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250hp/350 ft/lbs?

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American Thunder
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250hp/350 ft/lbs?

Post #1 by American Thunder » Tue Nov 25, 2008 1:48 pm

The '95 300 I rebuilt awhile ago is running great, it's got 4k-5k miles on it now, and I'm averaging 20-22 mpg. But of course I want more power.
I'm going to send out an older 300 carb head for professional porting, using larger 1.84"(I) x 1.54"(E) 351W valves. I'm looking at either the Comp Cam 252H or 260H, not sure which would work out better in this set up? I'm going to have the head milled to keep the compression up around 9:1, using the stock '95 EFI manifolds with 3" exhaust and single flowmaster muffler, no cat. I'll use the Holley 450 4V on an Offy dual port intake, and an HEI hybrid distributor arrangement with mech. and vac. advance. I've never built up a 300 before, but I'm shooting for 250hp and 325-350 ft/lbs of torque, is this fairly reasonable?
1977 530hp 302 Mustang II videos:
Smokeshow at 8000 rpm
0-90 mph speedometer view

1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

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Post #2 by CNC-Dude » Tue Nov 25, 2008 5:13 pm

Most any modern day engine can fairly easily produce 1 HP per cubic inch with the components we have available. I have done many of the Cheby equivalents to the 300, and have even had some that made 612 HP for competition in NHRA Comp Eliminator Naturally Aspirated. But I think your torque expectations are a little high....

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Post #3 by Harte3 » Tue Nov 25, 2008 5:44 pm

http://fordsix.com/forum/viewtopic.php? ... sc&start=0

Check that thread out for projected hp/tq of various combinations.

IIRC my DD results came up with 222 hp right at 300# tq with the 260 cam and a 600 cfm Holley.
'83 F150 300, 0.030 over, Offy DP, Holley 4160/1848-1 465 cfm, Comp Cam 260H. P/P head, EFI exhaust manifolds, Walker Y Pipe, Super Cat, Turbo muffler, Recurved DSII, Mallory HyFire 6a, ACCEL Super Stock Coil, Taylor 8mm Wires, EFI plugs.

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Re: 250hp/350 ft/lbs?

Post #4 by Lazy JW » Tue Nov 25, 2008 9:41 pm

American Thunder wrote:.... averaging 20-22 mpg....


Yikes! :shock: I would definitely NOT TOUCH ANYTHING! Mercy sakes alive!
Joe
"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
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Post #5 by CNC-Dude » Tue Nov 25, 2008 9:47 pm

Harte3 wrote:http://fordsix.com/forum/viewtopic.php?t=42347&postdays=0&postorder=asc&start=0

Check that thread out for projected hp/tq of various combinations.

IIRC my DD results came up with 222 hp right at 300# tq with the 260 cam and a 600 cfm Holley.
Yep, I was thinking something more in line with your torque #'s instead of his at 325-350 ft.lbs. Not to say his #'s aren't obtainable, just 300 is more accurate for what he is contemplating for mods....

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Post #6 by J.R. » Wed Nov 26, 2008 4:19 am

Lazy JW called it, with the 20-22mpg fuel mileage you're getting.

You could stick a turbo system on there with a rising rate fuel pressure regulator, so you'd have more fuel & power under boost, but keep your economy when your foot's being light on the throttle and the turbo is just idling around.

With mods beyond that, it could get ugly when the oil barons jack our gasoline back up to $5+ per gallon.

Just my 2 cents worth.

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Re: 250hp/350 ft/lbs?

Post #7 by American Thunder » Wed Nov 26, 2008 7:22 am

Lazy JW wrote:
American Thunder wrote:.... averaging 20-22 mpg....


Yikes! :shock: I would definitely NOT TOUCH ANYTHING! Mercy sakes alive!
Joe


I'm thinking with more torque I can run taller tires to drop the revs even lower. The best solution would be a stroker crank and a mild roller cam, I wish I could get them at a reasonable cost.

Straighter smoother ports that flow more readily without losing velocity, undercut larger valves, a cam with more lift and almost stock duration and a dual port intake with a small 4V carb would likely yield better torque in the same rpm range that it runs in now, so it would also have the power to pull the vehicle at a lower rpm. And of course, anytime I'd nail the throttle, it would pull like heck. The idea here is to increase cruising mileage and only have to sacrifice some mileage when I jump on it. So I'm greedy, yeah.

