What happened to Seans engine at spa?
I thought everyone knew about this:
[image]http://img.photobucket.com/albums/v222/Exiges/Seanspulleys.jpg[/image]
![http://img.photobucket.com/albums/v222/Exiges/Seanspulleys.jpg[/image]](http://img.photobucket.com/albums/v222/Exiges/Seanspulleys.jpg%5B/image%5D){kind=link}
Wonder how many more of King K’s engines have these bespoke items fitted?
So it would be really useful to know what happened and why, especially before the engine broke.
Is it possible that the broken items in the photo were badly designed, and/or engineered parts, or have you already discounted that line of investigation?
How were the verniers formed?
Plus it is significant that the inlet vernier broke on all 5 spokes and came free - undoubtably trashing valves, pistons, but the exhaust vernier is just cracked on two/three spokes.
IIRC both the vernier pulleys in Sean’s engine suffered the same fate.
Has anyone come across “ordinary” vernier pulleys, which have broken (& not just slipped) in a similar fashion?
Very sorry to hear of Sean’s misfortune, by all accounts the engine was a little belter. I suppose it goes to show that nothing is ever certain when it comes to engines, no matter how carefully you plan.
FWIW I have only ever seen one failure connected with Piper verniers and that was because someone didnt do the bolts up properly.
Commiserations all round.
Dave
Very sorry to hear of Sean’s misfortune, by all accounts the engine was a little belter. I suppose it goes to show that nothing is ever certain when it comes to engines, no matter how carefully you plan.
Commiserations all round.
Dave
Nice one Dave … I really wasnt expecting that response, I thought another [censored] fight was on its way.
Correct me if im wrong but i was under the impression the engine was still running fine and he had just noticed it in time before serious damage was done, Has Sean now stripped it down and found serious damage ?
How were the verniers formed?
They are machined from billet in 7075 and hard anodised
Looks like the webs are bit thin to me, probably suffered a fatigue failure due to “ringing”
Heard he luckily got away with it though, with no engine damage.
Bernard
I am typing my side of the story, so bare with me. why use 10 words when 10,000,000 will do!
They are machined from billet in 7075 and hard anodised
Looks like the webs are bit thin to me, probably suffered a fatigue failure due to “ringing”
Heard he luckily got away with it though, with no engine damage.
Bernard
At the thinnest the spokes are 3.5mmx13.5mm with a R8 rad, and there are 5 of them.
They are made of 7075 which is much stronger than the normal HE30
All stress analysis before the design was made and this last weeks points to adequate strenght, in fact redundant strength.
you didn’t read what I wrote about the BTCC engines -
Definitely too thin then. I agree they can handle the loads in the rotational direction, but I think what has happened is that there has been a resonance in a plane at 90� to the camshaft axis and that has caused them to fail at the point of highest stress, ie the mounting face.
Bernard
OK before I start I have no intention of getting into a slanging match on here, if it goes that way I will just stop posting.
Events unfolded as such.
Quaife let me down massively by not being able to fix my sequential gearbox in time following its demise at Donnington. So the car went back together with an MG ZR cup gearbox I had. However when we started the car up, the clutch was dragging and there was a bit of a noise from the gearbox. So it all came out again and went back together with a standard exige gearbox. The clutch drag was traced to a dodgy clutch master cylinder, so that was also replaced and all was good.
The car then went to have the fuelling checked, all was good. At that point I actually decided to lower the rev limit from 9,300rpm to 8,500rpm, as I knew the engine was only going to be in my car until after the Brands LOT race. My Quaife gearbox wasn�t going to be back even for Brands and to be honest the standard Exige gearing is soooo long, I knew I would be off the pace, so I didn�t want to bother revving the engine so hard as it wasn�t going to help me. There was no way I was going to miss Spa though and I thought a good showing at the last round at Brands would be a nice advert for the engine as it would go up for sale straight after. So off we went to Spa
Test day on Thursday, the car ran in the two, one hour sessions that were available to us and ran faultlessly, spent most of the first hour getting my head around the track and doing some tweaking to the suspension to get it handling nice. The car ran for the full hour of both sessions. Well actually from memory I think the 2nd session ended up only being about 40 minutes due to an accident out on track.
