stock l16 water pump vs 240/280 water pump

[Ranman72]

I have an l20b with a stock water pump with a fan clutch that sucks bought a new waterpump and the fan clutch was also bad when it was brand new 

I am going back to stock type water pump an aluminum radiator and electric fans

the stock z and l16/l20 lower pulley are the same diameter of 5.9 inches

but the water pump pulleys are very different

the l20 water pump has a built in fan clutch (non removable) and the pulley is 4.49 inches

the stock l16 pulley is 5.61 inches and

the z pulley is 4.57 inches

the l16 and z pulleys have different bolt patterns and different hub center size

my question is is there any advantage to the z pump with the smaller pulley opposed to the l16 with the larger pulley

if i am correct the larger pulley will spin the pump slower  is this diamiter difference significant in the rotation speed or not enough to make any difference 

[paradime]

Not the answer to your question, but... I had a Z water pump on an L20 and did away with the clutch. Turned out to be a costly mistake. I missed a shift between first and second and over revved the engine. The fan displaced so much air, it bent forward and shaved off a 1/4" of my rad. Be careful, I've seen guys use mini Weber grills to protect the rad. 

[flatcat19]

There are how-to threads about removing the clutch front the L20B water pump.

[Ranman72]

Not the answer to your question, but... I had a Z water pump on an L20 and did away with the clutch. Turned out to be a costly mistake. I missed a shift between first and second and over revved the engine. The fan displaced so much air, it bent forward and shaved off a 1/4" of my rad. Be careful, I've seen guys use mini Weber grills to protect the rad. 

wow thats a bad out come 

the revs are part of the reason for going electric 

the car has always run 15 degrees over the thermostat even with a factory style 3 core radiator 

i am installing a koyo and electric fans but just curious about the water flow   there will be no fan to bend like yours did 

[Ranman72]

There are how-to threads about removing the clutch front the L20B water pump.

not sure if there is any advantage to doing this if you can just put a stock pump on without the pos fan clutch 

but good to know it can be removed 

my l20b has a stamped impeller so i am going to change it out anyway with a cast type 

i have a cast one in the z type and the L16 just trying to figure out if one would be better than the other 

[flatcat19]

Pump with fan clutch removed is actually shallower than stock pumps without clutch.

 

Another advantage...it fits. No worries.

[banzai510(hainz)]

Most of the time the thermostat is closed so I dont think its going to a 240/280 ect pump is going to  move more water.

I always use a stock L 16 pump with the 510/521 pulley as the wholes line up for the pully.

 

alot of pumps are no being made in China.

i use the Atsugi and GMB but prefer the Atsugi

 

 

make sure the lower hose isnt getting sqeeze as you rev up the motor.

 

I drill a 1/8 hole in the stat and use a generic 54 mm 160deg . But this only work for cetain temp as if you live in a really hot climate you want the stat to close so the water cools before reintering the motor . If NO STAT then it gjust goes around then will still RISE up.

 

Just my thoughts

 

 

a 3 core should be a lttle better.

[metalmonkey47]

Isn't the offset very different as well?

[Ranman72]

Isn't the offset very different as well?

i put them side by side and it looked like they are the same or at least the pulleys were the same depth 

but I will probably just go with the stock one since it seems there is no real advantage to the z one 

[HRH]

The L water pumps are all the same internally as far as I know.  You aren't going to find a hi-flow version versus low-flow.  The pulley for the fan changes heights.  Either way, all you need is a '69 water pump for a 510, no clutch.  They fit the following vehicles:

 

Datsun 510 1968 - 1973
Datsun 521 1970 - 1972
Datsun 610 1973 - 1973
Datsun 620 1974 - 1974
Datsun 720 1981 - 1983

 

Part numbers for NAPA are 41130 (TFW) line code

And an altrom pump 152 9029 (ATM) line code

 

The altrom gets spotty with availability, and I just checked for you.  Yeah, nothing pisses me off more than having a part in my system that I can't get.  Anyway, the Truflow pumps are just fine.  Have one on the turbo car and the truck, no issues.

 

The 280z pump is a 41132 (TFW)  so perhaps there is a snout length difference.  I could go measure my cars but it's hailing out right now and I don't want to. ;)  That pump fits these motors and is also clutchless.

