I understand the basic principle of heads and cam, but I don't know exactly how they work. I don't understand all the numbers associated with different ones (lift, flow, etc...).

I'm wanting to do heads and a cam on my car this coming year, so I'd like to know a little more about what they really do and how they improve performance.

If anyone cares to offer any insight or point me in the right direction to find it myself, I'd greatly appreciate it.

One question I specifically have is how cams are different from each other and how you know how to pick one based on the numbers.

Thanks!

J

 

Well you're asking for a ton of info.....so let me see if I can find a few websites for you to read instead of working on my carpal tunnel

Here's a bit on head flow:

http://www.chevyhiperformance.com/techarticles/41598/
http://www.chevyhiperformance.com/te...98/index1.html

Then you might want to do some reading on www.compcams.com for some good cam info.

To oversimplify everything, the reason people upgrade cams and heads is flow. That is where your horsepower comes from....it doesn't matter if you have a nasty 396....if your heads (intake) don't support the volume and your cam isn't ground for your application....you aren't going to see nearly the potential that could be seen.

 

I'm no expert by far...but I would have to say it like this. Depends on the cam you go with....the bigger the lift and duration, the longer and deeper the valve will open. So if you got a huge cam but stock heads....your kind of choking the motor. The heads wont flow enough to get all that sucking in if you know what I mean. Also it wont flow as well. Thats why you always see guys doing heads with the cam to fully compliment the cam. Well I tried. Thats it in a nutshell in laymans terms. I'm WAY sure you'll get a better (correct) explanation, but I saw no one had replied to your post. I know how that feels.

 

Thanks for the replies guys.

So, when you do "heads and cam" what all do you have to replace (rockers, springs)? I'm a novice to some of the ways engines work. Any information you can give me will be great. It's ok if it is very basic!

J

 

Well it depends on how big you wanna go on the cam. You will definately have to change the springs at the least. If you go with a huge cam then you might have to do some work around the spring for bigger ones. I would also get some 1.6 rockers.

 

Cam + Heads =

1. Springs
2. Locks
3. Retainers
4. Seats
5. Valves (good idea, take it from me, look in sig)
6. Rockers (compliment cam)
7. Pushrods
8. Head gaskets
9. Intake gaskets
10. Timing set gaskets
11. Timing chain


:I think thats ereything. Dont forget you will also need headers and catback or cutout, and a good Cool air intake to really take advantage of the head and cam. You will also want PCM reprogramming to work with the cam and increased airflow. Also bigger injectors dont hurt, go big for future purposes. See the list just keeps adding up, make sure you have allllll your boltons and little things done before you do a head/cam swap....unless you have plenty of $$$

 

HOLY COW! That's a lot of stuff!

So, I know heads vary in price; good ones seem to be in the $2k-$3k range. Cams seem to run around $300. What does the rest of this stuff I would need cost (just a round figure)?

You mentioned having all the bolt ons. Could you please list what these would be? I always see "I have all bolt ons" but never really know what they are talking about.

 

Heads do not really cost that much, unless you buy AFRs. You can get your stock ones ported the best they can be ported by Lloyd Elliot (nightrain66 on the board) or phil at Advanced Induction (skarodom on the board i believe), I know Lloyd charges around 600 total, not sure about Phil.

All the other stuff you can get, your lookin at around 600 or so to totally load the heads.

All the boltons is...

CAI, Catback exhaust, headers, rockers, waterpump, injectors, throttle body, removing AIR and EGR, theres probly a few more. Then you have to handle the extra HP with traction which includes subframe connectors, lower control arms, control arm relocation brackets, shocks springs, lots of stuff in that area.

Dont jump right into heads and a cam before you know about the car, it sounds like you are pretty new to Fbodies and saw that heads and cam increase HP lots, thats true, but not unless you know what you are doing and how to do it, and when to do it, and how to drive it. No offense here, not being rude, thats just what it seems like to me, correct me if im wrong.

 

You are correct in assuming I am new to F-bodies. I just got mine about 2 months ago, but I've been looking into getting one for years.

The only reason I'm looking into heads/cam is because I've heard a couple people say many people blow their money on lots of little stuff and it's really better to just save your money and do the important stuff (heads/cam). Do you disagree?

