Mis-shifted 3rd to 2nd, engine underpowered now?
10-03-2008, 11:34 AM
#41
You NEED to do a leakdown test at this point.
The time spent doing that will tell you whether you need to pull the heads and swap out some valves or not.
If your pushrods aren't bent (which appears to be the case) and the engine was down on power it is highly likely that you did in fact bend/tweak a few valves.
If you get a decent leakdown on all eight holes consider yourself lucky and move on although if the car still doesn't feel right that would require further digging to find the problem.
I hate to be the bearer of bad news but if the car doesn't feel quite right and your pushrods aren't the culprit, its very likely you have a few bent valves.
Get a leakdown tester (or borrow one) and have at it....
Regards,
Tony
BTW....I consider myself a good driver when it comes to piloting high horsepower manually shifted hotrods (20+ years experience). About a year ago I nailed the infamous 3-2 shift for the first time at WOT (with my 383) and was data logging at the time....can you say 8507 RPM's
Three things saved my ***....one, Im **** about my engine assembly and thankfully was running good aftermarket parts....two, I run a solid roller which has better high RPM valve control, and three, I have a buttload of piston to valve clearance (.180 / .210). Car ran perfect after that but it shook me up for awhile....I do admit loving another "octave" in the exhaust note I had never heard before....LOL
Oh yeah....all of you who think you can run a mid 230's hydraulic cam without flycutting (or running aftermarket pistons) would have been crying if something similar happened to you (and it can happen to the best of us especially if your trying to pull off really fast shifts). Guaranteed you would have bent practically every valve and a good chance you might have bent one bad enough to break a head off and trash your engine.
The time spent doing that will tell you whether you need to pull the heads and swap out some valves or not.
If your pushrods aren't bent (which appears to be the case) and the engine was down on power it is highly likely that you did in fact bend/tweak a few valves.
If you get a decent leakdown on all eight holes consider yourself lucky and move on although if the car still doesn't feel right that would require further digging to find the problem.
I hate to be the bearer of bad news but if the car doesn't feel quite right and your pushrods aren't the culprit, its very likely you have a few bent valves.
Get a leakdown tester (or borrow one) and have at it....
Regards,
Tony
BTW....I consider myself a good driver when it comes to piloting high horsepower manually shifted hotrods (20+ years experience). About a year ago I nailed the infamous 3-2 shift for the first time at WOT (with my 383) and was data logging at the time....can you say 8507 RPM's
Three things saved my ***....one, Im **** about my engine assembly and thankfully was running good aftermarket parts....two, I run a solid roller which has better high RPM valve control, and three, I have a buttload of piston to valve clearance (.180 / .210). Car ran perfect after that but it shook me up for awhile....I do admit loving another "octave" in the exhaust note I had never heard before....LOL
Oh yeah....all of you who think you can run a mid 230's hydraulic cam without flycutting (or running aftermarket pistons) would have been crying if something similar happened to you (and it can happen to the best of us especially if your trying to pull off really fast shifts). Guaranteed you would have bent practically every valve and a good chance you might have bent one bad enough to break a head off and trash your engine.
10-03-2008, 02:37 PM
#42
You NEED to do a leakdown test at this point.
The time spent doing that will tell you whether you need to pull the heads and swap out some valves or not.
If your pushrods aren't bent (which appears to be the case) and the engine was down on power it is highly likely that you did in fact bend/tweak a few valves.
If you get a decent leakdown on all eight holes consider yourself lucky and move on although if the car still doesn't feel right that would require further digging to find the problem.
I hate to be the bearer of bad news but if the car doesn't feel quite right and your pushrods aren't the culprit, its very likely you have a few bent valves.
Get a leakdown tester (or borrow one) and have at it....
Regards,
Tony
BTW....I consider myself a good driver when it comes to piloting high horsepower manually shifted hotrods (20+ years experience). About a year ago I nailed the infamous 3-2 shift for the first time at WOT (with my 383) and was data logging at the time....can you say 8507 RPM's
Three things saved my ***....one, Im **** about my engine assembly and thankfully was running good aftermarket parts....two, I run a solid roller which has better high RPM valve control, and three, I have a buttload of piston to valve clearance (.180 / .210). Car ran perfect after that but it shook me up for awhile....I do admit loving another "octave" in the exhaust note I had never heard before....LOL
Oh yeah....all of you who think you can run a mid 230's hydraulic cam without flycutting (or running aftermarket pistons) would have been crying if something similar happened to you (and it can happen to the best of us especially if your trying to pull off really fast shifts). Guaranteed you would have bent practically every valve and a good chance you might have bent one bad enough to break a head off and trash your engine.
