Another LT4 Hot Cam ?
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Joined: Jul 1999
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Another LT4 Hot Cam ?
I've been looking at cam specs and have seen that quite a few of you use the LT4 Hot cam #24502586.
My question is have any of you run into valve spring problems? The reason I ask is that the valve springs recommended for the hot cam are#12495494 (16) or the 12361329 (1). The specs say that maximum lift is .525".
The Hot Cam with 1.6 rollers has .525" lift! I'm interested in the swap but I really don't want to swap out fatigued valve springs all the time.
Also with the cams duration of 218/228 @.050 and 112 lobe center is the stock LT4 computer able to compensate for this cam (and pass dyno emission testing)?
Thanks for your help!
My question is have any of you run into valve spring problems? The reason I ask is that the valve springs recommended for the hot cam are#12495494 (16) or the 12361329 (1). The specs say that maximum lift is .525".
The Hot Cam with 1.6 rollers has .525" lift! I'm interested in the swap but I really don't want to swap out fatigued valve springs all the time.
Also with the cams duration of 218/228 @.050 and 112 lobe center is the stock LT4 computer able to compensate for this cam (and pass dyno emission testing)?
Thanks for your help!
Race Director
Joined: May 2001
Posts: 14,165
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Re: Another LT4 Hot Cam ? (grndspt)
I have the LT4 Hot Cam in my LT1. I replaced the springs with the house brand from Internet Racers Supply. They have a max lift of like .550 So far they seem to be doing a very good job. I think the common thought is that the LT4 computer will run alright, but not optimal with the cam while the LT1 won't run worth a crap. Correct me if I'm wrong.
Safety Car
Joined: Mar 2000
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From: Bartlett, IL
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St. Jude Donor '06-'07-'08-'09-'10-'11-'12
Re: Another LT4 Hot Cam ? (Nathan Plemons)
I used my stock LT-4 Valve springs when I installed my HOTCAM, the stock springs on the LT-4 are the same as the ones in the kit.
Mike
Mike
Burning Brakes
Joined: Aug 2000
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From: Cincinnati OH
Re: Another LT4 Hot Cam ? (Nathan Plemons)
I think the common thought is that the LT4 computer will run alright, but not optimal with the cam while the LT1 won't run worth a crap
Safety Car
Joined: Mar 2000
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From: Hillsboro OR
Re: Another LT4 Hot Cam ? (grndspt)
The hot cam will not fatigue vavle springs. The lift specified is with 1.6 roller rockers and its not very agressive for 218 degree duration. I had a Crane cam that had 520 (1.6) lift with only 210 degree intake duration. That cam is harder on valve springs but still won't fatigue them. The LT4 computer can handle the cam but the idle probably needs to be raised a bit.
I think the MAF LT1 (94-96) computer will run fine with the hot cam as long as you raise the idle speed. My car ran fine and passed emissions with the stock LT1 programming when I had the Crane cam in it. 210/224 dur 112 LSA 520/550 lift w/ 1.6 rockers. Engine was 383 with AFR heads.
I think the MAF LT1 (94-96) computer will run fine with the hot cam as long as you raise the idle speed. My car ran fine and passed emissions with the stock LT1 programming when I had the Crane cam in it. 210/224 dur 112 LSA 520/550 lift w/ 1.6 rockers. Engine was 383 with AFR heads.
Melting Slicks
Joined: Mar 1999
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From: Nashville TN area
Re: Another LT4 Hot Cam ? (grndspt)
i'm running the crane dual valve springs (closed seat pressure is 120#) good to .600 lift with my hot cam.
and yeah, the hot cam is only .525 lift with a 1.6 rocker.. it's .492 with a 1.5 (stock) rocker..
my '94 LT1 (first year of MAF for LT1's) ran fine with stock programming, just bump the idle up a little with the idle set screw in the TB.. you will want to get the pcm reprogrammed tho to get max power.. i had shalin do mine (took the car out east) and he did a great job. always go for dyno tune if you can.. mail order pcm programs rarely give you what you pay for.
and yeah, the hot cam is only .525 lift with a 1.6 rocker.. it's .492 with a 1.5 (stock) rocker..
my '94 LT1 (first year of MAF for LT1's) ran fine with stock programming, just bump the idle up a little with the idle set screw in the TB.. you will want to get the pcm reprogrammed tho to get max power.. i had shalin do mine (took the car out east) and he did a great job. always go for dyno tune if you can.. mail order pcm programs rarely give you what you pay for.
