Melling HV vs Ported LS6 oil pumps
01-07-2010, 12:24 PM
#41
Engineers have no idea what goes on in the real life. Working with parts and tearing an engine apart because it trashed some bearings and running the autopsy to make sure what it died of speaks louder than anything written in a book.
Unless you work for melling, ill have to say that because you cannot prove it and we can find evidence to support it, that only points in one direction.
And as far as i know, restriction just builds pressure, not impedence to volume of flow. The surface area of the (well what used to be the rotors) is what builds the volume...
Unless you work for melling, ill have to say that because you cannot prove it and we can find evidence to support it, that only points in one direction.
And as far as i know, restriction just builds pressure, not impedence to volume of flow. The surface area of the (well what used to be the rotors) is what builds the volume...
Your last statement is a little fuzzzy to me, but one part is correct. A restriction does indeed build pressure. The 'not impedance to volume of flow' is a little off base. The restriction is the impedance, one in the same. Consider volume and flow the same, because they are. And well, the oil pump is what makes the volume. Without volume you cannot have pressure and without a restriction you cannot have pressure. That is correct. So if your engine clearances were too loose, your restriction becomes to big and your pressure decreases, UNLESS, you have additional volume to push through, hence the use and benefits of a HV oil pump.
Your HV pump will only pump the amount of oil that can move through the restrictions in your engine. Period. If there are looser bearing clearances, looser lifter bore clearances, looser rod side clearances, looser crank thrust, a DoD (displacement on demand) system using a VLOA, or any other condition that represents an area where more oil can flow, a high volume oil pump becomes a good choice so that good pressure can be sustained. The pressure and volume relationship is a commonly mis-understood one.
On the other hand, a HV pump in a engine where everything is in spec (clearance wise) will not be the culprit as to why an oil pan gets pumped dry, that is an incorrect belief. In the fore-mentioned example, the HV pump may not be necessary, but it will not cause a problem either.
Here is what happens, once all of the oil galleries and cavities within the engine are filled with oil, a pressure develops, when and if the pressure rises to the point the bypass is set at within the oil pump, the bypass opens and the oil is bled out of the pump (either back into the inlet or to the oil pan - depends), no more oil volume goes through the engine or upstairs under the valve covers. So how does an oil pan get sucked dry?
As I mentioned previously, if you are pumping an oil pan dry, 90% of the time on a race engine it is because the oil capacity is too low or the drain back path in the engine is a problem. Also, excessive crankcase pressure can cause a pressure differential to occur above and below the lifter curtain in the engine. This condition cause the top of the engine to act like a shop vac, causing oil to suspend in the top of the engine opposed to draining back to the sump. This is why vacuum pumps and or good breather/PCV systems are an important part of the set-up on Hi-Perf engines.
Even when a high pressure spring is used in the bypass, the oil pump still cannot push enough volume through the restrictions in the engine to empty out a pan with the proper oil level within it. And if somehow it did because the restrictions in the engine were excessively large, you would have other problems on your hands opposed to your oil pan being emptied out which is probably what many mis-interpret.
01-07-2010, 12:43 PM
#43
FormerVendor
The bearing clearances and the oil pressure determine the flow rate for the most part so a HV oil pump just starts bypassing sooner than a regular volume pump for the most part and can make more oil pressure earlier and at lower rpms. Now if you have really big clearances and run the really high pressure spring you could possible get into a lot more windage but overall I run moderate clearances with the HV and it does seem to work just fine.
01-07-2010, 12:49 PM
#44
I would have to tell you to tell the guys that this happened to that their engines died of some mysterious disease that is still unconfirmed.
You are saying that when the spring opens, there is absolutely NO MORE oil pushed by the pump into the oiling system? Must be one heck of a huge hole.
You obviously want to know more than I do about it. Its ok. We can just agree to disagree, but do NOT call what i am saying uninformed or that I am shallow on any subject engine related. To point the finger at me only gives 3 pointing back at you.
The reason that none of the engine builders get on here and argue like this is because it turns into instances like this, where there is always something somewhere that will dispute what is proven. Then random facts are posted, theories are postulated, and people start to have selective reading abilities. Believe what you want, but it does happen.
You are saying that when the spring opens, there is absolutely NO MORE oil pushed by the pump into the oiling system? Must be one heck of a huge hole.
You obviously want to know more than I do about it. Its ok. We can just agree to disagree, but do NOT call what i am saying uninformed or that I am shallow on any subject engine related. To point the finger at me only gives 3 pointing back at you.
The reason that none of the engine builders get on here and argue like this is because it turns into instances like this, where there is always something somewhere that will dispute what is proven. Then random facts are posted, theories are postulated, and people start to have selective reading abilities. Believe what you want, but it does happen.
