Could you please give me a reccomendation for my current setup.
"Stock DIY ported Iron" Heads@550lift-250/190 182cc's Intake with welded exhaust ports.
367 cubic inches
3550lbs with driver
3.55 gear
3800 convertor
28" Drag Radial
12psi Intercooled
6200 Rpm limit
Current cam was installed before blower
224/230@.050 .504/515w/1.5's 110lsa straight up.

Looking at:
1. Same cam profiles as above but going to 114lsa w/1.6's to get .538/.549 lift

2. Bigger 230/238 .515/535 on 115lsa

3. 230/238 with 1.6's making .549/.572 lift. But then I'd need dual springs with this which I'd like to avoid for street duability.

4. What about using the 238 exhaust lobe with the 224 intake. 1.6's intake only for 538/535 lift respectively on 115lsa.

Thanks. Todd

 

So, say you had a setup with some great heads and a perfect cam to match it such as the one you described here. Now, where, IYO, would that cam make power? Would it be more tourque down low rather than a lot of horespower up top (@ which RPM's)? Or not?

Also, what if we put a bigger duration cam with the same lift on that same setup? Would it have the opposite effect (less lowend torque, more HP up top)?

And what if we went with more lift and the same duration as the original? Then what would happen? I'm just trying to figure out the stuff involved in all this and what variables affect your motor in which ways. All help is appreciated. Thanks,

Brian

 

How's this for a hydraulic roller cam?

230/244 .622/.640 113LSA 1.6rr's.

As long as the heads supported it...whadda ya think?

 

Probably wont pass smog (I know it can pass a Texas sniffer...), but everybody loves that cam seems like. Thats the cc306, with a bootload of more lift though.

 

It seems as though some of you are forgetting that there is a limit on how "steep" a lobe can be. The 3100 series of CC XE lobes are about as steep as any hydraulic lobes. In fact, some say they are too steep! For example, the biggest #31xx lobe is #3194 which is 230 @ 0.050" and gives 0.584" lift with 1.5:1 rockers. Lobes this steep approach the milder solid rollers in terms of lift/degree. These lobes will be hard on springs and have fairly limited rpm potential. Unlike solids, the max spring pressure is pretty limited (~350lbs open) due the tendency of the lifter to collapse. This combination of a relatively weak spring and a steep lobe is why these cams don't rev like the slightly less steep "Magnum" series lobes used on the 306 cam.

I am using the 3190/3192 combo and it works great, as does the 3192/3196 that I have recommended to a number of people. I would guess the lobes 4drLT4 is talking about using 1.6 or 1.7 rockers to get thsoe lift numbers. They would have to have very odd profiles to give those lift/duration figures with 1.5's. If set up right (would need shorter pushrods) these might work, but rpm will be even more severely limited than the same lobes with 1.5's, so that has to be kept in mind. I am pretty sure that the cam would not pass emissions tests.

A bit of caution is in order when picking a cam. Unless you are pretty knowledgable it might be best to stick with something that someone else has used sucessfully.

Rich Krause

 

Rich,

Those lift specs are indeed using a 1.6 ratio. It would be mated up to maximum effort AFR 220 head, all the while keeping the runner size to a minimum, and dropped into a 396 A4.

Initially I was looking to keep the CC306, and running a Jesel 1.7 shaft mounted rocker...but that idea has been scrapped.

The heads will end up flowing 330+cfm @ .650...and I'd like to take as much advantage of it as possible.

The car is no longer a daily driver. I too think the Hydraulic cam above would end up giving the valvetrain fits....and I'd be better off going solid.

Because I'm not willing to go with an aftermarket computer just yet, I've got to keep the RPM's at, or below 7K.

Any other ideas guys???

 

You are talking about a high revving setup, for sure! I hope you have good rods, light pistons, etc.! You need a solid cam to really take advantage of those heads. The 7K limit will be somewhat of a limitation, but there are NA guys making good power even with the stock PCM (Jason Short, for one).

Rich Krause

 

I thought valve size was a limiting factor to the gains of added lift... you can only have so much lift before it's overkill? Right? Isn't lift supposed to be like 25% or 30% of your valve sizes, anything more than that isn't gaining you anything. Obviously a better set of heads, bigger valves, you'd want more lift.

 

That's one of the reasons why I said there's no point in exceeding 0.550-0.600"!

Rich Krause

 

I was under the impression that solid rollers are even harder on the valvetrain. Whats the deal????

Brian

 

You are able to run a much higher open spring pressure with solid lifters, than you can with hydraulic ones.

The lobe lifts that are being proposed by my builder for my hydraulic setup, seem to fly in the face of what most think can be tolerated, without going to a solid setup.

My main concern is how long my Comp 'R lifters would last before giving up....

 

Rich,

Yeah those two cam combos are very good, each one really for different displacements.

I have the first in a engine at my shop right now, and the other cam is sitting in my shop looking to go into a 400 SBC or so one of these days.

They are good lobes.

Bret