Hey guys,
when I bought my car, the previous owner gave me a cam shaft along with the car.

I'm not great with and am still learning the internals of engines...
how's this look/sound?

 

i dont know much about lift and duration but from the specs on that sheet id say its gonna give you a good amount of more power. the lift and duration are more than stock cams so you will most deffinitly feel a big difference.

 

alright thanks for the info,
would this much of a change without changing out any other parts cause the engine life to decrease?

 

That's a huge duration and you'll lose a good bit on the bottom end for your top end hp output. The higher the duration the lower your compression becomes in the low RPM's due to the intake valve staying open longer. So you might have a static compression ratio of 9:1 but when the car cranks it's actually lowering the compression due to intake staying open. That's what the ABDC stands for up there in your cam specs. The higher that number the more compression you lose. Here's a little deal to help you understand more:
The chart shows how timing the intake closing affects compression ratio.

Degrees Closing After Bottom Dead Center (ABDC)<<<<<<<<<<>>>>>>>>>>Subtract from static ratio

_________________________20----------------------------------------1.2

_________________________30----------------------------------------2.2

_________________________40----------------------------------------3.1

_________________________50----------------------------------------4.1

_________________________60----------------------------------------4.9


So if you have a static compression ratio of 9.1 in your car now with that cam's 40* ABDC then you'll lose around 3.1 for a total of 6.1. You want to stay in the 7.5 - 8.25 (Dynamic Compression Ratio (DCR)) range for pump gas and good performace from what I understand.

Remember, this is only a suggested guideline. There are many combinations out there that can throw this right out the window. I have a friend running a 10 second 72 Camaro with a static timing of 36* (rivited weights with no vacuum advance) and around 11.5:1 compression ratio running on pump gas that he drives daily.

I have a simlar camshaft with .480/.480 lift with 280 adv. duration (comp cams 280h) but I run 1.6 full roller rockers to give me a lift of .512/.512. With my ABDC of 66 I'm losing a lot of compression and have to make it up in the combustion chamber with better than stock heads.

Are you using the stock stamped rockers? What year is the engine also? You will also need to check and see if your springs and valvetrain will support that lift. Some stock valvetrains will support up to a .480 lift but it would be best to take measurments to ensure that everything will work. You want atleast a .060 gap in the springs at full compression (lift).

You can't just shove a cam in the engine as there are a lot of tolerances that you need to take in mind. Put too powerful springs in there and they'll slam the valves into the seats, tearing up the seat and the valve. Put in too weak of springs and you'll get valve flutter where the springs don't have enough strength to close the valves before their next cycle. Then there's pushrod lengths, rocker arm clearances, lifter preloads, etc.

 

im not sure about specifics,
could i find a manufacture date on the block?

 

Has the engine ever been changed in your vehicle? If not what year is it. ;p

You can check out these two pages to put you in the ballpark:

http://www.nastyz28.com/sbchevy/sblock.php
http://www.nastyz28.com/chevy-engine-code-stampings.php

 

you see, i'm not sure if it's been replaced cuz i just bought her about a month ago
but thanks for the links i'll check it out n tell you guys