Patrick's build thread. (IT RUNS!)
12-16-2014, 01:51 AM
#991
Rennlist Junkie Forever
Sorry to see this. I, unfortunately, understand the pain all too well....
It looks very odd. Maybe I missed something in the thread, but it looks like something bounced around in the bottom end.
Did the girdle come loose? (one ore more of the fasteners?)
I'd take the bare block and get it x-rayed.
And I'd have the crank balance checked.
Even if the parts are not good... I'd still do to try to see what happened.
TonyG
It looks very odd. Maybe I missed something in the thread, but it looks like something bounced around in the bottom end.
Did the girdle come loose? (one ore more of the fasteners?)
I'd take the bare block and get it x-rayed.
And I'd have the crank balance checked.
Even if the parts are not good... I'd still do to try to see what happened.
TonyG
Just a ton of possibilities with this. My engineer says he's seen this before on Kent Formula Ford motors due to vibrational issues. Yet again it's frustrating as we can't be 100% sure of the cause. Hence the possibility of repeating the process looms in the back of my mind. Having said that, we will be making significant changes to the new motor and other parts of the car which should remove much of the risks. In the meantime we will study the remains to see if anything else stands out. Just hard to determine which is the Chicken and which is the Egg at this stage.
12-16-2014, 04:09 AM
#992
Rennlist Member
Thread Starter
Thanks for all the good vibes guys. Much appreciated.
Hey Mike thanks for those links and no problem from me as far as any observations you make. We have pretty much arrived at a similar conclusion re the crank although questions can be asked as "Why did it happen then? Why not before?" I'm starting to think that there might have been more than one cause and it just finished in a clusterfcuk. We might have had a b/shaft skip a tooth which could have caused havoc. That there were more than one nut that loosened makes me wonder what the hell harmonics caused this. These probably have something like 130Nms on them when assembled.
Then add that we had two major structural failures with the d/sump pulley and then the b/shaft pulley in quick succession at almost the identical part of the track plus we were getting into the upper rpms by staying in 5th and into a 'back off vacuum' that puts a lot more stress on the motor than people might think.
The definition of insanity is doing something over and expecting a different outcome. So with the next motor it won't be the same. It will have a custom crank, rods, pistons and a great dampener. Plus we'll shorten the crank snout as much as possible by bringing everything a bit closer to the motor. I'm sure running the electric power steering pump in the cabin is a good thing that we've done already too. Should be a pretty interesting motor with quite different dynamics than this last one. Probably go down in capacity too which will help with harmonics/vibrations. Can't wait to start.
Yes the V8 Supercar was a blast! I kinda wish I was more ready for it, both as a passenger and driver. Certainly I was pretty ordinary and slow compared to Paul but the 7 second tutorial could have been a touch longer! Still processing it now. I think the most I could say as far as a comparison to my car is that it dances a bit more on the throttle with more weight, less tyre and Aero and higher polar ratio. The 952 is much more stuck to the ground and you just seem to have to drive it quite differently. Makes sense of course and both are fantastic in their own right. Privileged to have the opportunity to drive both.
Hey Mike thanks for those links and no problem from me as far as any observations you make. We have pretty much arrived at a similar conclusion re the crank although questions can be asked as "Why did it happen then? Why not before?" I'm starting to think that there might have been more than one cause and it just finished in a clusterfcuk. We might have had a b/shaft skip a tooth which could have caused havoc. That there were more than one nut that loosened makes me wonder what the hell harmonics caused this. These probably have something like 130Nms on them when assembled.
Then add that we had two major structural failures with the d/sump pulley and then the b/shaft pulley in quick succession at almost the identical part of the track plus we were getting into the upper rpms by staying in 5th and into a 'back off vacuum' that puts a lot more stress on the motor than people might think.
