I think for christmas im going to ask for a a new cam\rockers\springs.. its about time that i do this upgrade.. but i have been avoiding it so long because i know next to nothing about picking out cams.. so ill start off by listing my mods\setup

1. 350 TPI stock internals
2. T-56 tranny
3. Fairly well ported intake plenum and upper part of runners.
4. SLP 1 3/4" headers with y-pipe.
5. SLP catback with gay flowmaster muffler on the end
6. Gutted cat with 3" pipe inside of it.

Future mods
1. Custom burnt chip (done by me)
2. SLP\Accel\any other aftermarket runners\base?
3. Larger Injectors.
4. New heads.

Now this car will be my daily driver for a while, at least the next year or so.. And i need decent gas milage. im making about 13 MPG now and i think its cause i have a false lean condition or bad EGR.. im still diagnosing that problem, it will be fixed before i install a new cam.(i used to be getting around 16 MPG) So i still hope to be making no worse then 13 MPG after a new cam and fixing my current bad milage condition.. The engine is in very good running condition with high oil pressure etc. So im pretty sure it can take the extra abuse i might give it. But i know i probably can't have too aggressive of a cam because of my manual tranny.

But with all of that said. what kinda cam would be good with my mods? I would also like to get 1.6 rockers and i know i will need new springs.. But yet i don't wanna spend an extreme amount of money, (well have an extreme amount of $ spent on me). should i go and try to look for a used LT4 hot cam or something?? or should i get something new? what specs am i looking for? im sorry for being totaly ignorant here. but i need to start somewhere.. thanks..

EDIT:
yes emissions are important.. i wouldn't mind having a lopy idle as long as its drivable with a manual tranny car and wont' effect emissions to much.. in fact a lopy idle would be pretty nice.. but at the same time i dont wanna loose too much of my low\mid torque.. at least not now with the LTR setup..

im thinking something with simular specs to the CompCams 08-412-8 (XR258) with 206\212 @.05", with 110* lobe seperation, .487\.495 lift.. (1200-5200 RPMS)

or the CompCams 8-502-8 (XR269) with 218\224 @.05" with 112* lobe seperation .495\.503 lift.. (1500-5500 RPMS)



hmm now that i think about it. i wouldn't mind having some killer midrange torque. i mean i know with my mods that i already killed alot of my low end torque. so i don't know if it would be worth trying to get it back by getting a cam for low end torque. but a nice mid range would be nice. i don't wanna have to rev up to 4500 just to find my power.. and i don't wanna have to ever rev past 5000. well at least i don't think it would be safe anyways..

 

I too am looking for a new cam for christmas, and although I havent gotten a whole lot of help so far I have been pointed in the direction of the LT4 Hot Cam.

Brian

 

Contact comp cams. They're the best (IMO!) Their tech line is also one of the best I've ever dealt with.

You could also talk with a local engine builder or speed shop owner. They usually have the best info.

 

I can't tell you which cam to get, but do know that whatever you chose, ask a lot of people with similar setups and that exact cam!

I did and eliminated a few other cams and decided upon the one I have and am very happy.

But I'm running a carbed 305..........a little different.

 

well u see. my problem is i don't know anythign about cam.. about duration and lift and lobe seperation and stuff. so it doesn't me no good to just find a cam that sounds like it would work. what kinda specs do i need\want for my setup? or at least someone give me some good info about specs and what they mean. it seems like every other "what kinda cam" post i see. there are like tons of recomendations for what to get. but nope not mine.. and i THOUGHT i gave enough information to get SOME help....

 

Well if you are an idiot, I'm the village idiot!

What I did is read as much information as I could, not adds though. I looked at what other people with the same engine had and what their results were and I just copied!

 

top.. for another try

 

Roller or hydraulic?

 

have your specs handy, they want to know engine size, gears , transmission and stall if auto,intake. call comp and crane, i bet if you call the same company twice they'll give you 2 different answers. the point being they should be close to each other and give you an idea on what to chose. also ask other people with your setup.

 

roller

 

I hear good things about the ZZ4!

 

you're going to want something with anywhere from 210-220 duration (if you're worried about emmisions). The duration gives you the lopey idle. So if you wanna say **** emmisions then go to about 225-230 duration.

you will want your lift to be around 480-500.... most heads flow best at 500 lift.

and for emmisions you want a higher lsa (lobe separation) around 115-118 .... i think.


so a mild cam for you're choices could be similar to this 210/215 duration @.50. 480 int /494 ex lifts and 117 lsa.


A bigger choice would look like this...... 218/220 @ .50, 494 int/500 ex lifts and 115 lsa............

remember those specs are imaginary... just there to give you an idea..... with the bigger of the two cams you should run 1.5 rockers... most stock rockers arent really 1.5... they are inconsistant, 1.6 would be too much... but you could buy a smaller lift cam with more duration like this ...... 220/225 @ .50 450 int/ 470 ex and 114 lsa.... and run 1.6 rockers adn the 1.6's will bring the lift up to about the size of the bigger cam i mentioned........ but if you do decide to stay 1.5.... get aftermarket roller rockers for ratio accuracy.... i hope i helped... good luck

 

ok, stock cam is 207/213 with 117* lobe seperation. so it seems u were right about higher lobe seperation being good for emmissions.


so i definatley want something with higher duration then stock though right?? what about lift? stock is .413/.430 (i understand duration more then i do lift) both of the cams listed above have higher lift. so how important is lift? what exactly does it do?


thank you alot Marshall89ws6 for ur reply!!!!!!!

 

well the lift just tells you how much the valve opens up.... the duration tells you how long it's open for. To put it bluntly..... higher lifts enable more air and fuel to come in to the combustion chamber thus creating more hp.... and the closer the lift to .500 (on a stock or close to stock head.... with some exceptions of course.... like the swirl port 305 heads) the better the flow is through the heads. but for a mild engine you want something very similar to the lifts i mentioned in my last post.... a lift like that also isnt as hard on springs as something bigger obviosuly. just stick with the advice on that post and you'll be ok.

 

o and in case you didnt know.... when u get a cam ... make sure you get a cam and lifters package.... you might as well replace them while u are in there... buy new pushrods and springs as well...... new springs are really important.