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Old 03-24-2003, 11:46 AM
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Post Cam Selection...Please help!

Which cam should I go with for my 350 4 bolt that I plan to build. I want to have around 350hp and it has to be a crane cam.

BLOCK
Chevy 350ci
Bore: 4.00" Stroke: 3.48"

CYLINDER HEADS
Low Performance/Pocket Porting
Intake Valve: 1.94in Exhaust Valve: 1.6in

COMPRESSION
CR Ratio: 9.5

INDUCTION
Flow: 650cfm
Manifold: Dual Plane

EXHAUST
Small Tube Headers With Mufflers

Some I was thinking of are:

#5
www.cranecams.com/master/apps/chevy6.htm
(I was thinking more liek this one)

Anyway help me pick one out. <a href="http://www.cranecams.com]www.cranecams.com[/URL]

Thanks

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Old 03-24-2003, 01:04 PM
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You've narrowed it down enough to have answered your own question. Call Crane. They can recommend a cam for you.
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Old 03-24-2003, 02:11 PM
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If it is a street driver, I would avoid the cams rated for more than the 1500 to 4500 rpm range because you will give away street driveablity at that point. Further, with the price of gas you have, I wouldn't want to buy the poor mileage that the cams with the huge overlap will deliver. Since your heads will not handle a lot of flow, you would be defeating the intended purpose of the radical cams.
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Old 03-24-2003, 02:32 PM
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I would go with an L79 hydraulic replacement camshaft. It will give you the driveability and power that you are after. I'm pretty sure that crane makes factory replacement muscle car cams. <img src="graemlins/evil.gif" border="0" alt="[evil]" />

[ March 24, 2003: Message edited by: Jay396 ]</p>
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Old 03-25-2003, 02:19 PM
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Well I really want to have around 350hp and it isn't really possible with a small cam unless I have really good heads which cost alot of money...so I was thinking get a bigger cam to compensate for the lack of heads. can you explain to me the basics of a cam. I just want to know what to look for when seeking milage or speed what does the lope seperation have to do with these subjects, things like that...can you help explain?
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Old 03-25-2003, 04:30 PM
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THe lobe separation is pretty important. It is one of 2 factors that affect the amount of time that both the exhaust and intake valves are open at the same time (known as overlap).

Overlap is necessary to achieve high lift in the short period of time that the crank cycles (can't open the valves instantly). It also helps to pull more fresh fuel mixture into the cylinder because the exiting exhaust gasses create a "draft" that pull in the fresh fuel.

Tighter lobe separation tends to make the torque curve more "peaky"...fatter in the mid range than on the ends. Wider separation tends to flatten the torque curve out. This is speaking generally, and your engine combo has a huge effect on this.

Most cams for SBC have 110 or 112 degree lobe separation.

I still say you should call Crane for advice. You also should forget about making 350 HP with old stock castings on the street. 300 is more realistic.
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Old 03-26-2003, 05:13 AM
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Well the thing is they are big valves int/1.94in and exh/1.6in. Also I am getting them pocket ported which helps the flow alot. So I really don't see whats wrong with the flow of my heads I plan to get. I was told many times that it was possible for me to get into the 350hp with stock heads just a valve change and maybe a pocket port if needed but I should be able to do it without a pocket port.

<a href="http://www.cranecams.com/master/apps/chevy8.htm" target="_blank">http://www.cranecams.com/master/apps/chevy8.htm</a>

#5, #6, or #7?

Please, I want you to help me chose a cam based on what you seen in my specs of the motor.
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Old 03-26-2003, 05:38 AM
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what we have here is someone chasing HP numbers and not really having a clue about what makes a car go fast

you've completely neglected to mention what transmission you'll be running, what rearend ratio and the weight of the car your intending on installing it in,

if your going high stall torque converter or manual transmission then fine, go for high HP, otherwise, stick with low end torque, you'll be happier in the long run

[ March 26, 2003: Message edited by: andybird ]</p>
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Old 03-26-2003, 07:04 AM
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No I have not. I know that if I get a cam that operates at high RPM's I will need to have a higher gear ratio and higher than stock stall. That is why I am going with a 2400 Stall and shift kit in a 2004R. Also I have a 3.73 POSI rearend. The car weighs approx. 3500lbs.

First off I wouldn't of narrowed down these cams listed if I didn't think that they would suit my set-up...although I did neglect to say what the factors were. So with the info given what would be your decision?

<a href="http://www.cranecams.com/master/apps/chevy8.htm" target="_blank">http://www.cranecams.com/master/apps/chevy8.htm</a>
#5, #6, or #7?
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Old 03-26-2003, 07:34 AM
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224/234 SSI...Hundred bucks including lifters and delivery charge. that'll do it!
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Old 03-26-2003, 07:38 AM
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I have The Crane Muscle Car replacement cam (L79)in my Street Rod with ported stock heads headers running a 200R4 with 3.56 gears in a 9 inch I also have tuned port injection, I have great drivability and all the power that I seem to need right off idle and the car weight is about the same as you mentioned. The biggest problem is that at 65 to 70 MPH with the OD and 3.73 gears you will still be below the power band of all three of the cams that you mentioned. You did not say if you were going to use the car on the street or the strip. Hope this helps.
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Old 03-26-2003, 12:13 PM
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Well I want it to be a dual purpose. A street/strip engine.
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Old 03-26-2003, 03:09 PM
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maybe try 4:11's in that puppy or maybe 3:41's. i use the latter in my s-10 jimmy with a 305 and a 440/445 dual pattern cam with 58cc ported heads
and all i do is drop a gear on the highway at 65 and it puts the truck right at 3000rpm,right where i want it.i also use a 700r tranny,on the street if i give it half throttle from a full stop it usually lites it up not bad
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Old 03-26-2003, 03:44 PM
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OK, I ran the numbers and got a maximum HP of 299 with cam #7 but to be honest there's not much difference between the three - #5 292, #6 296. All of these were at 5000. Torque cam in at around 350 @ 4000 for all three. I forgot to look at the lobe separation on the cards but I ran 110 which is close enough. Without getting too much into overlap vs. port-flow theory, you cannot make up for poor-flowing heads with more cam. You end up hurting you bottom end too much and at 3500# you need all the torque you can get.

So then we stab in a Comp Cams XE 256 (212/218 .447/.455) and we get 286 peak HP BUT we average from 1500-5000 4 more HP and 14 MORE LBS. TORQUE. AVERAGE. I think thats what you should look at.

Why a Crane?

The Vandal
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Old 03-26-2003, 06:04 PM
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350 HP out of basically unworked 882 castings ain't gonna happen

1.94 intakes aren't really that big, actually most SBC heads have them. Also the exhaust valves should be 1.5"

The numbers The Vandal came up with are accurate I think
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