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......Hello Everyone, What determains whether to use or not use a high volume oil pump??? I have a 413 small block street/strip motor that will see no more than 6200 RPM. I've heard that high volume pumps use more HP to run but then oviously I don't want to burn my motor out to save 2 HP..... Thanks, Bill
The way I look at it is if I'm washing parts I want high presure, if I'm trying to lube somthing I want a lot. High volume pump is the way to go. I never thought about loosing H/P with it just think what you'd loose with out it.:eek:
this has alot to do with what you are running for lowend oil clearances if set up loose run the hv. if not stocker you may want to try a vortec oil pump they have hi hv and are the 3/4 pickup tube i think this is the way to go
.....hummm, not sure how he's going to 'set' it up. I'll ask him & speaking of 'how he sets it up', which is the best way to be 'set up'??? It's a street/strip car. Setting it up lose sounds faster, am I correct??? And if set up lose, what is the disadvantage??? Oh, when you mention the Vortec HV, did you mean that this it the way to go with either lose or tight set up>???? Thanks ;0 BillQuote:
Originally Posted by pat mccarthy
I go with high volume, but that being said doesnt high volume point load your camshaft and drive gears
I agree with Denny W on using normal rod and main bearing clearances on the street.
44,000 miles on my engine.
In fact, I'm not real sure about using overly large clearances at the strip regardless of oil pump or pressure in use.
Doesn't make sense to give the rod a .004 - .006 running start at the bearing.
Kinda similar to swinging a hammer from overhead as compared to a short swing of the wrist.
I note that some - if not all - NASCAR engine builders are running what amounts to stock clearances on their high winding long endurance engines.
If it works there it ought to work fine at the strip.
And . . . as a fwiw, NASCAR tuners will sometimes set the engine oil pressure at 30# so as to gain some HP for a qualifying run.
As far as the high volume over stock question goes, part of that depends on how the engine oil system is set up.
A couple of examples:
Little brother used to run built Olds 455's in his Henry J drag racer.
All the way from 463" overbored to 498" strokers and the bigger motor was 15/1 C/R running on alcohol.
The oil passages to the rockers are restricted so as to dump the majority of the oil into the rods and mains.
I believe some of the oil passages are enlarged as well.
He runs a high volume Milodon oil pump with the relief spring shimmed to about 60# with cold oil - tested on a bench device.
The 462" Buick in my 32 roadster runs roller rockers among other things and Kenne-Bell recommended the high volume pump to keep up with the added flow allowed by the rocker setup.
It helps #8 rod journal as well since this is the one that tends to let go in the late Buicks that are involved in drag racing.
The adjustable relief spring is set to 60# with cold oil and once warm, the Pennzoil 20-50 wt runs 48# pressure on highway trips here in the sometimes warm desert.
Too high a pressure can create problems, I've heard of bearings washing out, but that sounds kinda strange to me.
One big thing to look out for is cold engine oil pressure.
It's easy to hit 100# even with a 60# relief spring setup.
Oil filter cans have been known to blow out under cold oil and high rpm conditions.
Not that you would run your motor that way, just something to be aware of.
No need for a high volume oil pump, especially for a street/strip car. I have always used a standard pump, and several times, I have installed the high performance spring that comes with the pump. Never had a problem with oil pressure, and I have built several engines. The standard volume pump is more than adaquate. Here is a quote from an engine builder (performance and street) in Long Island, NY.
JohnQuote:
Now as to your question, we personally use no HV pumps in any street units UNLESS they have aluminum rods. It "stresses" the timing chain, it's tougher on the cam/distributor gears (moreso with the bronze setup), and it does take away a small amount of power from the unit. Probably not measurable, but true nonetheless. Thanks, Gary in N.Y.
P.S. I'm going to add this here but it's a debatable issue. The HV pump contrary to legend, MAY pump the oil away from the screen quick enough to cause main bearing damage. We use to say it would drain the pan. Splittin' hairs, whether it drains the pan or simply takes the supply away from the screen long enough doesn't matter, we repaired a bunch of front mains over the years from lack of oil. We installed the standard M77 pump with the same(M77020) spring I mentioned above and cured the problem. It basically only showed up with stock 4 quart pans. I'm not gonna argue this one!
