Hello everyone,
I previously had a RCSB with a 4.8 and went with a chopacabra cam and that was purely for CHOP!. Welll long story short I have another truck (RCLB 4.8) and wanted to know if the Hawks Sinister cam is too crazy of a cam for a 4.8 it is a car cam (ls1) at the end of the day. Specs are 230/236 .600"/.600" 112+4 LSA. I plan on keeping the SBE, & hand porting & decking the heads.

 

If your gears are LOW enough, and your stall is HIGH enough, the short stroke mouse motor will be plenty happy.
My wild-as guesstimate says the 4.8 with 230/236 is crying for 4.56 gears and 3600+ stall

 

If you plan on 11:1+ compression, 4.56 gears and 4500 stall, then sure go for it. Still pointless though unless you're running nitrous or boost. It's pretty proven that around 220* intake is max needed to squeeze all the power you'll get out of a 4.8L N/A. Basically you're just killing driveability and both low/midrange torque, with zero benefit in peak power.

For example, Summit's SUM-8720R1 218/227 .600/.600" 112+2 made same power as a whole host of much larger camshafts in a 4.8L. (Note: Ignore the title, all testing is without boost).

 

^^ echoing the above: will it run? sure. is it overkill? probably.

case-in-point: my builder, with concurrence from BTR, recommended a 231/248 cam for my little LS1 (originally speced for a high-effort 6.2). what saves its drivability in my car is its wide LSA (120°+5) maintaining compression... that and pushing 13psi through it.
even then, there was a marked decrease in sub-2500rpm torque (even in my little 3400lb car), but it carries through to 7000 now instead of falling off above 5500.

 

oh yeah... and you'll need to do dynamic compression calculations to see how much more static compression bump you'll need to maintain cylinder pressure.

going from stock 853s (10.1:1 SCR) & 2000 LS1 cam to the bump stick above with ported 243s (10.6:1 SCR), i've still got slightly lower cylinder pressure now despite pushing 2psi more boost.

 

Big heavy trucks like 8psi from a turbo.

big heavy trucks dont like big cams.

 

a big cam is okay so long as you've got a loose converter & plenty of gear so that you start everything from a mid-range rpm.

 

Or instant boost from a supercharger.

 

bigger isnt always better. It has been a long time since I've paid attention to the 4.8 world, but I remember it always responded amazing to a TR220 cam. some of the best N/A and nitrous 4.8 times were using it and it wasn't a nightmare to tune and drive.

 

OP,

We'll echo what others have stated. Big cams and loud pipes sound cool but not so great for driveability. We like what @68Formula suggested. Our SUM-8720R1 cam is a good fit for this combo and goals. The Holdener video of it in a 4.8 that 68Formula posted shows it maintaining the same peak power as most 22X cams. The bonus is the 8720R1 makes more torque across the range than most of those other cams. Pair it with our .600" lift beehives and it'll be happy out to 6,500+. This will have good driveability in a 4.8 even with stock gears and a converter. A 2,500+ stall converter and some 3.73+ gears would really help bring the truck to life and get the most out of the cam.

It'll have a nice steady lope to it. Regarding "lope". You can make any cam lope. It's all in the tune. Here's an example idle video of the 8720R1 in a 4.8.