (Accusump) to ensure oiling under all conditions.

I had a BBF on the dyno today, with a Peterson R4 dry sump pump.  It made 5 inches of vacuum at idle and at full song, was pulling 12 inches by itself. 

[gt350hr]

   Vacuum makes power, provides better ring seal and stops flutter. 14 and under is safe more needs DLC coated pins.

[GerryP]

Randy,

If you could, please do a once over lightly on why crankcase vacuum pulls oil out of the pin boss.  I've read that many times but have never seen an explanation for this phenomenon.  And does the vacuum pull oil out of other surfaces like cylinder walls or Second and Third rings?    In my mind, if the pressure is equal throughout the crankcase then the only things affected would be things on the other side of that pressure differential.  In that regard, I understand why crankcase vacuum is good for ring seal but can't reason out the other part unless the pin is somehow on the positive side of the pressure balance.  Maybe that's it but I can't see how.  Thanks.

[blykins]

This engine was 556 cubes and made 1163 hp @ 8500.  It indeed had DLC coated pins.

A dry sump pump that's good enough to pull crankcase vacuum creates a "depression" in terms of pressure.  Instead of there being copious amounts of oil flung around in the crankcase, the oil wants to go to the low side of the pressure difference.  Wrist pins are not pressure fed in most cases, so there is less oil going to them. 

[GerryP]

So are you saying the free oil in the crankcase is migrating to one of the pickup points?  If that's the case -and to be clear, I'm not disputing that- then is the same thing happening to oil on the walls and on the rings?  And what are the longer-term implications of using crankcase vacuum if it's depleting oil from critical surfaces?  After all, you can't use the same coating on the cylinder wall and rings as you can for the pin.

Again, not arguing the point just seeking clarity.

[blykins]

So are you saying the free oil in the crankcase is migrating to one of the pickup points?  If that's the case -and to be clear, I'm not disputing that- then is the same thing happening to oil on the walls and on the rings?  And what are the longer-term implications of using crankcase vacuum if it's depleting oil from critical surfaces?  After all, you can't use the same coating on the cylinder wall and rings as you can for the pin.

Again, not arguing the point just seeking clarity.

Yes sir.  In my particular case, the pan has 3 scavenge points. 

I would agree with you that the same thing could be happening to the cylinder walls.  However, this engine was sent back to me last year for a freshen up and the cylinder walls looked fine.  Now granted, this is a pulling engine that probably sees 25-30 pulls a season.  All-in-all, it's not a heavily used engine, but it is a max-effort engine.