Description
The Mishimoto Silicone GM LS V8 Heater Core Bypass Hose (MMHOSE-LSHB-BK) is purpose-built for LS swap projects and LS-powered racecars where a heater core simply isn’t part of the plan. Constructed from 5-layer silicone and finished in black, this bypass hose tapers from 3/4″ down to 5/8″ so it fits the in and out ports on your water pump, giving swappers a clean, direct way to route coolant without the heater core in the loop.
When you’re building an LS swap, you have two options for dealing with unused heater core ports: block them off or bypass them. Mishimoto’s Fabrication lineup takes the bypass route, which is the preferred method because it lets coolant continue to flow so your thermostat can function properly and helps you avoid overheating. The heat and pressure resistant 5-layer silicone construction is engineered to hold up to the demands of a performance cooling system, and this Performance grade hose is built as a specific-fit part rather than a generic universal hose, matching the exact port sizing found on GM LS V8 water pumps. Clamps are included, so there’s no separate hardware to track down before you finish the swap.
Vehicle Applications
This bypass hose is designed around GM LS V8 swap platforms and applies to a range of factory LS-equipped vehicles, including the Buick Allure and LaCrosse (2008–2009), Cadillac CTS (2006–2007, 2009–2015), Chevrolet Camaro (1998–2002, 2010–2015), Chevrolet Corvette (1997–2013), Chevrolet Impala (2006–2009), Chevrolet Monte Carlo (2006–2007), Chevrolet SS (2014–2017), Chevrolet SSR (2005–2006), and Chevrolet Trailblazer (2006–2009). It also covers the Pontiac Firebird (1998–2002), Pontiac G8 (2009), Pontiac Grand Prix (2005–2008), Pontiac GTO (2004–2006), and the Saab 9-7x (2008–2009). Whether you’re pulling an LS out of one of these platforms for a swap or building around one of these chassis, this hose is sized to match the LS water pump’s heater core ports.
Features
- Fits all GM LS engines
- Allows you to bypass the heater core
- Bypassing instead of blocking water pump ports lets coolant flow to the thermostat and helps avoid overheating
- 5-layer silicone construction is heat and pressure resistant for a durable, long-lasting solution
- Tapers from 3/4-IN to 5/8-IN for a precise fit on water pump in/out ports
- Perfect for LS swap builds
- Includes clamps
- Also available in Blue and Red
- Backed by the Mishimoto Lifetime Warranty
Specifications
- Brand: Mishimoto
- Part Number: MMHOSE-LSHB-BK
- Product Type: Fabrication
- Hose Material: Silicone
- Hose Color: Black
- Grade Type: Performance
- Universal or Specific Fit: Specific
- Clamps Included: Yes
- Hose Diameter: Tapers from 3/4″ to 5/8″
Frequently Asked Questions
What is the Mishimoto Silicone GM LS V8 Heater Core Bypass Hose used for?
It’s used to bypass the heater core on GM LS V8 swap builds and LS-powered racecars, which typically don’t run a factory heater core. It provides a clean way to route coolant flow instead of blocking the water pump’s heater core ports.
Why bypass the heater core instead of blocking the ports?
Bypassing is the preferred method because it allows coolant to keep flowing so the thermostat can function properly, which helps avoid overheating. Blocking the ports off does not allow this coolant flow.
What size are the hose ends?
The hose tapers from 3/4″ to 5/8″ to fit the in and out ports on the LS V8 water pump.
What is the hose made from?
It’s built from 5-layer silicone that is heat and pressure resistant, providing a durable, long-lasting solution.
Are clamps included with this hose?
Yes, clamps are included with the Mishimoto Silicone GM LS V8 Heater Core Bypass Hose.
Does this hose come in other colors?
Yes, in addition to this Black version, the hose is also available in Blue and Red.
âš WARNING (California Proposition 65): This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