In order to get my mileage as high as it is, I use the secondary roads on the way to work, so I can keep the truck at 40-45 mph, where it runs the best in 5th gear with the least wind resistance. Flat out at 60-65 mph, the mileage drops.
1977 530hp 302 Mustang II videos:

Smokeshow at 8000 rpm

0-90 mph speedometer view



1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

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Re: 250hp/350 ft/lbs?

Post #8 by inline300 » Wed Nov 26, 2008 8:03 am

American Thunder wrote:I'm looking at either the Comp Cam 252H or 260H, not sure which would work out better in this set up?



depends on port work, compression ratio, target rpms, etc etc

I'm shooting for 250hp and 325-350 ft/lbs of torque, is this fairly reasonable?


reasonable based on what? attainable, you bet.



Since your head is being professionally ported, Id imagine youll be getting a flow sheet, why not run those figures past a cam company, along with your other intended changes and just get a custom cam, they arent as expensive as you would think. Then you wont be asking yourself, should I went with the other cam. :D

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Re: 250hp/350 ft/lbs?

Post #9 by Lazy JW » Wed Nov 26, 2008 8:36 am

American Thunder wrote:....
I'm thinking with more torque I can run taller tires to drop the revs even lower.....


Bigger tires are gonna cost you in more ways than one :evil:
1. Initial cost
2. Greater air drag
3. Greater rolling resistance
4. Greater mass to accelerate.

Not much of anything else you have mentioned will help economy either, some of it will probably hurt. Tightening up quench is a desirable thing, also more compression within reason.
Joe
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Post #10 by rmt » Wed Nov 26, 2008 10:23 am

Bigger wheels/tires are also harder on the brakes. Faster wear and less braking ability.

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Post #11 by StrangeRanger » Wed Nov 26, 2008 10:57 am

The EFI 300 in stock form produces 230 ft-lbs peak torque. To get to 350 you'd need to increase peak volumetric efficiency by 350/230 = 1.52. I know the stock 300 doesn't flow particularly well but I don't think a 52% increase is in the cards, at least not while remaining streetable. The long stroke and the U-flow head both mitigate against it.

A couple of suggestions:

Rather than prepping a carb head, find an EFI head w/o the secondary air injection nozzles and prep it. Since you're running a carb and ditching the PCM you can unshroud the valves and end up with a near clone of the old 240 head with a bit more quench. This is a very good thing.

Rather than putting in an aftermarket cam, just use 1.75:1 Ch**y I6 rockers with your stock cam. Lift goes from .400 @ 1.61 rocker ratio to .435 @ 1.75 with a resulting slight increase in duration @ .050. Add a set of Cloyes adjustable timing gears advanced 4° and some aftermarket springs and combined with your prepped head you'll gain significant torque without sacrificing drivability or economy. You'll also remain compatible with today's ZDDP-free oils, that is not true of many fast-ramp aftermarket camshafts. Ch**y I6 specific roller rockers are available from Harland Sharp and others if you want to add the $$ to go that way.

As to tires JW nailed it exactly. One of the things we get for free with a 300 is a torque curve that looks like a horizontal line. That means that big changes in highway RPM, whether due to tire size or gear ratio, result in rather small changes in fuel economy compared to our V-8 inhibited brethren. The small gains from larger tires simply won't produce the results. Our trucks have the aero of an very large brick and the place to look for fuel economy is in the aero package, not the powertrain. The biggest gain I have seen on my truck is a documented 2 MPG difference from installing a soft tonneau. Obviously, YMMV. It smooths out the airflow behind the cab and over the bed. Running with the tailgate down is not equivalent; it increases the aero drag by increasing the size of the low pressure area behind the cab. Run the smallest mirrors you can; they make a huge aero difference at highway speeds. The other big source of aero drag is airflow under the truck. The higher the truck sits, the more airflow, the more drag. Smaller, harder, skinnier tires reduce both rolling resistance and airflow but may require a numerically lower rear end depending on how far you push the diameter reduction.

As JW has pointed out 22 MPG is golden and doing anything to alter that should be considered carefully.
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Post #12 by 80broncoman » Wed Nov 26, 2008 10:58 am

At 9:1 compression the 260 cam is the right one.

Is this vehicle EFI now? Or is it in something older?
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Post #13 by Thad » Wed Nov 26, 2008 1:00 pm

Why not SBC size valves and pocket porting when doing head work?

