I think I hurt something, valvetrain? (HELP!)
Thread Starter
Burning Brakes
Joined: Apr 2002
Posts: 934
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From: MO
I think I hurt something, valvetrain? (HELP!)
Friday night I took my car to the dragstrip and my first run I messed up my 2-3 shift and stuck it back in 1st! :eek: I have never done this before! I was like what the f%#@ for a sec then realized. The rear end locked up and hopped a few times then I slammed it into 3rd and finished the run just to get off the track. Kind of imbarrassing. Anyhow, my car never made a good pass after that! The best I got was a 13.06 and had a 13.22 and even a 13.38. My car runs 12.7's round robining it! I did this last trip to the trak like 8 times in a row! Mph was down by 4-5 also!!! I quit running it and watched my friends. On the drive home the car sounds different, the normal exhaust tones I get weren't there. Idle sounds differnt as well. It didn't pull as hard at the top of gears either.
I trailered it to a Shop in ST Louis yesterday to get my 4.11's installed and warned them of the problem so they don't go blast on it. They won't be done with the gears until next friday. They are not checking the problem.
I am going to pull the valve covers when I get it back, but this is driving me crazy right now. Any one ever had this happen? Or any ideas of what I did to my car????
Sorry so long...Thanks for any and all help!!!
I trailered it to a Shop in ST Louis yesterday to get my 4.11's installed and warned them of the problem so they don't go blast on it. They won't be done with the gears until next friday. They are not checking the problem.
I am going to pull the valve covers when I get it back, but this is driving me crazy right now. Any one ever had this happen? Or any ideas of what I did to my car????
Sorry so long...Thanks for any and all help!!!
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
Re: I think I hurt something, valvetrain? (James94LT1)
I think you're on the right track by removing the valve covers. Down 4-5mph is 40-50hp loss.
Does it rev as high as before? Floating the valves can reduce the rev limit causing earlier valve float thereafter.
How did your short times compare after the incident?
Does it rev as high as before? Floating the valves can reduce the rev limit causing earlier valve float thereafter.
How did your short times compare after the incident?
Team Owner
Joined: Aug 2000
Posts: 24,125
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St. Jude Donor '14
Re: I think I hurt something, valvetrain? (65Z01)
I'm guessing your running a hydraulic cam, check the push rods and the springs carefully. Find a very flat and smooth surface like a glass table and roll the push rods across, sometime they are bent ever so slightly, but enough to hurt performance.
Race Director
Joined: Sep 2001
Posts: 14,682
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From: NEwhere Ohio
Re: I think I hurt something, valvetrain? (James94LT1)
I have done this before, although going from 3rd to 1st may be more serious than hitting (like I did) 3rd instead of 5th at 125 MPH due to the high numerical 1st gear ratio.
In my case, nothing bad seemed (Cross my fingers ) to happen.
Maybe your valvesprings got weakened by the extra heat/ friction from hitting such a high RPM. Might want to check their spring rates if you have time.
In my case, nothing bad seemed (Cross my fingers ) to happen.
Maybe your valvesprings got weakened by the extra heat/ friction from hitting such a high RPM. Might want to check their spring rates if you have time.
Safety Car
Joined: Feb 2002
Posts: 4,286
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From: Guam
Re: I think I hurt something, valvetrain? (dizwiz24)
I would suggest a thorough checking of the timing chain and valvetrain components. They are the first to go in a situation like this. I have seen excessive stretch on a new timing chain from overrevving like you just experienced. Lifters and pushrods will normally click and complain if they are in any way damaged.
Thread Starter
Burning Brakes
Joined: Apr 2002
Posts: 934
Likes: 0
From: MO
Re: I think I hurt something, valvetrain? (65Z01)
I think you're on the right track by removing the valve covers. Down 4-5mph is 40-50hp loss.
Does it rev as high as before? Floating the valves can reduce the rev limit causing earlier valve float thereafter.
How did your short times compare after the incident?
Does it rev as high as before? Floating the valves can reduce the rev limit causing earlier valve float thereafter.
How did your short times compare after the incident?
Yeah you can feel there is definatley a loss of power. I noticed each run after the car wasn't pulling smooth all the way to 6000 like before, it seem to be running out around 5500. My friend said it didn't sound the same going down the track said it use to be crisp and clean now its kinda lagging.
I also notcied coming down exits ramps it use to crackle and pop a little and now its just a plain type tone.
My short times were up about a 1/10th - 2/10ths from the norm also.
But I don't have the slip from this first runs I goofed cause I through it out the window on the way back cause I was so mad at myself! But my friends cars were hooking and running there normal 60ft's.
My guesses are, pushrods bent, bad lifter(s),spring(s),could you flatten a cam this away? I didn't even think of the timing chain issure but with 73k that wouldn't suprise me much either????!?!?!? :confused:
Thread Starter
Burning Brakes
Joined: Apr 2002
Posts: 934
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From: MO
Re: I think I hurt something, valvetrain? (James94LT1)
I just read the article about gasoline. Here is one factor I overlooked.
I had put some Cenex 91 in it a week ago when on the road. I had about a half tank left added about 6 gallons of Amoco 93 and drove to the track.
Had just iunder a half tank when racing. It was a 90 degree day and about low to mid 80's during the runs. Could I have been getting knock counts and losing power? Other times were in 50 cool weather. I just can't imagine 3-5 1/10ths though.
:confused: :confused: :confused:
I wish I had my car so I could at least look into this now!
I had put some Cenex 91 in it a week ago when on the road. I had about a half tank left added about 6 gallons of Amoco 93 and drove to the track.
Had just iunder a half tank when racing. It was a 90 degree day and about low to mid 80's during the runs. Could I have been getting knock counts and losing power? Other times were in 50 cool weather. I just can't imagine 3-5 1/10ths though.
:confused: :confused: :confused:
I wish I had my car so I could at least look into this now!
Thread Starter
Burning Brakes
Joined: Apr 2002
Posts: 934
Likes: 0
From: MO
Re: I think I hurt something, valvetrain? (James94LT1)
Ok say there is a valve train problem, I am thinking if I have to tear into it, maybe its heads & cam time? Who is offering the best and most cost effective full port/polish jobs bigger valves etc???
I think I'll go with a cam from cartek, like the one Mackey is running.
Thanks!
I think I'll go with a cam from cartek, like the one Mackey is running.
Thanks!
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Joined: Nov 1999
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From: Memphis, Tn
Re: I think I hurt something, valvetrain? (James94LT1)
My guess is one or more bad valve springs. Replace the valve springs, then have the old ones checked. New springs would be a good idea even if the others check OK.
