downshifted into a wrong gear!!!!!!!! (in my HR)
03-17-2008, 07:47 PM
#23
Originally Posted by Peak350
The reason the rods would crack is because it isn't a smooth rev to redline and its not a loaded rev. The rods are in tension instead of compression and the crankshaft is loaded backwards. This throws balance off and the rods can get tweaked pretty bad. I'd be more worried about the vavletrain typically, but since no-one really knows the strength of the rods in the HR its something to keep in mind.
03-17-2008, 07:48 PM
#24
Originally Posted by Peak350
The reason the rods would crack is because it isn't a smooth rev to redline and its not a loaded rev. The rods are in tension instead of compression and the crankshaft is loaded backwards. This throws balance off and the rods can get tweaked pretty bad. I'd be more worried about the vavletrain typically, but since no-one really knows the strength of the rods in the HR its something to keep in mind.
03-17-2008, 07:48 PM
#25
Originally Posted by Peak350
The reason the rods would crack is because it isn't a smooth rev to redline and its not a loaded rev. The rods are in tension instead of compression and the crankshaft is loaded backwards. This throws balance off and the rods can get tweaked pretty bad. I'd be more worried about the vavletrain typically, but since no-one really knows the strength of the rods in the HR its something to keep in mind.
03-18-2008, 07:25 AM
#27
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Originally Posted by 350Zimo
How do you find out if they have been cracked. the engine runs smoothly, no knocking, no hesitation, . i know you are not saying that my motor has cracked anything whatever it is, but how does it feel? can you determine that just from driving or it has to be inspected
I think its pretty much like if you cook a rod it turns color and you have to drop the oil pan to see....you probably would have to inspect them each to know for sure.
On the BMW motors I'm (more so at least) familiar with the bottom ends will take 8-9k with 0 issues even in a mechanical over-rev. They are very stout, but they can also handle about 600 whp (from a 2.8/3.0L) with a thick MLS gasket, so the rods are a bit stronger than ours.
Thats why I say it could have happened. Its one of those things that 3 or 4 people on this forum can actually answer, and I'm not one of them.
03-18-2008, 08:47 AM
#28
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You'd honestly have to inspect everything, to know for sure.
FWIW, I over-revved my track car a few years back (SR20 motor) and it just spit up most of the rocker arms and dislodged a few things in the head. It was just a simple, put them all back in place and reshim everything job though. The bottom end was fine afterwards (crank, rods, rod bearings, main bearings, etc...) but I had to tear down everything to check. Wasn't very fun, but I built it up stronger in the process, so it was kinda worth it.
FWIW, I over-revved my track car a few years back (SR20 motor) and it just spit up most of the rocker arms and dislodged a few things in the head. It was just a simple, put them all back in place and reshim everything job though. The bottom end was fine afterwards (crank, rods, rod bearings, main bearings, etc...) but I had to tear down everything to check. Wasn't very fun, but I built it up stronger in the process, so it was kinda worth it.
03-18-2008, 09:03 AM
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Originally Posted by Justin@IOS
You'd honestly have to inspect everything, to know for sure.
FWIW, I over-revved my track car a few years back (SR20 motor) and it just spit up most of the rocker arms and dislodged a few things in the head. It was just a simple, put them all back in place and reshim everything job though. The bottom end was fine afterwards (crank, rods, rod bearings, main bearings, etc...) but I had to tear down everything to check. Wasn't very fun, but I built it up stronger in the process, so it was kinda worth it.
FWIW, I over-revved my track car a few years back (SR20 motor) and it just spit up most of the rocker arms and dislodged a few things in the head. It was just a simple, put them all back in place and reshim everything job though. The bottom end was fine afterwards (crank, rods, rod bearings, main bearings, etc...) but I had to tear down everything to check. Wasn't very fun, but I built it up stronger in the process, so it was kinda worth it.
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Lt_Ballzacki
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08-06-2021 06:19 AM
370z, accidental, arm, constantly, downshifted, downshifting, downshifts, gear, loxk, misshift, rocker, shifted, tiburon, wrond, wrong
