Boosting Basics, B230F Turbo Conversion Part 1
Boosting Basics: B230F Turbo Conversion - Part 1
Turbocharging your Volvo might be easier than you think. Arguably, starting with a naturally aspirated B230F is one of the best places to begin. All redblocks are known for being robust engines, but non-turbo variants have typically lived easier lives, with less stress over time, making them a strong and often overlooked foundation.
In this series, we’ll show you how to get meaningful performance out of a B230F using a practical home garage approach. Spend time on what counts, and understand the compromises you’re making.
Part 1 covers something every turbo conversion needs to address first, oil feed and return for the turbocharger. We start here because it involves drilling into the block in two locations, which introduces contaminants into the engine. Doing this early allows everything to be properly cleaned when the sump is removed later.
As part of any turbo conversion, we recommend bringing the engine back to “stage zero” at a minimum. Replace gaskets, eliminate oil leaks, and start with a clean baseline. Drilling the block first ensures any debris is removed during this process, rather than circulating through a freshly assembled setup.
Oil Feed & Return Setup
Copy what Volvo did, because it works.
Oil Feed
Use the factory oil feed location under the exhaust manifold. This is an M14x1.5 thread from factory, and the size works well for both ball bearing and journal bearing turbos. We don’t recommend going any smaller.
Start with a small drill bit and work your way up to 12.5mm, which is the correct size for an M14 tap. Drill straight to a depth of 35mm, which matches the factory oil gallery depth.
We used a WD40 straw to check depth, Marking your drill bit beforehand works just as well.
For the feed line, we used a Speedflow M14x1.5 to -4AN adapter.
Oil Return
Use the factory return location.
Run a large diameter drain line to avoid restricting oil flow back to the sump. Some turbos are sensitive to oil pressure and drain restriction, so this is important. The common aftermarket standard is -10AN.
This requires an adapter in the block to suit -10AN. Make sure the fitting you choose maintains an internal diameter equal to or larger than the hose.
We use a Speedflow -10AN male to ⅝" BSPP adapter.
Be aware this tap size requires a large drill bit for a hand drill. We used a 21mm reduced shank drill bit.
Again, start small and work up in size. Drill to approximately 35mm depth, until you break through into the sump.
Take care with a ⅝" TAP and your done.
Final Step
Clean all debris from the oil gallery and sump while the engine is open and being re-gasketed.
Next post, we’ll move into confirming internal engine condition and what’s worth upgrading before adding boost.