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lt1 vs "stock" cam

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Old Oct 8, 2011 | 04:55 PM
  #1  
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lt1 vs "stock" cam

hey to all i done my research and also measure my "stock" cam and lt1 cam seems back in 02 someone had the same problem i had

the cam that i pulled out wuz heavier also look identical

lt1 cam ofcourse lighter

measured and found out the "stock" cam had bigger lobes
than lt1 cam

cam numbers hopefull;y right order

lt1
gmpt bc 17-242
(more then likely wrong order)

cam in car
155 cpc bc

found specs on my lt1 cam but none on the cam in the car ps the car wuz rebuilt by previous owner im geussing maybe a 350 cam from a tpi????

my question is as follow cam spec for the "stock" cam

thanks to all
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Old Oct 8, 2011 | 05:57 PM
  #2  
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From: Salt Lake City, Utah
Car: 1988 camaro "SS"/ 1991 305/T5
Engine: 383 LT1 in progress/LT1TBI 355 soon
Transmission: Probuilt 700R4 3600 stall/ T5
Axle/Gears: Moser axles, 3.42 Eaton Posi
Re: lt1 vs "stock" cam

That looks to be an LT1 cam. I'll check the cam I have at home to be certain. I believe I have the same numbers on one of mine. If the dowel pin on the front of the cam is longer than the one in your car it "should" be an LT1 cam. you have to be careful though due to the fact that there are a few LT1 cams out there with different sizes. Hopefully you don't have a B body LT1 cam. I have the specs for it on my cardomain.
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Old Oct 8, 2011 | 06:57 PM
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Car: 92 firebird
Engine: 305 tpi "stock"
Transmission: slipping
Axle/Gears: 3.42 posi disk brakes!
Re: lt1 vs "stock" cam

idk its smaller then the "stock" cam i pullked out let me kno ive checked and double check ive got the specs from the lt1 but cant find the specs for the stock one
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Old Oct 8, 2011 | 11:27 PM
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Re: lt1 vs "stock" cam

The lobes on the stock TBI cam aren't bigger than the LT1 cam. I know it looks that way but it's because the BASE CIRCLE of the stock TBI cam lobes are larger. That's the round part where no lift is happening. The actual lobe (where lift is happening) is considerably smaller on a TBI cam than it is on the LT1 cam.
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Old Oct 9, 2011 | 12:40 AM
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Car: 92 firebird
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Re: lt1 vs "stock" cam

lets say my cam in my tbi car wuz a 350 cam from tpi from a possible rebuilt

is this cam better then my lt1 cam???
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Old Oct 9, 2011 | 09:49 AM
  #6  
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Car: 91 Trans am
Engine: built 360 TBI
Transmission: built 700r4
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Re: lt1 vs "stock" cam

Sounds like you did not read or understand Damon's reply.

Measure the lobes, subtract the base circle and multiply by 1.5 (1.6 if using 1.6 rockers) to know the lift numbers.

Post results.
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Old Oct 9, 2011 | 09:56 AM
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From: nc
Car: 92 firebird
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Re: lt1 vs "stock" cam

ok thats for the lift any formula for duration?
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Old Oct 9, 2011 | 06:35 PM
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Re: lt1 vs "stock" cam

cam in car
155 cpc bc
This is all that I needed to know....That is a STOCK L03 cam. 179/194* @ .050, .350/.385" lift, 109 LSA
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Old Oct 10, 2011 | 12:32 AM
  #9  
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From: nc
Car: 92 firebird
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Transmission: slipping
Axle/Gears: 3.42 posi disk brakes!
Re: lt1 vs "stock" cam

thats wat i wuz readingup on evidentally thats the peanut cam butidle fairlywell (must be a vacum line) i havent got to measure the lt1 cam i have to figure lift guyi bought it from told me lift but i wanna double check

besides confusedme when we measured the lt1 cam and mesuredsmaller then the stock could have measured wrong thanks for the help

neighbor never came up so i can measuremycam
probably just buy my own fromharborfrieght
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Old Oct 20, 2011 | 04:14 PM
  #10  
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Car: 92 firebird
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Re: lt1 vs "stock" cam

Originally Posted by thomas1976
Sounds like you did not read or understand Damon's reply.

Measure the lobes, subtract the base circle and multiply by 1.5 (1.6 if using 1.6 rockers) to know the lift numbers.

Post results.

after measuring the stock came to 440
and lt1 came to 510

i had to mess up somewhere

also i measured it in inches and mm all i have on my caliber (unless all of em do)

so im pretty sure im missing somethin maybe simplify excuses me for the stupidity i have in math



Originally Posted by Damon
The lobes on the stock TBI cam aren't bigger than the LT1 cam. I know it looks that way but it's because the BASE CIRCLE of the stock TBI cam lobes are larger. That's the round part where no lift is happening. The actual lobe (where lift is happening) is considerably smaller on a TBI cam than it is on the LT1 cam.
i did this my caliber its digital and it wuz the opposite lt1 cams lobes and base circle was smaller then stock
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Old Oct 20, 2011 | 04:28 PM
  #11  
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Car: 91 Trans am
Engine: built 360 TBI
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Axle/Gears: 10bolt/3.23
Re: lt1 vs "stock" cam

Could post the mesurements you mesured on each cams.
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Old Oct 20, 2011 | 04:45 PM
  #12  
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From: nc
Car: 92 firebird
Engine: 305 tpi "stock"
Transmission: slipping
Axle/Gears: 3.42 posi disk brakes!
Re: lt1 vs "stock" cam

need to gto get them from my house
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Old Oct 20, 2011 | 08:51 PM
  #13  
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From: nc
Car: 92 firebird
Engine: 305 tpi "stock"
Transmission: slipping
Axle/Gears: 3.42 posi disk brakes!
Re: lt1 vs "stock" cam

lt1
b= 1.05
l=1.53

stock
b= 1.05
l= 1.58

wich is strangw caUSE when i measure yesterday the base was hire i believe my csaliber from harbor frieght

call me stupid but the base circles are basical wat sits on the cam bearings?? if not heres the next measurements i did for the the other circle the skinest one (im cam stupid)

both 1.27
im doing something wrong. . . .
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Old Oct 21, 2011 | 03:35 AM
  #14  
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From: West-Central
Car: 91 Trans am
Engine: built 360 TBI
Transmission: built 700r4
Axle/Gears: 10bolt/3.23
Re: lt1 vs "stock" cam

Measure only the lobes of the cam. Take a look at the "Anatomy of a cam profile" pic, then mesure the intake and exhaust lobes.
https://www.thirdgen.org/forums/post...697-post1.html
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Old Oct 23, 2011 | 10:57 PM
  #15  
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From: nc
Car: 92 firebird
Engine: 305 tpi "stock"
Transmission: slipping
Axle/Gears: 3.42 posi disk brakes!
Re: lt1 vs "stock" cam

believe i found the lift i bought some heads from a fellow member and he help me measure them 480 and 460-480 lol cant rember but overall great cam!!!
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Old Oct 26, 2011 | 11:22 AM
  #16  
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From: nc
Car: 92 firebird
Engine: 305 tpi "stock"
Transmission: slipping
Axle/Gears: 3.42 posi disk brakes!
Re: lt1 vs "stock" cam

by eye that was the specs
with digital caliper tis is the specs
1.5 450/435
1.6 480/464
measured this one a second time and over and over came up with this

Last edited by dabird07; Oct 26, 2011 at 12:15 PM.
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