Don't need MAF to change heads that's a myth.

 

Sounds like I should look at headers and the Basani Y with cat. What are the least expensive headers I could look to get?

And will the Basani F-150 351 Y-Pipe fit my F250? (Just double checking!)

 

the Y pipe should. as for headers cheap buys you crap. jba,gibson,edelbrock,bbk are all great. bassani is the most expensive. plan on paying around 250 for a good pair

 

Edelbrock = $556, JBA = $528

Flowtech, Hedman, Pacesetter are all about 1/2 that.

These headers say "not legal for street use". Wondering if that will be a problem. Arizona is pretty relaxed.

 

OK.. technically you don't on a stock motor, but that just means you're doing mods in the wrong order and not getting full value from $$ spent. If you have a full exhaust and as much cam as will work with the stock pistons and computer, you will be very close to utilizing the full capacity of the 19lb injectors.

 

I'm not clear with what you've stated. "technically you don't on a stock motor"?


Let me clarify...some or all of which you might be aware of, but for the sake of others...

Speed density heavily depends on vacuum, it uses vacuum to determine engine load (among other sensors) and therefore refers to the timing/fuel tables. If you don't change the vacuum you can work with SD. It's tricky...and most would just simply go to MAF (like I did)...but that's not to say it can't be done.

People have run aftermarket heads, cams, intakes and been ok with the SD. Your best bet if staying with SD is a supercharger and FMU.

 

And just for clarity when I say stock I mean factory.. no aftermarket computers, chips, tricks or gadgets of any kind.

Yes, agreed. Keeping the vacuum is the trick, because the wilder the cam, the less low rpm and off throttle vacuum you have.

Yes.. the pre mass-air stangs responded well to all the typical bolt on goodies. But the stangs come from the factory with way more cam than the trucks. And the part about the FMU is most important. Increasing the pressure behind the injectors can make them perform like a bigger injector and provide more fuel than they would normally. You'll also need a boost retard ingnition box if you go beyond 4-5psi boost as well.
Both the blower and/or heads are big $$ relative to a cam upgrade, and without the needed extras it's a pretty low $$ to HP ratio. A cam should produce 50hp on a stock motor, similar to what a blower or heads would do without any other extras.

 

50hp...? What cam might that be?

 

Anything similar to the factory mustang cam. There's a 40hp difference in the two motors in stock trim, 185hp vs 225hp. And the factory cams are symetrical, meaning the intake and exhaust numbers are the same. If you get a dual pattern cam that puts more duration and lift on the exhaust where it's needed with the restrictive Ford heads, you'll get more power still.

 

There's a lot more to that 40hp difference than just the cam.

The intake manifold, throttle body, and air intake system are different. The 302HO also uses factory headers instead of manifolds and a different exhaust system.

If you switch a truck cam to a 302HO cam you won't pick up 40hp...you'll probably just mismatch the combo and end up with about 5-10hp.

The reason I asked was because I've never heard of someone putting a better cam in a stock 302/351 and picking up 50hp w/o changing anything else.

 

I'l agree about the differences mentioned, but the intake system is no restriction on the trucks. The exhaust certainly is.. and it's often the first thing modified. That should do it though, change nothing else and it should make as much if not more power than a 5.0HO.

 

The intake certainly is a restriction and not only is it a restriction but it is a change in the intake air charge's velocity. It's a give and take situation, if you want good velocity than it is going to be restrictive at higher RPMs as those parts cannot flow enough CFM to support the engine at high RPM.

The truck engine is completely designed for low end tq. The intake tubes are dual instead of single...it's a smaller diameter than a mustang engine to increase velocity. This increase in velocity sort of helps ram air into the cylinder as it's trying to fill at low RPMs. A lack of velocity at low RPM is what makes hi-po motors lack low end torque. A hi-po engine's head ports, intake ports, etc...are so large in order to flow enough air...that the intake charge's velocity at low RPM is poor and results in a lack of power at low RPM. At the higher RPM ranges these large ports are able to make more velocity and be more efficient (volumetric efficiency).

The throttle body has two butterflies in it which is also a restriction. One of top 10 things to do when upgrading these engines is to remove the intake system and change it to a different setup. You can either go larger and retain the stock style system or switch to a mustang style system. A mustang uses a single tube and 65mm TB that will easily outflow the stock dual 45mm truck TB in terms of CFM.

As we've all heard - an engine is basically an air pump and the more air/fuel we can move the more power we will make. If you change one part of the engine to increase that airflow (like putting a larger exhaust on it) all you're really doing is moving the restriction around. Now that you're exhaust flows enough - what would be the next most restrictive component....and the next.....etc....it's all about how much CFM the engine can pump. The stock engine is matched very well (designed to be) so that every component flows an appropriate amount of air (CFM) and there are not mismatches. If you have a mismatch where 1 part completely outflows another...it can/will result in improper powerbands and inefficent engines.

