ideas on a cam
Thread Starter
|
Junior User
Joined: Jan 2003
Posts: 58
Likes: 0
From: Montana
ideas on a cam
I am going to rebuild my 78 f-150 400 looking for ideas for a good cam. At the moment my engine has 130,000 miles on it and am planing on boring it .030 and i have an edlebrock performer intake and 600 carb on order. Any good ideas would be greatly appreciated. Thanks
Postmaster
Joined: Aug 2001
Posts: 4,270
Likes: 5
From: Delaware
These engines like dual energy cams, like Comp Cams 265 DEH.
What compression ratio are you aiming for?
What pistons are you going to use?
As someone else asked, what kind of use do you plan for it?
What compression ratio are you aiming for?
What pistons are you going to use?
As someone else asked, what kind of use do you plan for it?
Cargo Master
Joined: May 2003
Posts: 2,561
Likes: 1
From: Earth
I'm in the same boat as the original topic starter. I'm going with about 8.5:1 compression. It will be for a towing rig, and off roading. It will be in my '79 F350. How is the 268 for mileage? I was actually considering the 260. Any thoughts.
Postmaster
Joined: Aug 2001
Posts: 4,270
Likes: 5
From: Delaware
The 268H has 48 degrees overlap and the 265DEH has 50 degrees overlap. The torque and HP are very close, but the 265DEH holds up better at higher RPMs.
The 270HR has 30 ft-lbs more low end torque and better high RPM power. It also has 50 degrees overlap. The 260HR has the most low end torque at 485 ft-lbs @2000 RPM, but it drops off at high RPM. Although it still beats the non-rollers at 4000 RPM and above. It has only 40 degrees overlap and will beat the others in gas mileage.
The 260H also has 40 degrees overlap and 440 ft-lbs torque@2000 RPM. It falls off rapidly at higher RPMs. This wouldn't be very good towing at highway speeds.
These figures were with 8.5:1 CR, headers, 600 CFM carb, and stock heads. I would recommend porting the exhaust port to gain both low end torque and high RPM power.
The 270HR has 30 ft-lbs more low end torque and better high RPM power. It also has 50 degrees overlap. The 260HR has the most low end torque at 485 ft-lbs @2000 RPM, but it drops off at high RPM. Although it still beats the non-rollers at 4000 RPM and above. It has only 40 degrees overlap and will beat the others in gas mileage.
The 260H also has 40 degrees overlap and 440 ft-lbs torque@2000 RPM. It falls off rapidly at higher RPMs. This wouldn't be very good towing at highway speeds.
These figures were with 8.5:1 CR, headers, 600 CFM carb, and stock heads. I would recommend porting the exhaust port to gain both low end torque and high RPM power.
Trending Topics
Lead Driver
Joined: Mar 2004
Posts: 8,924
Likes: 153
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Postmaster
Joined: Aug 2001
Posts: 4,270
Likes: 5
From: Delaware
If you are concerned about gas mileage, then the less overlap the better. Hydraulic Rollers are the best, but quite expensive by the time you do all the valve train modifications. The 260H is probably OK, if your RPM's are not very high. There is a 255DEH, which may be suitable. I'll simulate that when I get on my home PC.
Postmaster
Joined: Aug 2001
Posts: 4,270
Likes: 5
From: Delaware
The 255DEH has only 40 degrees overlap and the torque is 448@2000 RPM, but it is not very flat it falls to 344@4500 RPM. It is slightly better than the 260H at high and low RPMs.
It all comes down to where do you want your power and how much do you want to spend?
It all comes down to where do you want your power and how much do you want to spend?
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
The 255DEH cam is a good choice for a flat tappet hydraulic cam. It will give excellent mileage and power over the range of speeds that everyday driver truck motors operate, generally 1500-3500 RPM. How many of us routinely cruise around or tow at 4000 RPM? We may occasionally hit 4000+ RPM but the majority of our engine operation time is in the 1500-3000 RPM range.
Of course if you are in to mudbogging you would look for a cam that operates well from 3000-6000 RPM...
danlee, -check out a 260/270HR cam. Just substitute in the proper valve timing numbers from a 260HR and 270HR cam.
Of course if you are in to mudbogging you would look for a cam that operates well from 3000-6000 RPM...
danlee, -check out a 260/270HR cam. Just substitute in the proper valve timing numbers from a 260HR and 270HR cam.
Laughing Gas
Joined: Feb 2003
Posts: 1,234
Likes: 3
From: In the woods of Oregon
I have a comp cams 268/218 494 lift. I'm running a stock 2v manifold, a 500 cfm Holley 2300, Hedmen headers,and turbo mufflers. I can turn my 15.5/35/15 TSL SX's with ease. I have a C6 and 3.50 gears. I can't complain with this single pattern cam. It pulls down low, and seems to rev up well also. For a heavy truck I can get up and go pretty quick.
Hope this helps
Hope this helps
Postmaster
Joined: Aug 2001
Posts: 4,270
Likes: 5
From: Delaware
The 260HR cam has 485 ft-lbs torque @ 2000RPM, and 364 ft-lbs @ 4500 RPM.
The 270HR cam has 461 ft-lbs torque @ 2000 RPM, and 400 ft-lbs @ 4500 RPM.
The 270HR cam is almost flat through 3500 RPM. It would be an ideal all around cam.
While no one is revving their motor to 4500 RPM, if you are towing on the highway at 2500 RPM, and get to a grade that requires a downshift, you don't want to give up 50 ft-lbs of torque because you are in a lower gear and your RPMs are in the 3500 range.
The 270HR cam has 461 ft-lbs torque @ 2000 RPM, and 400 ft-lbs @ 4500 RPM.
The 270HR cam is almost flat through 3500 RPM. It would be an ideal all around cam.
While no one is revving their motor to 4500 RPM, if you are towing on the highway at 2500 RPM, and get to a grade that requires a downshift, you don't want to give up 50 ft-lbs of torque because you are in a lower gear and your RPMs are in the 3500 range.