standard or HV oil pump? - Page 2

Rick Parker · #21 (**permalink**) 01-30-2007, 06:57 PM

Take note of the base plate design on this pump, it has been available for a few years now and is worth seeking out. It has the shaft supported by the base plate along with the pump body instead of just the pump body as was the only previous option. This design is also available for 289/302. It is a much better design, made by Melling.

http://www.precisionoilpumps.com/ima..._Race_Pump.jpg

1blackbb66 · #22 (**permalink**) 01-31-2007, 09:43 PM

Dwight and CobraEd have hit the nail on the head. Pressure and volume are two different things. You want more volume but not pressure. It's the pressure that is hard on the gear. I have run HV pumps on everything for years without problems but have always made sure the pressure is about 65 psi max hot. HV pumps keep the pressure up at hot idle which is a good thing. I would like to hear more engine builders thoughts on this subject.

Ray

jeffko · #23 (**permalink**) 02-01-2007, 05:32 AM

What you guys are not considering is friction. The more volume you put through the same passage, hole or hose the more friction you cause...ie pressure.

Most stock pumps run at 40psi and as low as 15psi at idle. The added volume and pressure that comes along with the volume is needed to force the oil into places it does not easily go under the tremendous forces applied to the bearings and machined surfaces in a high torque engine under full load. Anyone that has ever used plastigauge has seen how thin the space for the oil is and that is a static load. .0020-.0025 is not much of a space especially when you consider the piston driving the big end of the rod down against the crank to force it to rotate against the resistance of the rest of the drivetrain, rear wheels and weight of the car.

Nobody thinks twice about spending several hundreds of dollars on performance parts, but the distributor gear is very often overlooked. It's not that a guy won't buy the correct gear, but rather he is unaware of the problem. Last year there were 3 guys that munched distributor gears in our club and one of them twice in less than 500 miles. Murphy's law can apply at anytime, but most engine parts will perform to design when properly oiled. You can not expect a cast gear to survive against a heat treated, hardened steel cam gear. It will eventually fail.

By the way, I have built my engine and several others even though I would not consider myself an engine builder.

speed220mph · #24 (**permalink**) 02-01-2007, 05:56 AM

Ed: Don't use a high-volume pump unless your engine has extremely high oil clearances, as if it were worn out . Remember that an oil pump always moves the same volume regardless of what it bypasses to maintain the oil pressure set by the pressure regulator. So I suggest you don't install a HV pump and not waste the power as was done "in the old days."

J Persons · #25 (**permalink**) 02-01-2007, 06:30 AM

Quote:

Originally Posted by Rick Parker

Take note of the base plate design on this pump, it has been available for a few years now and is worth seeking out. It has the shaft supported by the base plate along with the pump body instead of just the pump body as was the only previous option. This design is also available for 289/302. It is a much better design, made by Melling.

http://www.precisionoilpumps.com/ima..._Race_Pump.jpg

I use this pump. Preision oil pumps are blueprinted, and are coated internally to reduce friction. They also feature an adjustable bypass spring so you can set your pressure where ever you want it. Well worth the money. John

vettestr · #26 (**permalink**) 02-01-2007, 09:26 AM

The life of this thread has surprised me a bit but I think it is because oil systems are a bit of a mystery. We all add the items common to the Cobra mystique (new distrib maybe MSD + oil cooler + roller rockers + and maybe a roller cam) AND RACING OIL VERY OFTEN, OR A HEAVY WEIGHT OIL.
If a STOCK engine other than the add ons, if the roller cam was stock but upgraded to more getty-up then it is still basically stock. The oil system needs to be balanced to the system. If all is stock then a stock pump with close attention to the oil weight and compatibility of cam/gear is fine. Oil temp is a major thing to get overlooked and often is run WAY to cold. The start up or warm up time is overlooked by many in addition.... come on guys are you always letting her come up to full temp before zinging the RPM ?
As an Ex- auto machinist, drag racer and parts store counter guy I saw what was killing engines all the time. I am talking in very general or stereo type terms here so bare with me a little. The average stock engine does not need 50 W. racing oil and way too many coolers out there without thermostats to control minimum oil temps. Ford's oiling system design does not have a high pressure bypass in the oil filter also but has only 1 at the pump body. Many stock oiling systems have a cooler and a remote filter added to them in a series configuration rather than a parallel design increasing the total restriction. This restriction forces the pump to push against this higher restriction to the point of bypass in some cases. If a T-stat is used then only hot oil would be sent through additional restriction of the cooler. Time to reach the oils minimum temp is also greatly reduced with a T-stat.
Low gage pressure is easy for all to see but the addition loads or wear from high internal pressure is not visible to the driver. As a driver all you can do is (in this order) verify the oils minimum temp is met and then the max is not exceeded. Run the lightest weight oil possible to not violate minimum oil pressure when hot and at an idle. If either of these are wrong then the engine design needs work.
I run modified clearances on all my Toy engines learned from past builds and these larger clearances are to remove engine heat and make parts live. Oil splash from these bigger #'s is also worked on inside but in the end it is still up to driver to watch the pressure and temp's to prove design is correct.
A high volume pump is not to intended to increase oil pressure but rather maintain the needed flow amounts to reach the minimum system pressure. The manufacturer sizes the stock pump to a stock need, it is only when demands for size or flow increase that a hi volume pump is intended to be used. The catch is many have increased the needs or want a little reserve over factory bottom line design. More damage is caused by to heavy of an oil and being to cold than inadequate flow in my experiences.

jeffko · #27 (**permalink**) 02-01-2007, 11:10 AM

Jeff, great comments for a bowtie guy.