The truth is you will not gain 50hp from a cam when leaving the rest of the engine stock, esp with a mustang cam. In order to get that 185 to 225hp gain...you'd need to switch EVERYTHING that is different about the 302HO onto the non-HO 302. That is even including the MAF sequential injection that the non-HO doesn't have (it's batch fire instead of sequential). If you threw a mustang cam into the truck engine....you'd have a mismatch. Now I've been told that a mustang cam isn't half bad for a truck but what it will do is change the valve events and the airflow will change in respect to the rest of the components on the engine. You'll have a cam that flows like a hi-RPM mustang engine....but an intake system that flows the opposite.


Believe it or not...but the factory exhaust system is not very restrictive in it's own stock setup. If you increased the flow of the engine than you will quickly surpass the exhaust system's flow....but only until you change something. In stock form like I said...everything is matched properly...you change one thing...there is pleanty of other restrictions inline.....until you do a head, cam, intake, exhaust change so that you cover every aspect of the engine's flow and make them all about the same level and intent.

 

I'm sorry to be the bearer of bad news but everything you stated there about the truck motor is completely wrong. You obviously have never taken apart a 5.0 truck motor. It has the biggest runners of any Ford engine. There are no aftermarket intakes with runners larger than the stock truck intake. Your horsepower and torque building theory is correct, but the 5.0 truck motor does not follow any of it and that's the main reason it was the weakest 5.0 in the stable.
The SD 5.0 mustangs had no problem making 250hp+ so you don't need sequential mass air to get to that level. Stangers did this with a few simple bolt on goodies that helped airflow.. because the intake plumbing is a bit restrictive on these cars, mainly the air filter. There is also no difference in the block or head castings between the truck and mustang 5.0 motors.. the heads are identical. The stang got a forged crank and pistons, but that doesn't help airflow any.
The only thing keeping the truck motor from making 250hp+ is the very restrictive exhaust and the cam. I can't help it that people don't realize this and change all sorts of other things in a futile attempt to make these motors work half decent.

 

Are ya kiddin' me? My truck came with a 302 that I pulled out last year and disassembled. Since then I've done the 393w for my truck in replacement of it. I also just took apart my 351 a few months ago. That's just within the last year. Please point out the "errors" in my statements about the truck motor...

Huh?? Larger in port size or larger in length?? Have ya heard of the Edelbrock Truck intake? Not only does it have larger ports but it has longer ports as well. How about the Trick Flow R series or other aftermarket intakes? There are a boat load of EFI 302 intakes from the aftermarket. There are definitely ones larger than the truck intake.



Please elaborate...I'd like to hear the reason for this statement of how it doesn't follow any of it...


Not factory equipped but of coarse you can achieve increased power levels and retain Speed density....ask any of the lightning owners doing 11s with SD.

Yup, heads are E7TE's and the blocks are the same.

I havn't heard about a stock 302HO having forged cranks but pistons yes...I think it started in 88ish but ended in mid 92 for mustangs.

But don't you understand why that is? It's terribly easy to increase HP on these truck motors because they were originally designed to be low RPM torque engines. That in it's inherit nature is going to have a low HP figure because of it's limited RPM use. A 302 truck engine drops off after about 4500 rpm (redline 5500). A mustang engine pulls hard to about 5700 rpm (redline at 6250). As we all know horsepower is a calculated figure (not a measure of a physical force) based on torque and RPM. It is how quickly work is done (torque is how much work). So when you change the exhaust and the cam - you're going to be moving that tq up higher in the RPM range. This is the opposite of Ford's original intent.

Sure you can change the cam and the exhaust system and maybe see an extra 50hp...but not just from the cam alone like you stated earlier. Also, it would take an extensively reworked exhaust (headers, y-pipe, hi-flow cats and mufflers, etc).

Realistically....you're making an attempt to say XYZ parts will make ZYX results....but unless you actually make those changes and measure the results....you're just guessing.

 

Yes, I've heard of and seen all those. You need to go look at that 5.0 truck intake again... and bring a good measuring device. The 5.0 truck runner cross section and volume is substantially larger than anything else, including the aftermarket.


None of the 5.0 trucks I have driven make any power beyond 3500rpm.. good luck even making an automatic equipped truck go past this. A stock mustang 5.0 drops off after 4500rpm. It'll rev more but it doesn't make any more HP.
From the factory the 5.0 truck makes less HP and torque than the 5.0 HO. I'm sorry but this a case of "been there, done that". I have done the full exhaust on a 5.0 truck.. longtubes, hi-flow cat and muffler, 2.5" plumbing throughout. You gain substantial low RPM torque, but the motor still does not build any power past 3500rpm. The next most substantial restriction to airflow is the cam. The factory truck cam is a pathetic little thing with something on the order of .360" total lift and 180 deg duration. You can't buy an aftermarket cam this small unless you order the OEM replacement. Drop anything else in there and it'll unleash the beast.