Care to provide advice on cam selection?

[David Claflin]

I've got a shortblock at the machine shop now getting a .030 overbore, and the rotating assy. balanced. This engine will be going into my daily driver LX which I believe has 200K on it, it did get fresh bearings and rings before I bought it over 2 years ago. It's starting to make bad noises when cold and on startup.
It has a 77MM mass air meter
75MM throttle body
GT-40 intake with 3" crossover tube to replace restrictive factory style dogleg
ported lower
ported edelbrock performers
30 pound injectors
EEC tuner
TFS Stage 1 cam (will be replaced, already sold )
1 3/4" longtubes
2 1/2" exhaust
5 speed
3.55 gears

The rotating assy is a stock crank, blue thunder 5.4" rods and KB forged aluminum pistons.

I've been using engine analyzer to learn more about how cams affect operation and had come up with a cam that uses the new comp cams XFI lobes 214/212 dur @ .050, .565/.546 lift 112 LSA

One cam grinder has said the cam he calls a stage 1 would work well and it is a 224/220 dur @ .050, .555/528 lift 111 LSA

Between the two which do you think would work best?
As I said the car is a daily driver but I do go to the track several times a year.
I'm inclined to get the one I came up with as I think it would do better mileage wise, but won't make as much power. Whereas the other cam will have a bit of a rowdy idle and make more power, but most likely use more gas.

I appreciate any suggestions you'd make.

[QWKSNKE]

First off, welcome to the site.

Next, I think you may have some of your numbers backwards in the specs. Your first number in the duration and lift specs should represent intake and the other should be exhaust.

In other words, I am hoping you meant to state the specs are 212/214 dur@ .050 and the lift is .546/.565.

If it were me and I would chose the one with a little more duration. something to ponder though, the guy that recommended the 2nd cam listed, did he ask other info about your car? Weight, gearing, etc..

[QWKSNKE]

Also, I don't think economy will be that much different between the 2 cams listed

[1Quik85GT]

I would stay in the 2teen-220 duration area, since you are running those Ed heads, and I would go with something with a tigher lobe separation. You must plan on using some NOS. With those cams your car is goin to be a slug on the street and lazy. I would go with something else.

[QWKSNKE]

You must plan on using some NOS. With those cams your car is goin to be a slug on the street and lazy. I would go with something else.

I agree. I thought maybe he was going to step up to at least a 4:10 gear

[coupe]

1) I'd have kept the TFS cam. :shrug:
2) You have a great combination, but I would use a split-duration & lift cam favoring the exhaust. And being fuel-injected, I would widen the LSA a little. Run a 114º

Although the heads' actual port-job would ultimately affect my decision, here's approximately what I would spec for it:

222/224º @ .050
278/282º gross
.525-ish" intake .530-ish" exhaust (with a 1.6 rocker)

114º LSA (intake Centerline 110º, exh. CL 118º)

Keep ramp-rates fairly mild for long-spring life...just a hair ov overlap below .050 would be nice.

Should idle nice and pull well up to 5800.

If it's between the two you mentioned...the first one would be better for your application...but the lift is a bit much.
Is that second one an Elgin?

[QWKSNKE]

Coupe, why would you have kept the TFS cam? Wouldn't it be way to small of a cam for his ported heads and ported intake?

The reason I ask is because both of his cams listed are a hair smaller than my cam I just installed


and David, you will need to look into a rear gear ratio change. Those 3.55's are not enough. Get with whomever you are speaking with and talk to them about the required gear ratio for the 2nd cam you listed.

For reference the specs on my cam are as follows..

Lift. .544/.568
Duration@ .050 228/236
LSA 110

This cam requires a 4.10 gear ratio in the rear

[coupe]

I'd have to "see" the port-work to evaluate it. But the cam is plenty for a 302/306.

My car on the 5-speed was a good example...not a whole-lot different setup than his really: 302, worked heads, port-matched intake, 3.55's and a 5-speed. 109mph...and multiple 107-108 runs.

It's great off-the shelf value. Crane makes it.

But his desires to go to the track alot, and get good mileage, warranted my suggestion. It would be very computer friendly too.

Another favorite of mine is Crane's Powermax 2030. It's emissions legal too! Here's the specs:

http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=444221&lvl=2&prt=5

[EZ SPEED]

my daily driver LX

I'm inclined to get the one I came up with as I think it would do better mileage wise,

but won't make as much power. Whereas the other cam will have a bit of a rowdy idle and make more power, but most likely use more gas.

