Other Projects - Car and Non Car Related

Yes so very true. I really appreciate the simplicity and the room that my '81 F150 has in it's engine compartment.

I was give the resulting mulch from some large stumps being ground. The 300 CI in my truck barely knew it was there, the springs said otherwise. Anyways it will be used for weed control on my garden and for some landscaping one I get a wheel barrel tomorrow.

Frank Wyatt wrote

I was give the resulting mulch from some large stumps being ground. The 300 CI in my truck barely knew it was there, the springs said otherwise. Anyways it will be used for weed control on my garden and for some landscaping one I get a wheel barrel tomorrow.

The 300 engine was the standard engine in trucks up to F600 [medium duty], while the 302 was never offered in any truck larger than a F250.

When the 302 is luggin and chuggin the 300 is still pulling strong.

Its crazy to me how that engine could be offered in trucks so big. They make low end torque yes, but still less than 300 ft-lbs. My truck has a 300 and I absolutely love it to the moon and back, but there is no denying they are pretty gutless. I cannot imagine one in a big truck like an F600.

On the topic of stump pulling though, I think the wildest thing I ever saw my father do with his was pull out a skid steer from an 8-10 foot deep ditch on a sheet of ice, in reverse. Either than, or rip concreted fences posts out of the ground without digging them up first. I don't think I'd try either with a newer trucks.

That said I've been really pushing to get my 79 running again, that's been priority right now with me being without a vehicle, which was my own fault when I banged up my bull clip swapped 95. I pulled the cam the other day with a flat lobe, so now I'm putting a fresh top end on her so I can at least drive it before I build my 429.

But it's where that torque is made combined with the gearing that makes the difference. It's right in the usable driving RPM. They don't rev high but don't need to. Not for a work truck.

I get that, but 250 ft-lbs is 250 ft-lbs no matter how you look at it.

And as much as people say "it's not horsepower that moves a load, it's torque" that simply isn't true.  Torque with no horsepower literally doesn't move anything.  It just leans on it.  Once it starts moving you have power.  Mathematically torque (in lb-ft) times speed (in rpm) divided by 5252 (a units constant) equals horsepower.  So literally, no power means either no torque or no speed.

The result of that is horsepower is what moves the load, no matter what cute saying say.  And a horsepower is a horsepower no matter what speed the engine is turning.

Where there is some truth in the old saw is that engines with low torque peaks tend to have flatter power curves.  For instance, if the power peak is at 4000 rpm and the torque peak is at 2000, as speed drops from 4000 the torque keeps climbing.  A bigger torque number times a smaller speed number means that  power doesn't drop very fast.  So a "torquey" engine is more driveable because you don't have to shift it as much to keep it in the power band.

But you can have too much of that good thing too.  Heavy truck diesels have such low torque and power peaks that they need to be shifted through LOTS of gears to keep the engine in its power band.

I think the main reason 300s were used in medium trucks while 302s were not is that the low torque peak means less wear and longer engine life.

Very true.  But there's another factor - clutch slippage.  It takes a certain amount of torque to get a truck moving, and the 300 will give you that torque at a much lower RPM than a 302.  So to get the truck moving from a stop you'll have to rev the 302 more to get enough torque.  And you have to slip the clutch to do that.

Perhaps the wear and tear on the clutch was a concern with why they didn't want the 302 in the heavier trucks?  

Good point.  But clutches see torque, not power.  So a clutch on a 302 that's revving higher doesn't necessarily need to hold as much as a clutch on a lower revving 300 (except that a 302 actually does have more torque than a 300...).

Nothing Special wrote

Good point.  But clutches see torque, not power.  So a clutch on a 302 that's revving higher doesn't necessarily need to hold as much as a clutch on a lower revving 300 (except that a 302 actually does have more torque than a 300...).

At a higher [less work friendly] RPM range!

No, it has more torque where the 300 has it's highest torque.  At least if you believe the published torque curves.  On paper the 302 is a much better truck engine than the 300.  I can't explain why the 300 is at least perceived to be a better truck engine in the real world.  Enough people believe that so there must be some real world reason.  Personally I've never driven a 300, and I know the mildly built 302 in my Bronco is no truck engine.  So I'm not doubting that the perceptions of the 300 being a better truck engine.  But it's not because it has more torque at low rpm.  The 302 actually beats it there.

I've driven both, but haven't really tried towing with either.  However, I can provide some info from Ford.

The tables below are from the 1984 Dealer Facts Book and can be found on the pages in the Documentation/Engines section.  

Let me try to summarize, although it ain't easy:

The 300 generates from 235 lb-ft of torque at 1200 RPM to 260 lb-ft at 1400 RPM, depending on the application.  But there are some that generate 245 or 250 at 1600 RPM if set up for high altitude or auto transmissions.

