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FFCobra Craftsman
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Discussion Starter #1
I am looking to buy the 351 W crate motor. I was just wandering what the best cam choice would be for mainly street cruzin

E cam or Z cam??

Thanks,
Mike O.
 

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Former Roadster Owner
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The E cam is very mild. --Very Very street friendly.

The Z cam is much more agressive, but would be just fine on the street in my opinion.

Hyd. Roller cams are very "Mild Mannered" by design when compared to other camshaft types.

The Z cam will make more power, need a better valve spring, and will make peek HP at a higher RPM due to its increased duration over the E cam.
 

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Former Roadster Owner
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1,861 Posts
Also,

What heads are you going to run? I think they will make the decision for you.

If the crate motor has low performance heads (and you are going to keep them)I wouldn't waste my time with a Z cam.

If you have decent head like, AFR 185's or something similar that really breathes well, then go with a cam like the Z that is a "match" for those heads.

Also, there are other cams out there. Trick flow has some great cams, Comps Xtreme Energy series are well desinged too.

Matching the Cam,compression ratio, heads, intake etc is very important.

--Dan
 

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he who lives by the sword. gets shot by those who
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Mike,
I just sent you a video clip with FMS F303 cam sounds
Ben Smith
 

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FFCobra Craftsman
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Call up Comp Cam and talk to a person. He'll ask all the things about your setup, if stock, what have you modified, how you want to use it, etc. Tell them where you want your power, or if you would like other characteristics. Sound like they have a lot of experience in this. Check them out. Glen
 

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OT Moderator
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Ben, could I get that video clip as well, I'm in the market for a crate 351 as well. Thanks.
 

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FFCobra Craftsman
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1,594 Posts
Here is a link to my 351/385hp FMS crate motor with the Z cam. Listen and judge for yourself between the two. The Z is fairly aggressive. You may, or may not, want that for your car.
Z303 Cam

For a more aggressive cam, listen to Jim Haar's at this link.
Jim's is a custom ground cam and I don't know what its duration or lift is, but it is a little more aggressive than the Z cam.

Paul
 

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Guys - my opinin is the E303 is way small for a healthy 351W. It works great in a 302 and frankly, it's pretty mild for that displacement too. I might use the E303 in a 351W if I were putting it in an F150 or something.

GT40 heads and 351W....I like Comp cams better than the FMS cams. I would want more exhaust duration with the GT40 heads to help the weaker exhuast flow, especially on a 351W.

If you are looking for an off the shelf grind from Comp, I would probably go with the XE274HR.

Specs are 224 intake, 232 exhaust @ .050 lift.
Lift is .555 intake , .565 exhaust with 112 lobe sep.

Also keep in mind even though you may see a camshaft with similar specs or close to it, the ramp rates and lobe profiles on the Comp cams Xtreme energy series are very aggressive. These cams are supposed to make more power than most grinds with similar specs. How much is hard to speculate.

The only cam that would be similar that I would probably not have a problem using is the Trick Flow stage 2 camshaft. It's a lot less expensive than the Comp stick. I believe Crane grinds the cams for TF because there is a Crane cam with these exact numbers.

Trick Flow stage 2, 224 intake / 232 exhaust .542 /.563 lift, 112 LSA
 

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Drop Ed Curtis a line at FlowTech Induction. He's the guru of small block cam guys according to the Mustang crowd. He'll grill you on every little nuance of your build and then custom grind a cam for your exact needs for only about $60 over a shelf cam.

Bernie
 

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Senior Member
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I had a similar question back in Aug.

The thread is here: cam help

I chose:
Comp cam's K35-425-8 with the roller conversion parts. Comp tech line suggested a tich milder but that was based on basics like gearing and engine weight and did not consider that I wanted a gallop at idle.

513 lift on in and 529ex with 230 in and 236ex at .05

Gives nice lumpy idle and is very drivable around town and scary up the revs.

First start is here: Startup
 

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Charter Member
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I have an X cam with a 302. Seems to drive fine and sounds great. The manifold has a huge impact on street performance. I had a single plane weiand that had power from 3000-6000. I switched to a edlebrock performer RPM dual plane and it pulls from 1500-6000. The hardest part for me is the carb tuning with the X cam. I couldnt get the Carter 625 to work with the low vacuum, I had to buy a BG Mighty Demon 650 DP - radical cam carb. THe cam lowers the vacuum and has a great impact on how the carb functions.
 

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After tons of research, reading, and talking to cam techline folks, I know that when I build up my 351W motor I will have EXACTLY what CWood has (see above). In my buildup, the Comp cams retrofit roller will be combined with AFR heads, a Weiand Stealth intake manifold, a BG Speed Demon 650 cfm carb, and MSD 6AL ignition/Pro Billet distributor.

The cam has a 110 degree lobe center, which contributes greatly to the nice lumpy idle -- the overlapping opening of the intake and exhaust valves sends confusing vacuum signals up to the carb, which creates that wonderful burbling idle.

This stuff is all carved in concrete for me. The only reason I haven't built it up yet is that I'm waiting for my roller to be completely ready, when I build the motor it will go straight in and run right away.

AJ
 

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AJ

Glad your careful research confirms my choice. I kinda went with gut.

The rest of my setup is a Edelbrock RPM intake
World products iron heads
holley 670
MSD 6AL with Billet dist
Holley mech pump

It is definately lopey...and rough under 1K RPM but I like the car doing the boogie at stoplights. I think you can get a reliable idle at about 8-900.
 

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FFCobra Master Craftsman
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1,399 Posts
Don't discount the boys at Ford Racing! The Z is the newest design in the letter series cams. In my 342, I got very nice numbers on the dyno. Since I'm carbed, and in the spirit of never ending tinkering, installed a Comp 286HR. Now this cam has a little less under 2200, only slightly more from 5800 to 6600(10HP).The Z would put me up in smoke just off idle. The Comp has a nano second stumble. More duration and .50 more lift makes for a slight increase in hp, but does change the driveability. If you're FI, you can run the Z, not the 286. Either one is really fun, but I live in a slightly remote area. Were I in a place with lots of stop and go, I think the Z might would be my cam of choice.
Being as the dyno guy is a SB guru, we looked at all the built SB mtr hp/tqu curves. Other cams couldn't equal the low end tq and high end hp of the Z. You could beat it on one end or the other, but none balanced as well.
Marc A
 

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check out crower's 15512 or 15513.
 

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FFCobra Craftsman
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Marc A
Thanks for that overview of the Z. Although I'm go-carting now, I haven't had it out on the road. Your description of it fits my needs precisely.
Paul
 
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