Specially prepared B230 Inlet Manifold by Anthony Hyde
Outside and inside pictures show the result of 55 hours dedicated hand crafting. This Volvo manifold was prepared in advance of fitting a programmable engine computer. All the effort better be worth a few extra horsepower ! - 3 beaut pics below

Good lighting is essential to see exactly what your doing way inside. Spend some time setting up lamps at both ends of runners.

The biggest challenge is removing the two casting joins in each tube. Machines can't get deep inside these curved oval areas, so the most effective way is to scrape out casting spots and irregularites in a controlled manner by using special hand tool scrapers and burr bits. Progress can be slow & tiresome, but when you reach and clean up new areas, there is a feeling of reward.
An 'S' shaped tool can be made using 1/4" copper tube, bent easily as required. To hold the burr bit, drill a piece of round steel , then tap the side for two small grub screws, then solder onto the copper tube.

Radiusing the entry tubes (see pics) was achieved with some fine half-moon type files and scraping (grind an internal radius into a steel blade), and finished off by using fine sanding discs attached to a Dremmel type tool.
Final finish was with fine bead blasting. When metal finishing is complete, thoroughly wash out manifold using hot soapy water and a bottle brush. The outside metal surface is sealed with a furniture polish - best is 'Johnson's Wax' wood polish (contains oil & wax) to keep the bead blasted alloy surface looking good for many years.


This trick shot was taken using a 'fish eye lens' on a digital camera.

The view is from where the throttle body attaches to the manifold plenum. Notice how every edge and transition has been rounded off. 'Flow through' would be far more laminar (smooth) than original casting.

Being manifold for a fuel injected engine, fuel is injected elsewhere, so the manifold serves to channel only air to the cylinder head. So the smoother the flow the better. Eg, race cars use very smooth carbon fibre for inlets and airboxes.


Thanks for visting,

Anthony Hyde





THROTTLE BODY - being machined (bored out) in the lathe. A face or mounting plate needs to be made first.

At the same time, the outside 'hose clamping surface' is machined round and a clamp lip improved.

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