The 302 generates 250 lb-ft at from 2200 to 2600 RPM if you stick with the 49-state engines.  But, the CA-spec engines are rated at much lower RPM but comparable #'s, which is very confusing.

Basically, what I take from that is that the two engines are capable of generating essentially the same torque, but the 300 creates it at roughly half the RPM.  I would think that would make starting a load easier with the 300 as you have max torque available w/o revving much.  But, as Bob pointed out, HP is a factor of RPM, so the HP will be much lower on the 300 than the 302.

Perhaps we are comparing a plow mule with a race horse?

Gary Lewis wrote

....  Basically, what I take from that is that the two engines are capable of generating essentially the same torque, but the 300 creates it at roughly half the RPM....

That's what everybody knows.  But every time I've seen actual torque curves they show that the 302 makes more torque at every engine speed than the 300.  Yes the 302 makes it's peak torque at a higher speed than the 300 does.  But the 302 still makes more torque at the 300s torque peak than the 300 does.

And again, I'm not saying the 302 is a better truck engine in the real world.  I believe everyone's "butt dynos" are accurately saying the 300 is better.  But the torque curves I've seen don't explain why.

Okay, for those that do not know me well, I will "fess up" that first I love the 6 bangers and have more head knowledge [from reading] than finger knowledge [although I can turn a wrench]. However, my personality and career choice have instilled in me the desire to document and report accurately, so I will share a little of what I believe to be true.

Based on what Gary posted [Ford documentation]:

 The 300 generates from 235 lb-ft of torque at 1200 RPM to 260 lb-ft at 1400 RPM, depending on the application.  But there are some that generate 245 or 250 at 1600 RPM if set up for high altitude or auto transmissions.

The 302 generates 250 lb-ft at from 2200 to 2600 RPM if you stick with the 49-state engines.  But, the CA-spec engines are rated at much lower RPM but comparable #'s, which is very confusing.

The 302/5.0L generates 5-15 lb-ft more than the 300/4.9L, but at a significantly higher engine speed. Whereas the straight six is recognized as having a relatively flat torque curve, the V8 is not known for having that same characteristic. So, it is difficult for me to understand how the V8 has more torque than the 6 cylinder at the 300/4.9L's maximum torque @ the 1200-1400 RPM range.

Let me address the footnote #1 under the first chart which was posted by Gary. This is regarding where the 4.9L engine was rated @ 260 lb-ft @ 1600 RPMs in trucks equipped with 2.47 rear gears and manual O.D. transmissions. Most are under the impression that the factory camshaft in all 240s, 300s and 4.9L engines had the same specifications from 1965-1996 [except for possibly industrial engines, i.e. H20 pumps, generators and airport tugs]. I cannot currently find this, but years ago, I ran across a Ford document which indicated there was a different engineering number for the camshaft used in the trucks described in footnote #1 [above]. Having owned a 1984 F150 with 4.9L engine, 2.47 rear gears and 4 speed manual OD, I can tell you this truck would routinely deliver 26+ mpg @ 65 mph and could cruise @ 55 mph [level ground] @ ~1230 RPMs.

My current 1986 F150 with 4.9L engine, 3.08 rear gears and 4 speed manual OD cruises effortlessly @ 70 mph [1950 RPMs]. It gets the best fuel mileage @ ~60 mph [~1675 RPMs].

At any engine speed of 1100 RPMs or greater, in any gear, the 1986 truck will accelerate without bucking. Overdrive is happier @ 1250 and above.

The 302/5.0L will absolutely spank the six cylinder if in an acceleration contest, but try to maintain any of the above described speeds with the 302/5.0 and have the same gears combination and I believe a marked difference will be realized.

Ford engineers realized this when the 300/4.9L was offered in F350s and F600s, but the 302/5.0L was never offered in any truck beyond the F250.

By the way, the 302/5.0L is a great engine and as such was offered in automobiles as well as trucks. The 300/4.9L engine was never offered in an automobile.

In the end, we all have our preference and that is okay. Lets all work together to keep this wonderful forum thriving!

I think you also need to look at the higher RPM of the 302 as more wear & tear on the motor and would need to be replaced sooner.

I can tell you my 81 F100 - 300 / T18 / 2.74 working RPM is just over 1000, shifting at about 2000 RPM and other than when on the high way where it is over 2000 RPM I don't see the need to bring the RPM higher than 2000.

When I get an over drive installed I will report on what I get but for now with the above setup I get about 14 MPG combo staying at 65 MPH max if I can on the high way and 45 on back roads. It will go faster with no issues but the MPG drop.
Besides its nice to take it slow.
My work truck (big rig) is slow so it is not a big deal for me to stay slow LOL.
Dave ----

Slight thread bump.

