Ford 4.9 300 I6 vs 5.0 302 V8

[360 4V]

Transmissions:
I have two picks for transmissions.
M5OD and AOD.
The M5OD Is light weight but the AOD is not. You can build a tough AOD but it is heavier than the M5OD. If I were trying to loose Bronco weight I would get a M5OD. It is cheap, rebuild kits are not too expensive and it should live for a little while in a Bronco weighing less than 4,000 lbs.

I would put a Dana 20 or NP 205 behind the transmission for simplicty and fiscal concerns.

Drum brakes have to go. They are heavy dead weight. Like a beer gut on an athlete. Steel wheels are heavy too.Eagle Alloys makes strong aluminum wheels for trucks.

Offroad tires vs. street tires of the same diameter and width I guss eat 1.5 mpg but we are stuck with those. I have thought about having a set of conservative street tread for driving around town and some aggressive offroad tires for wheeling. They could both be the same diameter so gearing would not change.

 

[360 4V]

How much does this Bronco weigh?

3,500 to 4,000 lbs?

 

[360 4V]

psbronco,
what were the results of your 300 swap? Is the 300 noticeably more torqey in an early Bronco compared to a 302?

I worry that an engine sitting lower in the chassis would interfere with the axle moving up during up travel. Then again mounting an engine lower in the chassis does improve performance.

 

[Gas Pig]

Thanks to all that has jumped into conversation. It's all been a very interesting read. As I gather from everybody input the swap is doable. The only real con was psbronco saying the EFI 302 would have been easier/quicker. Reading between the lines here..... why screw around doing a bunch of mods for a 4.9L when you more then half way there with a much simpler 302 EFI swap.

I kind of figured the 4.9 swap would be more "reinventing wheel" time then a straight up 302 EFI swap. So, if that 's the case what advantages does the 4.9 have to make it worth the time and effort of going with the 4.9 over the 5.0?

I already did an EFI 302 swap in my old 72 truck and it was fairly easy and painless. I had only real problem I had was a bad ECM / computer (tough to troubleshoot) but other then that it was well worth time and effort!

 

[Justafordguy]

Revelation on here has the 4.9 in his....

X2, and his works very well offroad.;D

 

[360 4V]

Don't get me wrong. The 300 is a great engine. I just think that dealing with it is a project in its self. You might as well buy a truck that came with a 300. There is nothing to gain by swapping in a 300. For the money, time and energy you might as well buy a cheap Ford truck with a 300 in it to play with. Have you ever read the Ford Six forums? It is really neat stuff. I am just not a big fan of engine swaps.

 

[fungus]

In my opinion, the 4.9 swap would be more of a novelty based decision than a performance based one. The 302/ 5.0 can be built into a very torquey powerplant with the right cam & valvetrain which, in general terms, can be done relatively cheap. I'd love to do a build with an EFI'd 4.9 just to do it though.

360 4V: in terms of tranny choices don't look past the ZF5 speed! F-250s came from the factory with these bolted to the back of the 4.9s. Gives you the best of both worlds as far as a crawler gear and the OD, no adapters required... Will also bolt right up to a 205 if you chose to go that route.

 

[360 4V]

fungus,
that is pretty fiscal thinking. The ZF-5 speed bolts right up to my small block Ford which bolts into a stock Bronco chassis and the ZF-5 speed bolts right up to a NP 205.

Somebody should write up a tech article on how to build a 302 with the best torque curve. Most of us are not drag racing so horsepower is not a practical objective.

 

[fungus]

Here's the 5.0 cam I stabbed in my 5.8 for the 68 project. Coming from several of my Bronco Bros on the Norcal board that run this cam it's a stump puller. It is not a drop in and go though as it requires head studs so some head work will be required to run it. I've got Edelbrock RPMs going on this with studs and roller rockers so it works for me.

http://www.summitracing.com/parts/CCA-35-308-8/

 

[markw]

Keep this going! I have a 4.9 EFI in my shop I plan to put in a project truck....just for the novelty. Have a 408 in the one I'm working on now.

 

[360 4V]

Does that camshaft have the standard 302 firing order or the 302HO/351W firing order?

 

[broncnaz]

fungus,
that is pretty fiscal thinking. The ZF-5 speed bolts right up to my small block Ford which bolts into a stock Bronco chassis and the ZF-5 speed bolts right up to a NP 205.

Somebody should write up a tech article on how to build a 302 with the best torque curve. Most of us are not drag racing so horsepower is not a practical objective.

