H31 & 17H Oil Pumps

[Andrew_L26]

Can't find any information on the two oil pumps I have. The H31 is what came on the L28 F54/P90a/flat tops. And I got a 17H oil pump with my turbo setup (I assume the 17H is from an L20ET but I can't find any info to confirm) which one will provide a higher flow/pressure and or be best suited to a turbo build with an oil cooler?

 

 

Cheers,

Andrew

[dat2kman]

Standard oil pump impellor height is 3mm shorter than the L28ET oil pump

Iirc,, 30 vs 33, or could be 32 vs 35 mm.

Pull one apart and measure.

[Andrew_L26]

Just to update this it would appear that the H31 pump has a 35mm impeller/rotor height and the 17H pump has a 40mm impeller/rotor height.

 

The H31 has a regulator spring height (uncompressed and used so it may have sagged) of: 52mm and a regular valve height of 30mm (including nipple)

 

The 17H has a regulator spring height (uncompressed and used so it may have sagged) of: 56mm and a regular valve height of 32mm (including nipple)

 

I'm assuming that the longer spring and valve allow for higher pressures and the larger impeller/rotor allow for more volume?

 

Cheers,

Andrew

[dat2kman]

Taller impeller gives approx 15% greater Vol, this is sold as a "280ZX-T" pump.

The springs are all standard.

Nissan Comp did an Option spring, that fits inside the standard spring, to cause pressuer relief valve to stay closed until a higher pressure was obtained, this will put extra wear on drivespindle gears.

An old simple trick, pack approx 4-5mm of washers into the large hex nutted screw, cap, this puts a bit more force onto the spring, increses press relief opening by around 6-8 PSI

 

Use feeler guages to check if impellor is within tolerances, and for end float.

You can use a sheet of 1200 grit wet/dry, to polish out any scoring on ends of housing, this can reduce the end float a bit, which increases vol/pressures. Place 1200 grit onto a sheet of glass, use a figure 8 motion and a little 10 weight sewing machine oil.