Guest Anonymous Posted July 15, 2001 Share Posted July 15, 2001 When I am running the car up on RPM, I just noticed that after 4K, the oil pressure starts dropping. Is that normal? I get 10psi per 1K until 4k, and then it drops. Thanks Ct.. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 15, 2001 Share Posted July 15, 2001 Chris, What gage and sender are using. I had the same problem with the datsun stuff and when I switched to autometer it regitsered like I thought it should. Mark Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 15, 2001 Share Posted July 15, 2001 You may be pumping oil to the top end before it can drain back to the pan. May have low oil level, poor drain back or a bad gage. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 15, 2001 Share Posted July 15, 2001 The gauges are autometer pro comp mechanical. Ct.. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted July 15, 2001 Share Posted July 15, 2001 If you are using a high volume oil pump, there is a possibility that it is sucking out most of the oil out of the pan before it has a chance of flowing back down. Just a thought. Remember, the oil is also beat to a frothy pudding at high rpms by your crank unless you have a windage tray and/or screen to combat that. Just food for thought. Davy Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 17, 2001 Share Posted July 17, 2001 Davy, It does have a Melling High Volume pump in it. That could be what's happeining. Is it time for a larger pan? Ct.. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted July 17, 2001 Share Posted July 17, 2001 I would think so, but just a larger pan won't solve all your problems at 5000 rpm! If you are going to the expense of changing the pan, you might want to look into a windage tray or something. Hopefully someone else will offer an additional opinion. You may want to ask John Coffey who races his Z on a regular basis. Likewise, Scottie GNZ does a lot of road racing (more than drag racing!), and Andrew B, Ron Jones, Rick B, etc, etc. drag race too. Hopefully some will chime in...guys? Davy Quote Link to comment Share on other sites More sharing options...
pparaska Posted July 17, 2001 Share Posted July 17, 2001 I've heard from some knowledgeable people that the hi volume pump is NOT the hot ticket, but the high pressure one. And for just the reason Davy stated. Quote Link to comment Share on other sites More sharing options...
Guest JAMIE T Posted July 17, 2001 Share Posted July 17, 2001 High volume pumps also use more HP to turn them. I always recommend a stock volume pump to those who chose to run the stock oil pan. I've heard of a 427 big block with a high volume pump that had, I think 80psi at idle. It must have been a very tight toleranced engine becuase when the guy installed a stock pump, it still had 60psi at idle. I've been playing around with oil weights in my 94 Z28 6spd, and I like to use Mobil 1 synthetic 0W30 Extreme performance oil. The engine revs very fast and smooth, but pressure is a little lower than with other oils. I will run this in every engine on race day. Its funny because NASCAR and NHRA builders use oil thats as light as water(or so it seems) in the qualifying engines to extract every last HP from an already max effort engine. Jamie Deathstar Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted November 25, 2001 Share Posted November 25, 2001 I think there are some good points and some miss- information here lets go through a few points (1)oil is the main cooling fluid (in) your engine and good CONTROLLED FLOW over the bearings and friction surfaces such as pistons,rings,cam lobes, lifters,cylinder walls,rocker arms,valve springs, and distributor gear is what does the main cooling by absorbing heat and carrying it away from the heated surfaces. (2)pressure has almost