lookin to work my truck engine ... any ideas??

[bobrock]

i have a 1988 dodge 250 pick up with a 318 engine thats very tired.. im on a low budget and doin all the work myself with the exception of the machining .. im lookin for torque and some midrange .. i definetly want to change the compression ratio .

i would also want to keep the same intake and carb..


i am lookin for that " rumble "at idle im puttin headers ... and dual exhaust but tryin to keep it quiet at the exhaust output
any ideas appreciated....bob

[stepside454]

88 has a carb ?

[R Pope]

A 1988 318 should have fuel injection, are you sure yours isn't a 360? They were carbureted.

[bobrock]

yep ... fuel injection ..

[R Pope]

Your 318 has a roller lifter camshaft, selection is limited. I chucked the injection on mine, I get much better mileage and power with an AFB on a hirise, but its a lot of work. Had to change Everything!
Any mods will throw the computer into a fit, and the '88-89 computer is a dog, can't be reprogrammed. Also its not available any more, so if it cashes in, you're out of luck.

[uglyvaliant]

If keeping the injection is what you want, they are correct, you'll be very limited in what you are ultimately able to do....

...but, there generally is a little fiddle room in there to work with to have a pepier ride.

First things first. If the 'teen is truely tired and down on power due to old age, just having a fresh engine will really do alot to improve it...so don't dismay.

First thing I'd do then would be find ways to free up some available HP.

If keeping the FI, then keeping the intake is obvious as well.

For the heads, you'll want to check the casting numbers...they should have "302" in there which is an excellent head to start with...if not, find some. They'll work great with a stockish 'teen.

Then invest is larger valves for it...1.88's like the 360. Just do some minor bowl work to account for the enlarged valves, and some gentle radiusing of the short side turn should be all you need. This will primarily free up HP. Your flow won't be as high as newer magnum heads...but in the end, it'll be simpler and cheaper than going with magnum heads.

Leave the cam as is...small changes could be made without throwing the computer for a whirl, but you'd want to have the stock cam reground...and while not too expensive, isn't as needed as the neck step.

Work in conjunction with the "swirl port" closed chamber heads by having the block "zero decked" with some good flat top pistons. Your compression will be high, but it'll be relatively detonation ressistant this way. Then just ensure good ring gaps, clearences, etc and go with a go with a higher power ignition (don't know if the ECU gets a signal from the distributer or not...if not, then go with a mopar performance unit...the more aggressive curver and higher power spark you can use will really wake things up for that stockish engine)

Then look to the exhaust. Get some patriot small tube tri-y's that are made for trucks (avail through summit) and true duals and there you go.

You'll definitely free up some power without throwing the cpu for too much of a loop...it's difficult to predict what power gains you'll realize.

The idea isn't to get more air and fuel in, as is TYPICALLY the case. Instead it's to make more power with the fuel and air you have been using all along...freeing up HP where it was once used to get air into and out of the chamber, and extract a more powerful combustion with what's there.

More torque, will certainly result, thus increasing power. There will also be an ability to rev a little more freely and higher resulting from the headwork, thus increasing your power...however, the FI won't have as much flexibility to keep up in this regard so predicting HOW much power will ultimately be realized is difficult.

I certainly would recommend a gear change to improve the torque to the rear tires making it feel stronger still too...

Of course...the BEST answer would be to change to a carbed set up...then you are pretty unlimited and can swap to a 360 with NO probs and get far more torque and HP. And with the correct tunning, you'll get AS GOOD a gas mileage as you did with that primitive FI set-up

[bobrock]

Hey Uglyvaliant ,
that was just the answer i was lookin for ..
thank you very much for takin the time for such a complete response...kudos bro

[R Pope]

The Hall Effect distributor in your 318 has no advance mechanism at all, it's handled by the computer. Minor head work and exhaust mods are about it, I'd say. I spent a grand on my EFI over the past two years, then chucked it when the first stuff I put on needed replacing again. Should have gone with the AFB in the first place!