Building 4.0 power

[JohnnyO]

Depends on which 4.0. If it's a later 4.0 SOHC, then the stock manifolds aren't very restrictive. Headers will help take advantage of other mods but by themselves don't make much difference. Zabteck has some 4.0 SOHC parts. www.zabteck.com

 

[Doug904]

The heads aren't good for power? The stock 4.0 OHV makes around 135 rwhp, with my ported heads, 422 cam, headers and tuning I make 196 rwhp, the heads are worth it in every aspect.

You must not be very familiar with Bird and his port work? You're asking if he's ever had a 4.0 on a flow bench, well considering he has his own in house flow bench and he flow tested both before and after EVERY set of Stage 3 cylinder heads he ever made for me then I would have to say yes, he has.

If the size of the exhaust was everything then in 98 when they went to the even smaller exhaust port they would have had to derate the engine's horsepower but they didn't. The intake port on the 4.0 has stayed the same through out the years and even on my truck I have a very mild port job on the intake manifold itself because it doesn't need it.

Headers for OHV, like the original topic, are good for small power gains but as before stated don't put them on an expect the world from just the headers. Get a 66mm TB, headers, good air intake and cat-back exhaust and you'll be as good as you can get with the 4.0 OHV, (90-94 because there's not alot of computer tuning available for them) After this start on the engine if you'd like and get the recommended items like a Comp cam, rocker arm's and aluminum spacers and talk to a few about getting the heads.

Later Doug

 

[86_cookiemonster]

its just my 02 that spending over 1000+$$$$$ on headers and porting heads to increase tyhe output of a NA 4.0 ohv is a wate of your money $$$$$ as in its not really worth the investment. I see guys spending over 5000$$$$$$ on NA v6 setup to completely flow, cam, and build the motor up to see maybe 40 more hp. To me 40 hp for thousands is a waste of time.

I find that hard to believe that they spend $5000 to only get 40 hp. You port and poslish the heads and thats good for 15-20 horse, and a 422 cam thats another 15-20 horse. That is no where near $5000, and is pretty dang close to an increase in 40 hp.

 

[Psychopete]

I find that hard to believe that they spend $5000 to only get 40 hp. You port and poslish the heads and thats good for 15-20 horse, and a 422 cam thats another 15-20 horse. That is no where near $5000, and is pretty dang close to an increase in 40 hp.

Granted that is a pretty high figure, but there's still going to be somewhat a large cost. You just don't blindly port/polish your heads and just throw a cam in there and that's that, there's more to it than that, and I think that's the main point he's trying to make.

There are other costs associated with making these changes. For instance, it would be a good idea to have the heads reworked and checked out while they're off the truck to begin with. Then you have the cost of head gaskets, intake gasket, head bolts, and probably custom length push rods, plus making adjustments to the valve train. Oil, coolant, other stuff replaced while you're in there, it all adds up pretty quickly.

I don't know if you've done this before, but running an aftermarket cam on old stock valve springs doesn't work so well (Beep Beep Richie! They ALL float down here! ). Plus other mods needed to even justify running the bigger cam. The cam profile is significant and everything else must match it well for it to work effectively.

Whether it's worth it or not is in the eye of the beholder. My 2.9L wasn't worth it, I'll admit to that (but it's still fun to drive!). But I sure learned a shit load of information in the process..

Pete

 

[turbo cat]

as for the usinjg a aftermarket cam with oem springs, been there got that shirt....it did last thru 50K of hard driving but its time was up (4.6L 2V with comp camms)

 

[Doug904]

When I sold them the stage 3 heads were $1100 with new castings, valves, springs and retainers basically ready to install and drive away.

The cam is around $300, pushrods and rockers $200. Gaskets another $150. As for the labor most places can easily quote you on a cylinder head replacement on a 4.0 OHV, that's written in stone. The cam may add a bit more because they have to remove the radiator and raise the core support but still I wouldn't figure it more then about $750 for the head/cam install complete.

I could easily build a nice street OHV for less then $2G, for another $1500 the entire engine with Forged Pistons but truly the only reason I would do so is if I plan on making major power with a good power adder.

