road car cam for my 318

-
Funny thing is if these cams were so great can't find much about them.
junkyardhero said:
super useful chart. absolutely zero information to be gleaned except for what could be interpreted.
Click to expand...
The few lsa cam shootouts show about a 3 lbs-ft average per degree of lsa so if held about the same for this engine a 112 vs 108 probably be around 12 lbs-ft at peak torque.
 
273 said:
Funny thing is if these cams were so great can't find much about them.

The few lsa cam shootouts show about a 3 lbs-ft average per degree of lsa so if held about the same for this engine a 112 vs 108 probably be around 12 lbs-ft at peak torque.
Click to expand...
That's an increase but not by much. If you are class racing, it may make a slight difference. Street, street strip, or Et racing. no big whoop.
 
Bewy said:
There is a LOT to learn from the chart below. These are some of the cams listed in DVs SBC book. As the engine cubes increase, the LSA gets tighter [ down to 104 for a 434 cu in ].

The most important aspect to take from below is that no matter if the engine is mild [ street/tow ] or wild, the LSA does NOT change for that engine size. What changes to alter the rpm range is the DURATION.

View attachment 1716319134
Click to expand...
That's certainly one opinion.
 
273 said:
Funny thing is if these cams were so great can't find much about them.

The few lsa cam shootouts show about a 3 lbs-ft average per degree of lsa so if held about the same for this engine a 112 vs 108 probably be around 12 lbs-ft at peak torque.
Click to expand...
OR any copycats. When an idea actually WORKS, others come out with their own versions. You know......like Harold Brookshire. You can STILL see his influence in the camshaft world TO THIS DAY with just about every single modern grind out there and a LOT of grinds that have been around for decades. I'm not knockin DV. Lord knows he's a genius. But to grasp onto his ideas, theories and opinions and call them gospel for everything under the sun is on the other side of stupid.
 
toolmanmike said:
That's an increase but not by much. If you are class racing, it may make a slight difference. Street, street strip, or Et racing. no big whoop.
Click to expand...
12 pound feet might not even get recognized on the butt dyno.
 
I went back to the OP's original post. An OD transmission with a 2.94 rear gear is suicide. Especially with anything but a stock cam especially if you are looking for low rpm efficiency at highway speeds. That's just a wrong combination.
 
toolmanmike said:
I went back to the OP's original post. An OD transmission with a 2.94 rear gear is suicide. Especially with anything but a stock cam especially if you are looking for low rpm efficiency at highway speeds. That's just a wrong combination.
Click to expand...
Probably could use more gear, 2.94 x .69 = 2.03 good ratio for Bonneville :)
 
I will disagree with the above.

The somewhat "granny" 1st in the 833OD is less of a hinderance and more of an advantage with a numerically lower final drive ratio.

However, a cam that has an operational range above the cruise RPM is certainly an issue.

Find one that "comes in" sooner, even one that's "done" at 4500.

Puts all your torque in the real world operating range.

Just above idle at freeway speed is not a bad thing.
 
YY1 said:
I will disagree with the above.

The somewhat "granny" 1st in the 833OD is less of a hinderance and more of an advantage with a numerically lower final drive ratio.
Click to expand...
It's a 42RH 4 speed OD not a 833OD
 
What is first gear in an 833 OD and what is the overdrive ratio?
 
I believe car 833OD are .73 and truck 833OD's are .69
 
Courtesy of Brewers-

1729784906083.png
 
toolmanmike said:
I went back to the OP's original post. An OD transmission with a 2.94 rear gear is suicide. Especially with anything but a stock cam especially if you are looking for low rpm efficiency at highway speeds. That's just a wrong combination.
Click to expand...
Not if his location is anything like Southern California. We cruise at 85mph here. If you’re going 60mph you’re getting run over.
 
str12-340 said:
I'm curious as to why that would make a difference - the 42RH also has lower first and second gears than say a 904 or 727
Click to expand...
2.74 vs 3.09

I take more issue with a final 2.03:1 in OD that's a pretty high ratio.

Your engine only needs to make like say 40-50 hp on the highway question is at what rpm (among other things) can it be made most effectively at.
 
Last edited:
@Newbomb Turk I asked for tune up info in post 12. Crickets. I guarantee (and I think you feel the same) that there is more mileage in the current setup.
 
toolmanmike said:
That's an increase but not by much. If you are class racing, it may make a slight difference. Street, street strip, or Et racing. no big whoop.
Click to expand...
If you are looking for mpgs its alot
my comp 268 110 lsa vs 340 cam 114 is night and day
Hi comp motors are more efficient all else being equal with 8.51 to 1 a lower lsa will pump up the psi and help all the way around.
108 will give more chop 110 is good
 
TT5.9mag said:
@str12-340 since you didn’t give a reference to what cam you’re currently running (beyond an rpm range) and it seems all you want is a new cam, here is where I’d start as a recommendation.

https://www.compcams.com/xtreme-energy-206-212-hydraulic-flat-cam-for-chrysler-273-360.html

I think in a 8.5:1 318 with overdrive and tall gears, (and if you let me get rid of the avs2 carb and tune a Holley VS for it) I could get reasonable mileage with it. I think 18-25mpg is not too far fetched.
Click to expand...
str12-340 said:
current cam is a Crane 15005
adv. duration - 272
.454 lift
1800 to 5200 rpm

Not the right cam for my use...
Click to expand...
 
That's the newly named old name "250" cam.

Was mentioned above.

800-4800 range.

Still a bump or 2 over stock with 432/444 lift.

I like it.

I have the next one up "256" cam on the shelf.
The only real world test info I have is a member who has one in a truck.
I'm itchin' to see how it does in a car.
 
This thread my be the winner, or at least in the running for "best thread about a realistic 318 cam*".
 
You must log in or register to reply here.
-

Back
Top