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Re: 250hp/350 ft/lbs?

Post #14 by THE FRENCHTOWN FLYER » Wed Nov 26, 2008 2:06 pm

American Thunder wrote:In order to get my mileage as high as it is, I use the secondary roads on the way to work, so I can keep the truck at 40-45 mph, where it runs the best in 5th gear with the least wind resistance. Flat out at 60-65 mph, the mileage drops.


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Post #15 by shmoozo » Wed Nov 26, 2008 5:26 pm

StrangeRanger wrote: ... Our trucks have the aero of an very large brick and the place to look for fuel economy is in the aero package, not the powertrain. The biggest gain I have seen on my truck is a documented 2 MPG difference from installing a soft tonneau. Obviously, YMMV. It smooths out the airflow behind the cab and over the bed. Running with the tailgate down is not equivalent; it increases the aero drag by increasing the size of the low pressure area behind the cab. Run the smallest mirrors you can; they make a huge aero difference at highway speeds. The other big source of aero drag is airflow under the truck. The higher the truck sits, the more airflow, the more drag. Smaller, harder, skinnier tires reduce both rolling resistance and airflow but may require a numerically lower rear end depending on how far you push the diameter reduction.


I wonder how much a lowering kit and perhaps some sort of air dam under the front bumper would help to reduce the airflow under the truck and decrease fuel consumption. Depending on how the truck is used that might be a viable option, though I suspect that the decrease in the fuel consumption from a lowering kit that wasn't pretty radical would be small enough that you'd have to also like the lowered stance for other reasons to justify the expense.

There's also the fact that a lot of guys seem to prefer lift kits for more offroad ground clearance, instead. To each his own.

:)

[Note and disclaimer: The bold, underlined blue text above is a link to a web page where you can shop for one particular brand of lowering kits, just to give an example of that sort of thing, and not to push that particular brand. I have no idea if that brand is any good or not. They were near the top of a Google search, so I snagged the URL to link here for illustrative purposes only.]

StrangeRanger wrote:As JW has pointed out 22 MPG is golden and doing anything to alter that should be considered carefully.


Yeah, from what I have read here there are a lot of Ford 300 inline six powered truckers who only dream about seeing numbers like that.
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Post #16 by wallaka » Wed Nov 26, 2008 5:42 pm

I'd imagine that lowering, plus a front splitter would do wonders for gas mileage. Plus maybe a tray underneath and a rear diffuser.
Down to 29 cylinders!
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Post #17 by mutt » Wed Nov 26, 2008 5:46 pm

i got this crackpot notion to bolt mud flaps along the fr bumper as a dam of sorts. Im waitin for some free mudflaps for the experiment.
A belly pan would be SO cool. The older doghouse models sport partial ones.....

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Post #18 by StrangeRanger » Wed Nov 26, 2008 5:46 pm

A 3"/5" drop combined with something larger than a Lightning style air dam would probably help the aero a bunch but the 3"/5" renders the end result pretty useless as a truck.

Fabbing an undertray to clean up the airflow under the engine compartment would help as well, but it would be a lot of work for an unknown return.

If you really want to go crazy on the aero thing, you can shave the drip rails off the cab, seal up the front end around the grille opening, add skirts to the rear wheel wells, etc, etc. When you're done, it's still a truck and it's still not going to challenge a Civic for fuel economy
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Re: 250hp/350 ft/lbs?

Post #19 by American Thunder » Wed Nov 26, 2008 6:32 pm

Lazy JW wrote:
Bigger tires are gonna cost you in more ways than one :evil:
1. Initial cost
2. Greater air drag
3. Greater rolling resistance
4. Greater mass to accelerate.

Not much of anything else you have mentioned will help economy either, some of it will probably hurt. Tightening up quench is a desirable thing, also more compression within reason.
Joe


Well, going from the stock 235/75R15s to 245/75R16s(80psi!) brought fuel mileage up 1 or 2 mpg, the ride is somewhat rougher, but worth it. I bought all four of them in very good shape, mounted on a 1952 Willys pickup for $75, so I couldnt pass that up. Taller tires are a lot cheaper than taller gearing! I have a set of 235/85R16 tires laying around when these wear out, which are slightly narrower and taller, which should create less rolling resistance.

