Verdict on HV Oil Pump

[buschguy]

I'm getting ready to pick up the last few pieces for my build. What is the verdict on the HV oil pump? I do not want any problems with cam failure. I picked up the Mopar purple 28AB cam and the Mopar performance springs (P4529214). I also bought the Crower camsaver lifters. Is the HV pump more likely to help or hurt me? It seems from reading a couple posts here and there, that there are questions to that effect. I am leaning toward a stock pump. What do you guys think?

[dwg86]

I would run a HV pump with the camsaver lifters. They will bleed some oil pressure. Although I don't have any experience with the camsaver lifters. I think a couple of people on this forum have used the camsavers.

I'm going to run a HV pump on my build.

[SilverXJ]

A HV oil pump is not necessary. It just soaks up horse power and puts extra stress on the cam gear. I have ran the Camsavers and now the bore grooves and never had a problem with oil pressure on a standard pump.

[buschguy]

Is there any chance the greater volume of oil will take too long to drain back down to the sump and starve the HV pump? Other than HP loss what are the downsides to a HV pump (other than having to beat your oil pan to fit it in)? I would think the HV pump would lead to cooler oil and better/ more lubrication. I am just trying to weigh both sides before I choose. Thanks for any input.

[gradon]

I bought it cause it was cheaper and came with the pickup tube vs the stock. I just changed the oil(6qts 10w30 brad penn racing w/ Mobil 1 301 filter) and at 2.5-3K+ rpm on the highway, the dash gauge reads 70-75psi(gauge max is 80, but pump is 75), so I'm assuming it's near/at max pressure and bypassing off the excess pressure(never did get around to T-ing the oil pressure sender to run a line to the dist & cam gear, which would've bled off some of the pressure). I've been curious about the psi that a 5w20 would show, but is there any in SL these days? I guess if I built it again I'd go for the stock pump and a 258 pan and save the time it took to beat the ish out of the 242 pan to clearance the HV and the girdle.

[IH 392]

A HV oil pump is not necessary. It just soaks up horse power and puts extra stress on the cam gear.

HV pumps are for high RPM MASSIVELY sloppy clearanced engines! all they do for a street engine is eat power and heat up the oil bypassing it!

[crustodd]

Hey Jeepers,
I'm using the Hesco HV pump on my 4.7. I've talked to Bernie a few times about the questions posed here. My oil pressure runs about 50-60 psi when cold, depending on the air temp. When the engine is TOTALLY warmed up it runs about 25-30 psi at idle, and around 50-60 at WOT. Initially it was reading high, even pegging the gauge, which turned out to be a bad sending unit. The Hesco pump are the Melling HV units that Hesco blueprints so that the are set to a MAXIMUM of 65 psi, if I remember correctly. I'm running 10-30 dino oil right now. The pan DID NOT require heavy "massaging" to get the pump to fit, even with the added stud girdle. My oil DOES NOT run hot. A point I'm curious about too. Is HIGH VOLUME and HIGH PRESSURE the same thing? If I have a hose with a high volume of fluid going through it that would make the fluid coming out under HIGH PRESSURE, correct? If the orifices that the oil is going through allow for a greater volume of fluid, that shouldn't result in greater PRESSURE than what a stock pump would produce, correct? I'm envisioning a storm drain pipe with a high volume of water going through it compared to a garden hose with a MUCH smaller VOLUME of water moving through it, but under higher PSI because the fluid FILLS the space, it's being pushed by a pump, and any volume increase would result in higher PSI. Overall, my HV pump seems to be working fine. NO complaints. Under WOT, it's nice to have the extra volume.

[Muad'Dib]

Hey Jeepers,
I'm using the Hesco HV pump on my 4.7. I've talked to Bernie a few times about the questions posed here. My oil pressure runs about 50-60 psi when cold, depending on the air temp. When the engine is TOTALLY warmed up it runs about 25-30 psi at idle, and around 50-60 at WOT. Initially it was reading high, even pegging the gauge, which turned out to be a bad sending unit. The Hesco pump are the Melling HV units that Hesco blueprints so that the are set to a MAXIMUM of 65 psi, if I remember correctly. I'm running 10-30 dino oil right now. The pan DID NOT require heavy "massaging" to get the pump to fit, even with the added stud girdle. My oil DOES NOT run hot. A point I'm curious about too. Is HIGH VOLUME and HIGH PRESSURE the same thing? If I have a hose with a high volume of fluid going through it that would make the fluid coming out under HIGH PRESSURE, correct? If the orifices that the oil is going through allow for a greater volume of fluid, that shouldn't result in greater PRESSURE than what a stock pump would produce, correct? I'm envisioning a storm drain pipe with a high volume of water going through it compared to a garden hose with a MUCH smaller VOLUME of water moving through it, but under higher PSI because the fluid FILLS the space, it's being pushed by a pump, and any volume increase would result in higher PSI. Overall, my HV pump seems to be working fine. NO complaints. Under WOT, it's nice to have the extra volume.

High volume and high pressure are two different things.

Its just like using a bigger size hose with the same amount of pressure. Its going to flow more than a smaller hose at the same pressure... thus high volume.

Now if you increase the pressure on the smaller hose you may be able to catch up with the bigger one volume wise... but that all depends on hose size etc.

The high volume pump will "bleed off" excess pressure... so technically the two pumps should maintain the same amount of pressure on the same engine with the same tolerances etc. Just the High volume pump will flow more at the same pressure. This is the way i understand it to work.

[IH 392]

High volume and high pressure are two different things.

