Long overdue - engine teardown pics of my turbo (non 996)
04-29-2009, 07:23 PM
#1
Race Car
Thread Starter
Long overdue - engine teardown pics of my turbo (non 996)
So, for those of you who dont know me or what happened, I overrevved my engine bending the exhaust valves racing.
In an interfernce motor (valves can touch the pistons if a timing belt/chain breaks), if you overrev the motor and the valve springs cannot bring the valves back to seat in time, the piston will strike the valves bending them.
I did not know this as I've been around mostly V8's most of my life (which are pretty much interference free unless you have too large of a camshaft). You learn something everyday.
So, I was racing my friends new BMW 335 coupe with mods done (~385hp) at the drag strip and he was pulling me hard out of the hole (he has 0 boost lag while mine makes almost no boost in 1st gear). When he was about 2-3 car links ahead, I was trying to go into 4th gear and about to make my glorious, fly-by pass for the win.
Well, I missed 4th and was trying to get it in when I actually put it into 2nd at about 90-100MPH.
Once I let the clutch out, the car tried to slow down rapidly and completely died. I tried to restart by letting the clutch out in 3rd but heard all the vaves being lightly tapped by the pistons.
All I thought that happened was I broke a timing chain initially. Needless to say, I had a lesson on what could happen in an overrev of an interference motor....
1. I'm not shadetree for nuthin'
2. Engine on stand
3. Flywheel side of motor
4. Bottom side of motor showing massive oil leakage
5. Intake removed
6. Cam covers removed - preparing to remove cam tensioners
In an interfernce motor (valves can touch the pistons if a timing belt/chain breaks), if you overrev the motor and the valve springs cannot bring the valves back to seat in time, the piston will strike the valves bending them.
I did not know this as I've been around mostly V8's most of my life (which are pretty much interference free unless you have too large of a camshaft). You learn something everyday.
So, I was racing my friends new BMW 335 coupe with mods done (~385hp) at the drag strip and he was pulling me hard out of the hole (he has 0 boost lag while mine makes almost no boost in 1st gear). When he was about 2-3 car links ahead, I was trying to go into 4th gear and about to make my glorious, fly-by pass for the win.
Well, I missed 4th and was trying to get it in when I actually put it into 2nd at about 90-100MPH.
Once I let the clutch out, the car tried to slow down rapidly and completely died. I tried to restart by letting the clutch out in 3rd but heard all the vaves being lightly tapped by the pistons.
All I thought that happened was I broke a timing chain initially. Needless to say, I had a lesson on what could happen in an overrev of an interference motor....
1. I'm not shadetree for nuthin'
2. Engine on stand
3. Flywheel side of motor
4. Bottom side of motor showing massive oil leakage
5. Intake removed
6. Cam covers removed - preparing to remove cam tensioners
Last edited by Tippy; 04-30-2009 at 09:45 AM.
04-29-2009, 07:27 PM
#2
Race Car
Thread Starter
7. Valve strikes shown and one head remaining
8. Cams removed and towers removed
9. Showing all pistons where valves struck
10. Topside shot with cams removed and cam towers removed
11. Need I say more?
12. Busted valve guide
8. Cams removed and towers removed
9. Showing all pistons where valves struck
10. Topside shot with cams removed and cam towers removed
11. Need I say more?
12. Busted valve guide
04-29-2009, 07:31 PM
#3
Race Car
Thread Starter
13. Jugs removed
14. All pistons removed - what a biatch. Those clips are really hard to get out without damaging the wrist pin bore.
15. Starting to remove the case bolts and nuts
16. Case halves, IMS, oil pump, and crank
17. IMS and oil pump out of case
18. Close up of IMS drive gear; made of aluminum; pretty impressed it has probably 200k miles on it!
14. All pistons removed - what a biatch. Those clips are really hard to get out without damaging the wrist pin bore.
15. Starting to remove the case bolts and nuts
16. Case halves, IMS, oil pump, and crank
17. IMS and oil pump out of case
18. Close up of IMS drive gear; made of aluminum; pretty impressed it has probably 200k miles on it!
04-29-2009, 07:36 PM
#4
Race Car
Thread Starter
19. Close up of bronze distributor gear. Again, amazing with sooooo many miles that it looks unused like the IMS drive gear.
