High volume or high pressure, high mileage engine

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09-08-2010, 04:35 PM
BigTruckDriver

High volume or high pressure, high mileage engine

The only cure for a high mileage engine is to get a rebuild and tighten up clearances, but looking for something to help out until I can get a rebuild. I have 2 oil pressure gauges on my truck, stock 350 sbc. One is located up by dist. and reads 50PSI while warm. The other is located at the oil filter and reads 25PSI while warm. These both are at idle 750rpm and with synthetic oil. I am going to replace the pump and gasket anyways so I am trying to find what might buy me a little more time. A high volume will get a little more volume and a little more psi?Thanks
09-08-2010, 04:57 PM
cffisher

I have rebuilt MANY SBC and always used high volume High presure wil not help you. I have heard , but never seen it that H/P will have an effect on cam brgs?? Don't know nor do I want to. My $.02:D
09-08-2010, 05:22 PM
1gary

Here is a interesting article you might want to review:

http://www.enginebuildermag.com/Arti...oil_pumps.aspx
09-08-2010, 07:17 PM
pat mccarthy

yep i see that they say somethings that just do not add up to me ? ok there is no more load on cam gear with a hv pump ? well yes there must be some .if so why do you used a HD pump drive? no need for a steel sleeve when on a stock pump the plastic sleeve go for many miles ? so if there is more load you could see more wear on gear them more hp to drive pump??????. you can not run pan dry with a hv pump less your drain backs are plug. it can happen i seen it .they sell oil pumps not build engines some drain backs can be better or re work at time of build some close down upper end oil to valve train to keep more oil psi on rods and mains. loose engine is worn out well yes but? i set race only engine up loose so i look to a bigger HV pump ? .well hear is some thing they did not say is what some guy said over 20 years ago that not worth much for evey 1000 rpm you need 10 pounds of oil psi ? well ok so your stock worn out engine going to 5000 grand needs only 50 psi well ok but seen them run on less . so if you driving most of the time at 3000 rpm then you only need 30 psi you have more then that so why pull the pump ?
09-08-2010, 07:33 PM
pat mccarthy

Quote:

Originally Posted by cffisher

I have rebuilt MANY SBC and always used high volume High presure wil not help you. I have heard , but never seen it that H/P will have an effect on cam brgs?? Don't know nor do I want to. My $.02:D

you do not want to know:3dSMILE:

well ok but the sbc chevy oils thru cam brgs the hi load of spring psi can close down oiling as the hi load on cam is it the lower part of the cam brg lets say 6:00 more or less that is were the oil comes up to oil cam so can get shut off alot of guys move the oil hole of the cam to 4:00 so oil can ramp under the cam this can be done on any engine with a 360 oil groove or cam bearing or block can be re work for this .some say a better cam brg must be used on hi lbs springs they sell them but we have used stock dur bond brg in engines with 350 on seat and 1200+ open on a older bbc they oil dif then the sbc
09-08-2010, 07:51 PM
BigTruckDriver

Quote:

Originally Posted by pat mccarthy

yep i see that they say somethings that just do not add up to me ? ok there is no more load on cam gear with a hv pump ? well yes there must be some .if so why do you used a HD pump drive? no need for a steel sleeve when on a stock pump the plastic sleeve go for many miles ? so if there is more load you could see more wear on gear them more hp to drive pump??????. you can not run pan dry with a hv pump less your drain backs are plug. it can happen i seen it .they sell oil pumps not build engines some drain backs can be better or re work at time of build some close down upper end oil to valve train to keep more oil psi on rods and mains. loose engine is worn out well yes but? i set race only engine up loose so i look to a bigger HV pump ? .well hear is some thing they did not say is what some guy said over 20 years ago that not worth much for evey 1000 rpm you need 10 pounds of oil psi ? well ok so your stock worn out engine going to 5000 grand needs only 50 psi well ok but seen them run on less . so if you driving most of the time at 3000 rpm then you only need 30 psi you have more then that so why pull the pump ?

I need to pull the pan to replace the gasket leak,since I am there I want to replace oil pump with a new oil pump and inspect whats going on.
09-08-2010, 07:56 PM
pat mccarthy

Quote:

Originally Posted by BigTruckDriver

I need to pull the pan to replace the gasket leak,since I am there I want to replace oil pump with a new oil pump and inspect whats going on.

well throw some new rod brgs in it :3dSMILE:
09-08-2010, 08:33 PM
1gary

Honestly I don't want to sound harsh or rude,but patch work repairs are just like it sounds...........

One point the link made was a change of a oil pump on a worn out engine leaves still a worn out engine and is not a repair.
09-08-2010, 08:38 PM
glennsexton

Replace the gasket and use a quart of Hilton's Hyperlube with four quarts of 10W40 every oil change until you're ready to do a proper rebuild.
09-08-2010, 08:43 PM
pat mccarthy

Quote:

Originally Posted by 1gary

Honestly I don't want to sound harsh or rude,but patch work repairs are just like it sounds...........

One point the link made was a change of a oil pump on a worn out engine leaves still a worn out engine and is not a repair.

well it is but he is ok with that new bearings are 20.00bucks for cheap ones and if the cranks not to bad he is in copper on rods and mains then past 004 on rods new bearings and throw mains in it .that would get it back up to ? better then were he at now then a new std oil pump i done it in the boat yard were they would not let me pull the crank out should not be that bad on a truck
09-09-2010, 12:11 AM
1gary

Quote:

Originally Posted by pat mccarthy

well it is but he is ok with that new bearings are 20.00bucks for cheap ones and if the cranks not to bad he is in copper on rods and mains then past 004 on rods new bearings and throw mains in it .that would get it back up to ? better then were he at now then a new std oil pump i done it in the boat yard were they would not let me pull the crank out should not be that bad on a truck

Pat-just thinking out loud,to put on new round bearings on parts that are worn with a taper or out of round could be very counterproductive very quickly and might be even worse than he is now.The new bearings are forced to conform to the way the worn parts are by wearing out.Please Pat your thoughts.
09-09-2010, 12:41 AM
pat mccarthy

Quote:

Originally Posted by 1gary

Pat-just thinking out loud,to put on new round bearings on parts that are worn with a taper or out of round could be very counterproductive very quickly and might be even worse than he is now.The new bearings are forced to conform to the way the worn parts are by wearing out.Please Pat your thoughts.

nope i do not see it that way if the cranks some what good it will work thats what oil is for is it going to last for ever no . bearing are made to conform some what if he came to my shop would i talk him in to a rebuild yes .i mic cranks and polish them all the time that have had over 100.000 mile on them i also have and see fresh ground cranks screwed up were a crank with some miles on it was better polished then ground .that is why i am looking to buy a crank grinder some day