For some reason, fuel mileage drops slightly when it's cold. Maybe it's causing the fuel to pool in the intake runners. Anyway, the truck went 325 miles on 15 gallons this week. (21.6 mpg) Also, this is a Bronco, not a pickup, so wind drag is probably somewhat better. You can tell how bad the aerodynamics (and tire drag) are on a vehicle by getting up to a certain speed and putting the trans in neutral and coasting along, watching the speedometer to see how quickly it drops. At 60 mph, the speed of my Bronco drops like a stone when I do that. At 45 mph, it drops pretty slowly, so I know the wind/tire drag isnt much of a factor at that point.
1977 530hp 302 Mustang II videos:

Smokeshow at 8000 rpm

0-90 mph speedometer view



1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

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Post #20 by American Thunder » Wed Nov 26, 2008 6:45 pm

Thad wrote:Why not SBC size valves and pocket porting when doing head work?


I already have some 351W valves laying around, and they're the correct height for the 300, as far as I know? If the 351W valves are indeed the same length as 300 valves, then the SBC valves are shorter than the 300 valves, which changes the rocker geometry. (The shorter valve also decreases the spring installed height, increasing the pressure) That will require different length pushrods than stock in order to bring the center of the tip of the rocker back in line with the center of the valve stem.

As for the rocker ratio change, I'm not fond of that idea, as using the higher ratio rockers also decreases leverage, which increases parasitic loss and cam lobe/lifter wear.
1977 530hp 302 Mustang II videos:

Smokeshow at 8000 rpm

0-90 mph speedometer view



1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

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Post #21 by mutt » Wed Nov 26, 2008 7:31 pm

ooooooooo.....skirts......THAT would be cool.....

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Post #22 by 9.ford.5 » Fri Dec 05, 2008 12:19 am

if you do a turbo right and dont overpower it you wont loose your 20-22mpg but you can get up around 230 hp with 500ft.lbs. torque easily a guy ran a turbo up to 18lbs once hit 250mh? i think with 575ft.lbs torque but he later cracked 2 pistons

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Post #23 by willowbilly3 » Fri Dec 05, 2008 8:18 am

Did you recalibrate the speedo when you changed the tires? Were you running the 235s at 80 psi too?
My experience with gearing is that it doesn't make that much difference in mileage, although it is always one of the first things trotted in mileage discussions. It takes a given amount of energy to maintain a certain speed and making the engine turn slower doesn't change that. As a matter of fact you may loose milage if the throttle plates have to be opened more on every incline and the manifold vacuum drops, especially if it drops below the level that opens the power valve or where port velocities go into undesirable numbers.
Case in point is the o/d pickups of the early 80s that came with 3.00 gears. They couldn't get out of their own way and labored so bad just to maintain highway speeds on flat ground that milage went down from what the non o/d 3.55 geared trucks had made prior to that

I just don't see you getting better than 22 but it will be interesting for all of us to see how this works out, we may all learn something
As far as the aero stuff, every little bit helps. I remember when it first became a consideration the mirrors were the first thing they cleaned up and claimed 1 mpg over the old west coast junior style. the plastic air dam was added and it helped too, even on trucks that didn't get lowered.
Even keeping your truck washed and waxed will help over a cruddy one.

What we need is a big snowmobile belt type of transmission that keeps the engine rpm constant at any speed, now that would do some difference in mileage.
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Post #24 by Lazy JW » Fri Dec 05, 2008 8:36 am

willowbilly3 wrote:
What we need is a big snowmobile belt type of transmission that keeps the engine rpm constant at any speed, now that would do some difference in mileage.


Yup. For the worse. :evil:
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Post #25 by Lazy JW » Fri Dec 05, 2008 8:43 am

American Thunder wrote:.....

As for the rocker ratio change, I'm not fond of that idea, as using the higher ratio rockers also decreases leverage, which increases parasitic loss and cam lobe/lifter wear.


Well.......... your original post stated that you want more power, which is a reasonable request. In order to make that happen, you really do need to get some more air into the engine, and that's gonna require getting the valves open either further or longer and probably both. Not sure how you're planning to do that without increasing the forces on the cam :?

Forced induction, perhaps?
Joe
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Post #26 by wallaka » Fri Dec 05, 2008 10:24 am

Lazy JW wrote:
willowbilly3 wrote:
What we need is a big snowmobile belt type of transmission that keeps the engine rpm constant at any speed, now that would do some difference in mileage.


Yup. For the worse. :evil:


Really? 'Cause CVTs get better gas mileage on every other vehicle they are put on. You're telling me that keeping the engine in the highest efficiency zone more will cause mileage to drop?

