Engine ideas...

[Timmy390]

If you are going from a 302..to a 408....that is a 35% increase in cubic inches. How does that translate to cooling load? Do you need 35% more radiator? Is it linear like that?

I'm sure I'm showing my age and misconceptions about stroker motors but the old school thinking was they ran hotter due to the increased angles and pressures due to those angles. Old school thinking was by stroking you were burning the candle at both ends so to speak. Increased heat and ware as well as stress to the rods. Increased ware really to everything. I'm sure stroker kits have come a long way since the old days. Flame away on on old man I guess......I like to think I know enough to be dangerous when it comes to FE's and FSB's (Suzuki 1.3L's as well) but maybe I'm just set in my ways.

I know I'm throwing a blanket over all strokers and that isn't the case for all but that's just how I see it.

I built my W with just a bit more compression than stock, better heads and bigger cam. It runs great and pulls hard but what's good for me isn't everyone's cup O tea.

Tim

 

[68ford]

Under almost all circumstances the heat production is the same. Hour bronco always takes the same HP to idle, accelerate slow etc regardless of engine size. Always takes the same HP to move the same weight. The only time more heat is being made is when you're burning more fuel. That is only when you're making more power than the old engine ever could make.

 

[McTuggernuts]

So went with a Blueprint 347, 415hp/415 ft lbs...wrestling between the NV4500 and AX15 transmissions. Any drawback to the more heavy duty NV4500 other than a little more lift for clearance?

 

[Broncobowsher]

NV4500 to AX15, that's comparing potatoes to olives. That's comparing a top loader 4-speed to a NP435 4-speed.

Why anyone looks at a NV4500 these days is beyond me, the ZF 5-speed is the go to choice for a decade now. That is if you want a truck 5-speed, which is your current 3-speed with an extra low gear below 1st and an overdrive for 5th. But gears 2-4 might as well be the old 3-speed.

But if you want a car like 5-speed, that is where the AX-15 and NV3550 (might as well add the Mazda 5-speed to the mix as well) fit in.

In a Bronco, I'll take a 351W over a 347 stroked 302 any day. For spent millions engineering a stroker for the little 302. Realizing the limitation they made a beefier block, crank, rods, main bearing caps, and even upped the size of the head bolts. raised the deck. The 302 was introduced as a 221 V8. 260 was the big option. Grew to 289 and was pushing the limits of the original little V8 design. Ford knew what they were doing when they wanted to make the little small block a little bigger.

 

[McTuggernuts]

NV4500 to AX15, that's comparing potatoes to olives. That's comparing a top loader 4-speed to a NP435 4-speed.

Why anyone looks at a NV4500 these days is beyond me, the ZF 5-speed is the go to choice for a decade now. That is if you want a truck 5-speed, which is your current 3-speed with an extra low gear below 1st and an overdrive for 5th. But gears 2-4 might as well be the old 3-speed.

But if you want a car like 5-speed, that is where the AX-15 and NV3550 (might as well add the Mazda 5-speed to the mix as well) fit in.

In a Bronco, I'll take a 351W over a 347 stroked 302 any day. For spent millions engineering a stroker for the little 302. Realizing the limitation they made a beefier block, crank, rods, main bearing caps, and even upped the size of the head bolts. raised the deck. The 302 was introduced as a 221 V8. 260 was the big option. Grew to 289 and was pushing the limits of the original little V8 design. Ford knew what they were doing when they wanted to make the little small block a little bigger.

Curious what the thought was between the heavy duty truck feel vs the car-like AX15 or NV3500. Thanks for the input.

 

[chuck1022]

I'm sure I'm showing my age and misconceptions about stroker motors but the old school thinking was they ran hotter due to the increased angles and pressures due to those angles. Old school thinking was by stroking you were burning the candle at both ends so to speak. Increased heat and ware as well as stress to the rods. Increased ware really to everything. I'm sure stroker kits have come a long way since the old days. Flame away on on old man I guess......I like to think I know enough to be dangerous when it comes to FE's and FSB's (Suzuki 1.3L's as well) but maybe I'm just set in my ways.

I know I'm throwing a blanket over all strokers and that isn't the case for all but that's just how I see it.

I built my W with just a bit more compression than stock, better heads and bigger cam. It runs great and pulls hard but what's good for me isn't everyone's cup O tea.

Tim

I was just pondering the idea that if a 302 generates xxx btu's...then adding an additional 106 cubic inches of heat production would generate xx more btu's. Therefore requiring more cooling ability.

