4.0 bore job

[Hellcat]

I really like my 92 Ranger with the 4.0. I am thinking about building a engine as a over the winter type project. Being a old school guy I think everything is better with more H.P. I looked into several stroker kits, but the price verses the claimed gains seem way out of line. I was wondering if anyone knows how much bore you can add to the 4.0 block ?

I am not going to be racing or anything like that. I am a hunter and will be driving up and down some steep mountain grades, pulling a few trailers etc. The 4.0 that I have dose the job OK but if it had about 50 HP more I think the truck would be about perfect for my needs.

 

[Big Jim M]

Boring it out and changing to new pistons and such won't give you noticeable HP. Swapping camshafts and cleaning up the heads won't either, for your intended purpose. Most gains that can be made in a rebuild are at higher rpm than the little truck usually sees.
Unless your ride is really burnt out a rebuild will not have noticeable gains in horsepower. You will have a more reliable engine but not much else.
For more off road power GEARS are what you need. It's good to have a newly rebuilt engine under the hood.. But don't expect any horsepower gains to be seen below 2,500 rpm. In fact for most power rebuilds there is a loss below that number.
However swapping gears for a lower ratio lots of power can be seen immediatly.
Big JIm

 

[Hellcat]

Boring it out and changing to new pistons and such won't give you noticeable HP. Swapping camshafts and cleaning up the heads won't either, for your intended purpose. Most gains that can be made in a rebuild are at higher rpm than the little truck usually sees.
Unless your ride is really burnt out a rebuild will not have noticeable gains in horsepower. You will have a more reliable engine but not much else.
For more off road power GEARS are what you need. It's good to have a newly rebuilt engine under the hood.. But don't expect any horsepower gains to be seen below 2,500 rpm. In fact for most power rebuilds there is a loss below that number.
However swapping gears for a lower ratio lots of power can be seen immediatly.
Big JIm

Jim

The truck seems to run great doesn't use or leak any oil, engine seems solid as can be. However it's going to hit 150k this year, I don't know how many miles the 4.0 is normally good for but 150k seems like a lot. This is my work/hunting truck. What gears do you think would give me a little more low end without killing me on fuel ? I don't need something that will pull stumps <lol> but with the automatic transmission I could use a little more grunt.

 

[MUDDING B-3000]

my 4L has 300, 000 on her an still purs likes a kitten. i have 456 gears in my truck but also have 36" tires but id say 410 gears would work nice in your truck but if u go up to say 33" tires id put 456.

 

[Big Jim M]

Nineteen years old?

Jim

The truck seems to run great doesn't use or leak any oil, engine seems solid as can be. However it's going to hit 150k this year, I don't know how many miles the 4.0 is normally good for but 150k seems like a lot. This is my work/hunting truck. What gears do you think would give me a little more low end without killing me on fuel ? I don't need something that will pull stumps <lol> but with the automatic transmission I could use a little more grunt.

If that nineteen year old truck really has only 150K on it it is indeed an unusually small amount of miles. At 150K with regular oil changes the cross hatching should still be visable in the cylinders.. Meaning it is almost broke in.
These modern engines should all get 300K on them if taken care of.
What size tires are on that ride? Your gear ratio should be on the drivers door post sticker. We'll need that also.
Big JIm

 

[Bird]

5# of boost would do wonders for your power without hurting the engine at all - Paxton had a kit out specifically for that series of Ranger / Explorer.


Bird