Off topic, I guess :D
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Post #27 by American Thunder » Mon Dec 08, 2008 11:17 pm

Lazy JW wrote:
American Thunder wrote:.....

As for the rocker ratio change, I'm not fond of that idea, as using the higher ratio rockers also decreases leverage, which increases parasitic loss and cam lobe/lifter wear.


Well.......... your original post stated that you want more power, which is a reasonable request. In order to make that happen, you really do need to get some more air into the engine, and that's gonna require getting the valves open either further or longer and probably both. Not sure how you're planning to do that without increasing the forces on the cam :?

Forced induction, perhaps?
Joe


I've been contemplating a turbo setup, but that could get costly in a hurry.
But that aside, unless my thinking on this is screwy, it would seem that a larger cam lobe with a 1.6:1 rocker would create less pressure on the lobe surface than a smaller cam lobe with a 1.75:1 rocker. Unless of course the larger cam lobe requires the use of a heavier valve spring, which shouldnt be the case here, where the cam is a low-rpm-torque grind. Hmm.
1977 530hp 302 Mustang II videos:

Smokeshow at 8000 rpm

0-90 mph speedometer view



1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

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Post #28 by American Thunder » Mon Dec 08, 2008 11:25 pm

Lazy JW wrote:
willowbilly3 wrote:
What we need is a big snowmobile belt type of transmission that keeps the engine rpm constant at any speed, now that would do some difference in mileage.


Yup. For the worse. :evil:


Maybe if the engine was specifically designed to run at the constant rpm, such as the case with a generator, but our truck motors arent.
1977 530hp 302 Mustang II videos:

Smokeshow at 8000 rpm

0-90 mph speedometer view



1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

American Thunder
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Post #29 by American Thunder » Mon Dec 08, 2008 11:54 pm

willowbilly3 wrote:Did you recalibrate the speedo when you changed the tires? Were you running the 235s at 80 psi too?
My experience with gearing is that it doesn't make that much difference in mileage, although it is always one of the first things trotted in mileage discussions. It takes a given amount of energy to maintain a certain speed and making the engine turn slower doesn't change that. As a matter of fact you may loose milage if the throttle plates have to be opened more on every incline and the manifold vacuum drops, especially if it drops below the level that opens the power valve or where port velocities go into undesirable numbers.
Case in point is the o/d pickups of the early 80s that came with 3.00 gears. They couldn't get out of their own way and labored so bad just to maintain highway speeds on flat ground that milage went down from what the non o/d 3.55 geared trucks had made prior to that

I just don't see you getting better than 22 but it will be interesting for all of us to see how this works out, we may all learn something
As far as the aero stuff, every little bit helps. I remember when it first became a consideration the mirrors were the first thing they cleaned up and claimed 1 mpg over the old west coast junior style. the plastic air dam was added and it helped too, even on trucks that didn't get lowered.
Even keeping your truck washed and waxed will help over a cruddy one.


The tire pressure increase helped, without a doubt. The old tires were 40 psi. But the gearing also helps, otherwise, 5 speed overdrive transmissions never would have been used. (I had to swap the 5 speed into my Bronco, as it's an '83 and it had a C4 auto) Gearing higher only helps mileage when the motor has sufficient torque to pull the vehicle along. A '95 300 w/ 5 speed in an older Bronco is a good combination for mileage. Careful distributor tuning is critical, too.

I figured on the engine making peak torque around 1800 and decent torque at much lower rpm, so I set up the truck to cruise between 1200 and 1500 rpm.
60 mph = 1668 rpm, good, but too much wind/tire drag at that speed. So I stick to the back roads and 45 mph = 1250 rpm.
I have more engine tuning and modifications to do when the warm weather returns, and I'm fairly certain I can squeeze a little more efficiency from the motor. My original estimate for mileage when I began this project was 24-25 mpg, and although it fell somewhat short of that, it's still a lot better than it was when I started on it.
I was figuring on the 390/450 4V and Offy DP intake to increase cruising mileage, due to vastly improved cylinder balance and fuel atomization. (I also expect it to decrease my mileage if I'm on the throttle heavily) with better cylinder balance, I can likely get away with more ignition advance, since there will no longer be a lean condition on certain cylinders. This will yield greater low speed torque, which will allow even higher gearing. (taller tires)
I'm not so sure about the cam selection, as I've always just selected camshafts based purely on performance.(V8s) And 300s are still fairly new to me.

