A Customers Honda Civic VTEC Engine cover Modifications came about due to the need of an improved oil breather system. Here as you can see we have added 2 x Dash10 alloy fittings to the side of the cover to improve the breathing system. These will be connected via a hose system to the Oil Catch Tank. This Tank build is posted previously in our blog – click here to see it.
Improving the breather system is a necessity on the engine as it has had various internal mods and turbo-charging to boost power to a high 400ish bhp. To cope with this sort of power upgrade, has meant all other systems being upgraded to suit. The breathing system included. This now includes crankcase and head breather additions piped through to an oil catch tank, which is baffled, with collected oil draining back to the sump.
As you can see we have TIG welded the two fittings onto the cover, sometimes TIG welding cast Aluminium can be unpredictable due to the nature of the material itself. Cast Aluminium is known for being “porous” and hence soaks up oil into the pores of the material. Until you heat the material (when welding for example) the contamination within the material will “burn out”. This process can leave a poor quality weld as if all the contaminants are not burned out or dont float to the top of the weld pool defects can be left in the finished weld – typically in the form of “porosity” or in the very least poor fusion between parent and weld metal.
In order to try to eradicate this problem on some castings I have been known to lay a first weld (to help draw out or burn out any contaminants), grind the weld back and then re-weld once “clean”.
We also have to be careful with cast materials when welding as they can crack due to the high concentration of localised heat in the welded area. It is therefore sometimes advantageous to evenly heat the material before welding. This then reduces the chance of “shrinkage cracks” upon the localised heat cooling. If the job has been warmed up or “preheated” prior to welding then the whole job cools more evenly and therefore there are less local stresses set up around the weld area as the whole job will “cool” and therefore “shrink” more evenly.
Note that we can usually modify cast aluminium sumps and covers, to any customer requirements, we have repaired smashed sumps and dropped engine cases, chopped sumps to improve ground clearance on race and kit cars, added sump bash plates to help protect them and welded in new fittings for breather take offs, oil take offs etc.
Thanks for reading 🙂
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www.flashcustoms.co.uk 