nothing to do with the pump you use ,its the resistance to oil flow that builds BACK PRESSURE in your engine mostly due to bearing clearances and the resistance of the pressure return spring in your oil pump! (3)the larger the voluum of CONTROLLED oil flow through your engine the better the internal cooling and bearing lubracation. (4)controlling your oil flow requires haveing a pump that provides large amounts of oil at LOW rpms, most pumps have enough pressure and voluum at the mid range rpms and almost every pump (with the addition of a high pressure spring and a large oilpan) will work at high rpms. (5)oil flow raises in relation to rpm and since its a non-compressable fluid, your main problem is not pressure but keeping a pressureized flow of oil on all surfaces, and the main problem is keeping more than enough oil in the sump around the oil pump pickup not in the valve covers,lifter gallery, and being whipped around by the rotateing assembly. (6)a high voluum oil pump with a high pressure spring(LIKE THE DYNAGEAR #M99HV) with the addition of a good seperator type windage screen like the MILODON #32250 (SBC) AND A GOOD OILPAN like the KEVKO 8-QT WITH TRAP DOOR OIL CONTROL GATES AND CRANKSHAFT SCRAPPER (THE WINDAGE SCREEN AND PAN CAUSE THE SPINNING CRANK TO ACT LIKE AN IMPELLER AND PUMP OIL BACK INTO THE SUMP)WITH A LITTLE SMOOTHING AND CONTOURING OF THE OIL RETURN HOLES IN THE BLOCK AND A HIGH FLOW OILFILTER AND AUX OIL COOLER WILL WORK WONDERS.AND ANOTHER THING TO BE VERY CAREFULL ABOUT IS TO MAKE SURE THAT THE OIL PUMP PICKUP IS 3/8"-1/2" FROM THE BOTTOM OF THE OILPAN, ANY CLOSER AND YOU SERIOUSLY RESTRICT OIL FLOW INTO THE PICKUP,(I NORMALLY BRAZE A 1/2"NUT TO BOTH SIDES OF THE BOTTOM OF THE INTAKE PORTS ON THE PICKUP TO MAKE SURE THE DISTANCE IS MAINTAINED)btw synthetic oil works better than dyno oil and has a wider temp> range AND YOUR MORE THAN FREE TO DISAGREE BUT AFTER BUILDING DOZENS OF STOCK CAR AND DRAG RACING ENGINES I HAVE NEVER LOST ONE DUE TO BEARING TROUBLES,SCUFFED PISTONS ETC. http://www.2timer.com/abmmotor/assembl.htm http://www.dorianyeager.com/oilfilterstudy1.html http://www.micapeak.com/info/oiled.html Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted November 25, 2001 Share Posted November 25, 2001 Interesting, my oil pressure falls some when I get into th eupper RPMs too. I THOUGHT it was because I'd removed the oil bypass feature to the filter. As a result I put in a System one filter hoping that the lowered restriction would keep the pressure higher - I was also worried about the OEM type filter exploding as it was leaking a bit around the seal (remote mount). Anyway, with the System 1 filter I still see some leakage around the seal and the pressure still falls but I believe it doesn't fall as much. I've considered porting the remote mount piece some but have yet to do it (I DID deburr the damned thing though!). At 5K+ I still see more than 40PSI when warm. I've pretty much just left it alone figuring it's getting enough. I didn't think the pump was a high volume unit - the gauge is a mechanical Autometer. I see as high as 80PSI+ when cold at lower RPM, 60PSI+ when warmed up and below about 5K. Actually it only falls under sustained WOT - I have to stare at the silly thing to see it and that's SCARY. Otherwise it hits a peak pressure and pretty much olds - it doesn't just keep climing way up. I DO have a big oil pan - something like 9 quarts (Moroso). I don't see 5K very often, 7K once in a blue moon How worried should I be? The lines to my remote mount are -6 but I suspect the remote mount could be ported a bit more. Was I chasing the right thing? Should I put in a bypass? I'm using the larger System1 "trashcan" looking filter with a stainless screen in it. Quote Link to comment Share on other sites More sharing options...