p.s. There are a lot of minor things I've taken into consideration. One of them is building the 3" exhaust so that the outlet exits under the side of the truck and is perpendicular to the airflow when the vehicle is moving. I counted on a slight venturi effect as the rushing air traveled across the mouth of the exhaust pipe to aid in exhaust gas evacuation. I wonder how much of an effect it really has?

p.s.s. A cool online speed/rpm/gearing calculator:
http://www.corral.net/tech/gearcalc.html
1977 530hp 302 Mustang II videos:

Smokeshow at 8000 rpm

0-90 mph speedometer view



1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

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Post #30 by rhetor » Tue Dec 09, 2008 12:04 am

more throttle = better efficiency.

This is probably why low numerical gears yield better efficiency. The throttle is open more for the same mph, which increases the efficiency of the engine.

Otto cycles are generally most efficient around WOT at the torque peak.

The CVT is a great idea for not only efficency but acceleration as well. Keep the engine at its hp peak (and make it really peaky with specialized components match) and you've got a speedster. You don't have to accelerate the mass of the engine either. Make the engine load as high as possible at the lowest rpm without ill effects such as pinging, and you get good economy.
300- mild head porting - 204/214 cam - 1.73 rollers - 2.5" exhaust DEAD AND GONE!

New truck- 71 F-100 302/AOD. Missing my 300 dearly. 302 belongs in a mustang, lifters tick, headers sound annoying, vibrates, is ugly, etc.

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Post #31 by THE FRENCHTOWN FLYER » Tue Dec 09, 2008 9:56 am

American Thunder wrote:
Lazy JW wrote:
American Thunder wrote:.....

... it would seem that a larger cam lobe with a 1.6:1 rocker would create less pressure on the lobe surface than a smaller cam lobe with a 1.75:1 rocker.


Friction at the lifter is inversely proportional to engine speed, meaning it's highest at cranking speeds and diminishes as speed increases. I wouldn't let that drive my quest for a more efficient engine. More valve lift in the same time frame is going to increase loads whether you get it by bigger lobes or more RA ratio.
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Re: 250hp/350 ft/lbs?

Post #32 by inline300 » Tue Dec 09, 2008 11:25 am

American Thunder wrote: 250hp and 325-350 ft/lbs of torque, is this fairly reasonable?



This thread will give you a couple examples of 325+tq. First example is a product of JMS Racing Engines, they should know how to rework your head and offer camshaft suggestions:

http://fordsix.com/forum/viewtopic.php? ... highlight=

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Post #33 by American Thunder » Tue Dec 09, 2008 5:58 pm

rhetor wrote:more throttle = better efficiency.

This is probably why low numerical gears yield better efficiency. The throttle is open more for the same mph, which increases the efficiency of the engine.

Otto cycles are generally most efficient around WOT at the torque peak.


I have found this to be true, especially when the engine can make power at low rpm, because revving it increases the stress on all the parts, which begins to drop efficiency. From my experimenting, the more torque you can build and the lower the rpm where it builds that torque, the better the mileage will get, when coupled with taller gearing. This is one reason diesels annihilate gasoline engines in mileage.
Speaking of which, diesels run at wide open throttle all the time anyway.(since they really have no throttle at all) There's a perfect example of what you were talking about.
1977 530hp 302 Mustang II videos:

Smokeshow at 8000 rpm

0-90 mph speedometer view



1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

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Post #34 by American Thunder » Tue Dec 09, 2008 6:10 pm

THE FRENCHTOWN FLYER wrote:
Friction at the lifter is inversely proportional to engine speed, meaning it's highest at cranking speeds and diminishes as speed increases. I wouldn't let that drive my quest for a more efficient engine. More valve lift in the same time frame is going to increase loads whether you get it by bigger lobes or more RA ratio.


