quote:Originally posted by Push1267:
Guys - Thanks for your input. That's really useful.
I'm not looking for all out max power and 7000 rpms, I still wan't it to be streetable. With the current cam, although it's a bit rough, it's actually very streetable and idles nicely in the 1000-1200 rpm range.
It seems from your comments that a single plane, or the price 2x4 set-up (which indeed seems like a nice set-up - and expensive) wouldn't hurt the low-end too much, but move the power-band up and increase top-end while still maintaning reasonable good street manners.
A ported victor jr with a QF 830 may be the way to go then, as the super victor is too tall to fit under the screen.
Regarding the heads, it's possible that they are limiting for a 427?. These are the flow numbers for the heads: Cam lift is about .600 in/ex.
Flow in CFM
.050 in 26.5 ex 24.0
.100 in 60.0 ex 52.0
.200 in 116.0 ex102.0
.300 in 168.0 ex134.0
.400 in 217.0 ex172.0
.500 in 260.0 ex181.0
.600 in 292.0 ex190.0
.700 in 305.0 ex200.0
Hi Kristian,
The challenge with the big stroker is that heads become the bottleneck. If you look at the port and valve sizes of 427's and 429cj's of the time there's a huge difference. I appreciate there are many aspects to this comparison, which are not ideal, but big bore, short stroke and big valve heads help the engine to hang on past peak with smaller cam.
You have a Windsor head, which limits options. You can do only so much before getting into the cam, but anything that helps the intake side would be good.
Easiest trial that can make a noticeable difference is the intake. You may change the carb if you like, but you can get a good idea just changing the intake. That may be just what you are looking for.
You could also get AFR225's. You would make noticeably more power everywhere, but still would not make a major difference in rev range. You already have a 2.08 valve (vs.2.1" of that AFR, less than 1mm difference), and if the valve curtain area goes to sonic choke, you need to begin changing lift and duration to make a difference in range.
You could talk to someone like Mike Jones (jonescams) to get a custom hydro roller that does what you want, without going miserable at part throttle.