Help with x flow oil pump

[Anonymous]

Can someone help me? I have 2 used oil pumps and I want to figure out if one could be used on the build up. The manual I have kinda glosses over checking the oil pump, so what am I looking for, what do I measure and what needs to be done before putting a used pump back in service? The more info the better.....

Thanks

 

[addo]

I have an "out there" opinion on oil pumps. So you may care to be reserved about what these remarks.

I believe a lot of oil pump replacements are unnecessary. You'll gain more peace of mind with a thoroughly cleaned and prepped block and all clearances verified during install. Never trust anything because it's new in a box. Your existing oil pump may be perfect now, or quite rebuildable.

The first indicator of wear is inside the cover. If it's not worn, that's great. If the gears have made wear patterns there, machine it flat. At a pinch, a fine linish and work on it with the oilstone (how's that for cheap!). If the grears have ground their way into the housing a little, you can also linish or mill this to restore clearance.

The clearance between the circumference of the outer gear, and the inside edge of the housing should be 8 thou (12 max). Note the mesh marks on the two gears. You can swap gears as a set but don't mix and match. If there are only mesh marks on one side of the gearset, they go towards the cover.

The bypass shuttle valve is a sliding fit you can barely see daylight through. Input drive clearance is slightly closer than that, but 3 thou is acceptable. Make sure the internal hex flat are well-defined, too.

The only figure I have for bypass spring pressure is 9½ pounds @ 1.078" length. May be totally irrelevant to the crossflow. You could shim it with washers or up the spring to increase pressure, too.

This help?

Regards, Adam.

 

[xctasy]

Outer Rotor to Pump housing Wear limit is 0.012"
end clearance of rotor to housing is 0.004"
Fit new oil pressure relief spring. This is very important. A used one isn't a good idea unless it meets the orginal spec.
Fit new anodized pick-up screen. It sheads fine metal particulates so they don't block things up, and is very important, more important than a new pump
No gasket of block to oil pump
Consider new oil pump only if you can't get the specs of the old pumps to agree. You can deck pump covers.

A word of warning which covers all Hydraulically cammed I6 and L6 engines, Ford, Chevy, Poncho, Chrysler. Heavy duty oil pumps with higher rates of flow froth up oil, and can drain a sump of a hard worked Henry. It's better to keep things close to stock and spend more money on an aftermarket sump or at the very least, over fill the stock sump if you are going to lean on the engine at the drags.

Adam is right on about oil pressure.

 

[Anonymous]

Ok I cleaned up thepump today and have some info. The cover has some small grooves so I can just have it sent out to be milled smooth. The clearance between the outside rotor and body is 10 thou so I look to be ok there. There are some real tiny grooves (scratches really) inside the housing and on the outside of the outer rotor.

That leaves the spring. How do I remove the spring without damaging the cap that holds it in? If I do remove it to shim the spring does a new cap have to come from OZ? I also can't figure out how to replace just the screen, does the whole pick up get replaced?