That's why the cam companies tell you not to idle a motor while breaking in a fresh camshaft. If you do, it could be bye bye lobes. In my low rpm torque motor, the cam lobes and lifters take a beating.
I was thinking the higher ratio (1.75?) rockers would move the majority of the pressure from the rocker fulcrum onto the lobe/lifter surfaces. And vice versa for the lower ratio stock rocker, which would be desirable, since you can get rockers with rollerized fulcrums, but those damn torque roller camshafts arent available for the 300 at a reasonable price, unfortunately. (I still can't believe Ford never upgraded the early 1990s 300s with factory roller cams.)
1977 530hp 302 Mustang II videos:

Smokeshow at 8000 rpm

0-90 mph speedometer view



1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

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Post #35 by American Thunder » Tue Dec 09, 2008 6:15 pm

I was talking to my machinist buddy about possibly using a cast iron core to regrind into a roller cam, but he talked to a guy that tried it, and it wouldnt live past a few runs at the strip. I wonder if getting it plated with an industrial chrome finish would make it last in a torque application where a very low spring pressure was needed. Hmm.
1977 530hp 302 Mustang II videos:

Smokeshow at 8000 rpm

0-90 mph speedometer view



1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

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Post #36 by CNC-Dude » Tue Dec 09, 2008 11:13 pm

Roller cam billets are made from 8620 steel, and once heat treated is extremely hard, almost like a bearing race! Hydraulic and solid flat tappets are cast iron and very soft in comparison and cant be made to be used as a roller....

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Post #37 by American Thunder » Wed Dec 10, 2008 5:58 am

CNC-Dude wrote:Roller cam billets are made from 8620 steel, and once heat treated is extremely hard, almost like a bearing race! Hydraulic and solid flat tappets are cast iron and very soft in comparison and cant be made to be used as a roller....


Yeah, that's the problem. And roller cams for the 300 are ridiculously expensive.
Why is it that iron distributor gears cant be used with steel roller cams, while a softer bronze gear is used with the roller cam, even though the steel roller cam is harder than the iron?
1977 530hp 302 Mustang II videos:

Smokeshow at 8000 rpm

0-90 mph speedometer view



1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

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Post #38 by CNC-Dude » Wed Dec 10, 2008 11:54 am

Because the bronze shavings(particles) are less harmful to the engine when the gear wears away. The cast gears will trash the engine bearings as it wears away and travels through the oiling system. The bronze gear was designed as an expendable wear item. I guess the cam companies figured it was cheaper for the user to replace a 30-40 dollar gear every once in a while, than the whole engine....Just for curiositys sake, how much are roller cams generally for the 300's and other Ford sixes. Im making some roller billet blanks right now for a cam company that are going to be used in some vintage 6's for Bonneville, as was wondering about the price difference in comparison.

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Post #39 by THE FRENCHTOWN FLYER » Wed Dec 10, 2008 3:28 pm

CNC-Dude wrote:... how much are roller cams generally for the 300's and other Ford sixes. Im making some roller billet blanks right now for a cam company that are going to be used in some vintage 6's for Bonneville, as was wondering about the price difference in comparison.


Last time I talked to one of the biggies it was about $700 for a finished cam. They said if I supplied my own cores I could save $200.
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Post #40 by CNC-Dude » Wed Dec 10, 2008 5:31 pm

Ok,thats not too bad! I saw on here somewhere that a person bought a Clay Smith roller cam and said it set him back $1500 bucks. Maybe he meant for cam,lifters, rockers,etc. Even though he didn't specify what all he got for that price.

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Post #41 by THE FRENCHTOWN FLYER » Wed Dec 10, 2008 8:29 pm

CNC-Dude,
Are you the same CNC-Dude as on the Inliners site? I enjoy reading your posts over there. We have the same heroes. If you are making cam blanks for the 300 Ford for roller cams did you know the lobes on a factory camshaft are not in alignment with the lifter bores - they are offset .100 to promote lifter rotation, which, of course, you do not want in a roller cam. You might want to reposition the lobes to insure full roller contact. GM cams may suffer from the same design flaw.

Sorry for hi-jacking the thread but I wanted to maybe save CNC some headaches.
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Post #42 by CNC-Dude » Wed Dec 10, 2008 10:00 pm

Yep, thats me! My cam grinder told me the simplest way to make the billet without any blueprint or drawing,was to make a special pointed pin to fit into each lifter bore. And place a stock cam in a block, and rotate the cam to transfer a scribe mark to create a lobe/lifter bore centerline reference. Of course you would put Dykem on the lobes so you could see the scribe marks.Then you would copy those dimensions to your blank. He said to leave all the dimesions .030 full(width,journals,etc.)and he could take it from there! Fairly straight forward....Glad you have enjoyed the other topics!

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Post #43 by Lazy JW » Thu Dec 11, 2008 8:31 am

wallaka wrote:.... You're telling me that keeping the engine in the highest efficiency zone more will cause mileage to drop?.....