I need some pros/cons of converting to a fuel cell. I had a new gas tank, and managed to poke a hole in it (long story).

Basically the stock replacement steel tank is heavy and bulky, but I'm sure helps with traction in the rear though I think the outlet is a size under what I need despite the line being 3/8. The sending unit works flawlessly and even the fuel gauge works great.

However, for a similar cost of a new tank with similar capacity, I can get a light weight, aluminum cell with a bladder. It would be installed behind the cab in the bed. My floor is rough in the bed, so drilling holes for lines would not bother me whatsoever. Downfall is that I have to plumb everything with expensive AN fittings (I do have 10 feet of stainless braided hose already). That, and I lose the use of my factory fuel gauge and I believe a gauge in general, tho I think there is a workaround for that. However, I HIGHLY trust well plumbed AN stuff over the hack job "fuel hose to 3/8 hard line back to fuel hose with dodgy clamps" to my mechanical pump. Having a bladder would help prevent punctures in the event of an accident and I would not have low spots.

Being in the bed wouldn't be any less accessible for filling, the vent would be easy to hook up and it would be above the floor away from any potential damaging debris (not that I plan on running anything over to begin with). I do not use the bed for cargo, this truck is a pure toy.


Is there any real reasons why I should NOT go for it?

I think you listed the cons on filling, running the supply, takes up room in the bed, no gauge, etc.
A cell is for race cars not for the street.

Pro don't have much.

As for the factory set up other than you poking a hole in it the supply of metal & rubber has been used for years and other than the rubber needing replacing as dose other supply lines.
I had braded break down and leak on my race car after sitting a few years. This braded line ran from the cell, mounted in the trunk, to my filter mounted under the truck floor and hard line from filter to the engine bay. I only used a little flex line from regulator on fender well to carb.

BTW they do make cells with fuel gauges and you can mount them out back where the factory tank was mounted. Look at hard wall like used in stock car racing. They are mounted out back and low.
Just my .02
Dave ----

 

FuzzFace2 wrote

I think you listed the cons on filling, running the supply, takes up room in the bed, no gauge, etc.
A cell is for race cars not for the street.

Pro don't have much.

As for the factory set up other than you poking a hole in it the supply of metal & rubber has been used for years and other than the rubber needing replacing as dose other supply lines.
I had braded break down and leak on my race car after sitting a few years. This braded line ran from the cell, mounted in the trunk, to my filter mounted under the truck floor and hard line from filter to the engine bay. I only used a little flex line from regulator on fender well to carb.

BTW they do make cells with fuel gauges and you can mount them out back where the factory tank was mounted. Look at hard wall like used in stock car racing. They are mounted out back and low.
Just my .02
Dave ----

Basically I just want it to be as safe and secure as possible. If I can get rid of any clamp connections, that would be prefered. At the carb and pump is easy, but on the stock sending unit it would be tough. Right now, it's a hodge podge of clamp here, hose there and while it does not leak it, makes me nervous.

I have thrown the idea around of ditching the mechanical pump, but I ran into overheating issues dead heading a Holley pump against a Summit regulator. The tank has no provisions for a return, no do I feel comfortable brazing on a new tank. The mechanical pump worked great but I'm afraid of blowing a diaphragm and filling my oil pan with fuel. I do have a brand new Carter mechanical pump I will be using, but it does stay in my mind.

This isn't a daily driver, but will spend 80% of its time on the street during the times it is driven, so keeping it as streetable/performancy as possible is the goal. I'm not worried about bed space, if a half empty bottle of Gatorade gets tossed back there that's about as much as it'll see. Part me says stop over thinking and keep it simple for sake of relability, part of me wants to spend money on go fast parts.


EDIT:

After doing a little research I believe I can modify the end of my sending unit to adapt a -6an fitting to the 3/8 tube. So I think I will order a stock replacement tank and plumb the sending to a section of braided hose, to hardline to the pump, then hose to the pump, then hose from the pump to the carb.

Angelo Voltura wrote

Part me says stop over thinking and keep it simple for sake of relability, part of me wants to spend money on go fast parts.


EDIT:

After doing a little research I believe I can modify the end of my sending unit to adapt a -6an fitting to the 3/8 tube. So I think I will order a stock replacement tank and plumb the sending to a section of braided hose, to hardline to the pump, then hose to the pump, then hose from the pump to the carb.

I think your edit puts you on a reasonable path.  And, this isn't a "go fast" part.  The truck isn't going to go any faster with either tank.  So go with a stockish setup and put your money where it will matter.