At the last race meeting that I competed at, a couple of weeks ago, in the final race of the weekend the clutch stopped working. I struggled on for last 6 laps (approx 25km of racing) with no clutch and massive vibrations form the motor at >6000rpm. When the motor and 'box was removed I found that the clutch cover had about a 4" crack and the cover had distorted. Over the last 16 years or so that I have been racing my current race Sprint I cannot believe the number of parts that I have broken.
I believe that 1km of racing must be equivalant to at least 100km of road driving. If money was no object (as in F1 and numerous other catergories) parts are "lifed" ie replaced after a given distance or hours of running. Of course it is false economy to reuse second hand or preloved items but sometimes due to lack of time/or money to find replacement new items you have no choice that to recycle previously used items.
To the best of my memory this is just some of the items that I have had fail while racing.
Broke all the flywheel bolts after the overdrive disengaged and re-engaged at >6500rpm in about 1/2 second.
Conrods, several with destroyed engine blocks and cylinder heads etc.
Pistons, many with damaged blocks and cylinder heads.
Head gasket, only 1 or 2.
Alternators, several.
Starter motors, to many to remember.
Clutch plates, several (now a button clutch)
Clutch thrust bearing seized.
Clutch cover cracked.
Blocks, several breaking the rear (#5) bearing cap from the block which is why we now use girdle plates and studs etc.
Broken 3rd gears, both standard ratio and wide ratio.
Overdrive clutch lining worn away.
Harmonic balancer cracking, non OE item.
Stripped crown wheel and pinion.
Cracking the axle tubes from the diff centre.
Trailing arms breaking.
Subframes cracking (near lower wishbone attach point).
Body cracking at front chassis rails and rear trailing arm attach point.
Wheels cracking, (non EO item).
Brake rotor cracking, (non OE item).
Brake booster diapragm failure.
I know that there are other things that I have forgotten (or I don't want to remember) but you must agree it is a fairly comprehensive list.
Mark
What have you broken?
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Paul Roberts
Breaking bits
The problem that seemed to re-occur most often in my short-lived racing career was the block cracking at the bearing webs. Given the cars have (in some quarters!!) a reputation for being fragile, are you suggesting that you have had more than your fair share of breakages or that this is just the nature of racing a 30 year old car? Would you ever describe the race cars as "reliable"?
Paul Roberts
Perth, Western Australia
Paul Roberts
Perth, Western Australia
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SPRINTPARTS
How long is a piece of String??
Reliable is not something that I would call this car. In fairness this car is just about to clock up 100 race meetings in my hands. We average usually 3 races per meeting, so I believe that I have done somewhere around 250+ races in this car.
I have always driven the car as hard as possible, as I believe that is how a race car should be used, but don't abuse it, and if it breaks try and build it so it won't break again.
I had another race Sprint that was in "Series Production" specifications, basically stock standard except for shocks and exhaust. That car was built proof and fast. I won the NSW State series when the motor had completed 6 seasons of racing and the only maintenance was to replace the timing chain once.
I believe that a well built and maintained Sprint is a fast and reliable car, but when you try and screw more and more from it reliablity will suffer.
Philip, generally has had better reliabilty than me, so it might be the driver. I do believe that pushing a 30+ year old race car does create more problems than sometimes you deserve.
Mark
I have always driven the car as hard as possible, as I believe that is how a race car should be used, but don't abuse it, and if it breaks try and build it so it won't break again.
I had another race Sprint that was in "Series Production" specifications, basically stock standard except for shocks and exhaust. That car was built proof and fast. I won the NSW State series when the motor had completed 6 seasons of racing and the only maintenance was to replace the timing chain once.
I believe that a well built and maintained Sprint is a fast and reliable car, but when you try and screw more and more from it reliablity will suffer.
Philip, generally has had better reliabilty than me, so it might be the driver. I do believe that pushing a 30+ year old race car does create more problems than sometimes you deserve.
Mark
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SPRINTPARTS
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Hans ten Broeke
Over the year we had not much broken at all.
