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Suggestions on cam choice for a 318 built for torque?

R

Reed

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I recently got what think is a true 44,000 original mile 1982 Ramcharger powered by a 318. The truck is totally stock and was maintained at a local dealership. The truck has part-time four wheel drive and is a big heavy un-aerodynamic box.

I would like to maximize fuel efficiency on the truck since it will be my daily driver. I am not expecting to get 20 MPG. Heck, if I got better than 13 I would be happy. The truck has 3.2 gears in the axles so I am only spinning around 2300-2500 RPM on the highway. I am going to use it as a daily driver and won't be racing it or off-roading it. I am thinking that a build focused on low-rpm torque rather than high RPM horsepower is my best option for increasing MPG.

To that end, I have secured an old Edelbrock SP2P two barrel intake and a set of 1987 318 heads that are the 302 swirl-port casting. I am going to keep the stock Holley 2280 two barrel carb and the stock tiny valves in the heads. I am also going to keep the EGR functional.

My question is the cam. Is it worth it to swap out the stock 1982 two barrel cam? If so, what cam would pepole recommend for low RPM torque in a 318 running the stock small valves and two barrel carb? I am trying to keep it running smooth and just improve fuel economy and torque.

Any constructive input is appreciated and welcome. Thanks.
 
You sure about the part time four wheel drive?
The addition of locking hubs will not make the four wheel part time. It will still be pulling the transfer and differential. Without the proper transfer case.
If you want to increase gas mileage ditch the 2 barrel and go to a 4 barrel small speadbore carb. 600 cfm would be plenty. The front barrels are way smaller than the 2 barrel. The back 2 only open when needed.
If I can get 15 out of an 82 D150 with 3:54 gears and little red 360 your 13 should be achievable.
 
Positive about part-time four wheel drive. The transfer case goes 2wd-4wd-n-4 lo. Still has the factory automatic locking hubs in the front. Part time 4wd was introduced in 1989 on the Ramcharger. Prior to that Dodge used full-time 4wd.

If I could find an Edelbrock SP2P four barrel intake or an Offenhause dual-port four barrel intake I would run a Holley 4360 450 CFM spreadbore carb. Until I can find one of those intakes, I am going to stick with the factory two barrel. That way I can keep the stock EGR system and not have to mess around with the kickdown linkage.

Any thoughts on a cam choice? Stay with stock or find an aftermarket "RV" grind?
 
Have not found an rv cam yet that was good for gas milage. But gas mileage and RV does not compute either.
I can vouch that our w350 class c with 440 will get 8 mpg on a good day. Is way less aerodynamic than your 4 wheel ramcharger and weighs it at just under 11000 lbs. and all that with 4:11 gears. Just do not drive over 55 mph.
 
Sorry, my post should read part time 4wd was introduced in 1980, not 1989.

By an "RV" cam I meant a cam designed for low RPM torque.
 
Part time 4 wheel drive was the norm before 72. Why anyone thought full time was better is beyond me.
As far as cams go you will just need to start compairing specs to your existing cam.
With the national speed limit of 55 in 82 and the 3:23 gears it has i doubt the 318 was built for high rpm torque.
As for part time 4 wheel the front drive shaft spins free in 2d with the engine shut off hubs unlocked and trans in gear or park?
 
Reed said:
Sorry, my post should read part time 4wd was introduced in 1980, not 1989.

By an "RV" cam I meant a cam designed for low RPM torque.
Click to expand...
I know what you meant its just that most rv's do not run low rpms unless 3200 at 55 is considered low rpms. That is something to take into consideration.
An e body small block cam may fit the bill much better. High rear ratio and heavy car they were not uncommon in the 60s and where capable of some decent gas mileage.
 
I'm looking for something similar, low end torque. There are custom cam grinders. Elgen Cams, which I think is in California could be an option. You fill out a form giving the specs. on your engine and what you want. They regrind your cam.
Crane Cams has some off the shelf cams, couple of them claim low end torque and smooth idle.
Just curious why you want to keep the EGR functional?
 
Properly functioning EGR potentially allows one to run more timing advance without pinging. I still need to verify the system works properly but for now I want to keep it. If I run into problems with it, disabling it is no big deal.

Perhaps I had my slang terms confused. I always understood an "RV" cam referred to a cam designed for low RPM torque in big heavy trucks. A cam designed for towing or for driving around in a heavy RV. I did not think an RV cam meant it was a cam specifically designed for using in a recreational vehicle.

I guess I will do some research and give Oregon Cams a call. I know they do custom grinds and they are almost local to me.
 
Far as I know "RV" cam is like you say, low rpm torque, heavy vehicle, street cams. RV just a term because that's the type of vehicle where they are commonly found. I don't know the specs. on an RV cam. And I suspect there are several different grinds that would qualify for that generic term. Personally, I think I'm going with a custom grind.
 
A custom grid would be a wise choice. But I would stay away from anything labeled rv cam just because of stated reason. Gas RVs usually do not run at low rpms.
 
I just looked and Comp has quite a few that are what your looking for. I would call and get there recommendation
 
Hey reed,
Look at lunati VooDoo series cams. Lunati cams are best for torque in mopars. Comp cams are not for Mopars. They just don't understand that mopars like a four pattern cam. Mike form MRL swears by them and, I do to. As for the 450 holley you will have nothing but problems with starving the engine.
Your on point with the heads but, intake and carb you should reacess the parts choice. A good intake would be a weiand action+ or street warrior and, the carb I would go with the new demon 625 nice small primaries and easy set up. The cam I'd go with a Lunati VooDoo 10200701. Then long tube headers for even more low end.
Now remove the fan for less drag, Heat control under the hood, and upgrade the ignition system, I've been trying out the plasma cores and a set of magnecor 10mm wires, High output coil and, upped my mileage by a full 1.5 MPG next is a fitch fuel cleaner. One other thing move the coil to the fender or firewall for less heat soak.
My build 318, 30 over hypereutectic speed pros with polished crowns a set of total seal rings. all king coated bearings, stock 360 crank lightened knife edged, polished stock rods for windage VooDoo 270/279-515/530, Lunati roller lifters, speedmaster 1.6 roller rockers, Cloyes street billet true roller chain, Melling HV pump with bottom cover oil P/U. home built baffeld oil pan, windage tray, lifter valley baffle. glyptal every surface that oil touches inside of block. toped of a set of heavily ported 302's, edelbrock air gap rpm performa intake and 725 cfm demon, speedmaster pro billet dist., and the rest you know 15MPG and sounds awesome 366 HP and 354 TQ
 
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