Low Deck 451 Oil Pressure

[hemi446]

Here's my two cent worth first when you run that heavy weight oil it does take more HP to turn the oil pump I run straight 20w oil with a friction modifier (BG MOTOR OIL ADDITIVE) all the time on the track. The oil has too lube & cool the internal rotating parts but you are not running a long time but you are putting the max load on all the time. On the line size the bigger the oil gauge line the quicker the gauge reacts to the change in the throttle movement and if you have a problem it with show up right away if the gauge is at 80 PSI on the top end and now your down as little as 10 PSI you most likely have a problem. You may not hear it but you may have a vibration that wasn't there before. So it's time to check it out before the whole thing goes south and you have a bigger problem.

 

[godfatherofchry]

Piston operated brakes are an entirely different application than a gerotor style pump. But for the sake of a 12 page argument, you're right. I'm wrong.

come on Rob,lay it on him don't give up that soon :violent1: but I know where youre coming from all you can do is try to help I have been around race cars my whole life hell I was even conceived at a race track after my dad had won a race.and I have never lost a motor of my own and you can ask anyone that knows me I twist the hell out of them.(it gets my glands activated )and I never felt so dumb until I try to help someone..I don't know maybe its me...OOOOOOOO well...........Artie

 

[godfatherofchry]

Here's my two cent worth first when you run that heavy weight oil it does take more HP to turn the oil pump I run straight 20w oil with a friction modifier (BG MOTOR OIL ADDITIVE) all the time on the track. The oil has too lube & cool the internal rotating parts but you are not running a long time but you are putting the max load on all the time. On the line size the bigger the oil gauge line the quicker the gauge reacts to the change in the throttle movement and if you have a problem it with show up right away if the gauge is at 80 PSI on the top end and now your down as little as 10 PSI you most likely have a problem. You may not hear it but you may have a vibration that wasn't there before. So it's time to check it out before the whole thing goes south and you have a bigger problem.

20wt oil WOW im glad Im not building your motors.and the difference in hp with 50wt race oil is around 3 hp (the top fuel guys run 70 wt.or at least used too..and most of the oil that's in your car or motor is for cooling.and if you look at the dry sump systems they run anywhere from 2 to 20 gal.and most or all nascar and road course cars run a cooler with them.............Artie

 

[txstang84]

Artie, I don't think anyone here is necessarily arguing your point of view, but as I mentioned in my own reply before-there are different schools of thought on this one, and yours is one of many...evidently, yours is to use the heaviest oil you can run and get the highest pressure you can. Others run a lighter oil, and to my understanding that's based on the intended usage of the vehicle and the way the engine is put together.


Mod motors, for example, whether dry sump or wet, usually run 5W-20...and those engines run over 8000-8500 rpm in drag race environments-some at 9500 rpm swinging a 4.165" stroke. They're not wrong either...different applications have different requirements, and different methods and specifications during assembly demand different accoutrements.

 

[RustyRatRod]

I know in Garlits' book he says run um loose with LOTS of oil pressure. No one can argue with his record.

 

[txstang84]

I know in Garlits' book he says run um loose with LOTS of oil pressure. No one can argue with his record.

This isn't a matter of anyone arguing...but the OP isn't driving a 500ci KB Hemi fed a couple dozen gallons of nitromethane, aspirated by a 14-71 blower, lit off by dual magnetos, pushing 8,000hp either. (although that is one helluva daydream)

Different needs based on the conditions...if big block Mopars truly need heavyweight oil pushed to/beyond 100psi to be reliably run on the drag strip, I'll bear all that in mind when my 383 project finally comes to fruition.

 

[IQ52]

As long as the cooling system keeps the engine heat down, the engine oil will be fine. Pressure has nothing to do with the load on the intermediate shaft, either. It's the volume that causes the drag. Once you have an HV oil pump, you have an HV oil pump. As long as you have the hardened intermediate shaft, you are fine. Stress on the shaft does not go up with pressure. If you have an HV pump, you have all the stress you're ever gonna have on the shaft right there. Stress does not increase with pressure, only volume. So, a standard volume pump has one level of stress and an HV pump another. Simple as that. I have always said that as long as the engine is not blowing oil filters off or apart, leave it alone. I think you are looking for trouble where there may be none.

I always thought pressure was a measure of resistance. The more resistance, the harder the pump must work.

If you are pumping up an inner tube by hand, is it easier to push the pump handle when the tire is empty or when it gets to 30 psi?

 

[hemi446]

Your right everyone has there on way of doing things and setting up there engine for the intended use. My way has worked very will for me and my customers. But since I have been doing all my own work in my own machine shop for 25 plus years I can afford to do it my way and when someone wants it done different I'm happy to let them go some where else because I don't want my name to go down with them if something goes bad. How many times has the machine shop been blamed because someone else assembled something wrong or didn't measure everything or check proper clearance. Thanks for letting me rant.