Where the hell are the engineer types that went to school for this.

 

[rguest3]

One plus is you can still get a Brand New AX-15. Wild Horses has this Transmission in a Complete Kit Form with really nothing else needed.

The AX-15 will do great behind the 347. Sportier feel and easy shifting. Add the B&M shifter and paired with the 4.11 and 33s, you will love it.

 

[Jdgephar]

I was just pondering the idea that if a 302 generates xxx btu's...then adding an additional 106 cubic inches of heat production would generate xx more btu's. Therefore requiring more cooling ability.

Where the hell are the engineer types that went to school for this.

Isn't it something like the law of conservation of energy. Energy is neither created nor destroyed. I agree with what was said earlier about the amount of heat created based on the amount of work needed (or horsepower used). Cruising still needs the same HP to move, regardless of 302 or 351. Unless you live at high RPM all day, your cooling needs should be met whether 302 or 351. But what do I know, I didn't need thermodynamics, I'm an electrical engineer. I guess I'll find out once my '72 is done with the 351 in it ;D

That extra 106 cu in only makes more heat when it adds more fuel and air than what was used by the 302, right?

 

[73azbronco]

I wnet nv4500 becauser that was the ticket 15 years ago. Now, they are hard to find new. Heavy But I don't care.

If I did this again, I would use a 6r80 and call it a day. Might still do that.

 

[73azbronco]

Isn't it something like the law of conservation of energy. Energy is neither created nor destroyed. I agree with what was said earlier about the amount of heat created based on the amount of work needed (or horsepower used). Cruising still needs the same HP to move, regardless of 302 or 351. Unless you live at high RPM all day, your cooling needs should be met whether 302 or 351. But what do I know, I didn't need thermodynamics, I'm an electrical engineer. I guess I'll find out once my '72 is done with the 351 in it ;D

That extra 106 cu in only makes more heat when it adds more fuel and air than what was used by the 302, right?

You will make gobs more heat if you use the gobs more power. All things being equal though, it could run cooler just driving around town, unless you get on it all the time.

 

[DirtDonk]

Curious what the thought was between the heavy duty truck feel vs the car-like AX15 or NV3500. Thanks for the input.

As they're saying, it all comes down to what you want from the Bronco.
If you're going to go off-roading, hauling lots of expedition gear, put large tires on it, or just beat on it hard, the 4500 and ZF might still have advantages.
They have low first gears for crawling or hauling heavy loads up a hill, and they have the physical beef to take lots of abuse (theoretically) before failure.
The occasional cruise on the street is not a problem with them, but they're biased to the dirt in an "old-school truck" kind of way.
So if that's what you cut your teeth on driving already, then the feel of a truck transmissions slower and clunkier shifting would not be an issue. I like them and don't have any trouble with their clunky shifting because I remember worse.

But if this is a street rig only, with maybe a foray now and then down some cattle trail on the back 40, and will spend most of it's time taking the kids (if you have young ones still) and family to dinner and ice cream in town for fun, then gets parked most of the year, then the smaller, lighter, smoother shifting transmissions with almost regular first gears are seemingly the better choice.
They're not exactly "car like" I would not say. But they're closer to it than the big boxes.

If all of the above pertains, and you're going to do it all, then you just decide which way you need to compromise. Granny gear and chunky shifting, or easier shifting around town and less drama during the install.
Granny gears are great in their place. You don't normally use 1st/low unless you have a poor choice of differential ratios vs tire size. You start off in 2nd which is not much different sometimes than first gear is with a stock trans. The medium low ratio of the AX15 (what, about 4:1 maybe?) can be utilized on the street if you need a little extra oomph, or you can still start in second if you prefer.

They're all decent boxes. But like John Sebastian used to say, "you just gotta finally decide" for yourself in this case and pick the one you like.;D

Paul

 

[sprdv1]

Well said and very true...

As they're saying, it all comes down to what you want from the Bronco.
If you're going to go off-roading, hauling lots of expedition gear, put large tires on it, or just beat on it hard, the 4500 and ZF might still have advantages.
They have low first gears for crawling or hauling heavy loads up a hill, and they have the physical beef to take lots of abuse (theoretically) before failure.

The occasional cruise on the street is not a problem with them, but they're biased to the dirt in an "old-school truck" kind of way.
So if that's what you cut your teeth on driving already, then the feel of a truck transmissions slower and clunkier shifting would not be an issue. I like them and don't have any trouble with their clunky shifting because I remember worse.