3.2 Pump in a 71 case

[sebastianroher]

I'm about to start assembly on my bottom end of the motor. I'm thinking about installing a new 3.2 pump instead of using the stock mag pump. Will I have to do any modifications to the case? I already have the oil bypass mod and piston squirters installed.

Thanks,

Sebastian

[Flat6pac]

the 3.2 is a 4 rib pump, basically the same as every pump after 1975 or the aluminum pump of 78.
Bruce

[sebastianroher]

But will this pump work for my '71 build? I just want a sufficient pump to run a front mount cooler and it will be for a "T" built to "S" spec.

Thanks,

Sebastian

[Inkblot]

Check out Glenn Yee Motorsports- Glenn will rebuild, port and polish your 3 rib pump, and reportedly gets better flow out of it than a stock 4-rib. I just sent mine; he does it on a core-exchange basis, so the turnaround time is really fast. I haven't installed it yet, but it looks great- almost a shame to have it all buttoned up inside the case
Wayne's book says use a 4-rib (no modifications necessary for mounting), but I really liked the idea of using something that an expert has looked it over and re-worked as necessary. Not an easy thing to swap out once your engine is back together!

Jake

[MBruns]

If you have done the bypass mods you are good to go, just need the bubble sump cover, I would mark the pump sections and disassemble and inspect it and if it’s nice leave it alone, that pump will be more than enough.
Mike Bruns

[sebastianroher]

Originally Posted by MBruns

If you have done the bypass mods you are good to go, just need the bubble sump cover, I would mark the pump sections and disassemble and inspect it and if it’s nice leave it alone, that pump will be more than enough.
Mike Bruns

I dug out my mag pump (It was in storage since 2015) and I think there are some sections where it might have sucked something up and damged the turbines in the pump. It is a little tight to rotate by hand. Anyways, I think I'm going to go with a 3.2 pump once I'm ready for assembly. Thanks for your input and advice.

[Matt Monson]

Originally Posted by Inkblot

Check out Glenn Yee Motorsports- Glenn will rebuild, port and polish your 3 rib pump, and reportedly gets better flow out of it than a stock 4-rib. I just sent mine; he does it on a core-exchange basis, so the turnaround time is really fast. I haven't installed it yet, but it looks great- almost a shame to have it all buttoned up inside the case
Wayne's book says use a 4-rib (no modifications necessary for mounting), but I really liked the idea of using something that an expert has looked it over and re-worked as necessary. Not an easy thing to swap out once your engine is back together!

Jake

This. These are the same pumps Ollie’s sells.

[chris_seven]

Originally Posted by sebastianroher

I think there are some sections where it might have sucked something up and damged the turbines in the pump. It is a little tight to rotate by hand.

There are 'gear' sections in the pump and any damage to the gear teeth will be obvious and easy to identify.

If you also inspect the inner faces of the housing for any obvious scoring or marking it will be easy to observe any damage.

If the pump is basically undamaged it will have enough flow to do its job and doesn't need any modification.

Chipped teeth, score marks and 'rubs' to the housing may allow the pump to 'spill' which will reduce output.

These pumps are very simple machines and generally provide robust and reliable operation.

As I have asked on a number of threads I would be keen to know how to increase the flow rate of a very simple pump.

The fluid being pumped is carried between the gear teeth and the pump housing.

The volume being pumped is proportional to the trapped volume, the number of teeth and the rotational speed.

Polishing inside the pump may reduce drag, which in turn will reduce parasitic loss but it doesn't affect the displacement of fluid and hence the flow.

Even radial pumps show little difference in their discharge volume with changes in surface roughness of the impellor but efficiency does improve.