I appreciate any suggestions you'd make.


Lee, it doesnt sound like he wants to install anything like a 4.10 gear ratio from these statements

[QWKSNKE]

I'd have to "see" the port-work to evaluate it. But the cam is plenty for a 302/306.

My car on the 5-speed was a good example...not a whole-lot different setup than his really: 302, worked heads, port-matched intake, 3.55's and a 5-speed. 109mph...and multiple 107-108 runs.

It's great off-the shelf value. Crane makes it.

But his desires to go to the track alot, and get good mileage, warranted my suggestion. It would be very computer friendly too.

Another favorite of mine is Crane's Powermax 2030. It's emissions legal too! Here's the specs:

http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=444221&lvl=2&prt=5

I guess my thinking is, if you have gone to the trouble of doing port work then use a cam that will utilize it. With the smaller cams such as the TFS 1 it would be a waste of time to do any port work on heads or intake. Porting is really going to shine in the .500 lift and up range so it seems to me that you would want to more lift and duration to utilize the port work.

Am I way off base?

[QWKSNKE]

Lee, it doesnt sound like he wants to install anything like a 4.10 gear ratio from these statements

I am still hoping for 25mpg out of my new setup :D

[EZ SPEED]

I am still hoping for 25mpg out of my new setup :D


Maybe with a 6 speed conversion added to your list :jester:

[David Claflin]

The specs I provided were correct, it's perfectly OK to have the intake duration be more then the exhaust dependent upon the application. In this instance where I have a very good exhaust setup and a comparatively restrictive intake the increased intake duration will help that. Remember too the stock cam had more intake duration.
The car is not a pig now with the TFS cam so I don't see how going to a slightly smaller cam will nake it into one. I've modeled several different cams with engine analyzer and found even the stock cam is up about 50 ft. lbs over the TFS cam at around 2K RPM.

[QWKSNKE]

The specs I provided were correct, it's perfectly OK to have the intake duration be more then the exhaust dependent upon the application. In this instance where I have a very good exhaust setup and a comparatively restrictive intake the increased intake duration will help that. Remember too the stock cam had more intake duration.
The car is not a pig now with the TFS cam so I don't see how going to a slightly smaller cam will nake it into one. I've modeled several different cams with engine analyzer and found even the stock cam is up about 50 ft. lbs over the TFS cam at around 2K RPM.


It may be ok to do that but it would be stupid to do so. You always want a cam to favor the exhaust because your exhaust valve is smaller than your intake valve. So favoring your intake with a cam is doing you absolutly no good beacuse your are not able to get all the exhaust gases out with such a small exhaust valve

[David Claflin]

There's actually quite a few cars on different sites that have a cam with reverse bias. Typically Fords with stock heads needed to have more exhaust duration to help crutch the poor exhaust ports; with aftermarket heads this is no longer necessary, most of the time. Again, it depends upon the entire system that is on the car. Ideally a cam should have lobes that are the same for intake and exhaust, the reverse bias I came up with was just tailored for my combination using engine analyzer. I used that program to come up with a cam for my 351 in the LTD that I had and it worked very well for a daily driver. If memeory serves it was 350RWHP/380RWTQ using small edelbrock heads, not the ones currently on this car.

[coupe]

...engine analyzer and found even the stock cam is up about 50 ft. lbs over the TFS cam at around 2K RPM.

:bs2: mine had no such effect.

The thing I like most about my TFS cam is that it has the same low-end as stock...maybe more. Of course the whole combination has everything to do with that. I've had people say my car felt like way more gear than 3.55's.

Biasing a cam toward the intake is a trend on turbo-cars these days (and seems to work well)...but as for an N/A application, you can leave it common or split duration and it will work fine. Most aftermarket heads even still have a little room for more cam on the exhaust, unless you get into the raised-port configurations.

The thing about it is, pretty much anything available will work in the car, but it's maximizing the things like your head-flow, intake, gear, application, etc...that make a good cam dfecision worth paying for the knowledge of an expert. I recommend giving Camshaft Innovations, CamMotion, FTI, or other professionals a call if you want to maximize the combo.

[EZ SPEED]

Biasing a cam toward the intake is a trend on turbo-cars these days (and seems to work well


Yep, the Turbo cams that I bought for my Mod motor were like that.