alright so im asking yet another question about my build and the cam, im going to use the stock bottom end assuming there isnt anything wrong with it when we look at it, im looking at different cams and im noticing that they all have recommended rpm ranges... im wondering how high can i safely push a stock bottom end? obviously i want to get a cam that i can fully use hopefully without ruining stuff down the line. thanks

 

you're going to get a bunch of opinions because there is no set line. Some hold till 6600 (rare) and some go at 6000. I spin my stock bottom end to 6300 and it's held up since i was rebuilt in 2006, but i've only put 9000 miles on it since then.

 

how many miles?
Are you going to do heads too?
Budget?
what can you live with driveability wise? is it a dd?

 

the most important part is making all your components work together

the questions above are very important, and also what are you doing about heads, stock - ported stock - aftermarket - ported aftermarket?

what exact other parts will you be using - everything is important here. for a mild build you should be able to get by with a off the shelf grind, but you also might want to consider having a custom cam grinded for your exact set up and what you want to do with it

 

Stock motor 6100 for 9+ years.

 

slowmarao; its just under 126xxx .. was a dd going to be a weekend ride, my budget is around $4000... and slowly going up, heads will be ported and polished+ valve job.. getting 1.6rr, spring recommendation?? ... new lifters, pushrods, 32lb injectors (to be ready for future modding), Pacesetter LT's, ORY, cat delete, cutout, 3000 stall/w lockup.... probably missing something here...

 

Comp cams for instance lists VERY VERY wrong rpm ranges. They assume a gen 1 carbed dual plane intake and in doing so their rpm ranges are all listed at least 500rpms lower than reality. So even once you decide how high to spin you will have to ask a few more questions here to see what the REAL rpm range of a given cam is. Now if you are looking at LT1 specialist's cams then the rpm ranges should be accurate.

If looking at the forums for dyno charts be aware things like ported heads or header selection also influence rpm range. A cam only motor with a certain cam might peak at 6100rpms but give it good ported heads and it might suddenly peak at 6400 and make good power well above that yet.

Far as safe rpms most of us get away with 6500, a loose rule for you then would be keep the duration mid 220s or lower on the intake.