chevy oil pumps

[grumpyvette]

Id need to point out that the differance between a standard and a high pressure pump is usually only the resistance in the bye-pass springs resistance, standard pumps generally have bye-pass springs that allow the bye-pass circuit too open at about 60psi-65psi

HIGH PRESSURE pumps generally have bye-pass springs that allow the bye-pass circuit too open at about 70psi-75psi

SPRINGS CAN BE SWAPPED!

 

 

 

 

 

http://users.erols.com/jyavins/solder.htm

http://www.tinmantech.com/html/faq_brazing_versus_soldering.html

 

THE QUICK WAY TO IDENTIFY THE DIFFERANCE BETWEEN THE BIG BLOCK PUMP AND

THE SMALL BLOCK PUMP IS THE SMALL BLOCK PUMP USES A 4 BOLT COVER AND SMALLER 7 TOOTH GEARS AND A 5/8" FEED TUBE FOR THE PICKUP

THE BIG BLOCK PUMP IS THE BIG BLOCK PUMP USES A 5 BOLT COVER AND LARGER 12 TOOTH GEARS AND A 3/4" FEED TUBE FOR THE PICKUP

 

THE DIFFERANCE BETWEEN A STANDARD VOLUUM AND A HIGH VOLUUM PUMP IS THE TYPE AND LENGTH OF THE IMPELLERS, BELOW THE IMPELLERS LENGTH IS SIMILAR, LONGER IMPELLERS AND LONGER PUMP BODIES ARE AVAILABLE

 

 

 

braze the pick-up tube to the pump body so the pick up is 3/8" MINIMUM, 1/2" maximum from the oil pan floor and use a large lump of MODELING CLAY (every mechanic should have some its great for checking clearances)on the pickup then install the pan temp. with no gasket and remove to measure the thickness of the clay

your local arts/craft store sells it in 1 lb blocks I usually use brite blue or black but suit your self, a digital caliper or even a ruler will get you the thickness measurement your looking for)

 

http://store.yahoo.com/teacher-parent-store/modelingclay.html

 

http://www.guildcraftinc.com/ProductInfo.aspx?productid=102-500

 

once its correctly possitioned ,remove the bye pass spring and gears from the oil pump,and have the pick-up brazeD or welded to the pump body, then after it SLOWLY AIR cools (DON,T DROP IT IN WATER LET IT AIR COOL)replace the byepass spring and gears, lube the pump,with assembly lube on the gears, check the clearances, check clearances again! and install! just be damn sure its brazed or welded in the correct location as that 3/8"-1/2" is critical to good oil voluum feeding the pick-up

http://www.epemag.wimborne.co.uk/solderfaq.htm

 

silver soldering is basically lower temp brazeing , the soldering metal flows over the surface and into micro cracks in the surace of the other metal forming a almost unremoveable bond to the other metals surface it allows you to stick iron to steel or brass to steel, it works more or less like normal solder does on copper but at higher temps and has a much stronger grip in addition too working on iron and steel

I vastly prefer the 5 BOLT BBC style pumps with the 12 tooth gears and thier larger 3/4" pick-up VS the small 4 bolt pumps with thier 5/8" pick-ups and 7 tooth gears. the oil flow is both higher pressure at low rpms and smoother in pulse presure spread,no! you don,t need it on a non-race combo, or even on some race combos but its nice to have and I willingly will loose a few hp pumping oil for better engine lubracation

[Guest FasterbyFosta]

So the bb and sb pumps are swappable?

[dr_hunt]

Melling makes a big block pump for the sbc, M77HVS, probably not necessary unless you are running .003 bearing clearance and then it is questionable IMHO.

 

Food for thought; for every extra .001 bearing clearance you roughly double the amount of oil that will flow through the bearings at a given pressure. So when running extra clearance make sure you consider either running the HV pump or a big block pump. IMHO the stock pump with a high pressure spring works for stock and mildly modified engines running tight clearances.

 

Also bigger pumps cost you HP and are harder on distributor gears. Dry sump is the best way to go but costs $$$$$$$.

[grumpyvette]

"So the bb and sb pumps are swappable?"

 

yes! but thats not always a good idea, stock, or nearly stock engines won,t require it,even many race engines, as has been pointed out and oil pan clearance issues may prevent it in some application, theres ,heres an old post that has this discussed

 

http://www.chevytalk.org/threads/showflat.php?Cat=0&Board=UBB64&Number=1129419&Searchpage=1&Main=1129364&Words=pump+grumpyvette&topic=&Search=true#Post1129419