Return to MarkOastler's garage

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Published on 21 June 2021

Not my mistake but a classic made by Moffat's crew (told to me by a former team member) which caused his disastrous outing at Bathurst in 1980 with a hurriedly-prepared yellow XD Falcon. Although the car was easily fast enough in practice to make the Top 10, it was haunted by low oil pressure and worrying smoke trails. The theory was that the rings in the freshly-built V8 wouldn't bed-in properly, so they did an overnight engine rebuild. Come the race, Moffat lasted only three dismal laps with smoke pouring from the rear of his car before it was retired. Moffat was tasting bile a few days later when a thorough engine teardown revealed the real cause - and it was such a simple oversight. The problem was traced to a build-up of silicone sealant in the dry-sump system. Excess beads of silicone had squeezed out of the joining surfaces between the engine block and the sump pan rails during assembly, dropped down into the oil at the base of the sump and instantly got sucked into the scavenge pump pick-up pipe when the engine was started. This had not been spotted at the track because (drum roll, please), to save time during the overnight engine rebuild, the time-poor crew had dropped the sump off still full of oil, covered it in Glad Wrap and put it aside until it was time to bolt it on again! So, the problem had nothing to do with piston rings; it was simply that the blocked dry sump system was pressurising and blowing all the oil back out of the breather in the boot-mounted oil tank. A small mistake with huge consequences!