Honda B-Series Block Port and Plug Conversion Options

Honda B-Series Block Port, Breather & Coolant Adapter Options

Honda B-Series engines have several factory block ports that can be useful when building a catch-can, crankcase breather, turbocharger coolant, or other custom engine-plumbing system.

The important thing to understand is that not all of these block ports serve the same purpose.

The rear B-Series block ports commonly used for crankcase ventilation and catch-can plumbing are completely different from the front coolant port used for turbocharger coolant-feed and other compatible cooling-system applications.

This guide explains the common JBtuned block-port options, what each one does, and how to determine which type of fitting applies to your build.

For customers looking specifically for the rear B-Series crankcase-ventilation fittings, see the JBtuned Honda B-Series Block Port Fittings.

Then add these two links in WordPress:

• Link JBtuned in the fourth paragraph to https://www.jbtuned.com/
• Link JBtuned Honda B-Series Block Port Fittings in the last paragraph to https://www.jbtuned.com/products/jbtuned-honda-block-port-fittings-honda-b-series.html

 

 

 

B-Series Rear Block Ports for Catch Cans & Breather Systems

Many Honda B-Series engines have factory block ports on the rear of the engine that can be used as crankcase ventilation points when adding an aftermarket catch-can or breather system.

The JBtuned Honda B-Series Block Port Fittings replace the applicable factory block plugs and provide connections for compatible aftermarket crankcase-ventilation plumbing.

These fittings are commonly used when you want to vent the crankcase directly from the factory rear block-port locations rather than relying only on valve-cover ventilation.

Early 1990-1992 B18A engines may have only one applicable rear block-port fitting location. Other B-Series blocks may provide additional usable locations depending on the specific engine and block configuration.

Always inspect your particular block before ordering rather than assuming every B-Series engine has the same port arrangement.

Link JBtuned Honda B-Series Block Port Fittings to:

https://www.jbtuned.com/products/jbtuned-honda-block-port-fittings-honda-b-series.html

 

B-Series -10AN Block Plug Adapter 

 

B-series 10AN block plug adapter

Identifying the Rear Block Ports
The rear block photo above shows where the applicable crankcase-ventilation locations can be found on a compatible B-Series block.
These are crankcase/breather locations, not coolant ports.
Which locations are available depends on the particular B-Series block being used, as well as which factory breather components are still installed.
For customers building a more complete catch-can or crankcase-ventilation system, JBtuned also offers the Honda B-Series Block Plug & Catch Can Breather Fittings.
The correct configuration depends on the engine, the factory breather arrangement being retained or removed, and the catch-can system being installed.
Link Honda B-Series Block Plug & Catch Can Breather Fittings to:
https://www.jbtuned.com/products/jbtuned-honda-b-series-block-plug-and-catch-can-breather-fittings.html

The B-Series -10AN Block Plug Adapter

Long-time JBtuned customers may recognize the JBtuned B-Series -10AN Block Plug Adapter shown above.

This adapter uses the factory breather-box location on compatible B-Series blocks to provide an additional -10AN crankcase-ventilation connection.

B20 blocks do not have the same factory breather-box port required by this particular adapter.

 

The B/D Series Front Block Port Adapter

B-Series & D-Series Front Coolant Port Adapter

The front block port shown here serves a completely different purpose from the rear crankcase/breather ports discussed above.

The JBtuned Honda B-Series & D-Series Front Block Coolant Port Adapter -6AN replaces the applicable factory front engine-block coolant plug and converts the port to a -6AN male connection.

The current JBtuned adapter is machined from aluminum and is designed for compatible Honda B-Series and D-Series engines with the applicable factory front coolant port.

One of the most common uses for this adapter is supplying coolant to a water-cooled turbocharger.

Instead of drilling and tapping another coolant passage or fabricating a connection from unrelated fittings, the adapter uses the existing factory coolant port and provides a proper -6AN connection for compatible coolant plumbing.

It may also be used for other compatible custom cooling-system applications where access to the factory front coolant port is appropriate.

Link JBtuned Honda B-Series & D-Series Front Block Coolant Port Adapter -6AN to your current product page.

 

Rear Breather Ports vs. Front Coolant Port

Although these fittings all install into factory Honda engine-block locations, they serve very different purposes:

• Rear B-Series block-port fittings: Crankcase ventilation, catch cans, and breather systems.
• Rear factory breather-box location: Used by certain B-Series breather configurations and by the discontinued JBtuned -10AN Block Plug Adapter.
• Front B-Series / D-Series block port: Coolant-system location commonly used to provide a -6AN connection for turbocharger coolant-feed plumbing.

Do not choose a fitting simply because two factory plugs or ports look similar. Make sure you understand which engine passage the port connects to and what you are trying to accomplish before removing a factory plug.

Which JBtuned Block Port Fitting Do I Need?

Adding a Catch Can or Crankcase Breather

For compatible B-Series engines using the factory rear block-port locations, use the JBtuned Honda B-Series Block Port Fittings.

Building a More Complete B-Series Breather System

See the JBtuned Honda B-Series Block Plug & Catch Can Breather Fittings for compatible applications where the factory breather arrangement is being modified as part of an aftermarket crankcase-ventilation system.

Need a Coolant Feed for a Water-Cooled Turbo?

For compatible B-Series and D-Series engines using the factory front coolant port, use the JBtuned Honda B-Series & D-Series Front Block Coolant Port Adapter -6AN.

Fitment Matters

Honda produced many B-Series and D-Series engine variations, and factory block-port configurations are not identical across every engine.

Before ordering, identify the engine and block being used, inspect the available factory ports, determine whether you are working with the crankcase-ventilation system or cooling system, and verify that the applicable factory port is present.

If you are unsure which fitting applies to your setup, contact JBtuned with your engine code, vehicle, and what you are trying to connect.

Installation Notes

Any time a factory engine-block plug is removed, make sure you have correctly identified the passage before installing an aftermarket fitting.

Clean the surrounding area before opening the engine and use the appropriate sealing method for the fitting and application being installed.

Connected hoses should be securely routed away from exhaust components, belts, pulleys, sharp edges, and other moving or high-temperature parts.

For coolant-system work, refill and bleed the cooling system as required and carefully inspect the adapter and all coolant connections for leaks before operating the vehicle.

For crankcase-ventilation systems, make sure the complete breather or catch-can system is properly configured for the engine and intended use.