I have a '92 B250 conversion van with a 318 and auto trans. I use it for trips etc. and to tow my pop up camper which weighs about 3000 lbs without gear. I was camping in the mountains this weekend and when going up a pretty steep grade for about 3 miles I was overheating. Granted it was a pretty hot day and the air was on in addition to towing a load. I know, I know, already 3 strikes against me. It could barely get to 30 mph in 2nd gear going up the hill.

Home now so obvious plan for the week is to change/flush antifreeze. So here's my question: Is there any advice for turning this into a better tow vehicle? Its really only used for trips so I'd like to be able to count on it. It seems to lack power I'm guessing due to weight of a conversion van plus camping gear, camper, people etc. Has anyone changed their cam to get a little more power out of the motor? Has anyone changed their radiator to get better cooling?

Advice appreciated!!

 

The first thing I would do is calculate the actual load you are trying to carry as that number will dictate the best approach. The 318 is a helluva strong motor but if the primary intended use is to pull 10,000lbs uphill with the a/c on, it would not be my first choice.

I can talk cams all day The Dodge 318 actually has a pretty hot cam for a factory engine (and not just the magnum, any 318). It is considered a performance upgrade to install a 318 cam in a 360. The lift could be improved and that will translate to more usable torque and better gas milage but the improvement over stock will be minor without additional modifications like a free flowing exhaust and better intake. I installed 1.7 roller rockers on mine and gained maybe 12hp/24lbs torque, but I think your non-magnum 318 comes with 1.5 rockers and I am told these 1.7 rockers will not work on that.

If you need to add more than about 30 hp/50lbs torque the simplest approach would be to swap in a 360.

If you are happy with your engine and have no interest in swapping it then the usual towing modifications would be: change to a lower rear gear ratio and add a large 1500+ cfm electric fan installed on the front of the a/c condenser. There may have been better radiators available at one point but today a dual core copper/brass is the best one I can find.

 

I think he has some kind of issue, modifications won't help. I also tow with my 94 318, four dirt bikes in my 8 X 10 all steel box trailer, camping gear, generator, everything but the kitchen sink, and 4 people. Going up Cajon Pass here in SoCal, I could easliy accelerate to 100mph if I needed to. So there's got to be some kind of issue with his engine if he's slowing down to 30mph, thats just from my experience.

 

Unlike your '94, the '92 Dodge van came with a non-magnum 318 rated 165hp, and somewhere around 240lbs torque. This is barely enough power to do the job described. Given normal wear and tear it may be putting out 20% less than that today. Just my opinion.

 

Blackvan is right you should check how much the Van is rated to tow in the manual. I believe it is something like only 2000 lbs and then again it also says it is more of an optional thing rather than something it is designed to do.

What I would change is your oil and filter you use. you want to upgrade them both. Also check your ignition coil, it is likely warped and a new one will give you extra power

 

Agree with most of the replies, pull quite a bit with a 360 and 3.90 rear end.

Bring your van and trailer to a private scale and find the weight. Then you know what # your pulling.

If your pulling 12-14,000lbs with a 1992 318 then you know the problem,
these vans are not featherweights.

Again I tow with my vans so I would love to help you but get a baseline with your weights.

 

I was thinking the same thing...If the motor is over 100-150k, it just may be plain ol worn out.

I would do a compression test to make sure the engine is compressing at 120+...if it isn't, you know what the problem is...

It also could be the tranny. But, still, a 20 year old engine without any major work would have problems with what he is describing.

 

Thanks for all the advice, this gives me a direction to go. I checked the axle ratio which is 3.5 and the owners manual lists towing capacity for that with the 318 @ 5000 lbs. If all is right it should tow 3000 lbs. fine. I have a Pilot travel center near me and I'll take it down there and have it weighed on the truck scale with and without the camper. I really should do a complete tune up since I've had it for 2 yrs and I really don't know when it has had one prior to me owning it. The plugs look good but I'll bet the coil and plug wires are original...

 

My two cents of observation is that you have an older conversion van with passenger tires. You have increased weight because of all of the conversion stuff hanging on the chasis, you are pulling a nominal weight, sure, but you said you were loaded down with gear and stuff, on a long uphill, with the AC on... I would bet the old girl was doing her best just to give you the 30MPH...

You might try load range E tires that you can pump up to 80# to decrease rolling resistance. You might also try turning off the AC while doing these long uphill runs and maybe cut down the weight of your gear just a bit?

Stev posted a message awhile back about increasing MPG's. I tried most of his tricks on my van, including putting new grease on the front wheel bearings, going to synthetic oil in the diff, and keeping the load range E tires pumped up. I tow a 1500# trailer with a 318 but have a 3.92 rear end which is much better for towing. If I keep the pedal mashed and downshift out of OD I can keep the speed up to 70 with my van loaded, but I do turn off the AC while climbing the hill, and I also let her slow down a bit as I top the hill to try and conserve some gas.

Have you checked the condition of your transmission fluid lately? Maybe the tranny is due for a tune-up at a pro shop.