Quote:
Originally Posted by big_G
The question I would ask is how much wheel spin do you get on the launch? If a lot, then a bigger cam can only help. You can stand to lose a touch of low end grunt, in exchange for more pull down-track. If you have little to no wheel spin..you would need a higher stall converter with a bigger cam.
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I don't spin at all on just engine. Even when launching off the transbrake. My 60ft is usually in the mid 1.5 range. It will occasionally spin on the 150 shot but only if the posi doesn't hook. That's only happened around 3 or 4 times. Most of the time it hooks and I usually pull mid 1.4 60ft times. This is launching off the foot brake and activating the nitrous at full throttle.
Quote:
Originally Posted by enkeivette
Don't know BBCs, but that duration is close to mine. Since you only have RPM heads, nothing too big, I don't see a reson to go crazy with the cam. You may just be giving up low end power for high rpm power that you'll just never see if you're not spending most of your time in the 7-8K range.
If you want to do it right, have that head ported and then go with a bigger cam to match. I can shoot you a desktop dyno program if you want to play around, it's helpful if you can find the flow figures for those heads at different lift points.
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These are the big rectangular ports with 315cc intake runners. The operating range according to Edelbrock is 2500-7000. Here's the info from Edelbrocks website including flow numbers. Remember that these numbers were before I ported the exhaust.
Highly-efficient 118cc open-style combustion chamber
High-velocity 315cc long/300cc short intake ports
Smaller-than-stock 11/32" valve stems promote excellent flow and lighter valve weight
Performer heads include drilled heat cross-over
Cylinder Head Specifications
Combustion chamber volume 118cc
Intake runner volume 315cc
Exhaust runner volume 110cc
Intake valve diameter 2.19"
Exhaust valve diameter 1.88"
Valve stem diameter 11/32"
Valve guides Manganese bronze
Deck thickness 9/16"
Valve spring diameter 1.55"
Valve spring maximum lift .700"
Rocker stud 7/16"
Guideplate Hardened steel
Pushrod diameter 3/8"
Valve angle 26°
Exhaust port location Stock
Spark plug fitment 14mm x 3/4 reach, gasket seat
Made In USA
Technical Notes: Bare heads will have valve guides & seats installed, but will require final sizing & a valve job to match the valves you will be using. Recommended spark plugs 14mm x 3/4" reach with flat gasket seat (Champion RC12YC).
Description Bare Complete
Performer RPM 454-R 60549* 60559*
Flow Numbers as tested by Edelbrock's SuperFlo SF-1020 flow bench @ 28" H2O #60559
Valve Lift / Int. / Ex.
.100 / 76 / 70
.200 / 146 / 132
.300 / 212 / 156
.400 / 255 / 181
.500 / 294 / 207
.600 / 314 / 228
I don't want to go crazy with a huge cam. My current cam pulls good to 6500 but I think the way the rest of engine is set up that I would benefit from a cam that pulled to 7000. When I dyno'd my car a few years ago when I first built the 454 it made peak torque below the 3000 starting point of the pull. That was when I had a little tighter converter that flashed to 3000. The one I have now flashes to 3600. I think a cam that makes it's peak around 4000 would wake the car up more.