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"Failure is always an option." - Adam Savage -
Re: Escort Sigma 1600 Race Car
OK heres the summary of the event.
Saturday morning I had the first chance to get out on the track. We had 25 mins of free practice.
The car handelled great but the engine was cutting off violently around 8000rpm's
At this point I thought I'd deal with it once I'm done with the first outing.
I made a short pitstop to check my tyre temperatures. My hidden agenda and cunning plan was to practise some grid starts to see what it takes to launch this car propperly. 6000rpm's and foot off the pedal. A hooge thud followed and it was pretty obvious what had happened. End of the free practise for sure. I was the second fastest driver on the track.
Thanks to all that's holy I had my spare propeller shaft with me so we made short work of changing the prop. We were pretty blown away what could possibly be the reason for the failure.
The thud was so immense it cracked the windscreen. I decided to try the car around the paddock to see that everything works. Car made a terrible racket when moved at all and was stiff as *ell to push.
We lifted the car up again to take a closer look. We all had missed the lower 4 link bars were all bent. The bent bars twisted the axle to an odd angle and that broke the propeller joint.
We had less than two hours to the qualifying run so it all seemed pretty grimm again.
Again by some unearthly strike of luck my father had packed two deasent lenghts of plumbing pipe with him to use as extensions when tightening the drive shaft nuts. The inner dia of them tubes was enough for them to be "slipped" over the bent link bars. So we did. We smashed the link bars as straight as we could and then hammered the *ell out of the plumbing pipes to "slide" them over the link bars and tack welded them on.
Re installing them proved to be a bitch since they defenately weren't the same shape as they were. It all took time and my qualifying was starting in a minute. I was all dressed up for my qualifying looking at my competition rolling to the track for theirs. Nervous.
"got it" was shouted under the car and I stormed in to the car whicj was still on jack stands. The car was lowerd and I had 10 minutes to do my qulifying laps.
I believe I tried too hard to push for a good position in the grid and could not even match my times on the free practice run. The engine was still cutting of badly and the engine seemed not to pull well. A disapointing 9th place in the grid.
Back to the paddock to figure out whats up with the engine. After some head scratching I notice the alternator was not charging the battery and the voltage was below 12. There's your problem. The alternator signal wire was cut. A quick fix and the alternator started to charge but the voltage did not raise enough. I've heard the optima batteries can be that way. They seem to take too much current in when charged that the alternator can't get the voltage up. We took a battery from my Transit van and the problem was fixed. We had 14 volts. I was ready for the first race.
The skies opened just before my start. No problem I'm all for wet races evens out the power differences and all.
I had a good start. The starting lights went out and and I launched for the inside line a bit of a traffic was in the way and I think I blocked someone behind me denting my right hand rear corner. At the main straight I was delighted to find out I was running fifth.
I have very little recollection of the details of the rest of the race. I never do. It was all so darn misty and pooring with rain none of us could see what was going on around us. I saw some tail light infront of me but I could not tell the difference. He could be far or he could just have dim rear lights. Ridiculous and dangerous. Soon the water on the track became so deep I could not use full throttle even on tha straights. It was like some higher force to the car and threw it side to side and sideways. Even at steady speed all of a sudden I found myself aquaplanning with no power over the car. I lost controll over the car several times only just avoiding collisions and most of the outings. I was overtaken by some caras and I overtook some. Some retired since they just could not see anything. Again ridiculous and fangerous. I was just waiting to see the red flags. I was not to retire due to weather conditions. The flags newer appeared. And I floated to chequered flag fifth. Engine worked nicely, but then again I did not nedd to rev it to 8000rpms so ne real answer wheter the problem was solved or not.
Come Sunday morning it was time for my warm up. Flooring it on the straight answered the question in my mind. The engine was cutting off.
Other than that it felt fine.
Back to the paddock for some serious head scratching. I read the datalogger to see what was going on during the missed beats. I found this
Grey line is throttle blue is RPM
the rpm dropped massively alltough the throttle was wide open then in a heart beat the revs were back up. Something was messing up the RPM signal.The sudden dive of the throttle line is due to a gear change. This beeing an Zetec SE I figured the engine had developed too much end float which started something at the 8000rpm mark to mess the signal. Lifted the car on jack stands and DTI'd the crank. 0,3mm of end float. No where near to cause any disturbance to the signal. I was clueless. It could not be a dodgy wire or a dodgy sensor since it only did it at 8000rpm mark.