20. Close up of IMS small journal. Really good shape again for the mileage!
21. Case shot and worn IMS bearing
22. Close up of IMS bearing wear. Pelicanites say it is ok, this will show on break-in.
23. Clean inside case for nearly 200k miles!
24. Chipped Nikasil plating where piston skirt resides. Probably blend and go back it.
20. Close up of IMS small journal. Really good shape again for the mileage!
21. Case shot and worn IMS bearing
22. Close up of IMS bearing wear. Pelicanites say it is ok, this will show on break-in.
23. Clean inside case for nearly 200k miles!
24. Chipped Nikasil plating where piston skirt resides. Probably blend and go back it.
04-29-2009, 08:49 PM
#7
Race Car
Thread Starter
Trending Topics
04-29-2009, 10:03 PM
#11
Three Wheelin'
Finally! Man part of me doesn't envy you and part of me wishes I was there. Love those german motors, a bitch to get apart, but wow do they wear well. Those internals look like they're just getting broken in.
Since you've done all the hard work taking it apart, allow me to help you spend some of your hard earned:
Maybe a little more stroke on a lighter crank while you're there? What are you going to do for pistons? Mahle or go really lightweight? Maybe drop compression a little for that giant turbo of yours? And since you chunked the liner, you know you need to bore over right? (j/k, well, not really, I'd love to see that project and I don't think you'll be able to blend easily up there without screwing with quench or eventually blowing off the new nickel, but who knows, try asking the LN Engineering guys)
Good luck Cory! Keep us posted, can't wait to see the bench dyno once it's built again
Since you've done all the hard work taking it apart, allow me to help you spend some of your hard earned:
Maybe a little more stroke on a lighter crank while you're there? What are you going to do for pistons? Mahle or go really lightweight? Maybe drop compression a little for that giant turbo of yours? And since you chunked the liner, you know you need to bore over right? (j/k, well, not really, I'd love to see that project and I don't think you'll be able to blend easily up there without screwing with quench or eventually blowing off the new nickel, but who knows, try asking the LN Engineering guys)
Good luck Cory! Keep us posted, can't wait to see the bench dyno once it's built again
04-29-2009, 10:03 PM
#12
Race Car
Thread Starter
Yeah, I hope I can get it back together.......j/k 
I lost count! 
I will keep everyone updated, I miss driving it soooo much. 
It was actually quite relaxing to do and just get away from school and work and do something I love.
It was actually quite relaxing to do and just get away from school and work and do something I love.
04-29-2009, 10:09 PM
#13
Race Car
Thread Starter
Finally! Man part of me doesn't envy you and part of me wishes I was there. Love those german motors, a bitch to get apart, but wow do they wear well. Those internals look like they're just getting broken in.
Since you've done all the hard work taking it apart, allow me to help you spend some of your hard earned:
Maybe a little more stroke on a lighter crank while you're there? What are you going to do for pistons? Mahle or go really lightweight? Maybe drop compression a little for that giant turbo of yours? And since you chunked the liner, you know you need to bore over right? (j/k, well, not really, I'd love to see that project and I don't think you'll be able to blend easily up there without screwing with quench or eventually blowing off the new nickel, but who knows, try asking the LN Engineering guys)
Good luck Cory! Keep us posted, can't wait to see the bench dyno once it's built again
Since you've done all the hard work taking it apart, allow me to help you spend some of your hard earned:
Maybe a little more stroke on a lighter crank while you're there? What are you going to do for pistons? Mahle or go really lightweight? Maybe drop compression a little for that giant turbo of yours? And since you chunked the liner, you know you need to bore over right? (j/k, well, not really, I'd love to see that project and I don't think you'll be able to blend easily up there without screwing with quench or eventually blowing off the new nickel, but who knows, try asking the LN Engineering guys)
Good luck Cory! Keep us posted, can't wait to see the bench dyno once it's built again