pparaska Posted November 26, 2001 Share Posted November 26, 2001 Hi grumpyvette - we went through this topic a week or so ago on Chevytalk, huh? You swayed me to looking for a high volume pump. Your theories make sense to me. One thing that makes sense is to do what we can to reduce spark scatter from lots of buildup and poor feedback inside the pump with lots of backpressure. Is this right? For years the idea of making channels in the pump case and cover have been done to provide a feed back channel to reduce/eliminate spark scatter from the oil pump having a drag on the distributor. Now Moroso (others) make a "blueprinted" pump with those grooves, etc. Milodon makes an 18750 that I want to use (high volume, high pressure, accepts a 5/8" pickup). I'm stuck with the 5/8" pickup since the Vette pan I'm using uses a special pickup that's 5/8". Does anyone that anyone knows of make a blueprinted pump with these grooves in a high volume, high pressure format that accepts a 5/8" tube? The HVHP pumps that I can find are blueprinted (Moroso 22112) use a 3/4" input tube. Moroso Wet Sump Oil Pumps I guess I can just pull out the Dremel and do it myself, but I'm getting lazy. I guess that MV55A Z/28 pump (standard volume, high pressure) is for sale now... Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted November 26, 2001 Share Posted November 26, 2001 you are not stuck with that 5/8" pickup they make the same pickups in 3/4", one of these people have one that will work with your pan. http://www.performancemarket.com/oilpan.htm or you can get a pan simular to the pan I just bought for my vette from MIDWEST MOTORSPORTS #mwm15120 --7.25" deep 7 quart available in right or left hand dipstick for $59-$69 (great deal for what you get and they can get you the correct pump and pickup too, www.midwestmotorsportsinc.com or with very little work you can get many available 3/4" pickups to work.BTW the part #1010 for the 3/4" pickup matching that pan is mwm ($19.99) so you can have a good matched setup with your big pump for under $100 and thats a road racing pan with 7 qt capacity and its only 7.25" deep for great ground clearence (its got 1/4" more ground clearence than most stock vette pans) Quote Link to comment Share on other sites More sharing options...
pparaska Posted November 26, 2001 Share Posted November 26, 2001 grumpyvette, thanks for the help. I'll look for a 3/4" pickup for this pan or adapt another or something. BTW, when I look online at the mwm 15120 pan and 15120K kit, it shows a left hand turn only claimer pan. Also, The vette pan I have is more like 7" deep. Yeah, splitting hairs, but anything to get it up a bit helps with the SBC in the JTR position. Is that pan (15120) really a road race pan and the web site is hosed? I ordered their catalog online. Thanks again! Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted November 26, 2001 Share Posted November 26, 2001 Chris T., does your setup justify/require a high volume pump? Just checking as that and too large a cam are two of the most common 'oops'/didn't need it' errors. Not saying you don't need it...just asking. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted November 26, 2001 Share Posted November 26, 2001 the pan is available left dipstick #15120 $59.99 or right dipstick #15121 $69.99 and yes the pan has a slight(3") kickout to the right side but the baffles all direct the oilflow to the rear of the pan for the pump pickup and the baffle doors only allow oil to move toward the pickup so what you have is a pan/pump layout that has a stock corvette configuration with an extra wide sump with far superior oil control. the only down side I see is that some starters may not fit but almost any of the smaller high torque ones will! and that if your headers are closer than 3.125" to the passenger/right side of the factory pan within 10.5" from the rear of the pan it may not work in your application.but otherwise its a much better pan than the corvette pan.BTW I forgot to mention that I just saw a artical that said if you use nitrious that the slight extra oil voluum from a high voluum pump spraying around in the sump greatly helps cool the pistons from the bottom side in some cases by over 100 degs and if a few extra shallow grooves in the rod mateing areas and a small hole in the web area of the main bearings pointed at each piston from the main bearings is drilled to direct oil at the piston bases even greater cooling can be accomplished Quote Link to comment Share on other sites More sharing options...
pparaska Posted November 26, 2001 Share Posted November 26, 2001 Sounds alot like the Canton Racing 6.5" deep 6 quart pan (which I think is better for left and right turns). Problem with many of the V8 Z conversions and these pans is that the block huggers point down at the kick outs, and you need to plan the exhaust around them. My exhaust is done and coated and I don't want to do it over. Quote Link to comment Share on other sites More sharing options...
John Scott Posted November 27, 2001 Share Posted November 27, 2001 ...and the pans, if its #15-240 cost an arm, leg and foot. (325.00) JS Quote Link to comment Share on other sites More sharing options...
pparaska Posted November 27, 2001 Share Posted November 27, 2001 JS, yeah, I think that's the pan - very expensive but it's great insurance if you're winging it around a road coarse AND you want the most clearance. Quote Link to comment Share on other sites More sharing options...
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