Friday, qually day. Went out for the 20 minute LOT qually, all was good, the car ran fine, was super revvy, even though the whole track could be done in 2nd, 3rd and 4th due to the super long gearing. With the talent (or lack of), power and gearing I had I ended up pretty much where I thought I would be in 10th. Then came the Heritage qually, we had 25 minutes for both Russ and I to qualify. I basically just did an out lap a fast lap (wasn�t very fast as I was stuck behind an Aston) and an in lap and gave the car to Russ, so he could get as many laps under his belt as time allowed.
The car ran fine, although when Russ pulled back into the paddock there was a bit of a top end rattle. The car was ticking over fine, it revved as normal and every now and then the rattle stopped. We turned it off and let it cool for a while before taking the cam cover off. Nothing was obviously wrong, so we put it back together and fired it up again. As before it ran as normal, idled as normal and revved as normal. We were trying to figure out which cylinder it was coming from when leaning into the engine bay I leant on the cam belt cover and the noise stopped, I wobbled the cam belt cover and the noise would come and go as I wobbled.
So we stopped the engine thinking that the bolts that hold the inner half of the cam belt cover had come loose and were catching on the back of the pulleys. So off came the cam belt cover and to our dismay the broken pulleys were what we found. The noise was actually the pulley tapping against the outer part of the cam belt cover. In the picture above where the pulley looks set back, that is because I pushed it back. It was actually sitting in its regular spot when we took the cam belt cover off.
As can be seen the inlet pulley has broken all five spokes on both the inner and outer wheels. The exhaust pulley has broken all five spokes on the outer, but I can�t see the inner, it certainly doesn�t look like the inners have broken, but as I haven�t removed them or anything, I can�t be sure.
The inner and outer spokes of the inlet pulley have broken in a very irregular jagged way and I am 100% sure, that nothing had gone out of time and no damage has occurred other than the broken pulleys. As said before in the paddock at Spa the engine started, idled, and revved as per usual. There was quite a crowd around the car at the time, I�m sure I have at least 20 people who can vouch the same.
So that was the story of Spa.
To add to the story of my rather naff 2007 race season. The reasons for my DNF�s at the other rounds this year are as follows:
Round 1 � Brands � All good, 1st in class
Round 2 � Snetterton � Electrical master cut off switch packed up
Round 3 � Oulton � I had decided to change the loom following Snett and I simply ran out of time and missed the race.
Round 4 � Silverstone � My memory is failing me a little here but we missed this due to the engine being back at Simons and something not arriving with him on time??
Round 5 � Castle Combe � All fine, I just realised I am not a fish and can�t drive in the wet
Round 6 � Donnington � Gearbox lunched itself
Round 7 � Spa � as described above
In conclusion, I have actually been happy with my 1.8. Simon has developed the engine over the year and we have tried many different things including cams and exhausts etc to improve it. It has always pulled strong and has revved for England. With the super closeness of the Quaife 6 speed sequential it made a great little package. We have had a couple of other issues which left us chasing a misfire running up to Donnington, these including, a broken injector plug, a faulty ECU and some out of balance throttle bodies.
It never quite made the power I had hoped, with a peak of 237BHP, although I know the exhaust that is on it isn�t ideal. I have only really had a few problems with the engine itself. The first is that it has pretty much always weeped oil from the crank shaft oil seal. The second is due to the flywheel, I believe it to be buckled and not strong enough. Basically when you depress the clutch the flywheel moves to the point that it comes into contact with the tip of the crank sensor. This is not crank end float as I have measured that and it hardly moves, but the flywheel does flex, plus when the engine is running, it has a certain degree of run out, in that it looks like a slightly buckled bike wheel when you spin it. Other problems have been Simons airbox that fell off about 4 times before I put the support stays on it. Plus I never really liked the airbox, its heavy and in my opinion terribly made and looked horrible.
Now as I have started the story I may as well finish it.