First engine build by Sprint spares as a hill clime engine there was a BRAS bearing made in the block for the jack shaft. this bearing ceased, started to rotate, blocked the oul feed to the camshaft and that one ceased to.
Than (12 years ago no money) I took a 1850 block and had it bored out to use the used pistons of the engine with the ceased jack shaft.
Everything went better and better over the time and we just continued to use this engine, actually with no more knowledge than a good normal road car mechanic.
We had a few "normal" problems with the Lucas alternators and starter engines.
But Wineke did improve her driving a lot and during a race in Oschersleben, near Magdeburg in former east Germany she totaled her car in an attempt to get from from 4' to 3' place in a big way.
We had to build a total new car and used a brand new body but again we continua to use this engine with standard OLD pistons.
The engine did perform great, but how stupid can you be, for a racing engine it is not enough to check oil and water you know.
At our home circuit Assen (Moto GP) it happened in a big way during time practise, meager blow up coursed (as far we know) by an exploded piston. parts of it found back in the air filter.
(We build and put together the new engine what was on its way for the next year including 7" clutch BMW motor bike valves F3 head, JE pistons, Quater master starter engine under the carbs etc etc whit in 24 hours including going home and back to the circuit and made it for the Sunday race. But that is an other story)
Again the only meager Lucas part did give in during practice in Zolder Belgium, AND DURING THE RACE ON SUNDAY THE BRAND NEW ALTERNATOR AGAIN laing 3 in a rain race. That did it for Lucas, we use now for years already a small Denso alternator.
The tires went wider over the years and the lower swivels and bearings start to fail in a big way.
The bearing life could be improved by using a full syntactic grease, but the lower swivels just could not handle the force, original where not longer available and the QH swivels where not an improvement, most they not even last a full race, with massive under steer at the last couple of laps.
We made our own now and they last already several years.
2 times the 3' gear sprocket went. and a 4.1 dif riped half the theet off
After a touch with the barrier, some time later a Froudenberg front poly start heavily to vibrate during a time practice at the Nurburg ring, this coursed also to a lot of loose bold and nuts including a broken gear lever during the race, I could not go over 6000 rpm, the whole car vibrated extreme, but I needed the points desperately.
I don't see the bearing swaps as a failure but maintains, to have more or less an indication, we very often "reed" the oil filter.
I still think good prepared engine (you have to learn and live with this engine) is pretty repayable
Tuch wood, but never had waterpump and head gasket problems till now, but I would not be surpriced if the head gasket will start to give problems with our new generation engines with 12.6 : 1 ratio.
Hans
First engine build by Sprint spares as a hill clime engine there was a BRAS bearing made in the block for the jack shaft. this bearing ceased, started to rotate, blocked the oul feed to the camshaft and that one ceased to.
Than (12 years ago no money) I took a 1850 block and had it bored out to use the used pistons of the engine with the ceased jack shaft.
Everything went better and better over the time and we just continued to use this engine, actually with no more knowledge than a good normal road car mechanic.
We had a few "normal" problems with the Lucas alternators and starter engines.
But Wineke did improve her driving a lot and during a race in Oschersleben, near Magdeburg in former east Germany she totaled her car in an attempt to get from from 4' to 3' place in a big way.
We had to build a total new car and used a brand new body but again we continua to use this engine with standard OLD pistons.
The engine did perform great, but how stupid can you be, for a racing engine it is not enough to check oil and water you know.
At our home circuit Assen (Moto GP) it happened in a big way during time practise, meager blow up coursed (as far we know) by an exploded piston. parts of it found back in the air filter.
(We build and put together the new engine what was on its way for the next year including 7" clutch BMW motor bike valves F3 head, JE pistons, Quater master starter engine under the carbs etc etc whit in 24 hours including going home and back to the circuit and made it for the Sunday race. But that is an other story)
Again the only meager Lucas part did give in during practice in Zolder Belgium, AND DURING THE RACE ON SUNDAY THE BRAND NEW ALTERNATOR AGAIN laing 3 in a rain race. That did it for Lucas, we use now for years already a small Denso alternator.
