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Small Block Oil Pump Questions #1657078 08/10/14 04:09 PM 08/10/14 04:09 PM
Joined: Jan 2003 Posts: 2,129 Vermont T TrWaters OP top fuel
TrWaters OP top fuel T Joined: Jan 2003 Posts: 2,129 Vermont	I have a m72HV pump equipped with what I believe to be a Milodon tall gear set and cover. The gear set measures out of the housing by approximately .250 inch. Anyone have an idea of how much additional volume this should produce? Is there such a thing as too much volume? 8235640-milodonpump001(1024x778).jpg (44 downloads)

Re: Small Block Oil Pump Questions [Re: TrWaters] #1657079 08/10/14 04:14 PM 08/10/14 04:14 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Quote: I have a m72HV pump equipped with what I believe to be a Milodon tall gear set and cover. The gear set measures out of the housing by approximately .250 inch. Anyone have an idea of how much additional volume this should produce? Is there such a thing as too much volume? Yes there is such a thing as too much volume.. depends on if you need the extra flow.. but if you have high pressure its just resistance and cost HP and heat... I dont know that pump you show but you can figure the percentage of difference

Re: Small Block Oil Pump Questions [Re: TrWaters] #1657080 08/10/14 04:27 PM 08/10/14 04:27 PM
Joined: Jan 2003 Posts: 32,394 Q Quicktree I Win
Quicktree I Win Q Joined: Jan 2003 Posts: 32,394	do yourself a favor and sell it and get a regular old oil pump

Re: Small Block Oil Pump Questions [Re: Quicktree] #1657081 08/10/14 04:48 PM 08/10/14 04:48 PM
Joined: Jan 2003 Posts: 2,129 Vermont T TrWaters OP top fuel
TrWaters OP top fuel T Joined: Jan 2003 Posts: 2,129 Vermont	I will add that this engine has full groove main bearings, as well as grooved main crank journals.

Re: Small Block Oil Pump Questions [Re: TrWaters] #1657082 08/10/14 05:19 PM 08/10/14 05:19 PM
Joined: Aug 2003 Posts: 43,228 Bend,OR USA C Cab_Burge I Win
Cab_Burge I Win C Joined: Aug 2003 Posts: 43,228 Bend,OR USA	Quote: I will add that this engine has full groove main bearings, as well as grooved main crank journals. Why both? I would save these main bearings for later and buy a stock set of single groove main bearings for this motor Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)

Re: Small Block Oil Pump Questions [Re: Cab_Burge] #1657083 08/10/14 05:46 PM 08/10/14 05:46 PM
Joined: Jan 2003 Posts: 2,129 Vermont T TrWaters OP top fuel
TrWaters OP top fuel T Joined: Jan 2003 Posts: 2,129 Vermont	It is an early hemi. The only main bearings available are full groove.

Re: Small Block Oil Pump Questions [Re: MR_P_BODY] #1657084 08/10/14 07:58 PM 08/10/14 07:58 PM
Joined: Dec 2006 Posts: 3,396 Pa Hot 340 master
Hot 340 master Joined: Dec 2006 Posts: 3,396 Pa	Quote: Quote: I have a m72HV pump equipped with what I believe to be a Milodon tall gear set and cover. The gear set measures out of the housing by approximately .250 inch. Anyone have an idea of how much additional volume this should produce? Is there such a thing as too much volume? Yes there is such a thing as too much volume.. depends on if you need the extra flow.. but if you have high pressure its just resistance and cost HP and heat... I dont know that pump you show but you can figure the percentage of difference Are you saying there is a difference between a high pressure pump and a high volume pump? When the oil galley in the block are unable to change size, how is it physically possible to have more volume without increasing pressure? They HAVE to be one and the same...

Re: Small Block Oil Pump Questions [Re: Hot 340] #1657085 08/10/14 08:03 PM 08/10/14 08:03 PM
Joined: May 2014 Posts: 108 Socal L littleVAL member
littleVAL member L Joined: May 2014 Posts: 108 Socal	volume is controlled by the size of the rotor/pump. Pressure is controlled by the relief spring. So if you have a high volume pump that is putting out more than can be used it will raise the pressure up to what the relief valve is set at and bypass the rest. . Last edited by littleVAL; 08/10/14 08:05 PM.

Re: Small Block Oil Pump Questions [Re: littleVAL] #1657086 08/10/14 08:09 PM 08/10/14 08:09 PM
Joined: Dec 2006 Posts: 3,396 Pa Hot 340 master
Hot 340 master Joined: Dec 2006 Posts: 3,396 Pa	Quote: volume is controlled by the size of the rotor/pump. Pressure is controlled by the relief spring. So if you have a high volume pump that is putting out more than can be used it will raise the pressure up to what the relief valve is set at and bypass the rest. . I understand that.. but I was just wondering if Mike was making a distiction between high pressure pump and high volume in his post. You cant increase one without the other.

Re: Small Block Oil Pump Questions [Re: Hot 340] #1657087 08/10/14 08:17 PM 08/10/14 08:17 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Quote: Quote: Quote: I have a m72HV pump equipped with what I believe to be a Milodon tall gear set and cover. The gear set measures out of the housing by approximately .250 inch. Anyone have an idea of how much additional volume this should produce? Is there such a thing as too much volume? Yes there is such a thing as too much volume.. depends on if you need the extra flow.. but if you have high pressure its just resistance and cost HP and heat... I dont know that pump you show but you can figure the percentage of difference Are you saying there is a difference between a high pressure pump and a high volume pump? When the oil galley in the block are unable to change size, how is it physically possible to have more volume without increasing pressure? They HAVE to be one and the same... Once you hit about 70psi you are opening the by pass and wasting HP(as small as it is) but when you by- pass the oil you create heat over what it makes during the normal pumping.. I have to have a HV pump due to all the leaks I have in my engine.. .003 rods and mains, PR oiling, and EDM holes for the roller lifters.. even with with a heavier oil I only get 20 psi hot at idle.. this is a street car... the EDM holes are twice as big as I thought.. they are .026 and I was told .013.. I pulled those lifters and put in a set of non EDM lifters and the pressure went right up to the 70 psi when priming with thinner oil EDIT Pressure is a by product of flow VS restriction.. if you have enough leaks you dont have pressure Last edited by MR_P_BODY; 08/10/14 08:20 PM.

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