The time spent doing that will tell you whether you need to pull the heads and swap out some valves or not.
If your pushrods aren't bent (which appears to be the case) and the engine was down on power it is highly likely that you did in fact bend/tweak a few valves.
If you get a decent leakdown on all eight holes consider yourself lucky and move on although if the car still doesn't feel right that would require further digging to find the problem.
I hate to be the bearer of bad news but if the car doesn't feel quite right and your pushrods aren't the culprit, its very likely you have a few bent valves.
Get a leakdown tester (or borrow one) and have at it....
Regards,
Tony
BTW....I consider myself a good driver when it comes to piloting high horsepower manually shifted hotrods (20+ years experience). About a year ago I nailed the infamous 3-2 shift for the first time at WOT (with my 383) and was data logging at the time....can you say 8507 RPM's
Three things saved my ***....one, Im **** about my engine assembly and thankfully was running good aftermarket parts....two, I run a solid roller which has better high RPM valve control, and three, I have a buttload of piston to valve clearance (.180 / .210). Car ran perfect after that but it shook me up for awhile....I do admit loving another "octave" in the exhaust note I had never heard before....LOL
Oh yeah....all of you who think you can run a mid 230's hydraulic cam without flycutting (or running aftermarket pistons) would have been crying if something similar happened to you (and it can happen to the best of us especially if your trying to pull off really fast shifts). Guaranteed you would have bent practically every valve and a good chance you might have bent one bad enough to break a head off and trash your engine.
Fix it better when it breaks! 
10-03-2008, 04:55 PM
#45
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At the Z pushrod! That is BAD. First time I got on my car hard I misshifted from 3rd to 2nd. It has the factory Hurst so I wasnt used to it. The only good thing is that I was shifting around 4500 and as soon as I let out the clutch I got a huge wake up call. Immediately pushed it back in and went on my way. Pulled over on the side of the road to check it out and no abnormal sounds or anything.
Getting a MGW soon to solve the tricky stock shifter problem.
Great info Tony! 8500 RPMs is a LOT to turn over on accident.
10-04-2008, 01:36 PM
#46
Sure is....LOL
But when your shifting WOT in the 7200-7300 range grabbing the next lower gear will tend to do that!
Honestly I stabbed the clutch quickly as the engine was exploding into the higher RPM's....if I hadnt it would have probably been slightly higher. I thought to myself as it happened that was easily 8K.....nope....it was a bit higher than that!
-Tony
But when your shifting WOT in the 7200-7300 range grabbing the next lower gear will tend to do that!
Honestly I stabbed the clutch quickly as the engine was exploding into the higher RPM's....if I hadnt it would have probably been slightly higher. I thought to myself as it happened that was easily 8K.....nope....it was a bit higher than that!
-Tony
10-04-2008, 07:26 PM
#47
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I'm with Tony..it can happen to anybody...happened to me when I was drag racing a mustang trying to eke out a win...I wasn't as lucky as Tony I bent at least half my valves. It was over 8 years ago so thankfully it's a little fuzzy. Along with Tony I was an experienced racer with well over 200 passes on that car along with many other manual cars.
10-05-2008, 08:16 AM
#48
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DO NOT DRIVE IT AGAIN. REPEAT. DO NOT DRIVE IT AGAIN.
first of all, i dont know why you would be flogging it like that after missing a shift and noticing something wrong.
pull the valve covers and check for bent pushrods, and any other problem.............naw. forget that, go ahead and pull the intake, accessories and heads. cause your gonna need some work.
one more thing.......learn to drive.
first of all, i dont know why you would be flogging it like that after missing a shift and noticing something wrong.
pull the valve covers and check for bent pushrods, and any other problem.............naw. forget that, go ahead and pull the intake, accessories and heads. cause your gonna need some work.
one more thing.......learn to drive.
10-06-2008, 10:17 PM
#49
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Well, i ripped off the head, and everything looks kosher, no piston to valve contact marks, valves look OK, I think I am going crazy. Anyway, its H/C time since i've already gotten this far.
10-07-2008, 07:42 AM
#50
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10-07-2008, 10:28 AM
#52
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im willing to bet it was an exhaust leak or a fouled plug. one of my plugs was a bit dark. And wehn i pulled off the passenger side head, the header kinda just slid right out of the y pipe
10-07-2008, 12:02 PM
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I'm just putting my motor back in the car after doing the same thing as well in the first round of an event a couple of weeks ago shifted 3-2 at 6800 RPM and it over reved to 8050 on the data logger.
Noticeably bent 5 valves and left marks on all but one piston.
Noticeably bent 5 valves and left marks on all but one piston.
