Shorter duration cam on Chrysler 2.2 engine
 

I have an 85 Dodge Daytona with the 2.2 turbo engine. Currently it has the stock 85 slider cam with 240-240 Duration. I have been wondering what kind of fuel economy benefits I would see if I were to swap in a 1989 model year cam that has 228-228 Duration. The 1989 cam is a roller cam.

If I could get a cam for free I would just try it out but it would probably be expensive to get one at the wrecking yard so I must figure out if it would be worth any fuel economy benefit.

Perhaps this sort of cam swap will be comparable to a geo metro cam vs a metro XFI cam.

I drag race a 2.5 motor that was switched from efi to the carb set up. This ia a 87 tall block that uses the roller cam. When you switch out cams you will also need to change the entire valve train too. The roller followers will be needed in addition to the different valves and springs. Since you have a turbo motor you need to make sure you have the turbo exhaust valves to prevent valve damage due to excessive heat.

If you have the slider cam head on a bench you can't hardley turn the cam gear, but the newer roller cam head you can. I think the rollers are also only a 410 lift while the others are a 460. If you shift at anything above a lowly 4600 rpm you are beating a dead horse, while the slider cam lets you rev the heck out of it.

On my car I went from a 2.2 with a Lambros racing 500 lift hydralic (495 actual) to the 410 lift roller and a 2.5 ltr. My 0-60' times improved, my 0-330' times improved, and my 1/8th mile times improved....but at that point the mph was even...the 1000' time was slower as was the 1/4 mile time and speed. I shift into high right at the 1/8th mile mark. The 2.2 efi cars and 2.5s were rated at the same hp but the bigger motor had quite a bit more torque. The extra cubes did not gain more hp due to the smaller lift cam.

Since you have one of our cars you can join the Shelby/Dodge auto club. There are several clubs around and forums too. For links to hot rod shops, forums, and clubs go to: Shelby Dodge Auto Club you do not need to have a Shelby. In the forums you can also find good info on all sorts of things even how to convert to E85. My user name there is Matchbox

Yea if youre looking for FE I would think the 2.5 would be better with its more low end grunt. I know the shadow is a real stump puller. The combination of the 2.5 and the lil mitsu turbo really get it going below 2500 rpms. It had no problem towing my dads ranger home 20 miles.

I had both the 2.2 and the 2.5 and observed the same fuel economy for both engines even though the 2.5 has more displacement. I actually prefer the 2.5 but I will keep my 2.2 since it is in perfect condition and has the pre swirl head pistons and head.

I am not concerned with a loss of high RPM power with a shorter duration cam. My car already has a custom programmable logic module, water injection, and an intercooler. A small loss of power will not be an issue. I am simply trying to figure out what kind of fuel consumption will be observed by going to a shorter duration cam. I found a wrecking yard in my area that is willing to sell a roller cam and followers for $25 but it sure would take a long time time to amount to $25 in fuel savings.