My decision to move to an audi engine for next year is for the following reasons. These reasons are all my opinion and I don�t really want to drag each, or any of them out in any great length:
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After chatting with Simon probably around the time of Donnington, I began to come to the conclusion that I wouldn�t get the 2 litre engine in November. I wanted it in November to give me a couple of months to get it in the car and then have the early part of 2008 to do lots of track days and stuff. I have been waiting for the engine since the start of the 2006 season and I guess I finally woke up and smelt the coffee.
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Simon wanted to do a few things to my car that I didn�t like. The exhaust that ran over the top of the gearbox, introduced all kinds of packaging and heat issues that I wasn�t happy with. Plus I wasn�t convinced about wanting a dry sump and all of the extra gubbins that goes with that.
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The engine is the only part of the car that wasn�t in my control and I never fully liked that, plus when Simon started saying that he wanted to do the install etc and if he didn�t do the install he wouldn�t be happy. I didn�t like that. I take pride in the work I do on my car and I don�t like other people working on it.
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Availability of spare parts. The 2 litre engines that Simon is making are full of specialist one off parts that are very costly and would take a very long time to replace. Simons estimate is that the crank would be over �6,000 to replace and who knows how long it would take. I am building two audi engines and I paid �550 for the one and �650 for the other. Fully built up with all of the extras I am putting in for reliability and extra power they only owe me a couple of grand each and I have had them both built in less than a week!!!
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With the current LOT regs I don�t think a normally aspirated car would be competitive in Class C, as mixing forced induction and NA cars of the same cc, you are just never going to have the same punch out of the corners etc.
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I hate being part of all of this bickering. One of the best things about racing over the last few years and especially this year with LOT is the friends I have made and the good times I have had and I hate being associated with Simon and all of the arguments he is involved with on the various forums. Plus having to constantly defend him where ever I go. Simons statement on one of the other threads where he is telling Russ that �realise that actually the engineering is more important than being matey� sums up our differences. I just want to go and have a good time razzing my car round at the weekend with my mates. I wish Simon all the luck in the world, but what he is trying to develop and what I want to do are just two different things.
Sean…
Simon I will give you a call some time next week to chat about you having the engine back, but I am OK with it in principle.
With regards to the flywheel, this was only something we found out ourselves when investigating the clutch drag problem just before Spa. In fairness though and thinking about it now I bet I have about four crank position sensors that have had there ends whacked throughout this year.
The flywheel doesn’t seem to cause any problems, the clutch works and it drives and revs great, but I do wonder if there are resonance issues with it, that may have caused other problems??
At the thinnest the spokes are 3.5mmx13.5mm with a R8 rad, and there are 5 of them.
They are made of 7075 which is much stronger than the normal HE30
I’ve just measured the thinnest part of the spokes on a Piper vernier, these are 7mm x 23mm and there are three of them with a much larger rad.
This gives the Piper vernier a total spoke cross sectional area of 483sq mm against 236sq mm for the ones in the photo, this is approximately half the cross sectional area of the Piper verniers.
According to my figures HE30 has a tensile strength of between 295-310MPa and 7075 470-540MPa which would suggest that the overall strength of those 5 spokes is approximately 13% lower than those of the Piper vernier.
Of couse my source data on the tensile strengths may not be 100% accurate but it is pretty close.
FYI the reason that vernier was done was because I have seen an engine with the currently available vernier with just 3 bolt fixings - despite the bolts being threadlocked togeather - slip as a result of being buzzed. Result = trashed valves and pistons - this was NOT my engine by the by.
Personally I have never seen a Piper vernier break or slip when properly fitted, have you discussed this with Piper and do you have evidence that can be forwarded? I’m sure they would be interested to hear that you are making that statement on a public forum.
I’d also be interested to know how you were able to check the fasteners torque settings on the claimed slipped vernier when the bolts had been threadlocked. Threadlocking does not make the clamping force correct, it merely stops the bolt from working loose.
If the bolt is inadequately tightened threadlock won’t help and it will also distort the torque reading when the bolt is being fastened and particularly when it is being unfastened.
Any vernier with inadequately tightened clamp bolts may well slip, that’s why it is important to torque them correctly.
Dave