 

[roccodart440]

General rule of thumb is 10psi per 1,000 RPM. Whether thick oil with loose clearnences or thinner oil with tighter clearences you need to be in that ballpark. Excessive oil pressure is not helping you or the oil.

Just as a reference the GT500 650hp mustang which is a FA engine to boot runs 5W oil.

 

[godfatherofchry]

buddy I don't think any of us are saying you're wrong. my self im saying Im not a big fan of thin or split wt. oil..and evry chry.motor I have ever had any thing to do with has had oilpsi.in the airea of 70 to 110 on fisrst starting and ideled in the area of 40 or 50 I have had one stock car motor that bluw the filter clean off the car at 7500 and yes that got changed with a weeker spring.but any ways I think its the nature of the beast..and I love them for it.that being said I drove a frends car or was going to (chevy:bangheadstarted with 70 psi.did my burn out stataged (first lite) started looking at the gages one last time looked at the oil and wow 10psi.I amedaly shut it off had them psh me out of staging area my buddy come running over whating to know whats wrong told him he laft and said it was normal to run it (and knowing the history of chevy guts all over the track) I told him not with my big *** behind the wheel.4weeks later he dumped the guts out of her.I put together a 454 for him my way lots of clearance 50wt. oil stretched the spring it ideled at 45 psi.and 80 threw the trapes and lived for two years tell it droped a valve..the keeper broke...so if that's beenworking for you I say stik with it:cheers:............Artie

 

[roccodart440]

(and knowing the history of chevy guts all over the track)

This is the type of comments that keep me away from 1 brand lovers.

I put together a 454 for him my way lots of clearance 50wt. oil stretched the spring it ideled at 45 psi.and 80 threw the trapes and lived for two years tell it droped a valve..the keeper broke...so if that's beenworking for you I say stik with it:cheers:............Artie

45 at idle and 80 at WOT and redline. No issue there at all. Over 110PSI... yeah, there's a problem there.

 

[vestracing]

The guy I bought the car and motor from finally sent me the engine builders name and number. Apparently he is a Mopar Top Sportsman racer so I am going to call him and find out the details on why clearances he built it for. Thanks for all of the replies.

 

[vestracing]

I really want to get an oil temp gauge installed for safety and I am switching over to methanol this winter and will need. Were do you guys install the oil temp probe on these motors?

 

[RustyRatRod]

I always thought pressure was a measure of resistance. The more resistance, the harder the pump must work.

If you are pumping up an inner tube by hand, is it easier to push the pump handle when the tire is empty or when it gets to 30 psi?

Hell if I know anymore, Jim. I know I am getting really tired of people changing the rules in discussions just so they can be right. Be it oil pumps, leaf springs or whatever.

All I do know is, what I have been for along time works for me, but I am sure someone will be along to tell me even how that's wrong. I am just growing tired if all the f^&ing experts.

 

[moper]

"All I do know is, what I have been for along time works for me, but I am sure someone will be along to tell me even how that's wrong. I am just growing tired if all the f^&ing experts."


That's totally wrong. Nothing has worked for you. I read it online.


Nothing wrong with doing what has worked. At least for me there's a lot I used to do that worked for me but mostly because I was lucky - not good. and even more that didn't work for long...lol. Nobody starts knowing everything and I've yet to see anyone die knowing it all despite their claims to the contrary.

 

[txstang84]

You can't be serious, Rob...if you actually thought that, you wouldn't have nearly 19,000 posts in a little over 3 years.

 

[RustyRatRod]

Yeah. I am. It's getting kinda old.

 

[CPMotorworks]

Hell if I know anymore, Jim. I know I am getting really tired of people changing the rules in discussions just so they can be right. Be it oil pumps, leaf springs or whatever.

All I do know is, what I have been for along time works for me, but I am sure someone will be along to tell me even how that's wrong. I am just growing tired if all the f^&ing experts.

Stomp your feet now and stick out your lip...

Really? pity party for poor Robby?

What Garlits did in the 60's with a TF on load has nothing to do with what is being discussed here.

I'm not trying to make you look bad Rob, your doing it your self by denying principles already well known. Saying it over and over doesn't make it true.
http://en.wikipedia.org/wiki/Pascal's_law

Pascal's law or the principle of transmission of fluid-pressure is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure variations (initial differences) remain the same.[1] The law was established by French mathematician Blaise Pascal

Pascal's principle applies to all fluids, whether gases or liquids. A typical application of Pascal's principle for gases and liquids is the automobile lift seen in many service stations (the hydraulic jack). Increased air pressure produced by an air compressor is transmitted through the air to the surface of oil in an underground reservoir. The oil, in turn, transmits the pressure to a piston, which lifts the automobile. The relatively low pressure that exerts the lifting force against the piston is about the same as the air pressure in automobile tires. Hydraulics is employed by modern devices ranging from very small to enormous. For example, there are hydraulic pistons in almost all construction machines where heavy loads are involved

Why do you use a hardened intermediate shaft if stress doesn't go up with pressure?
Pressure is the measure of resistance.
You can't fit 10lbs in a 5lb bag.

