484 purple cam..JUNK

[goldmember]

I have a 340 with a 4 spd.,single plane intake, headman headers, stock heads, holley 650 DP., 3.73 gears. It has the 484 /108 cam in it and I have tuned it many times. Getting it to idle and perform, drivability is terrible. I have decided today after another tuning session to get a new cam! rotestoes anyone have any suggestion? I would like good drivability, with a good sound..95% street driving
Thanks,With that combo you would be better off with an Edelbrock RPM and slightly shorter camshaft. UD H10 lobes on a 109 105icl would be a good start. It still should not be hard to tune what you have to run ok, just not a great 95% street build.

 

[wanta68cuda]

I had a similar problem with mine. We had to change the springs in my distributor to re-curve it and it fixed the problem. It might work for you.

 

[T67POWER]

It's the power valve.
The carb is your whole problem.
Run 71/81 jets with the rear power valve blocked off.
timing at 38 total.......unhook your vacuum advance.

If you have to turn the idle screws out more then a turn and a half then the idle circuit is to lean------a common problem with a cheap carb.


If i put my 750 holley hp on that 340, your plugs would look like they where run in a fuel in injection engine they burn so clean.

That cam is a great cam by the way.

There is a trend --- as of the last 10 years or so --of over estimating a cams ability to make more power then the next grind.

When your in the right ball park as far as your cam choice -- not to big or small moving to a bigger or smaller cam isn't really the problem solver you would think it is.
--the rest of the car is what makes your car faster then the next guy.

 

[SGBARRACUDA]

I ran the 484 cam in my 70 340 4sd. Duster. Installed it at 104 ran a Mallory unilite that was 20 degrees in at 2000 rpm and initial @ 18 . LD-340 intake 700 DP 3.91 gears. Performed very well and I never had to retune. Just had to keep replacing the rear tires!

 

[Dartnut]

I have that cam in my low comp 360 in my Dart Sport which is stock other than the cam, weiand dual plane intake, and a 600 edelbrock avs carb. Everything else is stock including exhaust and it runs well and is very driveable with 3:55 gears and a 4 speed. The initial timing is set as high as the starter will allow, and it is a good driver that sounds good and is very smooth. It runs at 180 degrees all day in the heat.
It's not all that powerful, but not bad for a low comp 360.
Advancing the timing made a huge difference on how it performs. After you get your initial carb settings done, timing is the first place i would start.

 

[longarm]

I did open the secondaries some. I have been doing this also, put the secondaries adjustment srew in from the top down for easy adjustment. Even brought the float levels up for crisp idle but that didn;t work well at stops. I will try some more tomorrow, after I get the floats correct. we put a snapon scope on it today to get it as good as it is, got it to idle at about 900, but driving it with the floats set high was a challenge, with idle all over the place. Thought about drilling the throttle plates but did not. It also sucks gas like crazy
Thanks

Might check the fuel pressure at idle and higher rpm,
haven't seen that mentioned.