200 or so HP possible??

[rock883]

I have a 91 explorer, and I would love to have more power(WHO WOULDN'T). I want to maybe get about 200 or so horsepower out of the 4.0. I know its possible, but what could I do to get it? I know you can get the engine bored over, put a cam in it, and all that other valve train stuff, porting and polishing, and all that great machnining stuff. I am about to get a 2" suspension and 33" tires (already have 3" body lift) and probably re-gear, so that will put me out about ($800 or so). But when I get more money saved up over the rest of the summer I would like to get more power, can I get around maybe 175 hp for something like $500-700 or so?? I probably woudn't do any of this stuff on my own and will be having a shop do it, so how much is labor for this stuff?? Thanks

 

[mike91]

The easiest way to get the horsepower is to throw a NOS bottle in your truck. Vanir technologies jsut came out with a new adjustable Vex bottle that comes with three different jets I believe - 55hp, 65hp and 75hp and changing jets takes around 5 minutes. It takes a competent mechanic around 4 hours or so, so figure in the labor rate $50? It would cost around $800-$1,000 total with labor, but you will definitely be over 200 horsepower easily. PROS: You will have the hp when you need it and you will feel a big difference in acceleration. CON: You have to handle with care - a 55hp jet would probably be best to use and you can't use it all the time - unless you want to burn out the engine or pistons.

You could swap for some Comp Cams and then have your heads rebuilt - ported and polished, new performance springs, etc. The camshaft should cost more than $200 for the part, maybe $150, but the head work could be a little more - in the area or $500 - $700 for fully rebuilt, performance heads. Unfortunately no one makes them for us so we have to have a machine shop do the work. PROS: High quality, natural horsepower always there when you need it.... all times. CONS: Costs more than the NOS when you factor in the labor.
** You can consider more engine work, but I am just showing the basics - the camshaft and the head will flow air more efficiently throughout the engine. My guess is that you would be able to achieve 200hp and a set of headers wouldn't hurt at all.

 

[Dignan]

Replace the exhaust, do something for air intake (MAF, Throttle Body, KKM, K&N, Drilled Air Box, etc.), and get a chip (they are on sale, check out the main page). You should be able to get 200hp and it would be easy. You could do the work yourself, I know you don't want to, but it is very easy stuff that most competant people should be able to handle.

 

[flyguy]

Im pretty sure you can get to 200HP with just bolt on parts like Dignan suggests. All do it yourself stuff. Then you move on to the engine work.

 

[SteveVB]

I think that with headers and a chip you could get what you want- 175hp-190hp . It would also be in your dollar range. Chip $200, headers $400-600 installed(educated guesses!). Tb if you want, wait on the MAF.

After that it gets expensive- the cam parts would cost close to $700 ( cam,lifters, pushrods,springs, timing chain) ,with no labor $'s to put it in. Good for maybe another 8-10%. If you are doing a rebuild the incremental cost is not that big but on its own costs some $.

Search the site someone had their mods dynoed and I think was getting the HP you want with headers and a super chip.

Have Fun

 

[flyguy]

On the subject of cams.. I was looking at the cams from Vanir Tech. http://www.vanirtech.com and all they said about the cam was that you needed new pushrods. Is that all you really need? Or do you really need to get everything else listed on their site? Hmmm..

Nick

 

[mike91]

It all depends on what/which cam you buy...

I personally don't know a damn thing about installing cams and choosing the right one for your engine. You are best talking to a pro about it and in most cases, your everyday neighborhood mechanic won't be the man for the job b/c he is used to doing things his way, while a cam needs special attention such as being properly degreed.

When choosing cams, they have "lifts" and "durations" and cannot simply be installed into the engine like a stock camshafts (I don't know what each mean). I know that depending on the lift and duration of the camshaft you may need to change your pushrods, as FLYGUY mentioned. In addition, you may need to swap the stock valve springs in the heads to achieve the proper performance of the cam. It was mentioned in another post that by installing the cam - the cam created a terrible ticking noise to the engine.... those are the lifters and are one thing you might want to consider replacing when swapping a camshaft. Like I said its best to consult with a pro like Vanir or Summit to learn how the camshaft works and so that they can help you choose a camshaft thats right for you - for our trucks, a "mild" cam would probably be in line.

 

[SteveVB]

Flyguy,

Do you need all of the stuff on Vanirs site? Not quite sure what you mean, but to install the Comp cams 410 grind (same as Svens street grind) in my 4.0 I am changing the Valve springs, using a new timing set, new lifters, the cam, and new pushrods. According to Sven the 410 was designed to use the stock springs so the stock retainers and locks can be used.

 

[flyguy]

Thanks for the info... On the Vanir site they also sell valve springs and other parts. But on the cam page they dont mention if you need them or you could benifit from them. It just says you need the pushrods.

Nick

 

[rock883]

Thanks for the replies guys. So I should get a larger TB, I might get ahigh flow cat, and maybe some headers and a flowmaster single in dual out muffler, and lets see here, I don't wanna get the chip because it requires higher octange fuel, which is something I wound't of minded doing about 2 years ago when the gas was only at 2 digits, compared to nowadays when it is $1.70 for premium. I already hve a KKM. What about any other things like those things?? So with all the exhaust and the intake stuff, should i have about 20-30 more HP? What else could I do for about $200 or so to get about 10 or so HP?? Thanks Also, what HP does my 91 have? What does the KKM do(HP wise)??

 

[rock883]

Another thing, how much would it cost to have my engine rebuilt?? It has 150,000 miles on it, so it owuldn't hurt to get it rebuilt.

 

[flyguy]

Ill do it for $10. But no guarentees! Hehe. J/K. I would say, so far, a high flo cat and the Jet chip have been my most noticable improvements. Then the KKM kinda helped everything out. I have a Jet Chip and I think it only requires the medium grade fuel. Not so bad.

Nick

 

[Big E]

I think if I was going to do some work for hp. I would defently rebuild engine and get bigger injectors. More fuel more power. And while I was rebuilding a nice mid range lift and duration cam wouldn't hurt. I already tryed to port the intake to the head. Nothing to remove. Oh almost forgot. Bigger vavles in the head. More air in the more air out equal hp.

Eric

 

[flyguy]

No point in getting bigger injectors if you dont have the air coming in....

 

[Big E]

Well thats were the cam and the bigger valves come in my friend. The bigger the valves and the longer they stay open the more air flow in and out. Right?

Eric

 

[flyguy]

heh. sorry. Did I just get distracted and stop reading your post or something? hehe. my bad.

Nick

 

[Big E]

Smart guy huh?

 

[flyguy]

hehe... Sometimes! Hey... thinking about ones truck all day can cause the mind to wander.

Nick

 

[Big E]

I know the feeling sometime.

Eric

 

[kilroy]

Easy solution, find a wrecked Explorer with the SOHC and take that along with the harness and computer, and you may also need the fuel pump. I think that puts out over 200 HP stock, if not it is easily modified.