Right cam and converter

[wattssf]

My fellow moparians,
I am seeking some advice on my current( been working on it 2 years) build. I have a 74 Dart with a 400 that I built(first build). I have KB pistons, ELD RPM performer intake,516 heads,ELD performer 750 carb, MP 509 cam, and stock rods and crank. I am wanting a mopar that I drive(or fly) on the weekends and maybe take to the strip a time or two just for fun. Should I change my current cam, or does it sound about right? I am looking for about 400hp. I have only driven it several times( due to those pesty grimlins) and to me it seems like I am not producing as much streetable power (2500-4500)as I was expecting. I am open to any suggestions. Also I was wondering what kind of stall should I use, depending on the cam setup? I know this one will be easy for a lot of you veterans so Iam anticpating every respond. Thanks.

[waldo67]

awsome cam but what compression ratio are you running that cam should pull to 6000 without any problems as for converter i would use a 2800 minimum 3200 max and put a gear in it 391 minimum that will help out things a bunch and put a holley on it 750 double pumper much better carb

[zij576ca]

I agree with Waldo67 - he's got the right idea and he's right about the cam. However, there are 2 MP '509' cams - one ground on a 108 degree CL and one ground on a 114 degree CL. For a street driven car I'd go with the 114 CL cam. Did you degree the cam when you installed it? What are the specs for your cam?

[waldo67]

stay with the 108 lobe seperation they make brutal power a 114 is to wide if you could get the cam ground on a 110 it would be alot better than the 114 but i dont think you can stay 108 they perform alot better

[DartGT66]

The MP 292 cam, at least the old design, is pretty high rpm cam and needs some CR to work well. It's not a good choice for low end torque. So, you might either change the cam to a less radical one, or get yourself a loose converter. 400 is a short stroke beg bore engine, and by nature it's a screamer and likes rpm. I would go with a PTC 9.5" converter, they are tight below the stall speed for good driveability and work well at the track too. I have one with 3.23 gears, and am pretty happy with it, works well in the street and does not give up much in the 1/4.

[zij576ca]

Originally Posted by waldo67

stay with the 108 lobe seperation they make brutal power a 114 is to wide if you could get the cam ground on a 110 it would be alot better than the 114 but i dont think you can stay 108 they perform alot better

The 108 CL cam is a drag racing profile. The 114 CL cam will give you the same performance but with a "friendlier" idle and response for street driving. Since you said the car is, or will be, mostly street driven, I'd go with the 114 CL cam, if the 509 is the cam you want. Actually, the original 284/284 "Purple Shaft" MP cam is plenty good for a street hot rod. I used it in my first 440 and was not disappointed.

[waldo67]

the main difference between the 108 and 114 is vaccum the 114 will pull a couple of pounds of vaccum at an idle and have a lazy power curve the 108 will produce a way more aggressive power curve snappier throttle response and and the shift point is the same so the best bang for the buck is the 108 ls and their is no streetability issue with the 108 e

[zij576ca]

In the Mopar Performance catalog the 2 509 cams are listed with these comments:

108 C/L - Drag modified comp
114 C/L - w/improved driveability

Originally Posted by waldo67

...and their is no streetability issue with the 108

Depends upon what your definition of "streetability" is....

Maybe Leonard Emanuelson, a past editor of Hot Rod magazine can explain it better. I quote from his article "What to know about changing a camshaft":

"Lobe separation angle, often referred to as the camshaft centerline, makes a significant difference in the way cams perform. Most resto cams are ground on 110-112-degree centerlines, a good compromise of power and fuel efficiency. Some drag race cams are ground on 104-106-degree centerlines to produce more mid-range torque, but they require many other mods to work successfully."

The full text of the article can be found at http://www.musclecarnews.com/Article...yId=2003-10-04

[wattssf]

Gentlemen,
Thanks for responding. I have the 108CL in my car now. I am about to put this motor in a car 73 Scamp(bodys in much better shape)with power brakes. Will this cam produce enough vaccum for them? Oh yea, I have a guy building me a stall converter w/2800, sound good? You guys are awesome. Thanks for the feedback.

[waldo67]

order a vaccume resivore from summit racing for the brakes and a 2800 will be plenty that 509 on a 108 cl will rock ive run them before in small blocks and they pull like a raped monkey