Sd455 advice
 

Any input or ideas on a good choice for a cam for a SD 455 4 Speed? I am not going to run the SD oil pump. Past experience with HP pump is it likes to blow oil filter off the engine. Not a good time. I am thinking about the ram air IV cam but would like to hear from other SD owners

http://forums.maxperformanceinc.com/...play.php?f=419

Best answered here.

Buy a real filter they dont blow off

Fwiw.... I think the RAIV cam is a poor choice for a "stock" SD 455. A lot of power can be gained with some minor tweaking on the engine. Do a search there are a few good SD 455 build threads on this Website.

You don't need 80 psi on a Pontiac unless it's a 700 HP race car

They probably don't make the exact grind anymore but I loved the Comp280AH10. It was 237 intake and 243 exhaust (duration @ .050" lift) on a 110-LDA. Ran great on the street in my 455/6X head Trans-Am.

Shooting for about that, 60lb pump.

Flat cam or roller?.....

12.24 ET Signature (CompCam i think) Cam spec below works for 9.0:1. good Brakes but barely idles COLD.

Presuming a hyd flat I'd go with the Voodoo 704 and if valve springs are stock I'd upgrade them.
https://www.lunatipower.com/voodoo-h...8-276-284.html

A lot of questions need to be answered before a cam (that'd be worth a poop) can be recommended.

Are all other components staying stock?

All of the components in this build are original GM parts. No porting, or ANY modifications to the heads.

If you are leaving the heads completely stock, you will have (+/-) 111 cc chambers and (+/-) 8.4:1 compression. I would lean toward the 704 Voodoo to maximize performance from a low compression build.

If you are not opposed to milling the heads and the intake to match - understanding that those components will likely always be mated - you could gain about a half point of compression and make better use of cams with more seat timing.

I have been running a 80psi since 2012 it will go over 100 psi when cold just bumping the throttle and have never blown a filter apart. When I had my ram air IV with the same pump never blew one on it either.

Keep in mind the Voodoo 704 cam card says 281 @ .006 for the intake.
Jim Hand's Bullet cam had 285 @ .006 at 10:1 compression verified by CamDR.

The engine only needs what it needs for valve seat timing. Once you have that get the lift / area right.

The 041 cam has the power band too far up for street duty.. No bottom end, I had one in a 462, I had to run full timing, it was a pain in the a$$...

I would try the Super Duty #10 Mackellar cam. Its a solid. I would use Crowers lifters with it with the oiling slot.. For a hyd cam I would use the Nunzi 2041, the Summit 2801/2802 or the 068...

I still think the 041 cam would work well, but there are better cam profiles now....
 

I think you'll find that the SD455 will 'tolerate' being over-cammed a little and still make TONS of power throughout the power band.

Definitely DO NOT run the 068 cam. Not with the SD heads.

Choke, choke, choke.

Our SD455 TA has the HO higher-lift version of the 041 cam in it. I don't recall the specs exactly. I think it achieves about .520 lift with 1.5 rocker arms.

Older-built, well-worn engine with Tri-Y headers, full exhaust, 3.08 gears and T400 with stock convertor.

Daughter drove it to 13.95 @ 100.5 mph on Hoosier 10" slicks shifting at 4,500rpms (with the shifter in 'D").

Absolute tire-scorcher on the street.

When we rebuild the engine next time, we'll put in a bigger camshaft.

:3gears:

One other thing that needs to be considered here is the relationship of compression / cylinder pressure the motor has and then pumping out of Exh the motor needs to do which allows the motor to draw in greater levels of Intake air and fuel.

As reacall and may even have to this day the old HO racing info from 75 or 76 they found in there testing a near 90 hp gain from doing away with the stock SD455 traverse muffler and installing duel Exh.

If you are still running this type of muffler then screw the Cam change and up grade the Exh because even if HO racing only got a 60 hp gain in power that's way more then a Cam change will ever give you with the rest of that motor stock!


If you already have a good Exh system on the car then I would no go bigger then the stock Cam other then using a new one with added lift, or just installing high lift rockers to the stock 744 Cam.

If you go bigger in duration I would mill the heads .050" to get the motors compression up into the low 9s.

I wonder if Ken can comment on the Exh test I recall them doing back then?

Wow, sounds like a top pick. Can you estimate a 1/4 Mile ET, MPH for 3850 Lb?