Product Summary

  • 1-inch tall thermostat riser features two 3/8-NPT ports for additional cooling lines
  • Compatible with SBC thermostats, coolant restrictors, and thermostat housings
  • Popular solution when used with Edelbrock Victor Series two-piece LS and Small Block Chevy water pumps
  • Black anodized 6061-T6511 aluminum with O-ring gasket for an easy leak free installation
  • Mounting hardware and NPT hose fittings not included due to the extensive fitment options
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Key Specs

MFG. Part #91039377
BrandSpeedway Motors
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Speedway Motors 91039377 Details

  • 1-inch riser includes two 3/8-NPT threaded ports for coolant lines
  • Can be used with thermostat housing or block off plate
  • CNC machined from 6061-T6511 aluminum bar stock
  • O-ring sealed base for leak free installation
  • Designed to be used on Edelbrock’s Victor Series 2-piece LS water pump

Keep Your LS Engine Cool Lap After Lap with A Two Port Water Neck Riser

GM’s LS engine family has become a popular engine for circle track racing these days. While the LS is the undisputed swap king on the street, when it comes to surviving lap after lap most racers have updated their LS race engine to use the popular Edelbrock Victor Series two-piece LS water pump. This water pump is popular due to the relocated traditional small block Chevy thermostat design, which places the thermostat at the top of the pump, like the location on the intake manifold of a small block Chevy. This is done for several reasons. One, the LS engine family is reverse cooled, meaning that the thermostat is the “gate keeper” for the radiator cooled coolant to enter the engine. Whereas a traditional small block Chevy thermostat controls the release of the hot engine coolant back to the radiator for cooling. It also eliminates the need for the standard degas tank design that the LS engine uses, reducing engine compartment clutter and simplifying the cooling system circuit.

With the Edelbrock Victor Pro Series water pump installed you can use normal small block Chevy thermostats or restrictor plates with a standard thermostat housing for high performance street use. But more importantly for racing, you can add a riser to the thermostat mounting pad to provide a connection point for two or more coolant lines that are traditionally routed to the rear of the intake manifold or cylinder heads to prevent steam pockets and even out coolant temperatures from front to rear on the engine.

Our two port risers are machined from 6061-T6511 aluminum bar stock, accept standard thermostats or restrictors, or can be blocked off completely with our matching block off plate. It seals to the water pump’s housing with an O-ring gasket for easy removal/maintenance. The two ports are tapped to 3/8-NPT and will accept the typical AN to NPT fittings to connect your cooling lines. We also offer a 4-port riser with 1/2-NPT ports if you need a riser with larger flowing ports for direct connection to your radiator versus using a traditional upper hose, as in sprint car applications.

Speedway Motors 91039377 Specifications

KEY SPECS
MFG. Part #91039377
BrandSpeedway Motors
GENERAL
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Ratings & Reviews

5

5 Reviews

Overall Assessment

Customers are extremely satisfied with the product's perfect fit, noting it works particularly well with the RPM Air-gap. Appreciated for being nicely machined, it stands out for its practical use in the 4-point coolant bypass operation. The product's quality and usability are confirmed by the recommendation of the superior selections available at Speedway.

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Product worked perfect for my application

5.0

a month ago

ET

VA

Verified

Used it to incorporate a fan temp switch

I would buy this again

5.0

6 months ago

Ran

Nbpt ma

Verified

Was exactly what I needed to add a port for temp sender

Would Recommend

I would buy this again

5.0

8 months ago

Hank

Surprise, AZ

Verified

Very well machined part. Perfect fit

Would Recommend

yesthe fit was perfect

5.0

9 months ago

frank nova

orange ma

Verified

its 1/2 inch instead of 3/8

Would Recommend

Great piece of hardware

5.0

a year ago

Assembly guy

Heart of Maryland

Verified

Nicely machined and fit my RPM Air-gap like it was ment too . I used this part for my first attempt at 4 point coolant bypass . Speedway has a great selection for this .

Would Recommend

Showing 5 of 5 reviews

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