Camshafts and fuel milege

[steiner_5000]

I was looking at rebuilding my 2.9 and was wondering if adding a mild camshaft would harm the fuel milege at all. I know it will improve power but at what cost? Im not looking to build a racing motor I just want to have a fresh motor with some simple upgrades.

 

[Acepilot1023]

The extra power is because of the intake valve being open longer, thus using more gasoline. I'm not sure how much, but yes, it will hurt your mileage. If it were me, I would say go for it. But I'm not worried about mileage in my truck, I drive it too hard for that.

 

[Big Jim M]

In General

I was looking at rebuilding my 2.9 and was wondering if adding a mild camshaft would harm the fuel milege at all. I know it will improve power but at what cost? Im not looking to build a racing motor I just want to have a fresh motor with some simple upgrades.

Camshafts add power LATER in the rpm range. For the most part if the engine is being used in the same rpm range there is little to be gained by swapping camshafts in a 2.9.

Big JIm

 

[Psychopete]

It's going to get worse because it's going to cause your foot to get heavier.

 

[RustedRanger]

If you get a good cam with specs similar to the stock cam you can gain some gas mileage and power at the same time. Camshaft technology improves all the time and has certainly improved since the 80's when the stock cam was designed. The RPM where the power is improved is determined by the specs,lift and duration. Comp Cams can grind cams for motors not listed in their catalog. If your serious give them a call and follow their advice on the specs. Just don't expect a huge gain from just a cam change.

 

[sblake01]

Without other mods such as head work, ignition, intake, exhaust, etc., what little you'd gain on a 2.9 from a cam change alone wouldn't be worth the expense IMO. Though it wouldn't increase power, putting the later, less crack prone heads on it would probably be a more worthwhile investment.