However I found an old moldy rpm sensor from the footwell of my Transit and decided to change it. The car got a reading and started up so I decided to leave it in since there was no harm in it.
Race two and 5th in grid. Lights on revs up lights off foot of the pedal. This time no drama, no snapped propeller shafts nor bent four links. The car launched nicely and I found myself running second in class third overall. There was one lower class R1 engined Sunbeam imp between me and the race leader. Again I have no accurate recollection of the details I was overtaken by the MK2 Escort behind me and soon after I overtook him back. I really pushed to run away from him and I thought I had when all of a sudden he managed to get his nose in the inside line and I was forced to let him pass me. My bad. My own mistake. I was now really pedaling to get past him again. He got past the R1 Imp running 2nd overall at the time and soon after so did I. I was now running third overall. All this pushing had mede short work of my tires and I noticed a malevolent Opel emblem in my rear view mirror. I decided to stop the hunt for the second place and consentrate on calmer more cleaner driving on third place to preserve my tires. And to secure the the third position. A podium finish is a rear treat for me which I've only had once before. The Kadett running fourth gave me a run for my money. We were running bumper to bumper the rest of the race and I was really trying to make the best of the overheted tyres I had left. During our cat and mouse I noticed the race leaders XE engined Escort MK1 pulling out of the race. At this point I was feeling pretty confident of the podium finish. I managed to hold my place with a 0,5 second lead. I finished second overall.
My first second. 
Oh, and the engine was running perfectly roaring all to way up to the limiter not missing a beat!"Failure is always an option." - Adam SavageComment
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Re: Escort Sigma 1600 Race Car
fantastic! and great write up too! Well done!Comment
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Re: Escort Sigma 1600 Race Car
Thanks Tristan!
Here is a link to a picture gallery
"Failure is always an option." - Adam SavageComment
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Re: Escort Sigma 1600 Race Car
Excellent write up
So you think that the link bars bending caused the prop to fail? Do you think it was just the hard test start that caused the bars to bend?
1968 MK1 Escort 1300GT
1969 'Big Wing' MK1 Escort
1972 MK3 Cortina 1600XL
1984 Sierra XR4i
And other junk I don't like to talk about!Comment
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Re: Escort Sigma 1600 Race Car
:d
"Failure is always an option." - Adam SavageComment
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Re: Escort Sigma 1600 Race Car
Honestly I doin't have a clue. The link bars have been there for 10 yers now with no issues. I did however extend them by an inch before the start ofthe season.
I believe it is the most likely theory that the force of the start did bent the link bars. The single piece RS propeller shaft is simply too strong to be snapped with a tiny engine like mine. Given that it is in the right angle."Failure is always an option." - Adam SavageComment
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Re: Escort Sigma 1600 Race Car
i'd say its more likely the the prop failed first, probably due to a fatigue crack in one of the UJ housings when it hit the floor it all locked up but as you were moving something else had to give and that was the link barsComment
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Re: Escort Sigma 1600 Race Car
I'm having hard time seeing how the propeller failing could bend the link bars. The propeller was new been on only at dyno and few track laps.
When the prop snaps clean of there should not be any forces subjected to the link bars.
Are the Burtons proprller shafts OE quality?
Somehow I have some prejudice towards these D&F propshafts now. Wheter its even justified or not."Failure is always an option." - Adam SavageComment
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Re: Escort Sigma 1600 Race Car
Good result, considering.
At least the engine is still in one piece anyway... unlike the propshaft
Well done for sticking at it, and look forward to the next race.
DaveComment
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Re: Escort Sigma 1600 Race Car
Markus,
Lower bars work in compression when launching the car. When calculating my rear end I found the compression load on lower arm is around 900kg (OK it depends on engine power, link attachment distance from axle centerline, rear ratio etc but generally the load should be not very far from that figure) - so if you had some imperfection in one of your lower arms, slight bend or kink maybe, it could have failed in the violent launch and then the other would follow immediately because it could not hold the double force.Comment
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Re: Escort Sigma 1600 Race Car
Fabulous write up Markus...what a brilliant result....in several ways......well done mate!Comment
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