The definition of insanity is doing something over and expecting a different outcome. So with the next motor it won't be the same. It will have a custom crank, rods, pistons and a great dampener. Plus we'll shorten the crank snout as much as possible by bringing everything a bit closer to the motor. I'm sure running the electric power steering pump in the cabin is a good thing that we've done already too. Should be a pretty interesting motor with quite different dynamics than this last one. Probably go down in capacity too which will help with harmonics/vibrations. Can't wait to start.
Yes the V8 Supercar was a blast! I kinda wish I was more ready for it, both as a passenger and driver. Certainly I was pretty ordinary and slow compared to Paul but the 7 second tutorial could have been a touch longer! Still processing it now. I think the most I could say as far as a comparison to my car is that it dances a bit more on the throttle with more weight, less tyre and Aero and higher polar ratio. The 952 is much more stuck to the ground and you just seem to have to drive it quite differently. Makes sense of course and both are fantastic in their own right. Privileged to have the opportunity to drive both.
12-16-2014, 05:38 AM
#993
Instructor
Woah... what unluck there.. I really hope you'll be up and running again in no time.
As for the v8sc experience: That was a short, yet great read, and boy you can't imagine how much i'd like to sit in one at some point in the future.. Not even mentioning driving one. It for sure had to be amazing.
As for the v8sc experience: That was a short, yet great read, and boy you can't imagine how much i'd like to sit in one at some point in the future.. Not even mentioning driving one. It for sure had to be amazing.
12-16-2014, 06:15 AM
#994
Rennlist Member
Thread Starter
Sorry to see this. I, unfortunately, understand the pain all too well....
It looks very odd. Maybe I missed something in the thread, but it looks like something bounced around in the bottom end.
Did the girdle come loose? (one ore more of the fasteners?)
I'd take the bare block and get it x-rayed.
And I'd have the crank balance checked.
Even if the parts are not good... I'd still do to try to see what happened.
TonyG
It looks very odd. Maybe I missed something in the thread, but it looks like something bounced around in the bottom end.
Did the girdle come loose? (one ore more of the fasteners?)
I'd take the bare block and get it x-rayed.
And I'd have the crank balance checked.
Even if the parts are not good... I'd still do to try to see what happened.
TonyG
The girdle had lose main caps. Our engineer has seen this in other i4's with bad harmonics. The crank certainly looks like one of the 'ringleaders'...
12-16-2014, 06:18 AM
#995
Rennlist Member
Thread Starter
Woah... what unluck there.. I really hope you'll be up and running again in no time.
As for the v8sc experience: That was a short, yet great read, and boy you can't imagine how much i'd like to sit in one at some point in the future.. Not even mentioning driving one. It for sure had to be amazing.
As for the v8sc experience: That was a short, yet great read, and boy you can't imagine how much i'd like to sit in one at some point in the future.. Not even mentioning driving one. It for sure had to be amazing.
12-16-2014, 08:43 AM
#999
Drifting
12-16-2014, 09:42 AM
#1000
Rainman
Rennlist Member
Rennlist Member
What was the weights of the crank, the flywheel, and the balancer?
Maybe the new crank should be left heavy, and the flywheel taken down in weight more (and maybe reduce wheel/tire weight as well)?
Maybe the new crank should be left heavy, and the flywheel taken down in weight more (and maybe reduce wheel/tire weight as well)?
12-16-2014, 03:32 PM
#1002
Rennlist Member
Thread Starter
12-16-2014, 04:15 PM
#1004
Three Wheelin'
"Engdyn was originally developed to study the dynamics of the crankshaft and its interaction with the engine block"
http://www.ricardo.com/en-GB/What-we...oducts/ENGDYN/
http://www.ricardo.com/PageFiles/846...r%20A4_4PP.pdf
https://www.ricardo.com/Documents/Do...er_kseries.pdf
http://www.ricardo.com/en-GB/What-we...oducts/ENGDYN/
http://www.ricardo.com/PageFiles/846...r%20A4_4PP.pdf
https://www.ricardo.com/Documents/Do...er_kseries.pdf
12-16-2014, 06:10 PM
#1005
Rennlist Member
Thread Starter
Not before Lunch Mike!