SP2P 2bbl worth the effort?

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gliderider06

gliderider06

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For a stock 318 ramcharger, would a 2bbl sp2p intake be worth the effort over the stock intake? I'm contemplating on buying one for my Ramcharger like this one.
20181018_173804.jpg
 
If your spending a lot of time and miles on the Hwy. it could be worth the effort. The vehicle is heavy & a aerodynamic brick.

How is your state of tune and A/F ratio? That is where I would focus.
 
Thanks. I already have a performer and a cast spreadbore, and a Holley 80457. It gets around 15mpg already, and I always try to improve on it. It's basically stock except for HEI ignition and dual exhaust.
Thanks, Paul
 
I think the OE 4bbl. & the Performer are about as good as it gets intake wise. If your carb is jetted to be dead on to slightly on the lean side for cruise, then that’s set. The best I can suggest after that would be a un restrictive air filter. LOL

Exhaust wise, be it off exhaust manifolds or headers, your dual exhaust is the way to go. Muffler choice has a small effect. It can be helped (minimally) with a H or X.

Otherthings, going on down the line would be ignition. I have found good results with the MSD 6A box and the stock distributor.

What is your tire size and gear ratio?
 
My first Magnum, a ‘79, had a 360 where I re equipped the 360 in the above fashion. Trap door air cleaner with a K&N filter, 600 AFB, iron intake, dual exhaust @ 2-1/4 off of the exhaust manifolds with an H pipe. The MSD fired the stock distributor.

The rest was a stock 904 & 2.76 gears rolling on 235/60/15’s. The best I would get was 20 mpg’s on the Hwy. But I did have an aerodynamic advantage as well as a weight advantage @ 3600 lbs.

Squeaking out more mileage out of the Ramcharger will be difficult. From where you stand now, anything you do for mileage will be minimal and small advancements. Some may not be cost effective.

Thinner & taller tires
Lower the vehicle
Lock up trans
Gear ratio change
Lighter vehicle weight
Less parasitic drag on the engine.
Oh! I forgot about a cam change.
 
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From what I have read, the sp2p intakes were simply to replace early OEM single plane intakes with dual plane intakes, 2 brl and 4 brl versions. It may not flow much better than a cast iron dual plane.
 
So for the beast, other than timing chain and oil pump, it's untouched. Has the factory Holley 2bbl. I have a K&N air filter in the stock housing with fresh air tube hooked up to housing. Manifolds with 2-1/4" pipe run into hooked turbo mufflers and a H pipe before the mufflers. Ignition is factory electronic converted to HEI, heavy and a med-light springs. 8* initial, 36* mechanical and 54* with vacuum.
Truck runs 3.21 gears and 31x10.50x15 tires. The old girl purrs at 62mph and actually gets better milage than my 97 Ram. Always try to improve on it, but i think I'm just about as best I'm going to get with the current set-up.
Thanks
 
Probably so. I think from here on out, it would be your own scientific experiment in the mileage search.

I found the MSD an advantage since it is a multiple spark at low rpm. Consider this and other timing specks from the distributor. It appears you have a few degrees more than I expected. But then again, it is what ever the engine likes.

Keep experimenting!
 
The four barrel having, smaller primaries, will get superior mileage over the two barrel, especially the large pattern one. I like what what I have read about the Edelbrock StreetMaster and the Offy Dual-port, but SP2P was developed for motorhome usage and is probably going to make the most difference on mileage. Are you running an EGR? EGR would take a lot of tuning (Special distributor curve and lean cruise circuit) but I think it would yield the largest single gain. Is this your '87 and does it have 302 high swirl heads and roller lifters? Go with a Tri-Y header set to maximize your intake combination. There are some R/V specific cams that may be worth looking at to improve mileage too. Just read the rest of your posting, I imagine Rob is right, you are very close to all your going to get.
 
I have a personal preference for a small primary 4bbl. on mileage searches. I have very good results with small square bores and small primary TQ’s.
 
rumblefish360 said:
Probably so. I think from here on out, it would be your own scientific experiment in the mileage search.

