NZ Performance Car – October 2019

Once we had the Junkyard K20 torn down to the bare block, it was

taken to Taylor Automotive to be cleaned and machined, starting

off with a trip to the hot tank to clean off 60,00km worth of grime. A

hot tank uses a preheated chemical solution to clean and is a very

necessary step in any engine build. Once cleaned, the block was

mounted into the boring machine to have the deck surface honed

and the bores oversized by 1mm to 87mm, including Wiseco’s

prescribed clearance of 0.0025”.

The first job was to skim the deck surface to ensure the block

and head would seal perfectly. Our low-kilometre block clearly

was not thrashed to death as when measured with a dial gauge

it was found only a few thou out, so only a tiny amount needed to

be skimmed off using a special tungsten tip in the Berco cylinder

boring machine. This tip is designed to remove both alloy and the

steel of the liner. Machinist Dieter made two passes giving us a nice

flat deck surface.

Before machining the bores, the big end girdle was also

torqued down to spec, simulating the stress the block will be under

once final assembled. The first step was to machine each bore

leaving 4-5 thousands of an inch for finish honing. While you can

hone the entire 1mm out, Dieter prefers to do it this way, as it not

Block basics

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