I would like to reiterate your comments on oil temps. Engine oil is designed to be fully functional at 212 degrees. It is also the temp that viscosity is determined at. I know of a few guys that run an oil cooler without a stat. Temps for the couple that have oil temp gauges pretty closely follow the water temp or actually a little lower. In affect they are changing the viscosity of their oil and consequently is too think to be 100% effective because the oil is to cold. I don't know much about it, but I have heard about something called bearing wash when using oil that is to thick for the bearing clearances. This is the reason I run mobile one in my other cars. It gets to its viscosity much quicker than standard oil, especially in cold Chicago winters. Even then I still give the car several minutes to warm up the oil. Anyway, the point is that oil temp is critical and you really should have a gauge to monitor it, even with a stat.

I should also clarify that my oil pressures are without an oil cooler which I am presently installing, but my pump was designed for the added restriction. I should loose about 10-15 psi depending on the hose routing. Last year was my first full year of the car being sorted out and the oil temp on hot days was sometimes 250 degrees.

hi-tech cobra · #28 (**permalink**) 02-01-2007, 06:41 PM

A HV or stock oil pump? Sounded simple, now I'm lost. Do I get a HV or stock pump or should I get the Precision Oil Pump and adjust the pressure (what should pressure be?).

Engine: 347, Eagle stroker, Comp Cams XE282HR, AFR 185 heads, blah, blah, blah. It's not great but I hope it's one mean little mother. It will have to tide me over until alum 427 is in the budget. My goal: drive the thing, it's been sitting for 8 years collecting dust. First wife made me pay dear for it, second wife not as supportive. Is there a support group for men with wives who hate cobra's?

How do you control oil temp, if the oil cooler keeps the oil from reaching optimum temp.

jeffko · #29 (**permalink**) 02-01-2007, 07:52 PM

Thats a very healthy cam. I like the extreme energy cams because the 112 lobe seperation makes makes a very good vacuum signal which produces good torque. With the 185s, upgraded springs and full roller rockers you will get the 450 at the crank and more. I would advise at least a 750 cfm carb and a victor jr or air gap intake. I would not be surprised if you made power closer to 500.

At this point this becomes more of a discussion than texting messages. PM me a phone number/time and I would be glad to call you and help if I can.

hi-tech cobra · #30 (**permalink**) 02-01-2007, 08:07 PM

Jeffko,
Air Gap intake, Proform 750 (mech. secondaries), meziere electric water pump, Cam has custom grind 110 lobe sep., Comp Cam mag roller rockers. Why spring upgrade on AFR's? Still confused about oil pump!
Thanks

olddog · #31 (**permalink**) 02-01-2007, 08:29 PM

I have some experience in the design and operation of gear pumps used to pump molten plastic. They are similar in design to an oil pump. FYI a small amount of the molten plastic flows through the bearings as a lubricant. Pump range is size from a few hundred lb/hr to several hundred thousands of lb/hr.

Torque is proportional and linear to the pressure. So, if you double the pressure you will double the torque required to turn the pump. The point is that increasing either the pressure or the flow will put more load on the distributor gear.

Pressure is the result of friction resisting flow. An orifice plate is often used to measure flow, by measuring the delta pressure across the plate (restriction). Flow is measured by taking the square root of the delta pressure. Therefore as flow increases, the pressure increases by the square of the flow. P = mF^2. The point being that a small increase in flow will result in a large increase in pressure.

No pump is 100% efficient, if the exit pressure is higher than the inlet pressure (delta pressure). Efficiency drops off as a factor of the delta pressure squared. So, as the pressure increases the efficiency of the pump and thus the flow will drop off. This all depends on the clearances in the pump. The point is don’t forget to blue print the pump.

Engine oil pumps have a pressure relief valve that opens, lets say at 70 psi. So no matter how much volume of oil the pump puts out, the pressure to the engine is limited to 70 psi. At 70 psi a certain volume of oil will flow to the engine, for a given temp and viscosity oil. If the pump is putting out twice this volume of oil then half is flowing to the engine and the other half is bypassing out the relief valve. Therefore half of the hp used to pump oil is wasted.

A high volume pump, with the same relief valve setting as a normal pump, is only going to supply more volume to the engine at lower rpm, when the pressure is lower than the relief valve. Once the relief valve is open the extra oil is dumped out the relief valve. It does nothing for the bearings, and worse it waists hp.

