What cam to use in a 318

-
furz4

furz4

Well-Known Member
Joined
Oct 18, 2007
Messages
451
Reaction score
60
Location
Marion, Iowa
This will probably open up a can of worms as this subject has been well covered but I am interested in some recommendations that folks have actually built and ran. Here are the particulars. Care is a 73 Dart swinger 3.23 geared 25" tires factory high stall converter in 904 with a TF-2 shift kit. Engine is 73 318 .30 over, with 9.2 compression measured. Has piston upgrade and running magnum cylinder heads with Hughes springs. Intake is a Dual plane air gap type, 600 CFM carb. Running 360 manifolds for now into full length dual exhaust. I may run headers but as this is a weekend cruiser mostly I don't know if I want to mess with headers at this time. I know the magnum heads flow well and with a better exhaust I was thinking some kind of single pattern cam would be best but if I want to run manifolds and full exhaust I should have something with a little more exhaust duration. Heads have 1.6 rockers and I would like to stay below .500 lift to avoid guide to seal clearance issues. Not necessary looking for maximum horsepower like a magazine build but something that will take advantage of the engine upgrades for good usable power.
 
Lunati's VooDoo 268 would be a good one. Nice and lumpy in a 318.
 
By the specs I bet that would be a good runner probably too much lift for my 1.6 rockers without cutting the guides down.
 
Call Mike jones cams or Oregon cam grinders and tell them your car specs.
 
I haven't heard 3/4 race for a while. I had thought of running something like the 340 manual cam but comp has similar stuff at .050 duration but shorter overall duration in their dual energy series. Another consideration would be I would like to be able to not have to run premium gas so perhaps a longer duration old school grind might be better suited
 
RustyRatRod usually just writes .750 roller!
LMAO!

6/8*’s smaller than a 340/360 would use.

For what you described, I have done. I was very happy with a 218*@.050. It made for a very good driver and power to 5500 with headers, 2-1/2 exhaust, LD4B dual plane and a 600 carb.

This is the max size cam I suggest with a stock converter without causing any issues. You should be able to run in the high 14’s will minimal effort.
 
I have a COMP XE268 in a very similar engine but a 4 speed and I love it.
 
The magnum cylinder heads will need to have the guide bosses cut down to run any decent amount of lift.
 
Here's a comp xe262h with 4bbl and headers with stock heads and cr, so you'd have better heads and cr but slight loss with manifolds, should be an overall gain on these numbers.
https://www.motortrend.com/articles/mopp-0312-318-long-block-bolt-ons/

TORQUE SUPERFLOW 901 DYNO-TESTED AT WESTECH
RPMBASEMOD 1MOD 2
2,000292
2,500287
3,000287338336
3,500272335340
4,000248326330
4500218309319
5,000188285296
5,500250258
HORSEPOWER SUPERFLOW 901 DYNO-TESTED AT WESTECH
RPMBASEMOD 1MOD 2
2,000112
2,500137
3,000164193192
3,500182224227
4,000189248252
4,500186265274
5,000179271282
5,500262270
 
What kind of lift do the Magnum’s handle stock?
 
I would call Hughes, give them your specs, and see what they suggest for you. Get yourself a real Chrysler cam, that is designed around the .904 base circle lifter- verses chevy blanks. :)
 
In my opinion, the 904 tap it diameter cam is overrated.
It shows benefits and Racing that’s so much of the street.

Hughes does have a trick spring kit for the magnum head for a lot more left. I think it’s two 550.
 
rumblefish360 said:
What kind of lift do the Magnum’s handle stock?
Click to expand...
i hear the .500 number bandied about, and after that it's spring seat and guide cutting time.

however i have heard of people running the 509 or 512 cams without doing anything but the hughes spring kit.
 
My crate cam supposedly has around .509-.513 lift don't know with what retainers.
 
Dan the man said:
Isn't this cam kinda big for a 318 with a 9.2:1 CR? 224* / 230* duration @ 0.050"? Just asking
Click to expand...
If you say so.

It works great for me but just like OP I am not a bracket racer or a number chaser. Make of that what you wish.
 
Dan the man said:
Isn't this cam kinda big for a 318 with a 9.2:1 CR? 224* / 230* duration @ 0.050"? Just asking
Click to expand...
No. I’d recommend that cam with a minimum of a 2,500 stall converter, & a min of 3.55 gears with the typical 727/904 trans.
 
Dan the man said:
Isn't this cam kinda big for a 318 with a 9.2:1 CR? 224* / 230* duration @ 0.050"? Just asking
Click to expand...
It's kind of considered middle ground for a street cam, above this level each step up you generally tend to start really trading bottom end power for top end power and gears stall starts to become more and more necessary. Obviously not set into stone.
 
You must log in or register to reply here.
-

Back
Top