Add power to the 300 i6?

Wondering if anyone found the 300 i6 a bit of an underpowered engine and was wondering if there were ways to bump the hp numbers a bit. Ive heard some insanely crazy good reviews on it though! Let me know if you have any ideas!

The short answer is from the factory it is set up as a low rpm work horse. To change that, you have to help it breathe more... in and out. What that means is a custom intake for a 2 or 4 barrel carb (or multiple carbs), ported head, different cam, and headers, split EFI manifolds, or the medium duty HD manifold. These parts cost some money, so most people opt for a V8 swap... but as the Frenchtown Flyer puts it, the 300 six is “the best kept secret in racing”. Clifford performance parts slogan is 6=8.

BullnoseHunter02 wrote

Wondering if anyone found the 300 i6 a bit of an underpowered engine and was wondering if there were ways to bump the hp numbers a bit. Ive heard some insanely crazy good reviews on it though! Let me know if you have any ideas!

In the middle of figuring all this out myself.

I just removed all the emissions system on mine. Went with an HEI distributor. For now, I want to get this thing running good. So I am reusing the factory manifolds and carb.

But, I am probably going with a hand made intake like this, and three single barrel carbs. EFI exhaust manifolds, and a cam upgrade.

in point of having the engine breath more, im probigly gonna open up the exause with headers and maybe do a carb upgrade if i end up with a 300 truck. Cooling was an issue with this engine if i remember right, ive read lots of storys of these engines overheating. so cooling, lessening the exuast restriction, and maybe turbocharging it are what my plans would be to make it suitible for me. Ive heard ford even made a concept 300 that was turbocharged.

It all depends on your expectation of what you are looking for the engine to do. It was used in the F 600 with a dump bed and handled that satisfactory, in fact the HD V8's used in those trucks didn't have power #'s that much greater. The biggest issue in my opinion is making sure that the engine is correctly tuned. An out of tune engine can easily lose 75 or more horsepower.

Its gonna be a daily driver, probibly not going above 65 all that much, getting some highway travel in occasionally but nothing really above 70. Mainly gonna be going to and fron school and then to work on the weekends. not hauling anything as of right now. im just concered this thing isnt gonna be able to get up to 65 when i go to get on the interstate, or handle the 55 mph cruse to work. Thats kinda why i wanted more power. 130 hp isnt a lot at all for this engine and was hoping to push those numbers closer to like 175-200hp.

Mine has the 300, all stock with nothing but a good tune and carburetor setting with a 3.25 geared 9 inch and it will cruise 60-65 no problem.  If you are not expecting neck whipping acceleration, then the 300 will do just fine. I had a '85 model with a 302 and it did not out do the 300 on acceleration but it did have more top speed but using that just gets you tickets. Plus maintenance is easier, at least on the carb version. However, the EFI 4.9{300} has a little more torque and more top end putting it on par or above a stock 302. Just my opinion though.

Well, that soundspromising tbh, The insurance company is gonna probibly be happier about a 6 anyway. I was just worried its so underpowered you cant really get up to highway speeds. Is the fuel economy simaler to a 302 aswell? Ive heard there is no real true number for the 300. The 302 get like 14-15 mpg from what i have heard.

BullnoseHunter02 wrote

Well, that soundspromising tbh, The insurance company is gonna probibly be happier about a 6 anyway. I was just worried its so underpowered you cant really get up to highway speeds. Is the fuel economy simaler to a 302 aswell? Ive heard there is no real true number for the 300. The 302 get like 14-15 mpg from what i have heard.

The 4.9L/300 can do well if driven conservatively: https://www.ford-trucks.com/forums/1325963-gas-mileage-recipe-4-9l-300-a.html

Thats not to shabby honestly, im not an aggresive driver so mpgs shouldnt be bad. I also read that turbocharging the 300 can shorten itslife expectancy quite a bit because it wasn't designed to run one on it. So... ill probibly just see what i end up with first and then go from there on it.

So what's the deal with camshaft upgrades for the 300L6?

I see RockAuto has Heavy Duty/Towing camshaft options...

https://www.rockauto.com/en/catalog/ford,1980,f-100,4.9l+300cid+l6,1120475,engine,camshaft,5260

Do most people just run the stock cams in them with the upgraded intakes and exhausts?

I can't answer that 'cause I've not built a 300.  But if you look at the fine print on the 300 six specifications tab you'll see that there were several different camshafts for that engine.  I wouldn't want to build an engine and assume that the stock cam was the right one for what I'm doing.  Instead, I'd want to put a new cam in it with what some cam company says is the right one.

I do belive this engine was used in some servere duty applications, i think i read that these camshafts allowed the engine to run at higher RPMs. So thats probibly why they offered em. Dont quote me though. So in short, the reason they offered multiple camshafts is so they could be used industrially.

BullnoseHunter02 wrote

Thats not to shabby honestly, im not an aggresive driver so mpgs shouldnt be bad. I also read that turbocharging the 300 can shorten itslife expectancy quite a bit because it wasn't designed to run one on it. So... ill probibly just see what i end up with first and then go from there on it.

That is the best thing to do.
Get it running and go from there.

I do not expect my 81 with a 300 six to be a killer but I am pretty sure it will do 55 and maybe even 70, the max MPH here. I also have a 4sp (granny low) and a 2.75 rear gear.
Only thing I have done is EFI exh. manifolds into the stock exh. system running the stock v1 carb.
I am looking more for MPG than top speed or power. My 02 Durango, 360 EFI v8/ auto OD /3.92 rear gear, gets about 15 mpg on a good day so anything close I will be happy.

If I come across other performance parts cheap I may buy them but for now the F100 will stay as it is.
Dave ----

Thats good to hear, was just worried that the 130ish hp didnt go a long way. Thanks for the help with that!

Last year, while driving to the Garagemahal Truck Show, I drove the 75 MPH speed limit on the toll road leading to Tulsa, and was cruising at slightly less than 2100 rpms. This is with a 4.9L engine, 4 speed manual O.D. and 3.08 rear gears.

Somewhere, there is a photo?

The Ford master parts catalogue lists a different cam for the fuel saver package, but all other Bullnose pickups used the same one.

My truck has 3.00 gears and I run a tall skinny tires. I have kissed 80 mph with it but I don’t like driving it that fast. It feels best around 62-67 mph on the highway. If I hit a long 6% grade it will drop to around 55 mph unloaded. It’s not a screamer but it will pull and pull all day long.

Thats really good to hear, it sounds like it lives up to the reputation ive heard about it. 2 words: Litterally Indestructible. Anyone got any war stories bout these engines? I just love hearing about what people put em through!

I have been around a few of these engines in industrial applications.  If you take care of them they do last pretty well.  

I know of a few pumps that had these for motors that probably had the equivalent of a million miles worth of hours with little more then oil and filter changes.

I think all the industrial versions of this motor received Forged cranks.  So if you really are looking to improve power I would search for one of those cranks.

Crazy Aussies...