With the porting of the heads by the guys you mentioned, does that mean polishing too? I see a lot of people say porting and I'm not sure if I'm supposed to assume polishing is included.

If I have a WS6, is there something I can do to make the intake better?

 

Yeah, a port job should be polished smooth or else you leave pitts in the aluminum which can hinder flow.

What you should ideally do is match the cam to the heads. Have the heads flowed, and pick a cam that will pretty much hit it's max lift when the heads are at their max flow. Before everyone starts yelling that it's not that simple, you also have to factor in the duration of the cam, the lobe seperation, how the car will be driven, and probably a dozen other variables.

I would hold off on the heads/cam until you do some supporting stuff. A good set of headers is a nice start, along with a good Y pipe and cat back system. A good clutch or torque converter is nice to have with a good cam/head package. Not to mention doing some suspension work to get all the power to the ground.

Don't forget that when you do heads and cam you're going to have quite a few other expenses than what was mentioned. Computer tuning and possible dyno time. New plugs. Coolant. Tools needed to do the job unless you already have them. And if you have someone else do it you will have to factor in labor costs.

I'm going to assume you have the ram air on your car. In this case, you can port the mass air sensor housing and remove the screens (don't do anything to the sensor itself because it's expensive to replace). Also, get rid of the ribbed bellows and replace them with smooth rubber pieces (look in the plumbing supplies area at home depot). Add a nice K&N filter and you should be set for a while. Oh, some people like to remove the plastic covering the filter (on the ram air box) they say it helps, I never noticed a big difference myself. If you don't have the ram air, invest in a good cold air induction kit like the K&N FIPK or the Moroso kit.

Welcome to the wonderful world of f-bodies.

 

I got a question, im pretty sure the answer is no.

but like my brothers ricer has twin cams, whats the advantage of that? and could it be implemented on our cars?

 

More cams allows the use of more valves. More valves can handle more air flow and with more air you get more power. Also, the valve train is usually lighter and this allows the motor to be reved much higher than a pushrod engine if the bottom end can handle it.

Yes, there is a company that makes 4 valve heads for small block chevy engines, but they are way, way, way too expensive for most people. Chevy made a 4 valve 350 for the ZR1 Corvette (LT5), but they won't fit into our cars without quite a bit of modification plus the cheapest I've seen one go for was like $12,000 bucks. Again, not cheap.

 

A sorta correction on that last reply. Dual cams cannot be implemented in our cars. Only one single cam will ever be used in our cars. You can get 4-valve heads, but still driven by a single cam.

The advantage to DOHC, dual overhead cam, is higher revving and usually more HP, but they do not normally produce as much torque as a pushrod engine, possible because of too much exhaust flow. Take for example a 32 valve mustang GT, they produce decent HP, but less TQ than HP if I remember correctly, on the other hand an LT1 or LS1 good old pushrod V8, simple but effective for a heavy car like an Fbody, 275hp, but 325 TQ, or 305/350 i believe for LS1s.

For the other remark your buddy made, he is incorrect. A head/cam LT1, just Head/cam, nothing else will make barely more HP than stock, whats the use of more air being able to go through the heads into the CC (combustion chamber) if you cant get the air in or out and supply it with enough fuel (injectors) at the right time (tuning).

He is definitely right on the clutch/convertor. If you have a stick and plan on driving it remotely hard your clutch will be gone in a few months/weeks. Invest in a good hard grabbing clutch, depending on what you have planned in the future. Or convertor, a nice 2400 stall or 2800 stall is pretty good for a mild setup on the street I believe, not an Auto guy but thats what sounds about right to me.

 

You're right, I should have been more clear on the heads. You still use a cam in the stock location and each lobe operates two valves via a single pushrod and some kind of levar mechanism which connects the two valves together in the head.

Huh

 

DAYUM

make it simple guys


as we know, the more air into the cylinder, the more fuel, and more power

so

the cam opens the valves that air in more

lift: how much it lifts the valves
duration: how long it keeps that valva on open pos for
LSA (for me how choppy it sounds :P)

heads is the last place where the air goes into the cylinder... the wider the tunnel that the air follows, the better

flow: how much air is coming in

i dont think it gets any easier than that