01-07-2010, 01:28 PM
#45
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i run a melling HV in my car 6800 rpm shifts no problems and maintains more pressure in the lower RPM's. Stock pan, with a truck filter 6 quarts of oil. and FWIW LMR recommended this pump to me, and there stuff speaks for itself.
01-07-2010, 01:36 PM
#46
I do not normally recommend it, I have seen a few probs with it. We have used them before and are not totally against them. It is normally our personal preference to not recommend some parts unless the customer specifically asks for them. We can and do sell them. We normally recommend the ported pumps, or the high pressure.
In the end, it is the customers call
In the end, it is the customers call
01-07-2010, 02:05 PM
#47
I would have to tell you to tell the guys that this happened to that their engines died of some mysterious disease that is still unconfirmed.
You are saying that when the spring opens, there is absolutely NO MORE oil pushed by the pump into the oiling system? Must be one heck of a huge hole.
You obviously want to know more than I do about it. Its ok. We can just agree to disagree, but do NOT call what i am saying uninformed or that I am shallow on any subject engine related. To point the finger at me only gives 3 pointing back at you.
The reason that none of the engine builders get on here and argue like this is because it turns into instances like this, where there is always something somewhere that will dispute what is proven. Then random facts are posted, theories are postulated, and people start to have selective reading abilities. Believe what you want, but it does happen.
You are saying that when the spring opens, there is absolutely NO MORE oil pushed by the pump into the oiling system? Must be one heck of a huge hole.
You obviously want to know more than I do about it. Its ok. We can just agree to disagree, but do NOT call what i am saying uninformed or that I am shallow on any subject engine related. To point the finger at me only gives 3 pointing back at you.
The reason that none of the engine builders get on here and argue like this is because it turns into instances like this, where there is always something somewhere that will dispute what is proven. Then random facts are posted, theories are postulated, and people start to have selective reading abilities. Believe what you want, but it does happen.
The only oil pushed through the engine is what the restrictions can flow, that is the point. It really is basic theory.....or should I say proven theory for the sake of argument.
I am not trying **** in anyone's Cheerios here, just stating some facts based on the 'real world', physics, engineering, the principles of fluid dynamics, etc. I am not 20 years old here going on 50. Sorry if what you read comes across in bad taste, that is the internet for you. Again, I don't think this is arguing, just don't take it personal. I'll let this thread go now.
Here is something that may be useful for some here. And no, I don't work for Melling. However George does, and is a good guy.
http://www.melling.com/Info/TechTipVideos.aspx
01-07-2010, 02:16 PM
#48
Nothing against melling either, but that is like me posting that a product made by us is better because of "x" and here is why. If we make the part, and we sell the part, and we show you why it is good, that is still a biased write up.
A 3rd party write up is the easiest to digest.
And i am pretty sure i have been in more than a few engines, and most of them were not LS. Not just for rebuild, but also for autopsy. I am not a doctor, but I can take a look anyway.
A 3rd party write up is the easiest to digest.
And i am pretty sure i have been in more than a few engines, and most of them were not LS. Not just for rebuild, but also for autopsy. I am not a doctor, but I can take a look anyway.
01-07-2010, 03:35 PM
#49
FormerVendor
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I won't let an engine built here leave without the Melling HV. We tend to run slightly looser clearances than some so the HV pump keeps our low RPM pressures up. Also, the added flow through the bearings helps keep oil and bearing temps down.
Shane
Shane
01-28-2010, 11:31 AM
#53
01-28-2010, 12:53 PM
#54
Teching In
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What are you guys seeing for oil pressure at Idle on the 10296's as i posted in the other thread I'm seeing 30-35 at idle warm but hits 40-42 by 2000 rpm trying to decide if i've got a problem on a 30k mile lq9.
01-28-2010, 12:54 PM
#55
FormerVendor
01-28-2010, 02:33 PM
#58
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Right now i've got some 5w30 strait pennzoil in it with some POS fram filter because i was only planning on running it for a day or two to get things cleaned out. But now with this noise its making up top and the lower oil pressure i'm wondering about the oil. filter and pickup O ring. Motor starts fast runs awesome just has some rocker(s) noise or some acc. is making noise up front.
01-28-2010, 08:21 PM
#59
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talked to my engine builder and he said cold 40PSI and warm 30-35 is fine as long as its climbing with rpms. I got on it a little bit tonight and hit 3500-4000 and hit 50-55lbs so i think i'm safe, noise seems to be a mix of things but not internal or rockers.. tonight everything was checking out so hoping i'm good.. i'll swap this oil out for some mobil synth in a week or so and we'll be good.
