Explain cams to me for my 305

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Apr 21, 2005 | 09:52 AM
  #1  
If there is a simple link or a thread I missed in my search then let me know. Otherwise...

I have an 86 Trans Am with a 305TPI and the only mods are intake and exhaust. I keep hearing people talk about putting in a new cam and whatnot. This is my daily driver so I want more power but I don't take it to the track or anything. Gas mileage is important too so hopefully this won't make it worse. Basically what are my options, how hard to install (how much should I expect to pay), etc. Thanks!!!
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Apr 23, 2005 | 04:18 PM
  #2  
Camshafts have been described as the brain of the engine. They basically open and close the intake and exhaust valves in relation to the different strokes of the pistons. To install a camshaft involves removing the engine from the car. You need specialized training to even attempt this. The main components of a camshaft are lift, duration and lobe separation angle. This link will explain these for you:

http://www.holley.com/HiOctn/TechSer.../IECCTech.html

Two of the industry leaders in camshaft manufactures are Comp Cams and Crane; however, there are others. GM Performance Products makes cams you could use. Here is a link to Comp Cams that will provide you with a choice of cams and what they will do in terms of engine operations i.e. torque, horsepower, fuel economy and idling:

http://www.compcams.com/Technical/Cu...ML/128-169.asp

Once you have a basic understanding of what camshafts do, their components, how they affect engine operations and what you want your camshaft to do it is time to consult a good auto mechanic.
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Apr 23, 2005 | 04:22 PM
  #3  
Quote:
Originally posted by BC GTA
To install a camshaft involves removing the engine from the car. You need specialized training to even attempt this.
No it doesn't, and no you don't.
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Apr 23, 2005 | 04:33 PM
  #4  
i think you can remove the front bumper, radiator and stuff like that to intall a cam ....i seen it done before with the motor still in the car
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Apr 23, 2005 | 04:38 PM
  #5  
Please explain how you would remove the camshaft without pulling the engine from the car. The camshaft comes out the front of the engine and it would be hard to get it out with the engine still in the car. Otherwise you would need to disassemble the front end, remove radiator and try to pull it out from the front.

To install a camshaft correctly would require knowledge of the four stoke internal combustion engine, degreeing in the camshaft, knowledge of how this relates to top dead center and bottom dead center. I would call that relatively specialized training. Not something anyone could attempt.
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Apr 23, 2005 | 04:46 PM
  #6  
Quote:
Originally posted by BC GTA
Please explain how you would remove the camshaft without pulling the engine from the car. The camshaft comes out the front of the engine and it would be hard to get it out with the engine still in the car. Otherwise you would need to disassemble the front end, remove radiator and try to pull it out from the front.

To install a camshaft correctly would require knowledge of the four stoke internal combustion engine, degreeing in the camshaft, knowledge of how this relates to top dead center and bottom dead center. I would call that relatively specialized training. Not something anyone could attempt.
Uh, do a search. You will find a few threads with really in-depth discussions into the matter. To sum up all that was said, you have to remove the radiator and undo the top bolts of those two arms that form an x in front of the rad. That's it.
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Apr 23, 2005 | 04:51 PM
  #7  
Nope. Rad has to be removed along with condenser positioned out of the way. The X in front of the rad may have to be let go, no big deal. Bumper can say. Engine does not need to be pulled at all.

The only knowledge required is which way to losen and tighten bolts. If you can handle that then a cam change is only a little harder.
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May 4, 2005 | 12:36 AM
  #8  
I'm really torn as to whether I want to attempt this. I found an L98 cam for $20 so I may bite the bullet. I also found a running 350 donor firebird for $300 so that may be worth the extra effort.
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May 4, 2005 | 07:35 PM
  #9  
Go with the donor car. Changing the cam involves pulling the intake(ALL), water pump, crank pully, timing cover, timing chain, radiator, cross-brace, condensor, and alot of time.

Daily driver and you want gas mileage, i wouldnt worry about the cam. Do more bolt ons. A set of 1.6 rockers can yeild you some gains for the price of a cam. With your .350i .385e cam with some 1.6 rockers you can get some around .400i 430e valve lift.

Good luck

Brian

(i dont know the lobe lift so i dont know the exact number) If you know the lobe lift then heres the formula:

Formula: valve lift = lobe lift x rocker ratio.
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May 4, 2005 | 09:48 PM
  #10  
yeah... dont forget you ALSO need to loosen the oil pan bolts to be able to remove the timing cover.
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May 4, 2005 | 10:41 PM
  #11  
Knew there was something there being forgot. Thanks KillJoy.
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May 4, 2005 | 10:45 PM
  #12  
Its not a bad job, and degreeing the cam is more preference than necessity on a mild cam in a stock engine anyway. Pull the old one, stab the new one, drive away.

And I wouldnt think of pulling the engine to swap a cam.
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