Question About 4.0 Mods and Tuning.

[TheMuffinOfEvil]

If I put new heads and a cam in my 4.0 ranger, wont I need to somehow tune the truck to work with the new parts? If so, how do I do this? Do I get an aftermarket computer or somehow take it to a dyno and have them re tune the stock one?

 

[zukirider21]

http://www.sctflash.com/

i believe they can take care of you. give em a call. they may be able to mess with (re-flash) your stock computer, or they may hook you up with some kind of plug-in job. all i've ever heard about that company was good.

 

[TheMuffinOfEvil]

I would acctully like some more thoughts on this, has anyone else done it? Do the performance heads and cam really make a big difference without rebuilding the rest of the motor?

 

[Big Jim M]

Ok Muff

I would acctully like some more thoughts on this, has anyone else done it? Do the performance heads and cam really make a big difference without rebuilding the rest of the motor?[/QUOTE]

I'll give it a try. Your engine is a bottom end horsepower engine. It should work fine with the stock gearing and stock tire size.

Changing the heads and camshaft will LOSE the bottom end and add to the far end of the rpm range.. Are you planning on 1/4 mile runs? If not then the changes you outlined will most likely give ya problems off road and generally around town.

Most guys that aren't happy with their 4.0's have installed taller tires and in doing so have raised their final gearing.. Making the 4.0 work it's ass off trying to get around town.

The answer for these guys is ALWAYS changing the gears out for lower ones. If they try what you are asking about they are only more confounded with their ride as the off the line efforts only get worse.

Big JIm

 

[TheMuffinOfEvil]

My current problem is this, its a 98 B4000 bone stock with the 5 speed, tire size 30x9.5 R15. This lovely truck has carried me almost 300,000 miles and I have finnaly blown the head gasket, I am doomed to rebuild it at least somewhat. I like the way the truck handles to a point, my biggest beef is that my rpm when on the interstate at around 80 is almost 3000 and I would really like to get that lower. I have about 5000 to spend an was just thinking of doing a full rebuild plus the new heads and cam. If there was someone around my area, charlotte NC I could pay to do the V8 swap I would, but have no desire to tackle it myself. Any advice on what to do instead of the heads and cam or go ahead if that will help with that I want. Any advice would be much appreciated.

 

[ranger480]

I have been in this situation with a ranger. You know your going to at least rebuild the complete engine with that many miles on it. And hope you did'nt do any other damage when your head gasket let go. A v8 swap is great but know what you are getting into, its a lot of work. And if you do it the correct way it will cost you some cash. You dont want to be pushing the truck around. Consider a good rebuild. I am not trying to discourge you from a v8 but give it some thought. Also driving long term at 3000 rpm will not be a good thing. your over half way to the max. If you could tame the rpms down a little your engine will love you. Everyone has their own ideas. 10 years ago i was in your shoes. I rebuilt the truck and correctly geared it. A friend of mine bought it a few years ago and still drives it.

 

[TheMuffinOfEvil]

I am so frustrated right now. I would love the V 8 swap but cant attempt it myself and have been unable to find a garage around here who will do it for anything but a truely INSANE price. I have about 5k to spend and if I want to keep this truck I am doomed to take the head off anyway and I would really like more performance from my truck, I just dont know what to do.

 

[Jay'94]

I'm currently doing a rebuild with a Ford shortblock. Having heads rebuilt by local machine shop. Doing a little flow work and port matching on intake-head-manifold. I hate loosening and tightening headers all the time so not going that route in cramped engine compartment even with the 3" body lift. I did look at a Tom Morano 4.3L stroker, didn't want to spend that much. He has a website, haven't used any of his products though.

 

[TheMuffinOfEvil]

Where on earth did you get your ford shortblock? My ford dealership says they can only get me a remanufactured long block. I would love to just buy a short block and put the performance heads on and go if you guys on the forums think that would be a good idea.

 

[Will]

What performance heads are you talking about? The only ones I know of are sitting on SOHC blocks. If you have $5,000 to spend, install a SOHC 4.0. I guarentee you a 50hp gain with no loss of bottom end torque.

The 4.0 already squeezes the fuel pretty hard. You won't gain torque. As was pointed out, the secret to horsepower is flowing more air. That is accomplished by spinning the motor faster, holding the valves open longer and making the holes larger. All of that makes the motor a less efficient low-rpm pump and a more efficient high rpm pump.

The SOHC 4.0 is a better design and the low rpm loss is barely noticable. The ports are big, round and straight through. It's the motor I would spend money on improving, not the old pushrod motor.

 

[TheMuffinOfEvil]

Where could I get a complete one? I feel like I am mechanically proficient enough to do a straight engine swap but not enough to attempt something like the V 8 conversion myself.

 

[TheMuffinOfEvil]

Also, could someone tell me what gears I have and what I would need to regear down to with my tire size to correct that problem, and if possible a rough price estimate.

 

[JohnPi]

Have you considered just getting a used engine with 80k-100k miles on it for around $300-$500 and just swapping it in? You'll save money, and you'll get something that's put together to factory specs. Rebuilding never makes sense to me on a really high-mileage engine since used engines are so cheap. And then you'll be able to spend some of the saved money on the new gears. I bought a used 1997 4.0L with 75k miles on it for $250 a few years back, thinking mine was on the way out (since sold it because my engine just keeps running). They're out there, and they're cheap if you keep your eyes open.

If you stick with the same engine, you won't have to play with wires, computers, fabrication, etc. Of course, if that's what you want to do, then have at it.

As for what gears you have, there should be a tag on your axle housing that shows what gearing you have. Check the Tech Library (http://www.therangerstation.com/tech_library/Axles.html)

 

[BlackBII]

If it were me, I'd put your motor back together and use the 5K to buy a vehicle that was made to do 80 on the interstate.

But...the SOHC swap is a good idea. Then you could supercharge it. Or, rebuild the OHV and turbocharge it.

 

[TheMuffinOfEvil]

More and more I am thinking of rebuilding the OHV and putting a low PSI turbo on it and calling it a day. Does anyone make a kit for that?