jonesy

I'm in the final stage of my 383, I've been playing with cam #'s and noticed that the Crane Cams CRN-119651 makes more power than the GM 847 ( on the computer) I did a search and tried to see if anyone has run this and found no results. what do you guys think? 240/248 .558/.558

thx,
jonesy

96capricemgr

I think you need to spend less time with simulations.
Look at the results you can find, do you honestly see "bigger is better" as a trend? I don't.

seawolf06

This is what I see when I compare that cam to the GM847:

This cam has:
Higher rated RPM: up to 7k, might be lower with stroker
Slower ramp rates/less agressive
More intake lift should mean more power
IVC is later so you'll need more SCR

My suggestion: Either custom or xfi. They seem to do well in stroker motors.

jonesy

the GM 847 cam makes more power than the CC 306 so is bigger better, in this comparison YES, so why wouldn't the 240/248 cam be a little better, seems how its designed for a bigger motor. I agree bigger isn't always better but its not that much bigger and was wondering if anyone is running it on here.

maro z28

I can't get at my valve events calculator. How much overlap does that cam have @.050 and how is the overlap oriented about TDC? To take advantage of being able to spin past 6500, you could probably benefit form overlap being more towards the intake stroke to help build hp past peak torque. That cam needs more SCR, as seawolf eluded to. You could also bump up DCR, but it would be at the expensive of overlap placement. As you advance the IVC, you continue to push overlap towards exhaust bias. JMO, though. Brett will probably chime in and put my advice to shame.

seawolf06

See reasons I listed above. @.050" duration isn't everything when it comes to cams.

Eric, the crane cam listed also has a good bit more overlap than the GM847 as well which could explain its higher suggested RPM range. Also, I'm pretty sure the LSA is 110 as opposed to 112 for the GM847. See Jonesy, there's A LOT more to cams than you might think.

jonesy

and I guess thats why they make adjustable cam gears. I'm new to the LT world but not in the cam world, I currently own a prostock diesel tractor that puts out over 2400 hp @ 4500 rpm, we spent hours on dyno with cams along with cam timing. you can take a 106 centerline, advance it 4 degrees and pick up 100 hp, and damn near 200 ft lbs of torque. I don't know it all thats why I'm asking, this car is for my son and was looking @ cam profiles and thought this might be a step-up over the 847, if I'm not mistaken I believe crane makes the cam (847). I appreciate evryones input and I know that people have differen't opinions on what cams work where, I just asked if anyone tried it and if they liked or disliked it. Seawolf , there are endless variables to go along with cams. If I wanted to install the more popular 847 cam I would install 1.7 rockers, but instead I got a deal on 1.6 rockers and thought the profile of 651 cam might work a little better, for our setup. Not trying to start a cam intellegence war, hell I can't even win arguements with my wife. thanks guys for helping out , I'm sure this thread will continue on.
jonesy
berrien springs, mi.

96capricemgr

Do you see "results" as dyno graphs or ETs? They are most definetely not the same thing.

seawolf06

You shouldn't put 1.7 rockers on the LT1 head anyway. Search around this forum and you'll find about a million cam threads.

Injuneer

Although you provided no info in your signature, or in the original post, appears you are talking about an LT1. I'll move this to the LT1 forum.

maro z28

1.65 are the biggest ration RRs I've heard of for an LT1.

Hey Jonesy...nobody wins arguements with their wives, or girlfriends, or girls that are only friends, or female co-workers, or girls that once were our friends but........well, you get the point!