SR71BLKBRD

iTrader: (1)

Hey guys quick question. I know generally the lobe seperation is what give you the lope in a cam but im curious if the cubic inches of a motor can change the sound a cam would have? For ex: does the same cam sound the same in a 350 as it does a 383?

Im looking for what my cam would sound like and there is a post of my cam at idle in a 355. the vehicle also has shortys and a different muffler. Should I expect the same overall sound as the 355 to my 383? I know the longtubes and the Borla will help but im just curious if ci does in fact change the sound?

my cam is on a 112 lobe sep and it sounded rather tame in the 355 then I searched and I found a cam with a 113 lobe sep with just a hair more lift than my cam with the 1.6's and it sounded noticeably more stout. As well as a lt4 hotcam which has similar specs to my lunati 60121 but it also sounded a bit more stout.
just trying to figure out what I should expect. Thanks in advance!

AlkyIROC

Larger engines can take a more aggressive cam. A cam that would be considered radical in something like a 305 may be more of a hot performance cam in something like a 406/434.

Cams with low lift rates can be loppy with a low LSA of 106 or 108. My BBC cam has over 0.800" lift but the LSA is only 114. Duration is under 300 @ 0.050". It idles very smoothly at 1200 rpm and doesn't have that loud crack sound in the exhaust like from a cam with a low LSA.

There are so many variables to a camshaft. You can have 2 cams with the exact same lift, duration and LSA but the valve timing is different and they'll perform differently. Even if all the numbers are the same, different cam grinders may change the area under the curve and they'll perform differently.

SR71BLKBRD

iTrader: (1)

From what I can see the cams seem to be almost the same until I look at the timing aspects of them.
the cam card for mine
lunati 60121
http://www.lunatipower.com/CamSpecCa...rtNumber=60121
and heres the video I referenced.

heres the cam I compared it to
Comp XFI268
http://www.compcams.com/Company/CC/c...csid=1110&sb=0

and the video I mentioned where it sounded a bit healthier.

Could the difference just be in the exhaust and im just thinking too much into it?

OrangeBird

iTrader: (1)

Since those two videos were made with two different video cameras of course the sound is going to be different between the two , even if the two cameras were recording the same car . Two different cars videoed with two different cameras will never sound the same whether they have the same camshaft or not .

UltRoadWarrior9

I could be wrong, but I think the OP is talking more about the 'rhythm' of the sound, not necessarily the frequencies involved like you are trying to point out.

Orr89RocZ

iTrader: (20)

Yes a given cam will sound different in 2 different motors. The different cube motors draw on the intake port differently and require different valve events to gain max potential out of a head port.

More importantly tho, small cube motors pass less air per revolution than a large cube motor. More volume generally means different sound.

Night rider327

iTrader: (13)

The rough, uneven, choppy sound comes from the cam's overlap. The overlap is where both intake and exhaust valves are open at the same time.

The overlap is longer (rougher sound) when the LSA is smaller or when duration is larger.

Yes the CID of the engine will change the sound. A mild sounding (and acting) cam in a 350 will be tame in a 383, but will be radical in a 305.

Also the compression ratio will change the sound. Higher compression, the more aggressive the engine will sound.

OrangeBird

iTrader: (1)

You very well may be right , since usually when folks talk about how a cam "sounds" it's the lope or gallop sound they are talking about , but then when he was mentioning longtubes and a Borla muffler I took that as more of the exhaust growl rather than the bounciness of the running .

SR71BLKBRD

iTrader: (1)

Thanks for the imput guys I appreciate it. Well the growl and rasp Is why I kept the Borla but I did mean the rhythm of the cam. I did take the two different cameras into account but they both seem pretty decent the cam shot with the lunati it picked up some background noise and still sounded pretty good. So it is safe to say the cam in the 355 from the first video is going to sound a bit more tame in my 383 :/
womp. I hope the exhaust makes up for it.

86LG4Bird

iTrader: (1)

You cannot go by what you hear in a video, or even what you hear live. The biggest reason for the differences will be the tune. Not exhaust. Not audio quality.
I have two L31 Vortecs, 350 ci, both with ZZ4 cams in two differenct vehicles.
The one with the fuel injection, tuned by me, has headers, throatier exhaust, and you could mistake it for a stock cam.
The one with the stock CCC carb and HEI distributor still runs exhaust manifolds and a quiet-ish Magnaflow muffler. At idle it sounds like it has some kind of wicked cam in it. And it's all because of the limited tuneabilty I have with the carb and timing curve. I expect it to change after Cliff Ruggles does his magic on the carb to work better with the reduced manifold vacuum of that cam.