I need some cam help.

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Jan 6, 2003 | 03:35 PM

97Z

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Instructor

Joined: Oct 2001

Posts: 184

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From: Stronghurst Il

I need some cam help.

Hey everyone,

I'v got this engine damn near put together. BUT I've been having some problems selecting the cam. im running a 10.5:1 Comp Ratio 383 c.i. Motown 220 Iron Heads. This is gonna be a weekend/random daily driver and Ill be putting a richmond 6 speed behind it later. What do you guys recommend for a cam. With the 6-speed ive calculated it to run about 60@ 1700. so Ill need some low end torque. Ive got to get back to work, but ill keep checking back on this. Thanks for your help. Mike. (if you need some more info, let me know.)

[Modified by 97Z, 8:37 PM 1/6/2003]

[Modified by 97Z, 9:25 PM 1/6/2003]

Jan 6, 2003 | 09:01 PM

J75

Racer

Joined: Feb 2002

Posts: 272

Likes: 1

From: MOBILE ALA

Re: I need some cam help. (97Z)

Give comp cams a call and they can give you a good recomendation.Their 260-268 series cams work real well.With a 6speed you might could run a little larger,I`m sure they can help you out.

Jan 6, 2003 | 09:21 PM

71roadster

Burning Brakes

Joined: Apr 2000

Posts: 1,145

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Re: I need some cam help. (J75)

Im going to run the comp cams xe274h in my 383, but my heads arent nearly as fat as yours so I am not sure if that is a good choice. I would give a couple af mfg's a call and see what they all say.

Chris

Jan 6, 2003 | 09:31 PM

The Money Pit

Melting Slicks

Joined: Jun 2002

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From: Orrtanna Pa.

Re: I need some cam help. (71roadster)

The ports on those heads are faily large,so if I were doing a 383 I'd stay more in the line of the Comp XE-274. I actually ran this in the 406 before my meltdown,and it was very strong,but in the 406 seemed too mild. With a big port comes slow intake charge velocity,and sluggish low end. The smaller cam will help offset the loss of low end.

Jan 6, 2003 | 10:16 PM

97Z

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From: Stronghurst Il

Re: I need some cam help. (The Money Pit)

Do you think I should go smaller on the heads? Im trying to get some big power out of this motor, but I don't want to have to be revving it in to the Stratosphere to get it. I would be happy to cruise at ~2grand on the highway @ 70. Now you've got me thinkin I went too big. :cry

Jan 7, 2003 | 09:16 AM

The Money Pit

Melting Slicks

Joined: Jun 2002

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From: Orrtanna Pa.

Re: I need some cam help. (97Z)

I'm not an expert,but have researched this quite a bit.Look at the LT-1 engine that makes 370hp with only 170cc runners on a 350. Look at Edelbrocks RPM head. Makes 420hp with only 170 cc's on a 350. I extrapolated the size I'd need to get the same sort of throttle responce,and figured I'd need 200cc's on the 406. Then of course looked at the flow numbers on the AFR 195's and found they were top dog. You said you wanted to cruise at a relatively low rpm,which means you want a torque motor,not a horsepower motor. I saw a 400 running the Edelbrock RPM heads make 450 hp,so power of this range is possible even with small heads.Ask around and see if others agree,and if it's not too late,return those heads and go smaller. :yesnod:

Jan 7, 2003 | 11:39 AM

97Z

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From: Stronghurst Il

Re: I need some cam help. (The Money Pit)

OK, Thanks for the respnses, Now I should say, I don't care if I have alot of response in 6th. I'm just worried about the engine being able to turn over a .62 O.D. W 3.73's out on the highway W/O Bogging.(it's gonna be used on long roadtrips.) BUT, I like the fact that I would be able to slam it in to 2nd or 3rd and pull like a raped ape with these heads. I'm pretty sure I'm not gonna be able to return them. I've had em for too long.

Do you guys think a this kind of an engine setup will be able to tun this combo over with out bogging? (I can ALWAYS downshift.) :cheers: :D