Anyone install a bigger cam after putting in 1,8 rockers?
07-10-2003, 11:22 AM
#1
Anyone install a bigger cam after putting in 1,8 rockers? I installed the 1.85 Comp Cams Pro Mag rockers and the 918 springs. All the cams you see listed on the LS1Tech advertisers websites are based on the stock 1.7 rocker ratio. That means you can't use a cam with a big lift from those lists of cams using the specs you see on those lists. You have to get a CSUTOM ground cam.
I'm getting approx .050 extra lift from the 1.85 rocker so that MUST be taken into account in the new grind. I called Comp Cams twice about an aftermarket cam. One tech told me they would grind me a 216/212 570/570 113 LSA cam. That's taking the 1.85 rocker ratio into account. Another Comp Cams tech told me DON'T change the cam after installing the 1.85 rockers because the computer is very "FINICKY" in the LS1 and the PCM would go bonkers. Which tech is right? Does anyone have experience with putting a bigger cam in after installing higher ratio rockers? He told me I would be back in the engine later putting my stock cam back in and the mew cam would be mine to keep. Could I just get a cam with say approx 520 or 525 lift and end up with the same lift I would have had if I got a CUSTOM ground cam using the 1.85 rocker ratio value?
I'm getting approx .050 extra lift from the 1.85 rocker so that MUST be taken into account in the new grind. I called Comp Cams twice about an aftermarket cam. One tech told me they would grind me a 216/212 570/570 113 LSA cam. That's taking the 1.85 rocker ratio into account. Another Comp Cams tech told me DON'T change the cam after installing the 1.85 rockers because the computer is very "FINICKY" in the LS1 and the PCM would go bonkers. Which tech is right? Does anyone have experience with putting a bigger cam in after installing higher ratio rockers? He told me I would be back in the engine later putting my stock cam back in and the mew cam would be mine to keep. Could I just get a cam with say approx 520 or 525 lift and end up with the same lift I would have had if I got a CUSTOM ground cam using the 1.85 rocker ratio value?
07-10-2003, 12:56 PM
#2
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Re: Anyone install a bigger cam after putting in 1,8 rockers? Try the cam in my sig. I've got 1.8 rockers on it now which puts it in the .56x lift range. With 1.85s it would be ~.574 max lift. That would be a nice cam I think. I haven't had any problems with tuning.
BTW, it's a nice cam for a supercharger as well...just in case down the road you want to put in a little more power
BTW, it's a nice cam for a supercharger as well...just in case down the road you want to put in a little more power
07-10-2003, 07:40 PM
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Re: Anyone install a bigger cam after putting in 1,8 rockers? I have a lingenfelter GT1 cam 218/229 .560/.560 113lsa and Crane gold 1.8 rockers. I have not had the car tuned yet so it is not running well, but i have had no p/v clearence problems and it sounds like a monster. I hope to get it tuned here in a couple of days so i will know real soon how they perform together.
07-11-2003, 05:47 PM
#4
Re: Anyone install a bigger cam after putting in 1,8 rockers? if you are going to use 1.85 rockers with a cam, you just have to make sure that the max lift is not over the limit of the valve springs and p-to-v clearance.
I "could" use 1.8 ratio rockers with my TR224/224 (I have 987 duel springs) but it would bring me under the 0.080" safe p-to-v min so.....
I "could" use 1.8 ratio rockers with my TR224/224 (I have 987 duel springs) but it would bring me under the 0.080" safe p-to-v min so.....
