[Malibu73]

Just wondering because I'm about to buy it for my sbc 350 (bored .030 over so it'll be a 355).

How does it sound? How's the RPM range? How's the power?

I know it'll be different because of people's different intakes etc...

But I'll be using an Edelbrock Performer intake.

[bracketeer]

Most hotrodders I have seen here sway more to the Comp XE cams. I have used the XE268H and was happy with it. But I buy strickly Crane Cams these days.

[Malibu73]

Yeah, I was looking at that one also, but was told the 270H was better for power steering and power brakes. This is in a street car by the way.

The diff. between the 268H and the 270H is like 6 in the lift. The 268H is 218 and the 270H is 224....

[killerformula]

Originally Posted by Malibu73

The diff. between the 268H and the 270H is like 6 in the lift. The 268H is 218 and the 270H is 224....

Those are duration numbers you're comparing.

K

[Derkyb]

Between myself, dad, brother, uncle, and cousin we have run the 256 -268's comp XE cams in 283-355ci engines and all have seen the same results. They have very crisp throttle response and excellent low end torque with respectable top end, however they dont have that snappity snap sound at idle but when you step down on it they sure do make some noise. I decided to try something different in my 496 and went with a 292 magnum and it sounds like a pro stocker at idle havent tried it on the street yet though. If you want more sound at idle id say go with the magnum if you want a good all around street cam go wit the 270 XE IMO.

[Velyx21]

I have the 292, in my 327 O_O its pretty wicked.. need high comp and good heads, and a good stal for it tho. but i like its powerband

[strikingthematch]

I have the 270 mag. in my 355.
Engine runs great.
It really picks up power above 2500 rpms but the idle is good.
It is noticable but not even close to dieing.
I idle at 900 rpms and have no trouble dirivng the car. All power opt. (steering, brakes) work just fine.

I will say though I only have a 1200 stall and would suggest a higher one along the lines of 2000 depending on your gearing. (mine is stock 2.73) It really likes to sit above that 2000 rpms mark to make power now this is with heads made for 1800 and above flow so each set up will be diffrent. The 270 is suppose to be the biggest cam you can put in with a stock conv.

I have headers/intake so all that was taken care of. How this cam would be on a bone stock engine I can't really say. But it does work very well for me.

Chris

[Malibu73]

Originally Posted by killerformula

Those are duration numbers you're comparing.

K

D'oh, that's what I meant


Thanks for the input you guys; a little info about what the engine will have:

Comp Cam 270H Magnum
Edelbrock Performer Intake
HEI Ignition
Quadrojet Carb
Roller Rockers
Comp Roller timing chain
Hydraulic Lifters
Short-tube headers custom fit for ’73 Malibu Sedan
2-Bolt Mains
HV Oil Pump
Bored .030 over
Stock torque converter
Rebuilt Turbo350 tranny innit (700R4 going in later)
2.5" Dual Magnaflow exhaust system.
Balanced Crankshaft



I think the gears are still stock, and we'll be using the stock TQ converter. That's one reason this cam caught my eye, you can still use your stock
converter with it.


Edit - Specs on Cam:

Intake Exhaust
Valve Adjustment 0 0
Gross Valve Lift 0.47 0.47
Duration At 0.006 Tappet Lift 270 270

Valve Timing At 0.006
Open Close
Intake 29 61
Exhaust 69 21

These Specs Are For The Cam Installed At 106 Intake CL
Intake Exhaust
Duration At 0.05 224 224
Lobe Lift 0.313 0.313
Lobe Separation 110

[GoneNova/406]

if you're looking for perf. and sound use 1.6 rockers with the 270 mag.i have the 280 in a 406 and the 1.6 and it sounds and runs good in a very heavy vehichle.

[baddbob]

What heads are you running? What pistons? What is the static compression ratio? This cam will need 9.5 - 10.1 compression to have any decent off idle power IMO. If you're running dished pistons and large chamber heads it'll be overcammed by far. The cam must match the compression ratio for good overall power. If you get it right a good pump gas street engine will pump 150-180psi of cranking compression. If too much cam the cranking compression will be low and so will low rpm power. Consider using steel shim headgaskets on your rebuild- jegs and summit sell them for dirt cheap.

[Malibu73]

Originally Posted by GoneNova/406

if you're looking for perf. and sound use 1.6 rockers with the 270 mag.i have the 280 in a 406 and the 1.6 and it sounds and runs good in a very heavy vehichle.

I'm pretty sure they're 1.6 rockers, i'm not certain though.


baddbob

I will try to find out that information

[Malibu73]

Hey all, just found out the size of the valves. Their 2.02/1.94. We think the rockers are 1.6 also, but I'll know the size of the heads/rockers for sure tomorrow.

[Malibu73]

Those are the valve sizes, our machinist just got done boring our block .030 over and just received the pistons he ordered.

He's going to measure the combustion chamber CC's and tell me in a few days when he's done grinding the valves so I can figure out the CR.

It's gettin' done

[Malibu73]

Are those weird valve sizes for sbc? 2.02/1.94?

[Malibu73]

Actually the valves are probably 2.02/1.60. The new pistons are dished from Sterling, and the heads are GM.