Safe RPM before float

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May 22, 2009 | 10:12 AM

#21

JoeGibbSilverado

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From: Memphis, 10

i think hes referring to a 5.3, not a 6.0, big

May 22, 2009 | 10:24 AM

#22

BlackGMC

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From: Fort Worth - TX

These are my shift points:

Normal
1->2 6400
2->3 6500

Track
1->2 6800
2->3 6900

I used to shift the 2->3 at 7100k in the 1/8th so i would not have to shift into 3rd... my rev limiter is set to 7300.... Mods in sig...

May 22, 2009 | 10:27 AM

#23

BlackGMC

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From: Fort Worth - TX

On the orginal topic of valve float, i thought that really only affected non-roller cams? It was my understanding that roller cams do not have the problem of floating the valves...

May 22, 2009 | 11:22 AM

#24

TXsilverado

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From: Humble Texas

Quote:

Originally Posted by BigCountryx

For real, no one else has? I went 14.16 on a mail order tune, full exhaust, factory 20s with half worn Goodyears (traction problems), 30% TM still enabled (zero tranny Mods), full weight plus bedrug, probably 100 extra pounds in the cab, 3/4 tank of gas, not to mention I weigh 250. DA was 1257. Shifting at 5800. I'm amazed no one else has dropped some weight and busted 13s.

were talking 5.3 motors...im suprised nobody has done it yet too. people usually just take the easy route and throw in a cam and converter and go deep into the 13's. i had pretty much every bolt on on the 5.3 with reduced weight and the stock cam.

May 22, 2009 | 11:25 AM

#25

TXsilverado

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Quote:

Originally Posted by BlackGMC

On the orginal topic of valve float, i thought that really only affected non-roller cams? It was my understanding that roller cams do not have the problem of floating the valves...

i floated the stock springs with the 226 cam. 7100 is UP THERE. your probably not gaining anything by pulling your combo that high

May 22, 2009 | 11:29 AM

#26

BlackGMC

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From: Fort Worth - TX

Quote:

Originally Posted by TXsilverado

i floated the stock springs with the 226 cam. 7100 is UP THERE. your probably not gaining anything by pulling your combo that high

Well on the same day shifting my 2-3 at 6600 netted me 8.4x twice.... (EDIT I am not sure if it was 6600 or 6800)
Bumping up the 2-3 to 7000-7100 i ran 8.34 twice...

Last edited by BlackGMC; May 22, 2009 at 11:34 AM.

May 22, 2009 | 01:58 PM

#27

JoeGibbSilverado

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From: Memphis, 10

charlie did my shift points first at 6300, ran 14.3s 14.4s, bumped them up and i went 14.21, every little bit helps

May 22, 2009 | 02:17 PM

#28

PathfinderJr

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From: Texas

Quote:

Originally Posted by BlackGMC

I used to shift the 2->3 at 7100k in the 1/8th so i would not have to shift into 3rd... my rev limiter is set to 7300.... Mods in sig...

Did you ever install rod bolts on your 4.8 for that high of rpm or are you pretty confident the short stroke makes it a non-issue? Just wondering for my 4.8 and future mods...

May 22, 2009 | 02:19 PM

#29

BlackGMC

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From: Fort Worth - TX

Quote:

Originally Posted by PathfinderJr

Did you ever install rod bolts on your 4.8 for that high of rpm or are you pretty confident the short stroke makes it a non-issue? Just wondering for my 4.8 and future mods...

Nope.... If the motor blows, then i have a perfect excuse to build a bigger one...

However, i do richen up the mixture a little bit past 6600 and drop timing a degree or two to be on the safe side...

May 22, 2009 | 04:02 PM

#30

TXsilverado

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From: Humble Texas

Quote:

Originally Posted by BlackGMC

Well on the same day shifting my 2-3 at 6600 netted me 8.4x twice.... (EDIT I am not sure if it was 6600 or 6800)
Bumping up the 2-3 to 7000-7100 i ran 8.34 twice...

well hell, if you tested it nobody can argue it. ive been told that i shift too high by a few people but it was track tested on mine too. if i go past 6900 i gain nothing. that was before the ported fast 90 though. hopefully i dont have to shift any higher now. 6900 is already iffy on my stock rod bolts and high mileage motor.