has anyone ever run this big of a HR on a stock bottom end:
TN-239XR 239/245 duration, .577"/.576", 112lsa
with ported LT1 heads and a 3800 stall of course
im not worried about streetablity
jesse

 

That cam is probably too big for the LT1 heads. It's going to want to peak after the LT1 heads run out of air. Even then, the stock bottom end isn't going to hold up too well, since the cam is going to peak very high.

 

anybody know where it would peak?

 

No one will know how good it is until it is tried...

You should run a rev kit to get it to make power up real high where it should though...

But would i run that cam in a stock bottom end lt1... no.

 

i saw a couple of dyno graph of the 236/242 on ported heads/stock bottom end and they peaked around 6200 and 6400. does anybody know what springs will this take? i have comp r lifters already.....thanks for the input.
jesse

 

And i bet you they would peak higher and make more power if a rev kit was used.

My xe 230/236 peaked at 6400 without a rev kit. A larger 236/242 shouldnt peak lower than my smaller cam...

It will be hard for a hyd roller setup to make power where it should (high 6k) with a large cam without real large springs (which arent great since you can collapse the lifter) or a rev kit.

 

Jesse you need to talk with either dave (my dave), or joe overton. Give them the specs on your heads, the set up, and let them get your cam for you. I know dave has run a few 240/250 hydo rollers in 383 cars, but not sure what he would say for a 350.

dave can be reached via http://www.lt1dave.com

joe can be reached
http://hometown.aol.com/one94ta2try/...age/index.html

 

That's not huge in a 350, if the tuning is there & the topend works well together as a package... not huge at all. Noticeable, will probably surge below 1700rpm or so.. but that isnt a big deal really unless you just like to lug your stuff for the heck of it. Methinks it'd peak in the 6700ish range, but that can be manipulated a bit either way.

 

You can't just compare grinds by duration alone, The XE grinds have large .05 durations compared to there .006 because of the aggressive lobes. They will float sooner and peak lower than older grinds with less aggressive ramp rates.

I totally agree with atljar though, talk to someone like Joe, Dave, Bret Bauer, or Phil^ who can optimize the cam to your ported heads.

-brent

 

Joe's cam smooth as my old LPE cam but pulls harder than the 847 best of both worlds

 

sent you some email phil

 

I know this isn't what you're looking for, but I just installed a 233/239 in my car. It has close lift numbers to the cam you're looking at and I just used Combo's 612 springs, locks and retainers.... with comp R lifters.

 

thanks madwolf, im not sure of the PN of my springs all i know is they are good to 0.600 lift and are dual springs......i need to send lloyd an email......
Jesse

 

Those springs should work just fine.

 

i hope so, last time i tried to change springs, i dropped a valve end up getting the heads done....so it all worked out good....
Jesse