 

Datsun 240Z 1970 - 1973
Datsun 260Z 1974 - 1975
Datsun 280Z 1975 - 1978
Datsun 280ZX 1979 - 1983
Datsun 810 1981 - 1981

[Ranman72]

The L water pumps are all the same internally as far as I know.  You aren't going to find a hi-flow version versus low-flow.  The pulley for the fan changes heights.  Either way, all you need is a '69 water pump for a 510, no clutch.  They fit the following vehicles:

 

Datsun 510 1968 - 1973

Datsun 521 1970 - 1972

Datsun 610 1973 - 1973

Datsun 620 1974 - 1974

Datsun 720 1981 - 1983

 

Part numbers for NAPA are 41130 (TFW) line code

And an altrom pump 152 9029 (ATM) line code

 

The altrom gets spotty with availability, and I just checked for you.  Yeah, nothing pisses me off more than having a part in my system that I can't get.  Anyway, the Truflow pumps are just fine.  Have one on the turbo car and the truck, no issues.

 

The 280z pump is a 41132 (TFW)  so perhaps there is a snout length difference.  I could go measure my cars but it's hailing out right now and I don't want to. ;)  That pump fits these motors and is also clutchless.

 

Datsun 240Z 1970 - 1973

Datsun 260Z 1974 - 1975

Datsun 280Z 1975 - 1978

Datsun 280ZX 1979 - 1983

Datsun 810 1981 - 1981

thanks for the info 

I wasn't thinking there was a high flow I was only thinking the smaller diamiter pulley woulkd spin the pump faster and move coolant faster 

it might also spin faster and wear out faster  :thumbup:  :thumbup:

[Lockleaf]

Faster isn't always better. It can increase foaming at the impeller. Acura Integra vtec motors ran a "slower" water pump than the non vtec, supposedly because it was believed that the motors would be used at higher rpms, so they slowed The impeller down to prevent cavitation from over spinning it.

 

For what that is worth when taken with a grain of salt.

[datzenmike]

L series 4cylinder pumps seem all the same inside but later Z series with larger cavity and cast impeller inside. Yes they will interchange if you also change the fan blades.

 

L series..................................................................................................................................Z series

 

 

 

L series..................................................................................................................................Z series

 

 

L series

 

 

 Z series

 

 

Take a good look at the Z series pump. The impeller is taller and sits in a deeper cavity. All L and Z series (4 cylinder) pumps will swap. Don't know about the L sixes.

[spdcrazy]

mike, are you saying a Z pump will fit in the L housing? without scrapping on the back side?

 

I'm interested in this as well.

[datzenmike]

The complete pump will swap not the internal parts. The cast impeller is taller but sits deeper (frontward) in a deeper cavity. I've run Z series pumps for years on an L series timing cover..

[spdcrazy]

sounds like I need a z water pump for my l20b then, the factory belt pulley will fit still correct?

[datzenmike]

I think they are the same pulley. You will need the plastic fan blades too and check fan diameter will fit your shroud.. again I think they do.

[racerx]

This is just for future reference...what is the benefit of running a Z pump?

[banzai510(hainz)]

Its sounds COOLER!!!!!!!!!!!!!

 

faster it spins the more cavitation and ruin the front timming cover

[flatcat19]

I'd stick with what you know works.

 

 

Cut the clutch off that L20B pump.

[G-Duax]

There is also a shaft diameter difference between some of the L4 pumps, and the Z pump.

No idea what an L20b had, too lazy to uncover my son's old L20b powered ex-Imsa 510 to see.

But early L4 pumps had a 12mm shaft, and the Z pump has a 16mm shaft, with a 31.7mm pilot (.002" under 1.25" - Weird!).

 

I'm just in the middle of making an 8mm timing belt accessory drive for my latest build, and am going to the Z pump to get the larger shaft diameter.

[racerx]

I have an L18, stat at 160, stock radiator but 3 core ( modine - ebay ) , no fancy alum. Rad stock fan and been running at around 170 degrees, maybe 175 if stuck in traffic for like 15 min.

[shacks510]

I got an L4 pump from O'Reilly. I forget the brand, but I think it's a repackaged Airtex (cast impeller). I have it on my LZ22 with a 160 thermostat with two 1/8" bypass holes that I drilled, and a Koyo. Temp stays right around 170; unless it's very cool out, or I'm in slow moving traffic, then it'll creep up to 180. I'm using a stock mechanical fan with no shroud.

[datzenmike]

Get and use a shroud. It increases the fan's efficiency at low speeds.

[Ranman72]

just to be clear 

when i was referencing a z pump I meant the l series 240/260/280z pump 

which a=had a smaller diameter pulley and the bolt pattern is different than the l16 pulley 

It seems some of these answers are for a z22/z24 pump