Nope. I agree about having the engine run at its peak efficiency zone. But snowmobile variable belt drives aren't the most efficient means of power transmission.
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Post #44 by American Thunder » Fri Dec 12, 2008 10:20 pm

Chromium plating is at least as hard as bearing races, if not harder. So again, I'm considering whether a reground iron camshaft core with chromed lobe surfaces would survive in a roller application. Spring pressure would be low, and the chrome plating should eliminate any wear issues of the soft cast iron. I wonder if the flat-tappet-style cam lobe offset would screw it up when you reground it as a roller?
Side benefit of a chromed reground roller iron cam would be that you could use the stock iron distributor gear. Also, in the regrinding process, you could eliminate almost all base circle, so that the lifters would ride lower in the bores.(necessary when using the taller roller lifter)
You could maybe use some stock 5.0HO roller lifters, too. (used ones are cheap, or free)
1977 530hp 302 Mustang II videos:

Smokeshow at 8000 rpm

0-90 mph speedometer view



1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

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Post #45 by TCIC 300ci superbeast » Fri Dec 12, 2008 11:21 pm

chrome plating is vary thin.... i think the max plating build up is .005" may be wrong.... that would wear fairy fast.
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Post #46 by Lazy JW » Fri Dec 12, 2008 11:26 pm

Industrial hard chrome can be applied to well over .030", it just costs more. We have it done routinely on feed rolls, etc. for sawmill equipment.
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"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
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Post #47 by TCIC 300ci superbeast » Sat Dec 13, 2008 12:26 am

but how long would that last? when it under presser 24/7
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dec.1978 f150xlt custom 4x4 "six shooter" parts truck for super beast

2004 2.0 dohc 5speed focus DD "toycar"

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walk softly and carry a big six

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Post #48 by CNC-Dude » Sat Dec 13, 2008 1:12 am

American Thunder wrote:Chromium plating is at least as hard as bearing races, if not harder. So again, I'm considering whether a reground iron camshaft core with chromed lobe surfaces would survive in a roller application. Spring pressure would be low, and the chrome plating should eliminate any wear issues of the soft cast iron. I wonder if the flat-tappet-style cam lobe offset would screw it up when you reground it as a roller?
Side benefit of a chromed reground roller iron cam would be that you could use the stock iron distributor gear. Also, in the regrinding process, you could eliminate almost all base circle, so that the lifters would ride lower in the bores.(necessary when using the taller roller lifter)
You could maybe use some stock 5.0HO roller lifters, too. (used ones are cheap, or free)
Roller cams have a different lobe centerline in respect to the lifter bore than flat tappet camshafts do, as you mentioned, and cant be altered or offset or changed. Making the base circle smaller is only going to weaken the camshaft further than than it already will be. How will you plan to keep the lifters from turning in the lifter bores?? The guide bars for a 5.0 wont work, because the lifter bore centerlines are much farther apart on the 6 than the 5.0. I think you should contact a cam grinder to discuss other available options....

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Post #49 by Lazy JW » Sat Dec 13, 2008 8:58 am

TCIC 300ci superbeast wrote:but how long would that last? when it under presser 24/7


I dunno. Chromed feed rolls last at least ten times as long as regular steel. This application on cams is far, far out of my range of knowledge. It is an interesting thought though.
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"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
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Post #50 by American Thunder » Sat Dec 13, 2008 11:46 am

For the lifter locating bars, if they were too short, I'd cut them in half and add steel to the center as necessary.

Ideally, I'd want to run the longer 240 rods with some forged pistons, bushed for full floating pins, and then install a roller camshaft with a grind running only slightly more duration and lift than the stock cam. I figure with the combination of longer rod for greater piston dwell times and increased "area under the curve" of the roller cam, the engine would breathe substantially more freely even with a stock head on it.
Basically, cheating a way around the limited head flow. Side benefits of course include the typical reduced piston skirt pressure on the power stroke, less friction from the rollers, and an engine life probably twice as long as a stock 300. (Meaning, I'd probably get old and die before it did)

Eventually, I will end up buying a roller cam for it either way, but I'd rather save some money if possible.
1977 530hp 302 Mustang II videos:

Smokeshow at 8000 rpm

0-90 mph speedometer view



1983 4x4 Bronco - '95 300 converted to carb, 5-speed, 3.55 gears and 9" rear.

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