Its just like using a bigger size hose with the same amount of pressure. Its going to flow more than a smaller hose at the same pressure... thus high volume.

Now if you increase the pressure on the smaller hose you may be able to catch up with the bigger one volume wise... but that all depends on hose size etc.

The high volume pump will "bleed off" excess pressure... so technically the two pumps should maintain the same amount of pressure on the same engine with the same tolerances etc. Just the High volume pump will flow more at the same pressure. This is the way i understand it to work.

This correct, you can have all kinds of volume and virtually NO pressure, and you can have all kinds of pressure with virtually no volume.
Restriction (bearing clearance) creates the pressure, the size of the pump (taller gears) creates the volume.
If you need a high volume pump your bearing clearances are LOOSE!!!, and even the NASCAR guys only say that you need 10 psi for every 1000 rpms.

[crustodd]

Hey guys,
Yeah, your response is what I thought to be correct. So, if we're running around 25 psi at idle with either the stock OR the the HV pump, the end result is the same? And around 35-45 psi at 3000-4000 rpms is roughly correct? It seems like the stock psi is about the same as the HV pumps across the board just more fluid VOLUME, not pressure? Factory Ferrari uses the same basic rule-of-thumb as NASCAR. But, that would suggest the factory pressure is high?

[Brian E]

This may be old news but I just received my new Mopar Performance HV oil pump from Summit. I kind of feel ripped, it has the following markings on the side M81A HV sound familiar? My old Mellings stock pump was a M81A so I figure the pump is nothing more than an over priced Melling HV pump! And to top it off I paid 92.00 and the mellings is only 72.00 at Napa, and the Mopar Conection sells the Mopar HV pump for 62.95! I feel like I just got...? well you know.

[tirod]

Thanks for the heads up on that buy.

I haven't been able to justify HV pumps for a street motor yet - but I seem to sell one for every Chevy rebuild in town. My question is, with stock oil passages, stock bearings, and stock clearances - how do you pass more oil? Pumping more oil into the same size system will increase pressure in order to flow more volume. Therefore, more power consumption and hp loss.

Do you get more bearing protection? Since most street motors don't see continous 6000 rpm operation, don't have loose clearances for racing, and don't have optimized oil systems, I don't see it. Perhaps someone has some back to back dyno runs to report.

For me, it's another "race engineered" part with more bragging rights than performance - like 20" dub rims with stock brakes.

[SilverXJ]

Even with my grooved lifter bores oil pressure never drops lower that around 20 with 10w30 oil and a standard pump

like 20" dub rims with stock brakes.

God I hate that.

[Brian E]

Well i believe a stock pump is fine 99 percent of the time. I have gone through my Titan motor many times and found no clearance issue at all but my idle pressure after long highway runs and long abusive off roading events always drops to 18 20 lbs. I do not like the idea of the bearings not staying floated well. And since everyone and their brother has cam issues I want to fling some extra around in there. Since I am increasing volume I am proabaly going to drop oil weight as well. I have always used straight 30 or 40 depending on the time of year but will probably drop it to 15-40 from now on. I always use Rottela since I work in a diesel shop and it is basically free. I will post up all the changes when it is finished. I am in the Mayo hospital in Jacksonville the rest of this week.

[Flash]

OK, time for a little story telling
All thew this is not a 4.0/stroker or Jeep for that matter, i thing it will help.

My first 340 eng i built(first learning experience) had a stock oil pump, and the gauge would go to "0" at idle (aftermarket gauge showed 5psi) started using a a 20-50 oil to keep pressure in it.
Ended up pulling the pan rechecking my bearing with plastic gauge and installing a HI Volume HI pressure pump. pressure would hold a 10-15psi at idle hot. Years later when i stuffed a intake valve threw the cylinder wall(That,s a big story all by its self ) Builting my next 340 eng. I Scored a set of NOS connecting rod for my build.(note, old rod had way to much oil clearance between the two rod on the big end.......Hind site, this was were all my oil and pressure was going but i didn't realize it yet )
The NEW rods were right on spec, and the old were not!!!!!!! .017"-.022" between 2 rods.
The only thing different with this motor compared to the first one, was the new rods and a bigger cam.

The oil pressure was crazy! Cold, the 80 psi guage would pegged at idle! when the eng was hot and at idle, it had 60 psi(i still can't believe i didn't burst a oil filter.)
I race it this way for many years(this eng never saw the street) It has been resting for many years, waiting for it next rebuild as this eng is vary old now(build over 15 years a go)

took it out to our local 1/8 mile drag strip, last year(6800 feet above sea level)and it ran a best ET of 10.17
took it out latter that year with the only change being............I got rid of the 20-50 and when with a synthetic 5-20 motor oil (with 2 bottles of the GM additive to protect the cam of course ) pressure are now back down inthe 20's at idle.
took it back out to the track and ran a best of 9.78!!! That's over 1/4 of a second better ET with Just a oil change

The reason i told you this story is that thing can be missed on a rebuild, especially if its you first one! And oil pressure can be low.
If every thing is up to spec, a stock oil pump will be more then enough for your build........... Will a HV oil pump give you added insurance on you build, ...........I us to thing so, now i just think its steeling HP. And seance our 4.0l/stroker get a little hungry on dist gears with a HV pump, i will stick with just a new stock pump on my jeep.

there is "exception", to all Rules, and this one is no different.
If your going to remove or raise the rev limit of you jeep, a HV pump might be a good idea........But then you should do some research on here about adding extra oil(sprayed) on the cam and dist gear!!!!!!!

sorry for the long story, but don't know how to do it any different way