looking into a cam....help!!
Jul 25, 2006 | 11:39 PM
#1
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From: Jxn,Mississippi
looking into a cam....help!!
ok as of now i'm looking into replacing my stock 97 5.7l cam. i've been really looking @ the LQ4 cams and what i'm wondering is how it would sound/perform w/ my motor. can anyone give me any help/advice here.
Jul 26, 2006 | 06:11 PM
#6
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From: Houston,Texas
Here's what you can do:
Thanks to "hog" for the info. If he comes in here he can elaborate more: The site pretains alot to the GENIII motors if you want more help on your GEN1 motor go to fullsizechevy.com tons of info for the 96-99 OBS vortecs:
Thanks to "hog" for the info. If he comes in here he can elaborate more: The site pretains alot to the GENIII motors if you want more help on your GEN1 motor go to fullsizechevy.com tons of info for the 96-99 OBS vortecs:
Originally Posted by hog
For the stock heads, you dont want to go over 0.475" of valve lift. You can add CompCams 26915 or 26918 valve springs and use up to 0.525" of lift. The clearance issues are with the valve seal/retainer clearance.
A nice roller cam from GM is the 1996 LT4 Vette cam. It has .446"/.450" lift with the stock rocker arms and 203°/210° duration at 0.050" on a 115° LSA. It is GM part #12551142. This cam will idle nicely and will give power gains throughout the rev range.
A slightly milder GM roller cam is the 1995-97 LT1 camshaft with .447"/.459" lift with 1/5:1 rocker arms and 201°/208° duration at 0.050" it is GM p/n 12551705.
Both cams will be easy to tune, will pull excellent vacuum for power brakes and will deliver very good fuel economy.
If you used the upgraded Comp Beehive springs, you could setp up to the GM LT4 Hotcam with 0.492"/0.492" of lift with 1.5:1 rockers or 0/525"/0.525" lift with 1.6:1 rocker arms and 218°/228° duration at 0.050" on a 112° LSA.
This cam has an agressive idle, fuel economy will drop and sint advised for a heavy vehicle.
If you use 1.6:1 rocker arms you will need to enlarge the pushrod holes in the heads. Just run the next sized larger drill bit through them. The 1.6:1 rockers bring the pushrod closer to the fulcrum point of teh rocker, possibly causing the pushrod to rub on the ehad. Some get away without t doing this, some dont. I personally had to drill teh holes larger when I did my frineds car with the LT4 Hotcam and GM 1.6:1 roller rockers.
There are MANY aftermarket roller cams as well.
peace
hog
A nice roller cam from GM is the 1996 LT4 Vette cam. It has .446"/.450" lift with the stock rocker arms and 203°/210° duration at 0.050" on a 115° LSA. It is GM part #12551142. This cam will idle nicely and will give power gains throughout the rev range.
A slightly milder GM roller cam is the 1995-97 LT1 camshaft with .447"/.459" lift with 1/5:1 rocker arms and 201°/208° duration at 0.050" it is GM p/n 12551705.
Both cams will be easy to tune, will pull excellent vacuum for power brakes and will deliver very good fuel economy.
If you used the upgraded Comp Beehive springs, you could setp up to the GM LT4 Hotcam with 0.492"/0.492" of lift with 1.5:1 rockers or 0/525"/0.525" lift with 1.6:1 rocker arms and 218°/228° duration at 0.050" on a 112° LSA.
This cam has an agressive idle, fuel economy will drop and sint advised for a heavy vehicle.
If you use 1.6:1 rocker arms you will need to enlarge the pushrod holes in the heads. Just run the next sized larger drill bit through them. The 1.6:1 rockers bring the pushrod closer to the fulcrum point of teh rocker, possibly causing the pushrod to rub on the ehad. Some get away without t doing this, some dont. I personally had to drill teh holes larger when I did my frineds car with the LT4 Hotcam and GM 1.6:1 roller rockers.
There are MANY aftermarket roller cams as well.
peace
hog
Jul 26, 2006 | 06:28 PM
#7
I've got a nice little LPE cam in my vortec 350,I love it and it gained 30rwhp on the dyno with this cam I have and a nice flat curve unlike what these engines are stock.Stock they start falling pretty hard after about 4500RPM but mine pulls all the way to 5600 with ease and a nice smooth curve.