The tires went wider over the years and the lower swivels and bearings start to fail in a big way.
The bearing life could be improved by using a full syntactic grease, but the lower swivels just could not handle the force, original where not longer available and the QH swivels where not an improvement, most they not even last a full race, with massive under steer at the last couple of laps.
We made our own now and they last already several years.
2 times the 3' gear sprocket went. and a 4.1 dif riped half the theet off
After a touch with the barrier, some time later a Froudenberg front poly start heavily to vibrate during a time practice at the Nurburg ring, this coursed also to a lot of loose bold and nuts including a broken gear lever during the race, I could not go over 6000 rpm, the whole car vibrated extreme, but I needed the points desperately.
I don't see the bearing swaps as a failure but maintains, to have more or less an indication, we very often "reed" the oil filter.
I still think good prepared engine (you have to learn and live with this engine) is pretty repayable
Tuch wood, but never had waterpump and head gasket problems till now, but I would not be surpriced if the head gasket will start to give problems with our new generation engines with 12.6 : 1 ratio.
Hans
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gmsclassics
- TDC Member
- Posts: 669
- Joined: Fri Oct 06, 2006 9:57 am
- Location: Auckland, New Zealand
I bought my car at auction in late 2000 as a standard road car with 14 owners and 200,000 km on the clock and have steadily developed it since.
I had quite a bit of trouble early on with front wheel bearings (cured with Castrol HTB) and all ball joints (cured with machined nylon inserts).
Also had a lot of problem with oil getting past the oil seals on the rear axles and onto the brakes and tyres, resulting in some wild spins! Cured by using g’box front oil seals.
I spent a lot of time curing high water temps and understeer around this time. The odd item broke, such as a rear trailing arm and the head gasket twice.
After 18 months I acquired the running gear from another race car and ran that for 3-4 year without problem.
Then:
• Paddle clutch exploded taking out the flywheel. Took the opportunity to rebuild the g’box that had minimal synchro left of 3rd gear.
• Next the pinion in the rear axle dropped some teeth, taking out the LSD!
• Lost compression on No 2 & 3 cyl. Part of the piston between the rings on the exhaust side had broken away.
• When that was fixed, using modified TR7 pistons, two meetings later the camshaft and sprocket parted company. Head is repaired and ready to go on but I have now damaged the tendons in my right hand so have to wait for that to heal before I can get going again.
Also miscellaneous problems with
• overdrive solenoid coming loose
• replacing starter motors (but not alternators).
• Minor fire when wiring chaffed.
• Chassis leg cracking at rear right subframe mounting - twice.
• Clutch master and slave cylinders leaking
• Chewing out bushes on front suspension
Over this time I have done 47 events including a couple of hillclimbs (that would equate to over 200 races in total) so I probably shouldn’t complain too much, especially as most of the replacement parts have themselves been secondhand!
Geoff
I had quite a bit of trouble early on with front wheel bearings (cured with Castrol HTB) and all ball joints (cured with machined nylon inserts).
Also had a lot of problem with oil getting past the oil seals on the rear axles and onto the brakes and tyres, resulting in some wild spins! Cured by using g’box front oil seals.
I spent a lot of time curing high water temps and understeer around this time. The odd item broke, such as a rear trailing arm and the head gasket twice.
After 18 months I acquired the running gear from another race car and ran that for 3-4 year without problem.
Then:
• Paddle clutch exploded taking out the flywheel. Took the opportunity to rebuild the g’box that had minimal synchro left of 3rd gear.
• Next the pinion in the rear axle dropped some teeth, taking out the LSD!
• Lost compression on No 2 & 3 cyl. Part of the piston between the rings on the exhaust side had broken away.
• When that was fixed, using modified TR7 pistons, two meetings later the camshaft and sprocket parted company. Head is repaired and ready to go on but I have now damaged the tendons in my right hand so have to wait for that to heal before I can get going again.