Building a 4.0 OHV is ok but trying to believe the dream that you'll have an extremely fast one n/a is just not feasible. Spray it, Blow it, or Turbo it and then you'll have a moderately fast engine.

My truck ran a new best at 8.129 in the 1/8th mile and I'm shooting for 7's but I did an intake and nitrous kit to my Mustang GT and I'm easily in the 7's. So just remember you're doing this because you want to....

 

[woodyedmiston]

Flaming Dean (no offense, but - you might want to reconsider that handle)

This response is exactly what I mean - I hope you are keeping up with this string. If you will spend some time poking around the site you can learn a lot about the specifics of this engine, a lot of good advice, some choice opinions, and some interesting ideas. There is a lot you can do with your truck that is fun. Speed and Fast in a truck is not always that good of an idea though. Within reason you can do all of the above - but to MAX OUT on every area of speed, fast, pretty, sporty, safe, crazy etc. with one vehicle is not practical. You can spend a lot of money making a truck go a little faster or spend a little money making it more fun. There are limits to everything. At the same time I like Turbo Cat's approach - don't tell him it's crazy he's having fun spending his money the way he wants.

Let me ask and answer some questions for you:

Can any engine be modified to produce more power?

Yes - an example are the early TR-2/3/4 engines. They were very heavy and I always wondered why British Leyland made the engine for a so-called sports car such a boat anchor. Turns out they used the same block for the British Leyland tractor. Making a TR engine into a racing engine was labor intensive and expensive. Anyone who ever had a Triumph will tell you it was a heck of a lot of fun to drive without any modification. Although it is not a tractor engine that I'm aware of - the 4.0 would make a much better generator engine than it would a supercharged, high winding Champ car engine. The engine was designed by engineers to have lot's of torque, be able to pull pretty heavy loads, and drive well to the grocery store with the wife. (I was very proud of my little Ranger yesterday, it towed a 5000+ generator to Houston to power up our home office - no power because of Hurricane Ike) In other words it was desgned to be a hard working truck engine. Just like it's predecessor the 428/460 V8.

How can I make my truck go reallly fast?

Put a bigger engine in it. The tech section will tell you how to install everything from a 302 to a 7liter engine. The 4.0 will take the Ranger faster than it is safe to drive it. It is designed to have a high center of gravity and haul people (Explorer) and boats/trailers etc. (Ranger) and does not go around corners well. It can't handle a lot more speed around corners because it's not a sports car. It can go fast in a straight line with a bigger engine so you would think it might be a great drag car and many are - but IDEALLY - a good drag vehicle has more weight over the back wheels. Think about the 40 Willys coupe. It would make a really great tow vehicle for the vehicles you want to drive fast - 4wheeler, Formula Ford, motorcycle, etc.

I want to build something totally radical?

It's been done. Honest, this is no tall story:A few years back a guy known as the Michigan Madman campaigned a 1957 Plymouth Fury in drag racing. The rear axle was from a two ton delivery truck, the clutch was from a Tug Boat (that's what the magazines at the time all said) and the engine was a 16 cylinder, 1710 cubic inch Allison aircraft engine.) It would smoke the tires from one end of the track to the other, it looked wicked and the engine was so big the drive sat in the back seat. A guy named Arfons came along and put a GE jet airliner engine on four wheels and started blowing flames all over the place and no one ever heard of the Michigan Madman again.

Wash it, wax it, open the door for the girl you can get to ride with you, and tell her she is more important to you than your truck - you'll get the kind of "throttle response" you are really after.

You asked for thoughts. Those were mine.

 

[Bird]

Wash it, wax it, open the door for the girl you can get to ride with you, and tell her she is more important to you than your truck - you'll get the kind of "throttle response" you are really after.

That is ABSOLUTELY the best advice I have ever seen on any forum concerning mods to already decent vehicles....................


Bird

 

[DeanMLFlame]

well thnks for all the imput. i'm really hoping to make it a drag/street truck. Just for fun! so now i can use a lot of this info for that. I do agree that traction is the big issue cuz i can break the tires loose no problem(with a full tank) and i don't want that. I would like to build a Triangle 4 link with coilovers and put her on a diet. Anything i can do for weight loss and suspension thoughts?
And to woodyeminston - DeanMLFLame is my guitar model. i'm not a flamer!