[laser-red-nova]

I'm running the chevy "hot cam" right now. For driveability and 15 inches of vacuum it is great. But I want a cam with more rumpy idle. I can't go over .490 lift because I have Vortec heads. So I need about 220 or 230 duration with under .490 lift and it must be a roller cam. Anybody have any ideas? I will be running a Leeds vacuum pump for vacuum.

 

[Stroker Ace Ventura]

*following

 

[67 canso sd]

Have you thought above working the heads a bit, it will open up a ton of options. When I did mine, i opened the ex up to 1.60 and opened the spring seats to accommodate larger springs and did screw in studs. The head work wasn’t all that bad $$ wise. Machine shop did valve seats and and spring seats, i did the rest, 110 lobe sep so a fair bit choppy idle. I can’t post video or sound clip. Unless someone can post for me. If you don’t want to mess with head work, looking for even more lump 108/107 lob sep, thats were it is, all in lobe sep. Sorry Didn’t look specs up for you cam..
This what im running

COMP Cams XR276HR Dyno Results - COMP Cams®

Dyno Results for Chevrolet 350 Small Block XR276HR Camshaft

www.compcams.com

 

[lwlevens]

^^^^^ Yep the lumpy sound you're looking for is in the Lobe separation angle (lsa). Stick with a 106,107,108

 

[67 canso sd]

Ahhh so many options.

Vortec Cylinder Heads Valve Lift - Tech Article - Chevy High Performance Magazine

Read Chevy High Performance magazine's technical article on modifying Chevrolet small-block Vortech cylinder heads.

www.motortrend.com

 

[67 canso sd]

Biggest thing with vortecs, although they “swirl” nice and flow nice..They need to breathe.. bigger ex valve…and minor porting… bam… you have a really nice head for cheap.

 

[dewers0820]

I'm running the chevy "hot cam" right now. For driveability and 15 inches of vacuum it is great. But I want a cam with more rumpy idle. I can't go over .490 lift because I have Vortec heads. So I need about 220 or 230 duration with under .490 lift and it must be a roller cam. Anybody have any ideas? I will be running a Leeds vacuum pump for vacuum.

any time you change your cam, you might need to change your converter and rear diff gears,

 

[laser-red-nova]

I already changed the springs and put screw in studs in. My cam has a lobe centerline of 112. Is that the same as lobe seperation?

 

[xMLMx]

You'll go down a dark hole if you want to select a cam for "sound at idle".

What compression does the car have? How important is power production to you? How about vaccuum? Usable engine speed?

Getting a car that sounds radical but runs like a dog because it has too much cam is... Well... Ill-advised.

 

[Stroker Ace Ventura]

You'll go down a dark hole if you want to select a cam for "sound at idle".

What compression does the car have? How important is power production to you? How about vaccuum? Usable engine speed?

Getting a car that sounds radical but runs like a dog because it has too much cam is... Well... Ill-advised.

TOOK THE WORDS RIGHT OUTTA MY MOUTH!

Lumpy cams are not necessarily good performers, they just sound scary... It's all in what your heads can flow and the compression/volumetric efficiency of the rest of your parts/RPM.

DO THE MATH!!!! You'll be far happier in the long run and your engine will too!!

 

[67WAGGONE]

I love my Voodoo Retro Roller from Lunati and would support it but the lift seem a little bit out of the ball park...

• Advertised Duration (Int/Exh): 262/270
• Duration @ .050 (Int/Exh): 211/219
• Gross Valve Lift (Int/Exh): .507/.515
• LSA/ICL: 112/106
• Valve Lash (Int/Exh): Hyd/Hyd
• RPM Range: 1600-5600

With my Hughes 25-2800 stall converter it really comes alive and matches well in the low to mid range.

 

[lwlevens]

Your hands are pretty much tied cause you can't go over .491 lift and .220 duration unless you change out the heads with bigger springs. You should change out the lifters with a new cam (but you do have roller lifters.) So don't know if it's really worth it for a lumpy idle. Unless you keep the specs of the cam you have now with a tighter lsa. What is the lsa on your cam now? It would say on your cam card.

 

[67 canso sd]

What is the duration on your cam, lsa? If you change the cam out you need to change out the lifters also. Look into thumper cams...all bark no bite.

You beat me to it, buddy just got his AC Cobra on the road last summer. 429 with a Mutha thumpr 107 lob sep. he just wants the bad ass sound at idle… especially with those leg burning side pipes and maybe blow some skirts up.

 

[67 canso sd]

I already changed the springs and put screw in studs in. My cam has a lobe centerline of 112. Is that the same as lobe seperation?

Did you cut down the valve guides? If you did then your cam options open up, or maybe not cut enough? Mine is .502/.510

 

[lwlevens]

This stupid [email protected]@ grid again

 

[lwlevens]

Easiest way to call summit or Jegs tell them what you got and did to the heads,cam specs, tell them what you want and they'll point you in the right direction.

 

[laser-red-nova]

To be clear. Sound is more important than power to me. The guides have already been cut, 90% of the time your car is rolling up to a car show and the sound is what I want. Power is down on my list. I'm not going to the drag strip with it.

 

[lwlevens]

Go with a thumper cam then that's what they're known for, stay around the same specs of your cam now, and you'll get that lopey idle.

 

[laser-red-nova]

All the "thumper " cams are over .500 lift. Can't use them. I know they sound good.

 

[Peewee0413]

If you're running vacuum for brakes, then go with 108 lsa. Why not get a custom grind or get new heads that can handle the lift.

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