What determines tach redline?
Thread Starter
Burning Brakes
Joined: Sep 2000
Posts: 806
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From: Baton Rouge LA
What determines tach redline?
When I run hard, my tach redlines before every shift. How accurate is the digital dash, and what determines the redline? Valve float? Bottom end? Do you think the engine is actually at redline? Will this hurt it?
Thanks in advance
Thanks in advance
Pro
Joined: Oct 2001
Posts: 682
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From: loxahatchee fla
Re: (scorp508)
your REDLINE is basically determined by the valve float rpm and the strength of your engines bottom end, for most cheveys running stock or nearly stock lower end components 4000feet per min. of piston speed is a limmit you should not exceed, yes you can get away with it SOMETIMES but sooner or later that engine will fail if you do!
example: 4000fpm +48000 inches travel for the piston so your 350 has a 3.48" stroke x 2 for each revolution=lets say 7" so 48000/7=6857 rpm max but of course if your engine floats the valves at a lower rpm then that rpm is your redline!
example: 4000fpm +48000 inches travel for the piston so your 350 has a 3.48" stroke x 2 for each revolution=lets say 7" so 48000/7=6857 rpm max but of course if your engine floats the valves at a lower rpm then that rpm is your redline!
Race Director
Joined: Oct 2000
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From: Enter Post Count Here
Re: What determines tach redline? (Nitro Junkie)
My car outruns the tach like crazy, I have the stock governor in the tranny and so I know its shifting right at 4,900 rpms, right where I drop below 400 lbs of torque, so I'm pretty happy with this setup.
The weakest part of my engine is the lifters, which redline at 6,200 rpms, but I'll never take it that high. :eek:
The weakest part of my engine is the lifters, which redline at 6,200 rpms, but I'll never take it that high. :eek:
Race Director
Joined: May 1999
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From: Plymouth MI Formerly Milford, MA MI
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Re: What determines tach redline? (NoWorries)
Hmmmm I still have the stock lifters and I shift at 6250 for my fastest runs
Race Director
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From: The Top of Utah
Re: What determines tach redline? (Nitro Junkie)
I echo the above concerning the stock tach and rpm limits imposed by the valve train and bottom end. Even with a ported intake, you shouldn't WANT to tax it's rpm limits. Now, with some additional modifications, that may change.
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From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
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Re: What determines tach redline? (L98Terror)
I know my tach is off, I shift past 6,000, but in reality, I think it's really 5500.