 

[RustyRatRod]

Stomp your feet now and stick out your lip...

Really? pity party for poor Robby?

.

No I don't mind getting things wrong happens a lot. I am upset because we are fixin to start losing stuff. Just took it out in the wrong place. Thanks for the compassion.

 

[inkjunkie]

I understand what you are saying BUT.....what good will a large line do when you are feeding thru a very small fitting? The fittings become the restriction....had this very discussion a while back with a trans shop about running larger cooler lines.....Not looking for a war, just to understand....

well if you get the fittings to go with the big line you will see what I mean.if you call summit they sell the big line in a kit I think the whole kit is like 60.00 bucks but if you get just a line (can't remember the size 4 I think)here better yet (sum-G2960 3ft.line kit 24.95)there I even looked it up for ya and is cheaper than I thought.try it I think you will be impressed.and it will last you a life time If taken care of.............Artie

After I typed the first thing I quoted my brain un-locked itself & I realized what I was thinking was not at all what is being discussed. I was thinking about increasing the volume of flow....from my understanding (lets just say I am talking about a trans & the cooler).....increasing the size of the lines themselves is not real beneficial unless the size of the fittings goes up as well. For example, lets say you had a 1/4" npt adapter threaded into a cooler. And you had a 5/16" line attached to it. There would be no real benefit, other than a slight increase in capacity, by swapping the 5/16" line for say a 1/2" line.....the restriction at this point is the 1/4" npt adapter. A larger line will do nothing to increase the flow...at least that is my understanding of it....

 

[CPMotorworks]

After I typed the first thing I quoted my brain un-locked itself & I realized what I was thinking was not at all what is being discussed. I was thinking about increasing the volume of flow....from my understanding (lets just say I am talking about a trans & the cooler).....increasing the size of the lines themselves is not real beneficial unless the size of the fittings goes up as well. For example, lets say you had a 1/4" npt adapter threaded into a cooler. And you had a 5/16" line attached to it. There would be no real benefit, other than a slight increase in capacity, by swapping the 5/16" line for say a 1/2" line.....the restriction at this point is the 1/4" npt adapter. A larger line will do nothing to increase the flow...at least that is my understanding of it....

The small copper/plastic lines dampen the signal/pulses in the system. It isn't flowing anything as its a dead end. The gauge is less sensitive/reactive to fluctuations in the system. Use a -03 or -04 braided brake line and AN fittings and you will be surprised at how much the gauge will pulse at idle. And yes, if you pay attention you can see when there is a 5lb drop (or more) in normal pressure when say a bearing gets wiped. I always tell my customers to use a braided line for that reason, much less its safer and less likely to leak.

 

[hemi446]

I haven't been on the forum long enough to be right or wrong on anything and with all the crap I get for running an AMC I think everyone has a point and we all need to take it into account every ones good & bad experience's after all isn't that what it's all about. And by the way I have broken, distroyed, crashed more stuff than I can remember and if was made by the General it was the first to give it up. That's why I like Mopar so much it's the great cars and almost indestructible. How many guys run 833 transmissions instead of a Munchy. Thanks Guys

 

[CPMotorworks]

No I don't mind getting things wrong happens a lot. I am upset because we are fixin to start losing stuff. Just took it out in the wrong place. Thanks for the compassion.

My compassion and your situation has nothing to do with trying to point out your statements regarding oil pressure vs loads to be false.

 

[moparlover]

the bottom line is when it's at operating temp it runs at 75-80 psi crossing the finish line which is fine.
it's actually good. i cant say i'd want it running at 45 psi crossing the line or at 110.

i think you got a nice setup and lots of detractors here

and i dont think "power robbing" losing 1.2 horsepower or whatever from too thick too much volume too much pressure or whatever will even be noticed by your big horse 451 clydesdale motor lol

p.s. the REAL reason the cars nowadays come with 0w20 or 5w whatever is because you get better mileage. EPA estimates. government incentives. etc. it's not for "tight clearances" like bench racers like to spout. less resistance is less work to pump it so you do save some power, and get a tiny bit of mpg. they are using every trick in the book to get their mileage ratings higher.

 

[airwoofer]

We have always ran vr1 20w50 in all of the big blocks we have raced as well. Another question: with the indy head oiling lines coming out of the rear of the block where can I install an oil temp gauge? I am switching over to alcohol over the winter and want to be able to monitor oil temperature.

How are you regulating how much oil gets fed to the indy heads? I have separate lines running to my indy heads from the main galley on the World block, no tees just two complete separate lines. Right now I have 0.090 orifices in the block and will have a set of 0.050 ready when I take the motor to the dyno. Want to balance pressure overall and flow to the heads, with not too much or too little up in the valve covers.