Plus, if you read any of the popular engine building manuals, they will all tell you to stick with a standard pump. At least any book that I have read, anyway.
the big pick up is stock to the vortec gm engine stock 5/8 and now on all new chevys 3/4 all not to many engines have as small 5/8 a pick up ? this sucks up the oil ? so like a small straw in a malt ? so it would take you less work. i will buy you a malt and give you a small straw ?? i did not say open any thing up in the oilpass ? no .so you will not dry it out with the stock pan. BOY lets start a pissing countests:whacked: yes you run them oil clearances any where YOU want. but you may want to think about them nascar boys engines. they all use a much smaller main and rod size is not stock they use the best money can buy parts they do not move as much lower grade stuff.by this i mean the rod getting out of round at hi rpms and the block to and have the best money can buy cranks so at this point could we move the bearings clearances up ?you bet . but i have built many engine i could make a list but will not bore you with it. BUT never lost any bearings abit loose . stock 350 chevy they give you a running oil clearances from 1.5 to 3 now is for stock .003 is to much but not for racing so when you say stock ?? what do you mean ? a chevy small block with the rods on the big side of spec and a stock crank std and the rods running a clevite77 will get you .003 on the rods with the rod at the small end this is where i put all of may bore housings will get you with the same mich 77 .002.5 now if we use a king cr807am you will get.001.8 now all i will say on this is there is no stock clearances there is a low and a hi so i build all stock engines with a round .002 about with a stock pump but not race stuff loose is better as far as the rods getting hammer out by adding a .001 no way , the bearing rides on the oil YOU HOPE i have seen housing bores go out of round if they were a stock size? ok small side of spec things may have been very bad with a big size crank and you never want to dry any thing up on a top end on a big block less you drag it only and i still do not do it .or you own a valve spring company:3dSMILE:
Good morning Pat! So I guess it's not just me that has nothing better to do on a beautiful Saturday morning. John
i need to stay in to day if i go outside and drive some thing FAST to day the cops may be looking for me later:whacked:Quote:
Originally Posted by 1JohnnyO
the cops will not be looking for denny or me today? good work denny you know i do not try to hard to talk some out of hv pump less it is stock engine with a stock pan and i thought the 2.200 rods with that 4.750 stroke were spining fast at 8000 rpms
yes they do i have guys give me there stock stuff i rebuild it STOCK now they have mccarthy performance race engine ??O BOY that is why i think the newer3/4 pickup oil pump may be a good way to go
My understanding on the Olds 455 restrictors is that they help the bearings to live in a highly stressed - drag racing - engine and the lesser amount of oil supplied to the roller rockers is sufficient.Quote:
Originally Posted by DennyW
Since drag racing doesn't create the heat loads endurance engines do this is probably one reason they get away with lesser oil flow up top.
Kinda funny that the late Buicks - 430-455 - have the opposite problem and want additional flow up top when roller rockers are used.
The restrictor bit on the Olds engines is a commonly done deal and recommended by Olds engine specialty shops.
maybe so on the olds but not on the chevys oil is needed to cool the valve spring to keep them happy. i did one buick 455 every thing you would do on a chevy will not work to good on them. they have a very weak block and very bad oiling
a guy here in town i know with an el-camino and a built 406 sbc keeps having massive pressure build up, he actually blew the breathers out of the valvecovers and the dipstick! talk about to much psi i keep trying to figure out his dilemma could it just be to much oil pressure thats its pushing the motor apart from the inside out!?
no .to much blow by or he running a vacUpan type breather on a full EX this will not work you have a breather problem you need to vent the crank cass if not it will do it for you it will blow the oil pan seal out or any seals rear or front seal.
Denny, good info, but it's basically the same as I have read before. I use only Mellings pumps too. The books I was referring to are a general engine building manual, two big block chevy books, and one small block chevy book. If I had them here, I would post the authors, but they are at my garage. But they all state that there is no NEED for a high volume pump in almost all instances. I suppose if it makes one feel better to have one in there, go for it. But between the books and articles I have read, plus the advice of two machinists that I know, and two performance engine builders (one of them quoted above), I dont see a need for it. If I were building a race only engine of any sort, I would consider some different choices. Otherwise, it's gonna be a standard pump for me, with a high pressure spring. I have been reading posts for years about this choice, and it seems to be a 50/50 mix of opinions. I cant see that ever changing!:D We're supposed to get that 94* temp tomorrow, and for the next few days! Well, I guess it's better than snow. John
melling pump are ok .about four years ago i had a bad one . loose well to gear was big .the well was to big or the gears to small and use a stock gm pump to replace it L88 type i think they are much better on that and the body of the pump seam to be made better to . i use to spend alot of time on them ant-cavitation slots debur the gears and set end play never seen zip from this stuff so stop doing it but i still will work down the well for less end play
hes got the typical breathers in the valve covers and the lines running tot he headers. its just differnt to see a guy shoot his dipstick out!
that is why you can not run line to the headers ! if so you have to run egr valves this is a one way valve on the headers to keep the EX out of the valve covers if he is using them he may have one that is bad and like i said this is what is called a vacUpan type and will not work on a full EX . if you let off the gas it will not pull a draw to suck the blowby out of the vavle covers and blow the stick out of the dipstick i know this first hand :LOL:Quote:
Originally Posted by gassersrule_196