I found the MSD an advantage since it is a multiple spark at low rpm. Consider this and other timing specks from the distributor. It appears you have a few degrees more than I expected. But then again, it is what ever the engine likes.

Keep experimenting!
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I've spent many many hours with the distributor, springs, limits, vacuum cans etc... maybe, an MSD is the next step.
It has the EGR hooked up and functional. It does not have a roller cam and it has 302 heads.
Thanks
 
FWIW, I didn’t mention that my Magnum was also under the states thumb of the upgrading to Ca. emissions. I had to have a working egr valve, vapor canister hooked up, catalytic converter or as in my case, 2 of them. I got them from Summit and they were a high flow design. It did pass emissions tests.

The otherwise stock ‘79 - 360 did keep up with stock mustands of the day.
 
Hay Rumblefish I, feel sorry that you have stupid smog laws in N.Y.. My friend up in Newburg can't get a smog because of a cat that is not available but you folks can have rusted floors and rockers . Makes no sense . Can't have a gun but can get a 9 month abortion . I moved to N.H. just because of the b.s. in southern new England .
 
383Scampman said:
Hay Rumblefish I, feel sorry that you have stupid smog laws in N.Y.. My friend up in Newburg can't get a smog because of a cat that is not available but you folks can have rusted floors and rockers . Makes no sense . Can't have a gun but can get a 9 month abortion . I moved to N.H. just because of the b.s. in southern new England .
Click to expand...
Thanks but let’s correct something.

“You can have a gun in NY. Rifle or pistol “
It is actually easy to get one.
It’s the wait time & jumping through hoops that is retarded!

New York is not southern New England. There is no Southern New England. New York. It is the North East.

I agree on stupid smog laws!
I’m for laws that make sense, not to make money or Inconvenience people.

Aftermarket cats are available. As long as a cat is there and the engine passes smog is all that counts.
 
I think EGR got a bad rap because people didn't understand it, all that well.
I wouldn't retrofit it to my engine unless forced to, but I have had good success tuning with/around it. It's a Part-Throttle device and when correctly working, you should never know it's there, under load or at WOT.
Anybody running a long-period cam already has some to a lotta EGR at rpms up to 2000 rpm or perhaps a lil higher. Chrysler exploited this in the early years, and so were one of the last car-companies to adopt EGR hardware.
 
AJ/FormS said:
I think EGR got a bad rap because people didn't understand it, all that well.
I wouldn't retrofit it to my engine unless forced to, but I have had good success tuning with/around it. It's a Part-Throttle device and when correctly working, you should never know it's there, under load or at WOT.
Anybody running a long-period cam already has some to a lotta EGR at rpms up to 2000 rpm or perhaps a lil higher. Chrysler exploited this in the early years, and so were one of the last car-companies to adopt EGR hardware.
Click to expand...
FWIW, The EGR valve closes with a lack of vacuum.
I forgot what I tested it to BUT it would be similar to going around someone on the Hwy. or getting in the Hwy. I think is was around 10 or 12 inches of vacuum.

Once the valve closes, it’s just like any other pre smog intake, just air and fuel running through it.
Magen the valve is open, it introduces exhaust which is an inert gas. This allows you to advance the timing more than without it. That is also IF you can use it or need it.
 
And being that the exhaust partially neutralizes the fuel/air charge and increases enthalpy of the mixture, you can run a very lean cruise circuit while the EGR is on. Going with programmable EFI makes it work even better and yields larger gains, but for the cost, it better be a big difference. Affordable Fuel Injection would be my go to, all over the counter nineties ford based system.
 
Back to the original question. The 4bbl sp2p is great when used for its intended purpose. I've had a couple on 318 trucks and they are great for low end power, pulling a load at lower rpms. It was just what I needed in a truck that hauled firewood and building materials.
 
IMO, I don't think either one will be of much benefit. That's a heavy vehicle.
 
I had a 84 Ramchargers with a stone stock 318 2bbl. Dual exhaust. 3.21 gears. 14 miles to the gallon. 31x10.5 tires. I put in a 360 4bbl. 17 mpg. Carter Thermoquad and performer intake. Kim
 
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