Going to a higher relief valve setting (spring) on a stock pump makes the most sense to me. However all the bearing and other clearances need to be, on average, near the middle of the specs. A loose engine is going to need more volume to build the same pressure.

I have never been a big fan of high volume pumps. I’m sure there are times in all out racing that it may be useful in certain engines. Most Ford pushrod engines suffer from a poor designed oil system, and a high volume pump will do little to solve that.

1blackbb66 · #32 (**permalink**) 02-01-2007, 09:39 PM

Hey Hi-Tech...You feel a little dizzy?
I know I do.
Good stuff, thanks everyone.

Ray

LMH · #33 (**permalink**) 02-01-2007, 10:35 PM

Hi-Tech
If you use an oil cooler, you should also use a thermostat to prevent oil from running throught the cooler when it's cold.
Stick with a standard volume/standard pressure pump for a street engine.
Larry

vettestr · #34 (**permalink**) 02-01-2007, 10:55 PM

Hey Hi-Tech and Jeffko,
Hi-tech it looks like a sweat combo and fact she is a stroker alone tells me she is not a Stock engine. Many of the aftermarket parts listed like your Eagle recip. assembly have a little extra clearance built in to them. The clearance I believe is opened up from stock is the rod side clearance and I know they have a nice radius on the crank pins so a Hi volume pump in my opinion would be right in line.
I know there are other schools of thought here and have read some of the stock hard liners support and I respect their opinion to run what they want. My 2 cents is too suggest running a higher volume pump. You asked what to do if oil temp was low running a T-stat with a cooler. If cold that is an easy fix with simply blocking the coolers air flow. Even though all systems have a bypass valve the systems are ON BYPASS very seldom if at all. It is rare for any stock or aftermarket pump to go on the bypass mode with exception to last resort or just before other things fail. When on oil pump bypass no filtration is done it is just dumped back into the pan.
Jeffko... That is from a chebbie guy so the best I can do. LMAO !! Your oil temp is not that bad at 250*, I would rather see it at 250 than at 150* all day long. Then again I raced an old Chrysler's (well kinda) for years so who knows. All this talk about oil and pumps reminds of the days before knowing better or at least good sponsorship. We would wait till the alky floated on the oil so we could pour it off after separation and run it again. We would get 2 to 2 1/2 quarts of alky in the oil after a weekend.

jeffko · #35 (**permalink**) 02-02-2007, 06:27 AM

vettestr, I certainly agree about the higher oil temp. Ideally I want to get as close to 212 (minimum) as I can.

By the way, the drilling an .040 hole in the right bank plug is an old bowtie trick I learned from my days of being on the dark side.

hi-tech cobra · #36 (**permalink**) 02-02-2007, 06:58 AM

LMH you wrote: "you should also use a thermostat to prevent oil from running through the cooler when it's cold"

Is this some kind of by-pass valve that is thermostatically controlled? I live in Jax, FL so is it necessary? Me thinks get the car running and then see what oil temp is doing!

Some things can get so darn complicated. Like the distributor gear. Comp Cams tells me I need a Melonized distributor gear for my roller cam. MSD tells me 1/2 the time: "We don't have a melonized gear." and the other 1/2 they tell me part# 8598 has a melonized gear. Ford Racing tech tells me to get a composite gear. Summit sold me a steel Ford Racing gear, they said it had melonizing on it, Ford said it does not. What the ..............!

My brain hurts.

Dwight · #37 (**permalink**) 02-03-2007, 02:55 PM

How do I increase the oil temp? I have a 5.0 EFI, 7 qt Canton oil pan, remote oil filter and no oil cooler. Oil temp is 160 low side and 180 hot. Oil temp sensor is in the oil pan close to where the dip stick enter the pan. The oil should be at it's highest temp in this area. Suggestions?????
Dwight

jeffko · #38 (**permalink**) 02-03-2007, 09:13 PM

My first inclination would be that your gauge is not reading accurately, because this is quite improbable. My oil temp and water temp gauges and probes are the same so if you can put the oil temp lead on the water temp gauge and see if you get the same readings. I would say you definetly have a problem if they are and I am not sure how to cure it, but I will try to research it. Let us know what you find out.

Shelboss · #39 (**permalink**) 10-24-2007, 08:18 PM

A steel gear is good for OEM roller cams but not solid rollers. To date, the only option has been bronze. I was looking for info on the new Comp Cams composite distributor gear and saw another thread on this subject. Supposed to solve the wear problem associated with the bronze gears, but burnishing the cam gear also recommended along with blueprinting mating parts.

Rick Parker · #40 (**permalink**) 10-24-2007, 08:30 PM

Several years ago (after reading an article in Circle Track) I contacted the company that made the composite material that was to be used in the gears. I spoke with one of the engineers. At the time they indicated Comp Cams was going to be the vendor and that the gears were at that time only approved for dry sump application because the composite at that time did not have the strength needed (after R&D) to be used in a wet sump application for anticipated pressures in a race engine. Things may have changed by now.