Also miscellaneous problems with
• overdrive solenoid coming loose
• replacing starter motors (but not alternators).
• Minor fire when wiring chaffed.
• Chassis leg cracking at rear right subframe mounting - twice.
• Clutch master and slave cylinders leaking
• Chewing out bushes on front suspension
Over this time I have done 47 events including a couple of hillclimbs (that would equate to over 200 races in total) so I probably shouldn’t complain too much, especially as most of the replacement parts have themselves been secondhand!
Geoff
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Paul Roberts
Horsepower
Just curious ... what sort of horsepower are your race cars producing?
Paul Roberts
Paul Roberts
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SPRINTPARTS
Horsepower
Easy answer to this, NOT ENOUGH.
The current crop of front running cars in the catergory that we compete in, leave us for dead in the power stakes. Most of the cars are using late model motors, ie Honda, Toyota, Mazda which are very tunable and parts available to up the horsepower, while we struggle with 30+ year old technology and nil performance parts or back up available except for what we develop ourselves.
It is many years since either of the cars where on a dyno, which I am not a great believer in the output figures, I rate my in performance in lap times. Recent changes in suspension spring rates seem to be offering best performance gain v's $$ spent.
Mark
The current crop of front running cars in the catergory that we compete in, leave us for dead in the power stakes. Most of the cars are using late model motors, ie Honda, Toyota, Mazda which are very tunable and parts available to up the horsepower, while we struggle with 30+ year old technology and nil performance parts or back up available except for what we develop ourselves.
It is many years since either of the cars where on a dyno, which I am not a great believer in the output figures, I rate my in performance in lap times. Recent changes in suspension spring rates seem to be offering best performance gain v's $$ spent.
Mark
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gmsclassics
- TDC Member
- Posts: 669
- Joined: Fri Oct 06, 2006 9:57 am
- Location: Auckland, New Zealand
I get past more cars on the track by outbraking and carrying more speed through the corners. The biggest improvement in lap times has probably come from me learning how to drive the car properly, using the ripple strips etc. It is really satisfying to come out of a corner in front of a car with more horsepower, that just passed you on the last straight!
Next biggest improvements have come from getting the suspension set up correctly for the type of tracks, tuning this with camber/castor, the best tyres, getting tyre pressure right. LSD is invaluable coming out of slow tight corners. Engine horsepower is dreadfully expensive and reduces reliability.
Geoff
Next biggest improvements have come from getting the suspension set up correctly for the type of tracks, tuning this with camber/castor, the best tyres, getting tyre pressure right. LSD is invaluable coming out of slow tight corners. Engine horsepower is dreadfully expensive and reduces reliability.
Geoff
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grelley
Reliability
First of all I havent broken a gearbox, diff, or driveshaft or axles. I have broken several rods, blocks, heads, pistons etc over the years, but have normally always found a cause for the problem. I had a lot of problems cutting out small end bushes, which in turn could lead to broken rods, damaged blocks, pistons and heads. This turned out to be caused by not warming the car up long enough before a race, and running quite heavy oil. I eventually fitted a thermostat to the oil cooler line and this stopped the problem. After another rebuild, in which I went to a dry sump system, I again had a series of problems breaking rods, pistons, blocks, heads etc. This was happening after 3 meetings. I eventually traced this to too small a pipe from the dry sump tank in the boot to the oil pump. By repositioning the oil tank, and fitting larger lines, the problem was overcome. My last engine did about 1000 racing Kms which I was very pleased with. It was losing power so I stripped it for a rebuild. The only problems were the fire rings on the head hasket had extruded out into two of the cylinders, and a crankshaft thrust had picked up. Other than that it could have gone back together, but I took the opportunity to rebuild it. Unfortunately I have not used it much since. I dont think the Sprint engine is that unreliable, and a lot of the weaknesses can be rectified, ie stronger rods and pistons, steel main bearing caps, bearing girdle plate, forged pistons etc. HP wise I think around 210 - 220 hp. My Group A M3 is only 5-6 seconds per lap faster on the same circuits.