This week we have a story where tiny part which literally costs nothing caused a major failure. There was a two car Mustang convoy, a husband and wife team driving. The lead Mustang was driven by the wife and the husband following in his Mustang. The lead car was forced to come to a very abrupt stop with no power. A little background to the failure was the distributor itself. Each distributor has a drive gear on a shaft held in place by a pin. This gear is rotated which then rotates the shaft which has the rotor arm attached at the top under the distributor cap. When the rotor makes contact with metal parts of the distributor, this completes a circuit for the timing of the spark as it rotates in the distributor cap. That gear’s shaft pin had sheared and allowed the distributor to effectively freewheel with the rotor arm not spinning inside the distributor. Within a few split seconds there had been a significant amount of fuel still being dumped into the engine’s cyclinders and exhausted back out and mixed with some hot vapours, all without being ignited. The unburned fuel and hot vapours were clogged at the exhaust mufflers without any real pressure to move them out the exhaust system.
Left is the arrowed space where the pin should have been. The video shows the gear spinning on the shaft.
The next sequence of events would see the gear re-engage just enough to spin the rotor arm again. This allowed a spark to fire in the wrong cylinder and at the wrong time. The end result was a massive backfire which then ignited all the unburnt fuel and vapours lurking in the exhaust. Such was the force of the ignition of the unspent fuel and vapours, the pressure had blown apart a relatively new muffler fitted by us and expanded the muffler on the other side. The force of the pressure observed from behind by her husband; the force of the shockwave had lifted the rear of the car up and had a pretty spectacular shower of flames and sparks.
Luckily the driver was quick to react and pull the car over safely, promptly followed by her husband. He checked that she was fine and had a quick look under the car and realised it was temporarily dead and would need to be towed to us.
Now rumour has it that it sounded like a gun had gone off inside the car such was the volume of the backfire. Contrary to her belief at the time, her husband didn’t fire a .50cal at the back of her car. We can confirm that there are no bullet holes on the back of her car. 😄
Moving on, the car was lifted up on our ramps to see the full damage to the exhaust. The mufflers were removed and replaced with the same set up. We have to say that we have never seen a backfire of this scale to blow apart a couple of month-old pair of mufflers.
We inspected for any additional damage and once we were happy we replaced the distributor. We cranked the engine by hand to make sure all was well before we fired her up. The timing was reset and she purred like a kitten.
Classic leMans (part 2)
Paul sent us some more photos of the classic race, but it was a bit late to include in last weeks post, but we do have them here for you.
Thanks to Lob Monster for sending us the pics of what turned out to be a great weekend which was had by all.
No sooner had they got back from their travels that they set of for this weekends Santa Pod race weekend.
Paul did state “it feels like he has lived in a tent for few weeks”. Coming up soon is the Mustang Owners Club of GB who will be having a Santa Pod race day of their own. We will be bringing you some pictures from that as well.
Adam has now sourced a selection of 2015 – 2017 brake calipers for the Mustang ecoboost. These will be added to our webshop soon.
Next week Adam will respond via this blog again about shipping costs as we had a rather uninformed email ‘demanding’ we explain our costs. We will be showing you the shipping charges for a pallet to the UK. So if you want to know what it cost we will show you exactly we we pay to get your parts to the UK.
Stay Safe & Take Care!