Most of the RV type cams like the one listed the edelbrock performers or other cams with similar specs are the key you may not attain 300 like torque as that stroke it has is its key but you can get close. Basicaly transmission /axle gearing is your friend when it comes to V8's

Basic rules for a torquey 302 is keep things on the smaller side smaller cam, smaller heads, and decent intake and headers. I'd also opt for a smaller carb like 500 cfm for a 4v. There is no one engine build that will be suited to everyones needs as gearing, tire size, transmission and vehicle useage/driving styles are all factors that need to be considered. the engine should be built around those factors. but for the most part one build can cover most people.

 

[360 4V]

The 460Ford forum has a vast archive of engine builds to paint a genaric picture for new people to conceptualize what works and what doesn't. Obviously everything is not black and white but recipe-examples of what does yield target results does help people get started. I am partial to torky engines because I have driven plenty of cars that made plenty of torque in the better part of the torque curve but were very weak at low rpms. Low end torque is addictive. That is what matters to me 95% of the time. Most people would call that driveability.

 

[360 4V]

How would you compare a 330 V8 with a 4.030" bore and 3.25" stroke to a 330 V8 with a 3.55" bore and a 4.165" stroke? Do you predict one the make more torque in the better part of the torque curve? Do you predict one to make more torque outside the better part of the torque curve?

 

[broncnaz]

Many people over build engines. Then they endup being unhappy with there vehicle because of lack of driveability. Mostly because they build a engine thats to high strung and dont change the gearing to allow it to get into its powerband quickly. Thats why you need to plan the engine for the whole vehicle and its intended useage.

I'd consider the engine in my 73 slightly over built because I used pretty big heads on it but it runs great with my setup. maybe I could pick up a little more lowend with smaller heads but with the NP435 I dont think I'd see much gain. and overall driveablity is about where I want it.
Yeah we probably should start a engine build section to give people a idea of what a lot of us are doing but for the most part the camshaft is the main factor that really determines the where powerband will be. Most of the cams we use will put you right where you want to be.

 

[fungus]

Does that camshaft have the standard 302 firing order or the 302HO/351W firing order?

The Comp 35-308-8 cam is the 5.0 HO/ 351W firing order.

 

[broncnaz]

How would you compare a 330 V8 with a 4.030" bore and 3.25" stroke to a 330 V8 with a 3.55" bore and a 4.165" stroke? Do you predict one the make more torque in the better part of the torque curve? Do you predict one to make more torque outside the better part of the torque curve?

I'm going to assume that by better part of the torque curve you really mean which one has better lowend torque. as better part of the torque cruve is subjective. But I know you are looking for lowend torque.
Pretty much hands down the engine with the longer stroke will always make more lowend torque. Shorter stroke engine can make just as much or even more torque but will need to rev up high to do it.
Basically its just like comparing the 300 and 302. A 302 will need to rev a bit more than a 300 to make the same torque. take this example a 81 300 reaches peak torque at 1600 RPM(243ft lbs) where a 81 302 makes peak tq at 2000 RPM's(243 ft lbs.) now you may be able to build the 302 to make peak torque a little lower but you may lose some torque in the process. because the short stroke just wont build the torque at lower RPM's

 

[dead road]

I don't know about the weight or how easy one would fit into a bronco. However I had an 1989 work truck with a 300 six efi and I loved the way it ran and drove. I have always been a FE block lover for the low rpm torque. This motor reminded me of that type of power. You can drive them with out shifting gears. 20mph to 100mph all in high gear. And I believe it got decent mileage for a full size truck.

 

[360 4V]

By "the better part of the torque curve" I mean't area under the torque curve. If some factor is worth an additional 10 ft/lbs of torque at an obscure and weak end of the torque curve but gains nothing or even gives up some torque in area under the torque curve then it is bad. If the better part of my torque curve starts at 1,800 rpm in a 302 then I can get a torque converter that keeps me in the better part of the torque curve better. If the torque curve comes on strong at 1,400 rpm then a tighter torque converter is indicated.

I hope that helps with my idea about better part of the torque curve.

 

[broncnaz]

I get what you mean now. but consider that most torque cruves on low RPM engines are fairly flat pretty much meaning that from idle to the peak such as 1800 RPM your not going to notice much of a differance if you give up or gain 10 ft lbs. A lot of the time with the engines we tend to run once the torque curve starts your only going to see about a 50 ft lbs max change from the start to the peak.
Things such as better heads can add torque under the peak although sometimes they will cause a loss of torque if they are to big. So you have to be careful when building for max lowend torque. Of course most of us want the torque peak around 2200-2800 RPM so the engine can loaf when crusing down the hiway any losses on under 2200 rpm are not noticed due to transmission gearing.
torque converters are a whole other ball game and I'm not all that well versed on them as there are factors other than just stall speed that come into play.