Ok,, Rpms vs Procomp Vicotor js,vs indy??

Ok,, Rpms vs Procomp Vicotor js,vs indy?? - 10/07/12 03:47 PM

I have ran , RPM , vs stock heads, My friends have run (still does) rpms, and a set of the Pro comp victor jr knock offs, full cnc port job, flow of @ 340s350s @620lift, the rpms flowed 291,
my question is, I have watch him switch heads off the same motor, put 1.6 rockers instead of the 1.5 and saw no pick up??
I have RPM heads now but will be building a 500 cu over winter,,
he has ran a 500 cu with both sets of heads with no improvement,
why would I switch heads if there is no pick up to be had with set of $2200 and bigger rockers at cos of $400??
Is there enough pickup in say the Indys over other such heads???
Knowing that Indy heads would be over 3 grand!! is there enough pick up to justify??
My thinking now is no , unless I want to push the RPM of the motor thru the roof??

Posted By: MoparBilly

Re: Ok,, Rpms vs Procomp Vicotor js,vs indy?? - 10/07/12 04:09 PM

Dennis,
What are you looking for? Why are you building a 500, was the current shortblock not good enough? The application, intended use, and goals for a combination have as much to do with head selection as flow numbers.

Attached picture 7410657-Dale04.jpg

Posted By: Big Squeeze

Re: Ok,, Rpms vs Procomp Vicotor js,vs indy?? - 10/07/12 05:53 PM

Quote:

I have ran , RPM , vs stock heads, My friends have run (still does) rpms, and a set of the Pro comp victor jr knock offs, full cnc port job, flow of @ 340s350s @620lift, the rpms flowed 291,
my question is, I have watch him switch heads off the same motor, put 1.6 rockers instead of the 1.5 and saw no pick up??
I have RPM heads now but will be building a 500 cu over winter,,
he has ran a 500 cu with both sets of heads with no improvement,
why would I switch heads if there is no pick up to be had with set of $2200 and bigger rockers at cos of $400??
Is there enough pickup in say the Indys over other such heads???
Knowing that Indy heads would be over 3 grand!! is there enough pick up to justify??
My thinking now is no , unless I want to push the RPM of the motor thru the roof??

Like Billy, said, what do you want to do? Whats your car run now and how much quicker do you want to go? What's your current buildup??

By your post its obvious you have a lot to learn and there's a lot of good info and smart people on this site....as you've figured out, bigger isn't always better and going to a higher ratio rocker doesn't mean an instant power increase...

Posted By: dennismopar73

Re: Ok,, Rpms vs Procomp Vicotor js,vs indy?? - 10/07/12 07:08 PM

Quote:

Dennis,
What are you looking for? Why are you building a 500, was the current shortblock not good enough? The application, intended use, and goals for a combination have as much to do with head selection as flow numbers.

Sorry for the confusion!
Well my current set up is a 383 w 440 crank rod rpms (otb) have been flowed @ 292 at 600, , 12.5 c, stx21 w.1.5 rockers,
456 geared 5200 vert (ta),on alcohol,
runs currently 6.70 1/8 @ 103.4 mph 1.423 60, (no 1/4 passes as yet)
I am down on cubic inchs , and as this combo is a rather old tec build up (1977pistons) Runs great , just want to get into the 9s ,
I want to build a 500cu motor over winter, but was looking at upgrading heads, .
I have been observing some of my friends combos, mainly their choice of heads, , trying to figure what is the better head to go with ,After seeing a couple combos in use, and saw that they had changed heads, from RPM to a Pro comp style Victor jr head , saw that they was not much of any pick up, over the same set of heads I now have, would the Indy heads be any better for a 500cu, ???