Specs On The Cam For 383 Road Runner Engine HAPPY 4th TO ALL!!

[bake68rr]

It's my understanding one of the things that makes the 1968 Road Runner engine different from other 383's is the cam. Does anyone have the specs for the two cams?
Thanks

 

[BeepBeepRR]

Factory Canshaft Specifications

Factory Camshaft Specifications Factory Camshaft Specifications '383 High Performance' Lift............. .431"/.431" Duration...... 268*/268* Overlap....... 48* Found in the; * 383/330 HP ............ {1963/1964/1965} * 426/365 HP ............ {1964/1965} Regarded as a 'Mild...

www.forbbodiesonly.com

 

[bake68rr]

Very good, to make sure I am reading it right, 1966 through 1970 standard 383 is
Lift............ .425"/.437"
Duration..... 256*/260*
Overlap...... 32*
The 383/335HP for 1968 and 1969 it is listed under '440 HP'
Lift............. .450"/.458"
Duration...... 268*/284*
Overlap....... 46*
Is this correct?
Thank you BeepBeepRR

 

[R/T Boy 67]

Yes, the 383-335 hp used the 440 hp cam

 

[GTX JOHN]

NHRA specs that are often generous
when given by Mopar:
268/284
.467/.483

As my elder memory recalls

 

[Photon440]

Very good, to make sure I am reading it right, 1966 through 1970 standard 383 is
Lift............ .425"/.437"
Duration..... 256*/260*
Overlap...... 32*
The 383/335HP for 1968 and 1969 it is listed under '440 HP'
Lift............. .450"/.458"
Duration...... 268*/284*
Overlap....... 46*
Is this correct?
Thank you BeepBeepRR

The only variation was cars with air conditioning, which still came with the standard 330 hp. cam.

 

[bake68rr]

Hi again, I hate to be a pain, does anyone have a service manual, publication or documentation showing the specs for the 1968 383 Road Runner cam? The engine builder installed a standard 383 cam, when I found out I showed him the information above. He said he would be more than willing to make it right at no cost if I had some type of documentation. I understand his point so any help would be appreciated.
Thanks again

​

 

[68BabyBlue]

The only variation was cars with air conditioning, which still came with the standard 330 hp. cam.

My 440 GTX has a standard 383 cam that was installed by the original owner, who owned the dealership when the car was new. He wanted maximum torque when using the car as a tow vehicle, and running factory A/C. It’s still in place
today, and works nicely in a street driven car that will never see the track. Used in this fashion, I prefer it over the factory high performance cams I had in previous stock GTXs.

 

[bake68rr]

My 440 GTX has a standard 383 cam that was installed by the original owner, who owned the dealership when the car was new. He wanted maximum torque when using the car as a tow vehicle, and running factory A/C. It’s still in place today, and works nicely in a street driven car that will never see the track.

Hi 68babyBlue, I had a full restoration of the car done and would like to keep everything the way it was from the factory. That is the way I received it from the original owner 51 years ago, even have the original hub caps and Inland shifter. I may have to accept it but given the choice I'd rather have what it came with.

 

[Jeff Peterson]

Here’s a factory ‘68 ad that actually lists the cam specs

 

[68BabyBlue]

Hi 68babyBlue, I had a full restoration of the car done and would like to keep everything the way it was from the factory. That is the way I received it from the original owner 51 years ago, even have the original hub caps and Inland shifter. I may have to accept it but given the choice I'd rather have what it came with.

I appreciate your feelings. My GTX is restored to near concours, my decision not to go 100 percent oem was made easy by the fact the few mods on the car were done by dealer long before the car was ever titled. As a practical matter, no observer, hearing the idle, or riding in the car, has ever detected the cam change, including the guy who finally sold it to me after 28 years of ownership.

 

[oldbee]

My ad is a little different

 

[68BabyBlue]

My ad is a little different

View attachment 1689732

These are the specs I’ve always seen, never saw the numbers in that RR ad before, got my curiosity aroused.

 

[bake68rr]

These are the specs I’ve always seen, never saw the numbers in that RR ad before, got my curiosity aroused.

68BabyBlue and oldbee EXCELLENT, should do the trick.
Thanks so much!

 

[RemCharger]

Hi again, I hate to be a pain, does anyone have a service manual, publication or documentation showing the specs for the 1968 383 Road Runner cam? The engine builder installed a standard 383 cam, when I found out I showed him the information above. He said he would be more than willing to make it right at no cost if I had some type of documentation. I understand his point so any help would be appreciated.
Thanks again

​

 

[lewtot184]

The numbers in the road runner ad reflect the whole closing ramp. The 268/284 numbers cleve off part of the closing ramp. I went thru this trying to measure seat timing once. The only way i came up with 268/284 was measuring the opening at .006" and closing at .009". Kinda crazy but those cams have very long closing ramps. Intake lift was .447, exhaust was .460. 115lsa with 2 degrees of advance ground in.

 

[oldbee]

The numbers in the road runner ad reflect the whole closing ramp. The 268/284 numbers cleve off part of the closing ramp. I went thru this trying to measure seat timing once. The only way came up with 268/284 was measuring the opening at .006" and closing at .009". Kinda crazy but those cams have very long closing ramps. Intake lift was .447, exhaust was .460. 115lsa with 2 degrees of advance ground in.

Soooo, Plymouth lied again?!!! The Dodge’s I remember,always ran rings around the Plymouth’s. ( from “old” memories).

 

[lewtot184]

Soooo, Plymouth lied again?!!! The Dodge’s I remember,always ran rings around the Plymouth’s. ( from “old” memories).

actually the Plymouth add is accurate. I don't get the reasoning for 268/284.

 

[Photon440]

These are the specs I’ve always seen, never saw the numbers in that RR ad before, got my curiosity aroused.

The advertised duration numbers are usually looking a little bigger than numbers taken at .050" lift.

 

[hunt2elk]

What is the "Power Pack" column under the 440 cam specs entail?