Monday 21 March 2011

Mallory Test = Disaster!

I was nervous about the the test day, Mallory isn't my favorite circuit and i find it the most intimidating, but i was more worried about a serious mechanical problem with the car. My concerns would soon turn into reality........

It didn't start too well, battery was dead on the bus, then i damaged the rear tub mounting bracket as i drove the car over it. The trip there was at least uneventful and we arrived bang on 8am ready to sign on. After unloading i took the car for a slow spin around the paddock and everything was fine. I went out for the first session at 9 and did about 3 laps, taking it very steady, but could already tell it was going to be a flying machine compared to the blade!! Coming back to the pits and removing the bonet showed i had a small oil leak somehwere around or near to the oil level sight glass. It was only a small amount of oil and the levels was still fine so i headed out again. I started to push a little harder, but was still taking it very easy, i had no gear indicator or shift lights as these were still set for the blade so probably went no where near the rev limit. Returning back in we then set about trying to track down the oil leak.

The oil leak was only minor, but was coming from the union between the oil cooler and hose and it wouldn not tighten anymore. So we decided to remove the pipe to investigate further, this showed that the end we had had fitted on the old hose was the wrong type and would never seal properly, bugger! The leak was very very minor so at least it wouldn't stop the day, but dad being dad, came up with a solution using an o-ring, and "bang, the leak was gone". Whilst dad was doing this i set up the shift lights and gear indicator, something that would have been less fiddly if i had remembered to bring my laptop along!! By the time this was all done the 2nd session was well underway, but it was still worth a run out, but as i went to use the reverse the car went dead, no power!!! Bugger!!! I thought it was the master fuse, but a flick of the master switch and it came back alive again, but as soon as i tried to crank the engine it died again. I started to fear a serious electrical sort, until a waggle of the battery terminals showed they were lose!! A nip up with the spanner and i managed to get out on track for 1 lap before the flags came out!!

We again checked over the car, the oil leak from the cooler union was cured, but there was still dampness around the sight glass, very very minor but a leak none the less. It was either the glass seal itself or the cover plate directly above it, but not something we could sort with stripping the engine down a bit. The oil level was still perfect and not dropped so it would be fine for the final session. With 15minutes to spare we set up the new video vbox camera system and refueled.




In the final session I slowly started to build up the pace and started to use the full rev range, although still not really ragging it, and getting to terms with the swapped over gear change. I saw Al in my mirrors and thought oh dear this could messy (actually i thought wahoo a race!!), the circuit was damp and i was still being cautious (as was Al), but now the purple peril was behind i was hoping to start stretching the cars legs, unfortunately the following lap, whilst going down the start straight, there was an almightly bang, a horrible vibration, plumes of smoke and no engine power. I quickly pulled off onto the entry slip road of the pits and contemplated jumping in the lake.....

Pushing it back to the bus i knew something big had happened, i was hoping it was an exploded diff, but was pretty sure it was the engine. After removing the bonnet the damage was obvious, a hole in no1 barrel and crankcase, bugger!!!!

I was pretty sure it wasn't oil starvation as i had been keeping a very close eye on the oil pressure around Gerrards during the day, but unfortunately my data logger wasn't running. Luckily watching back on the video, the oil light is just visible in the bottom right hand corner. It does flicker on coming into the hairpin, but this is because the engine revs have dropped right down due to changing all the way down the box. Nowhere else does it come on so i was then confident it was not oil starvation, but a strip down of th enegine would need to be done to confirm this.  At least my new video kit worked well, and it captured the moment of destruction very well



Back home we took the engine out and stripped it down










 As you can see the big ends and crank are perfect, so the conrod failure was caused by oil starvation and the a seizing big end. So we can only conclude there was a fault with the conrod, either in caused in manufacture or by an excessive stress load during the its lifetime in the bike.

So making Mallory race 1 was looking fairly dubious on Thursday, until i decided to take the bull by the horns and start a nationwide hunt for a replacement. Malc at Yorkshire engines who supplied this engine offered me a replacement at cost price, but hadn't got one in stock, Andy Bates was on the look out for me, but then i stumbled across one in Stoke for a good price, so i shot up there and picked it up the same day.

So its now operation fit engine 2 and hope for the best next time out!! Fingers crossed!!

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