Cam Help

[nj85z28]

Ok, now make fun of me all you want, but motor work makes me nervous. now every place ive asked about TBI performance, i hear the same thing-camshaft. now the question is, how much of a pain in the ass is it to change the camshaft w/o totally messing something up. the car is a 89 RS 305 TBI. (btw, if anyone can help me, give me advice or any help will be greatly appreciated)

[Koll]

Ok, now make fun of me all you want, but motor work makes me nervous. now every place ive asked about TBI performance, i hear the same thing-camshaft. now the question is, how much of a pain in the ass is it to change the camshaft w/o totally messing something up. the car is a 89 RS 305 TBI. (btw, if anyone can help me, give me advice or any help will be greatly appreciated)

1) Take off intake.
2) Take out lifters
3) Pull out cam
4) Insert new Cam
5) Replace Lifters
6) ....
7) Profit!

[camaro2you]

thats pretty much it, take off timing chain cover and timing chain

[Tru2Chevy]

You'll have to take off the valve covers and loosen the rockers too, then re-set valve lash when you are done.

It's pretty easy, and if things go smoothly you could get it done in an afternoon.

- Justin

[deadtrend1]

a haynes manual is pretty dead on when removing and installing the cam. Follow that, and other questions can be posted here.

Make sure you change your springs if you change a cam. I didnt and about a month later it just crapped out on me.

[NJSPEEDER]

it is really easy. when teh time comes there are more than a few of us here that have done teh swap before. just give us a shout and we will be gald to lend a hand. the usual labor rate applies, a 6poack each and some cheese burgers :P

later
tim

[nj85z28]

sounds like a deal to me, what cam is recommened for such and application

[deadtrend1]

Most people use the LT1 cams with the LO3's. They are abundant, cheap, and don't make the ECM have a heart attack when you put it in.

[9secfirebird]

haha dont forget to torque everything properly... i saw a cam sprocket snap off cuz he overtorqued the bolts haha

[deadtrend1]

Or if your cam hates you like it did me ... the dowel pin worked its way forward a few months later and rubbed a hole the size of a half dollar in the timing cover.

[nj85z28]

is that what a "cam button" is for?

[deadtrend1]

no. I only used a cam button once on a flat tappet block. The goes between the timing cover and chain sprocket.

The reason it did it on me is cause the LT1's dowes are longer to drive the opti-spark (achillies heel of the Lt1's) and it ground it down and it just walked foward a little

[nj85z28]

ok j/w

[Batman]

If you change it yourself be VERY gentle taking it out and putting it in, if you mess up a cam bearing it is a whole lot of work. Very good swap though, worth the money.

[bokey]

I have been hearing the same thing as nj85z28 has. I have been doing my research, but still do not understand how just switching out the cam shaft increases preformance. I thought you would have to switch/rebuild the heads, replace the rockers, put in new pisonts, rings, etc. to get a real preformance gain from the cam shaft. Maybe I am just missing something (and I'm pretty sure I am lol). Could you help me out with this one?

[Tru2Chevy]

I have been hearing the same thing as nj85z28 has. Â*I have been doing my research, but still do not understand how just switching out the cam shaft increases preformance. Â*I thought you would have to switch/rebuild the heads, replace the rockers, put in new pisonts, rings, etc. to get a real preformance gain from the cam shaft. Â*Maybe I am just missing something (and I'm pretty sure I am lol). Â*Could you help me out with this one?

The camshaft determines how quickly your valves open (ramp rate), how much they open (lift), and how long they stay open (duration).

The stock cam usues very conservative designs to make the car idle smooth and keep clean emmisions. A properly chosen aftermarket cam will allow more air and fuel into the cylinder and allow better evacuation of the burned air and fuel out of the cylinder. This is how you make more power.

- Justin

[bokey]

I have been hearing the same thing as nj85z28 has. I have been doing my research, but still do not understand how just switching out the cam shaft increases preformance. I thought you would have to switch/rebuild the heads, replace the rockers, put in new pisonts, rings, etc. to get a real preformance gain from the cam shaft. Maybe I am just missing something (and I'm pretty sure I am lol). Could you help me out with this one?

The camshaft determines how quickly your valves open (ramp rate), how much they open (lift), and how long they stay open (duration).

The stock cam usues very conservative designs to make the car idle smooth and keep clean emmisions. A properly chosen aftermarket cam will allow more air and fuel into the cylinder and allow better evacuation of the burned air and fuel out of the cylinder. This is how you make more power.

- Justin

Thanks alot. Another question ... if it creates more power does it create more torque? As far as I know it doesn't.

[Tru2Chevy]

Thanks alot. Â*Another question ... if it creates more power does it create more torque? Â*As far as I know it doesn't.

Yes, 99% of aftermarket cams will increase horsepower and torque over a factory cam. There are several good cams out there for the 2.8/3.1 motors.

- Justin

[bokey]

Thanks alot. Â*Another question ... if it creates more power does it create more torque? Â*As far as I know it doesn't.

Yes, 99% of aftermarket cams will increase horsepower and torque over a factory cam. There are several good cams out there for the 2.8/3.1 motors.

- Justin

http://www.cranecams.com/?show=browseParts&lvl=2&prt=5&Vehicle_Type=Auto&Cylinders=6&Engine_Make=CHEVROLET&Year=1991&Engine_Size=2.8-3.1%20L&partNumber=250801&partType=camshaft

Thats the cam that I want to put in. It seems pretty decent to me. BTW, I know how it increases HP, but how does it help increase torque?

[Tru2Chevy]

http://auto.howstuffworks.com/horsepower.htm <-- Read that.

I don't know what other mods you have planned to support that cam, but every other stock part of the 2.8/3.1 motor (besides the rotating assembly) will run out of steam between 4500 and 5000 RPM.

- Justin

[Batman]

That's a pretty big cam for a street car. It doesn't start making power until 2500 RPM. You may need a stall converter if you have an auto. Ideally for a car that breathes as poorly as a 2.8 you want to make your power as close to idle as possible, since the factory intake is gonna run out of air up top. Look for something more in the 215-220 degree range intake and exhaust, that 238-240 is an awful lot unless you are gonna run it all out at the track.

[bokey]

...The cam has a fair idle, so i know that will get me through inspection. The i like the durations on it. Its much better compared to the stock cam. As for other mods... I have to get a new rear end, posi is the obvious choice. Thinking about a 3.73:1 posi from another camaro. I was thinking about putting on a set of header, which would help that breath much better... still trying to figure out what else I should do with it IF i get the cam...

[foff667]

fwiw most aftermarket cams will require some degree of tuning to get your a/f ratio back inline...bokey & nj85 i would talk to him..the lt1 cam is still mild but the specs on the tbi cams are horrible so it'll seem huge in comparison...i dunno about that v6 cam bokey...looks pretty large to me.

[foff667]

as far as cams making more hp/tq...hp is a derivative of tq so if you make more hp your gonna make more tq and vice versa cuz basically hp is made up. Cam swaps are actually pretty easy...if njspeeder can do one anyone can ;) :lol: