High Volume BBF Oil Pump - Bad Idea???

Colt Macara wrote:What are the reasons for dissing the Melling 84DHV. My machinist/build adviser and I are having a gentleman's disagreement...

IDT-572 wrote:An engine only needs as much oil as it needs to protect or operate it internals. Any more than that or any less could be very bad, or may have minimal effects.

If theres not enough volume and pressure to fill all the oil voids with a little left over for good measure, bad things happen.

A little bit too much, still probably no ill effects. But a high volume high pressure pump on a tight clearance, street engine with a stock pan, now your gonna see the problem with a hv hp pump. One pumping the pan dry. Some say washing the bearings out,(I dont subscribe to this). Then there is also the problem with over heating the oil at highway speeds. Plus the added parasitic drag of turning a HP HV pump for no need. I have also seen numerous tme oil pump drive shafts twisted off and cast iron gears destroyed.

Now to answer your question, is there reasons not to use, or is it bad to use a HV HP, you have to understand that the specs of the engine and the intended use of the engine is what determines what pump to use and not to use............

Also ther will be over lap where both style pumps will work surfice. Will they be perfect in the over lap deal, no..........But the engine will run and survive.

There a variables in every build that require a builder to survey what he is dealing with and then make the decision on what pump to run.

This is not a yes/no question. No definate exact answer.

Stock builds to stock block nitro builds (70 weight oil .006-.010 clearance) to all out all aftermarket parts builds. All require a thought full look at the oiling system and all are different.


I just don't know how to explain it any better than that. Not saying it's the right answer to your question, just saying it answered to my best ability.


If that don't surfice, you neede to talk to Albert somemore.............  Hope it helped.........

Paul Kane wrote:

Colt Macara wrote:What are the reasons for dissing the Melling 84DHV. My machinist/build adviser and I are having a gentleman's disagreement...

^^^Stop right there.^^^

If you have commissioned a professional engine builder to build you an engine then you ought not be second guessing him, either directly or outside of the established agreement.  You should trust him and let him build your engine based on his professional expertise.  This can also apply to machinists who machine to specifications based on their build experiences.

If you do have a valid question, then present your case directly to him just once, let him respond, and then leave it alone.  If his perspectives and reasoning rub you the wrong way more times than not, then perhaps you should seek a new engine builder with whom you are more comfortable--just be sure you are truly qualified to make such an executive decision and that it's not based on internet rhetoric or online "fat chewing."  Besides, ask 10 different engine builders the same question and you could get 10 different answers, and so going online can't possibly help at this point...nor do the online experts have any idea how your commissioned guy is executing the job.

78ranger wrote:Then you decide. Based on your expertise and plans for clearances etc.

Colt Macara wrote:

78ranger wrote:Then you decide. Based on your expertise and plans for clearances etc.

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Wow!
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IDT-572 wrote:I try to give everyone a fair shake and try my best to help.

But this guy beats anything I have ever seen. I don't even know what to say now.  

I don't know how anybody could explain it any better than what people here have already posted.

To the poster:  If you cant figure it out from whats been said here, where probably there is more 460 Ford (factual info) shared than any other site on the webb, you need to just take up basket weaving.............  

DILLIGASDAVE wrote:

Colt the info you have received from these guys is pretty straightforward, why are you making this harder than it needs to be. It's starting to sound more like you are just arguing for the sake of arguing.

You want a 100% "yes/no" answer to your question, and there isn't one, the "right" answer all depends on your combo & it's intended use.

In a nutshell......

(A) tight "street-use" bearing clearances combined with a HV pump can often overheat the oil (and also put excess drag/wear on the oil pump drive shaft + cam/dizzy gears) since the excess oil volume will have almost no place to go resulting in it continually being recycled through the oil pump's relief valve over & over again.

(B) a "race" combo with looser bearing clearances and higher RPM's might (or might not) need the HV pump because the looser bearing clearances can (depending on the combo) give the extra oil volume someplace to go.

Realistically the best guy to tell you if you need a HV pump or not should be the guy building/machining the engine for you. He knows what components he used in your engine, how tight/loose he set the bearing clearances at, and the engines intended use. Nobody on this site is a mind reader, they don't know how your engine guy set things up.  

So at this point you have two options, either use the HV pump or don't. Continuing to argue about it isn't going answer your question.