Product Summary

Mechanical Water Pump Type, Cast-Iron Housing Material

  • Completely new water pumps feature severe-duty roller & ball bearings, close tolerances & modular impellers for maximum flow & reduce cavitation
  • Kit includes a Speedway Motors 1937-1948 Flathead Driver Side Water Pump & a Passenger Side Water Pump as well as gaskets
  • These pumps also have modern ceramic seals on a heavy duty 5/8" shaft, making the assembly exceptionally strong & more efficient
  • Forged all-new high-nickel iron casting with a premium black painted designed for use on systems with 5/8" drive belts - 1937-48 Ford & Mercury Flatheads
  • Pulley diameter measures 4.35" with a belt width of .63" & an overall pump height of 9"

Comes as a Kit

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Key Specs

MFG. Part #91603023
Water Pump TypeMechanical
Water Pump StyleShort Depth
Housing MaterialCast-Iron
Housing FinishPainted
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Need To Know

Quick and Easy Returns

Return Policy

Speedway Motors 91603023 Details

 We got your back with our Speedway Flathead Water Pump Kit! Both water pumps and needed gaskets are included to simplify your Flathead engine build, so you can spend more time and money on other aspects of your project!

Kit Contains:

  • (1) Speedway Motors 1937-1948 Flathead Driver Side Water Pump
  • (1) Speedway Motors 1937-1948 Flathead Passenger Side Water Pump

Speedway Motors 1937-1948 Flathead Water Pumps

Original Flathead water pumps have always suffered from unreliable bronze bushings and carbon seals. They almost always leaked and even Ford manuals warned mechanics not to tighten fan belts too tight. The excess slack allowed belts to slip and lose contact with the generator and water pump pulleys, causing more cooling and power problems.

Speedway's completely new water pumps feature severe-duty roller and ball bearings, close tolerances and modular impellers to provide maximum flow and reduce cavitation. They also have modern ceramic seals on a heavy duty 5/8" shaft, making the assembly exceptionally strong and more efficient. All mounting areas are spot faced for improved fit and sealing.

  • For Wide Belt Pumps
  • All-new high-nickel iron castings
  • Severe-duty roller and ball bearings
  • Ceramic seals on sturdy 3/4" shaft
  • High-flow modular impeller reduces cavitation
  • Gaskets included
  • For systems with 5/8" drive belts
  • Pulley diameter: 4.35"
  • Belt Width: 0.63"

Factory replacement for 1937-1948 Ford and Mercury cars and trucks. Includes gaskets.

Water Pump Features 

Charts

Speedway Motors 91603023 Specifications

KEY SPECS
MFG. Part #91603023
BrandSpeedway Motors
Water Pump TypeMechanical
Water Pump StyleShort Depth
Housing MaterialCast-Iron
Housing FinishPainted
GENERAL
Pulley Type CompatibilityV-Belt
Pulley Diameter4.35"
Groove Count1
Belt Width0.625"
Housing ColorBlack
Mounted Length3.31"
Pilot Shaft Diameter0.63 Inch
Overall Height9.00"
Gasket(s) IncludedYes
Sold in QuantityKit

Ratings & Reviews

4.7

11 Reviews

Overall Assessment

Customers expressed satisfaction with the product's high quality and excellent fit. Users highlighted the product's superior practicality with the added fins and larger bearing, noting it effectively reduces heat, thus improving its overall performance. They also appreciated that the product is robust and long-lasting, making it a superior choice. Installation was generally straightforward, though some pointed out minor adjustments required due to casting material. Regardless, customers not only recommend the product but are inclined to repurchase due to its reliable and efficient performance.

4.7

11 reviews

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Would buy this again

5.0

6 months ago

Rook

Grand forks ND

Verified

Water pumps fit perfect and came in a few day and had it up and going in no time. Hard to find parts for these old flat head motors. Glad they stock stuff like this

Would Recommend

Great part good price

4.0

a year ago

Willie

Middleburg Fl

Verified

Worked well on my flathead

Would Recommend

Perfect fit

5.0

2 years ago

Wildland

Bowling Green Va

Verified

Good quality pumps. Fit great on my 48 ford flathead.

Would Recommend

Great Quality and Fit!

5.0

2 years ago

Bhotrod

Constantine, MI

Water pumps arrived quickly and packaged great! Fit like a glove on our freshly built 59ab Flathead V8. Thank you Speedway!

Would Recommend

Yes

4.0

4 years ago

Ike

Ontario Canada

I bought this pair this week .and just installed them. They look and feel great...but when i installed the driver side i had to grind away casting material around the upper left bolt hole to allow the pump to seat against the block.The passenger side was much thinner in this area and seated fine. Just a heads up.

Would Recommend

Great Product

4.0

5 years ago

Dirtdigger

South Dakpta

Verified

good fitment

Would Recommend

I would purchase this again.

5.0

5 years ago

Sonny

Keenesburg Co.

installed them on my 40 Ford PU and the added two fins an larger bearing should be long lasting pumps. It definitely ran alot cooler.

Would Recommend

Excellent service means I'll be back!

5.0

5 years ago

Kym the suffering wife

Geraldton Western Australia

Verified

Living in country Australia makes it difficult to find parts for the engine my husband is rebuilding. Until he found Speedway motors that is. He's ordered several parts from here now and has decided to make them his GOTO supplier

Would Recommend

I would purchase these again

5.0

6 years ago

Jackie

Ball Ground,Ga

Verified

rebuilding my 48 flathead

Would Recommend

Yes

5.0

6 years ago

N/A

Texas

Verified

Everything fit up great

Would Recommend

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Questions & Answers

Fitment

  • 221 Ford Flathead V8

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Customer Impersonation Script