here's a stock cam dyno graph, no idea why you wind it out to 6k



here's a gm847 stock heads dyno graph

 

i did alot of playing arund a few years ago with a stock lt1 at the 1/8 mile drag arund here and it seemed to like +1 in 1st +2 in 2nd and left 3rd and 4th alone and it gained me 2 tenths and every other combo never saw anything higher of a gain than that. reving it up past 5800rpm always netted a slower time at the track no matter what kinda tune or where the shift points were. That tells me power stops in the 55-58 area. But this is just MY experiance with a 1995 lt1 with stock CAM<HEADS<INTAKE

 

Thanks for the graph MYLTWON cause it looks like right about 56-5800 it stops making power. And spining it any higher is just asking for spun bearings and broken rod bolts to me.

 

I thought the consensus said 6300-6400 was safe for a stock short block. I agree with the bone stock graph falling off around 5500 because mine did too. After adding the 7/16 studs, 1.7's, guide plates and good springs I was able to get another 300-400 rpm in the upper range. I do know that shifting my car at 5600-5700 rpm nets me 13's at the strip. I'll stick with my 12.82 @ 3900# shifting a little higher.

 

well you acted suprised when I stated that but you were comparing apples to oranges, a .507/.520 lift isn't very far off lift wise from some of the smaller aftermarket cams.

6300-6400rpm may be safe for some but it's really a case by case basis and there's no real truth about it being 100% safe. my old motor had rod bolt stretch with a cc503 setup that shifted under that limit. these motor's were not built with the rpms people take them to in mind, add into that natural wear and tear from age along with the possibility of neglected maintenance and a hard life, its hard to tell what a motor can take. Excessive rpms is one of the biggest killers of motors.

 

FWIW i did a bunch of pulls on my stock bottom end lt1 on the dyno up to 6800 rpms with no problems. By a bunch i mean at least 30-40 pulls

 

no one is saying it's gonna sling a rod or develop a knock just because you did it once or even a few times. all that is being said is that when using a motor with 14-18 year-old rod/main bolts of "good enough" quality, on balancing job that is not unique to the motor, with God knows how many miles, years of abuse and neglect, you shouldn't be suprised if you rev it to the moon with some decent regularity and something bad actually happens.

 

alright so ill just rip her to 7k and report back

 

probably would have been better for me to say my 210xxx stock bottom end lt1 block

 

that's a great testament to longevity, but it's still a crap shoot. my cam only setup stretched a rod bolt only being revved to 6200-6300rpm for a year or so at 140k miles.

 

i had one motor last 200 miles at 6500rpm with 186k and another 5 months with 6800rpm and 60k on it. Im just trying to help someone else not loose there engine is all im doing