cam choice.....

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hidden_threat

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I have a 74 360 that I'm building to put in our 73 Duster and I'm having issues deciding on a cam. The motor is basically stock and I'm going to add a double roller, a weiand dual plane manifold, a complete MSD ignition system( Dizzy, coil, and box) and I have a very nice 750 holley also. I was thinking of the .509 purple shaft cam but have read that it won't like the low compression. I've used the .484/ .284 purpleshaft in the past but wanted to go a little bigger this time around. I like the idea of the Hughes whiplash cam but its outside my budget at $250 without lifters. I also have a 727 with a 3k stall for the car. Can anyone guide me in the right direction with this? I have never installed a cam before.
Thanks
 
Call a cam company or more than one. Give them as much information as you can. Then you can get a feel for what will work best for your combination.
 
So you're talking about wanting to go bigger than the MP 484/284 in a stock compression 360? You must not care if you end up with a dead dog then.
 
Isn't that Purple cam rated at .241@.050?
I will assume you want a bigger cam to go faster. This is a problem since you lack compression for a big cam.
Try a slight smaller cam for increased torque to better power the car throughout the entire run rather than waiting for it to come in. Use as much lift as the heads will tolorate before they stall.

Second issue is lack of converter. At 3K, it is not enough for the current cam. This the other reason to drop in cam size. A cheap and easy way out is a set or Rhoads lifters. Try them. They can take up to 10*'s of duration out of the cam with the proper preload. (Possible pushrod length change.)

You also failed to mention gear ratio, tire size and the cars weight.
 
If you are dead set on the 509 cam, get the 108 LSA camshaft and install it at 100 if it has valve to piston clearance. Most of the time the 484 cam will outperform a 509 except maybe the last 500 rpm of range. Same deal with a 484, 108 lsa install in the 100 range, that will get the low end back.

Those are basic 105+ mph set up in the 1/4.

Hughes cams are horribly overpriced IMO.
 
This is a new build. I don't have the cam yet. I'm trying to figure out the best cam for my existing parts. I used to run a stock lower end in my 68 satellite with the .484/ .284 cam, a stock 340 intake and mild pocket porting and gasket matching. That car went 13.02 with no converter and a 3.23 gear. So from the sound of it the .484 is the best bet to run.
In reference to "install it at 100" can someone explain that to me?
 
hidden_threat said:
This is a new build. I don't have the cam yet. I'm trying to figure out the best cam for my existing parts. I used to run a stock lower end in my 68 satellite with the .484/ .284 cam, a stock 340 intake and mild pocket porting and gasket matching. That car went 13.02 with no converter and a 3.23 gear. So from the sound of it the .484 is the best bet to run.
In reference to "install it at 100" can someone explain that to me?
Click to expand...

No converter huh, so was it a stick? :D
 
did I miss something do you intend to drive it on the street or race only? or both?
 
The "install it around 100" is in ref. to degreeing the cam.
 
If it's new build spend money on new pistons to get your compression up to and usable range to work with your cam choice.
 
im with the idea of running a smaller cam,if it is mostly a street car.id rather have something with better "manners" street diving,and give up a little max et/mph at the track.but thats me.that being said id look at the old isky 280 mega.
 
:D I run the 280/474 purple cam and it works pretty good on the street. Of course gears and converter play a key role in any aftermarket cams success! Lobe degrees is 110 vs 108 of the 284/484 cam. Just a suggestion. O:)
 
I agree with the others you should be looking for a smaller cam.
If your not willing to run the compression, gears and converter for that cam your just building a slower car. Once you go above about 270 cam you start trading bottom end power for top and without proper gearing you'll see little if any benefit from the extra peak power.
 
If you want that lopey sound and don't want to pay Hughes prices I think there is to other similar cams .
I think Crane makes a series called the beast for low cr and comp makes the thumper for low cr . Also you can use a thin head gasket it will bump the cr slightly .
I'm not sure if either the thumper or beast cams work well no exp ?
I just think they will give that killer lope at idle ?
 
273 said:
i agree with the others you should be looking for a smaller cam.
If your not willing to run the compression, gears and converter for that cam your just building a slower car. Once you go above about 270 cam you start trading bottom end power for top and without proper gearing you'll see little if any benefit from the extra peak power.
Click to expand...

x2
 
People that say "I have the 484 cam in my stock compression motor and it runs good" have not one CLUE what a good running motor really is, because an engine with 8:1 compression is horribly over cammed with the 484. Even with the cam timing advanced. All that does is mask the loss of bottom end torque. You would have a much broader flatter torque curve with a smaller matched camshaft, properly degreed.

I would MUCH prefer an engine to BE a high performance engine than just SOUND like one. A true high performance engine will sound like one regardless of how it is cammed. You don't have to have a rumpty rump to sound good.

If all you want is something to sound good then put a Comp Thumpr in it and call it a day.

Of course all this is JMO and worth just that.
 
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