Holden VB Commodore Piston Fix - Our Shed

By: Glenn Torrens, Photography by: Glenn Torrens

Date: 10.08.2019

Classic cars are a great, relaxing way to cruise to the local pub. Or frustrating enough to drive a person to the demon drink!

First task for my engine fix was to drain the fluids and remove the cylinder head

Removing the sump requires lifting the engine within the engine bay – hence the engine lifting bar

With the sump off, and the big-end cap removed, the bruised No 1 piston and its rod are finally on their way up and out

Thankfully the spare piston I’d sourced was identical to the damaged one from my engine

Test-fitting the second-hand piston confirmed it wasn’t wobbly

Replacement piston slides home – hose offcuts on con-rod bolts guard the journal against abrasions

My ‘new’ piston - dressed in a ring compressor – ready for installation

The sump is clean as a whistle and ready to be reinstalled

Classic cars are a great, relaxing way to cruise to the local pub. Or frustrating enough to drive a person to the demon drink!

First task for my engine fix was to drain the fluids and remove the cylinder head

Removing the sump requires lifting the engine within the engine bay – hence the engine lifting bar

With the sump off, and the big-end cap removed, the bruised No 1 piston and its rod are finally on their way up and out

Thankfully the spare piston I’d sourced was identical to the damaged one from my engine

Test-fitting the second-hand piston confirmed it wasn’t wobbly

Replacement piston slides home – hose offcuts on con-rod bolts guard the journal against abrasions

My ‘new’ piston - dressed in a ring compressor – ready for installation

The sump is clean as a whistle and ready to be reinstalled

Glenn sorts out the piston woes in one of his ever-expanding fleet of Commodores

Embarrassingly, I’d damaged one pot in my 1979 VB Holden Commodore wagon’s 3.3-litre engine. Bugger! I hoped I could simply fix the damage in No 1 cylinder by removing the cylinder head and sump and replace the damaged piston without the hassle of a complete strip-down.

First task for my engine fix was to drain the fluids and remove the cylinder head

I asked around my Holden-loving mates for an old engine I could strip for a piston and rod. Luke The Towie put me in touch with his mate Blake who had an old motor that I could – hopefully – use one piston from. We did each other a favour; Blake got rid of an old engine he didn’t need, and I got the engine parts I did!

Removing the sump requires lifting the engine within the engine bay – hence the engine lifting bar

To remove the sump, the engine needed to be lifted within the engine bay so after I removed the cylinder head, I used a borrowed engine lifting bar (thanks Juddy!) to raise the engine. The sway-bar was dropped, too, allowing me easy access to the con-rod bolts before the damaged piston/rod was slid out. The ‘new’ second-hand piston was removed from its donor and checked for size (thankfully both engines were factory standard so the dimensions matched – neither had been bored over-size) and the rings from my engine swapped to the ’new’ piston.

With the sump off, and the big-end cap removed, the bruised No 1 piston and its rod are finally on their way up and out

Then – to cut a long story short – it was simply a matter of reassembly: Piston and con-rod installed (also using the same con-rod bearing); sump on; engine block lowered back into the car; head re-installed with a fresh gasket; manifolds re-installed; fluids re-filled, and the electrics connected.

Thankfully the spare piston I’d sourced was identical to the damaged one from my engine

I checked my work and thankfully the engine fired instantly. At last, several weeks after disaster struck during what began as a relaxing afternoon fixing a few simple things, I was once again able to go cruising!

My ‘new’ piston - dressed in a ring compressor – ready for installation

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