Been playing around with a dyno sim on the computer..looking at the projected hp that the modifications to the engine could make. With the cam..intake..600cfm carb..exhaust and ignition all upgraded..it looks to be about 211 hp and 309 lb/ft of torque. Do these sound reasonable? Lower or higher than what you've heard? I'm running an offy c intake...600cfm carb comp 260h complete cam kit..efi manifolds and converted to duraspark 2. I know the numbers could change with many variances..was just curious if these were respectable numbers?

 

I'm guessing that you're messing around with Comp's dyno calculator?
Pretty cool program. I remember messing around with it quite a bit.

I think the numbers are pretty reasonable.
One thing to keep in mind is that horsepower comes from RPMs (which is why the stock 300 doesn't make much).

HP = (Torque * RPM) / 5252

The stock numbers are:
122 HP @ 3000 RPMs
255 TQ @ 1400 RPMs

If you reverse the formula:

122 HP @ 3000 RPMs = 214 TQ @ 3000 RPMs
255 TQ @ 1400 RPMs = 68 HP @ 1400 RPMs.



Going off of that, you bring your torque up to around 280 to 300, that'll probably be around 2000 - 2500 or so RPMs. That'll obviously taper off (like it did originally by going down to 214 @ 3000). But, with a higher flowing engine, better carb, exhaust, etc. you'll be able to do 4500 RPMs easy. If you can hang on to even 225 TQ by 4500, you'll be at 192 HP.

Torque can be easy to make. It just depends on how long you can hang on to it through the RPM band for your horsepower.
That's why you see these diesels that make 450 tq that only make 100 - 150 hp. Just no RPMs.


So, I think 200hp/300tq is pretty reasonable for a nicely built 300.
Just so I don't overshoot, I stay conservative with mine and usually estimate around 180/280.

 

It's all good numbers over stock now..I wonder if it goes by hp and tq at the flywheel or wheels?

 

I don't think they rated vehicles at the wheels until the 90s or 2000s. A shop dyno will, but manufacturers usually list just the engine power, not what the vehicle gives. (The higher the number, the better the marketing).

Granted, they're more honest than they used to be. Pre-72, they were rated on what the engine COULD do, with no accessories and non-real world conditions.

The 300 was rated at, I think, 175 hp back then. It didn't have more power (which is a common misconception), it was just rated differently so they could brag bigger numbers.

I often have to remind my Dad of that when he talks about his old 50s/60s Chevys with their 250hp - 300hp V8s, etc. "Yeah, but that's OLD horsepower Dad."

 

Haha it does make sense for marketing. 200/300 doesn't sound bad to achieve. That's just through camming and the intake..carb..and exhaust swap. I wonder if advancing timing will bring numbers up? I have the timing gears from comp where I have to line up the timing dots..could you advance these?? Just curious.

 

SOME cams have different notches on them so you can set them to different degrees, but I don't believe the Comp cams do. The 260h I got didn't and only had 1 setting. Fine by me, I don't want to mess with it. Plus, I still have to pass emissions and that can throw that off a lot. I think that's more of a racing thing.

And no, considering just how underpowered the 300 was from the factory (a 1bbl carburetor and a 1 7/8" exhaust on a 300 cubic inch engine?), an extra 50 - 100hp is really not that difficult.

 

I know porting helps a lot..but I can't do that as of right now. I know the better flow of exhaust will help too along with the more lift the 260 has. I know some came with propane carbs..I wonder if the specs were close? I also wonder if they make propane mixer 2 or 4 bbl carbs.

 

Yeah, a good port on the head really brings everything together. Without doing it, it'll be the bottleneck in your system. You'll still LOVE the gains (I noticed a huge difference), but it won't be all it can be.

Propane and propane accessories are something I know very little about.

 

Ok hank hill..teach me haha

 

I learned (the hard embaressing way) a long time ago that torque is wherre it's at and not horsepower, Having been and still am an FE engine guy my clock was cleaned coming off the line by a 300 Six, by none other than my mother ( LOL ) although eventually my 410 wound out and horsepower came into play the torque of that 300 6 coming off the line left me sitting smoking my tires and yes I've never lived it down and my pride/ego was bruised badly, a different truck and another 390 vs a 300 six cemented it. I got stuck in the mud pulling a travel trailer out, My brother with a 300 six in his truck not only pulled the travel trailer out but my truck which was still connected to it with ease. The moral to this story is TORQUE ratings, not Horsepower ratings is what makes an engine!

 

I've always been a big block Fe fan myself. I love torque..I'd rather pull a house down! But even with my mods..309 tq is still less than an fe isn't it? I used to have a 360 til it blew..

 

Completely agree! Torque is what makes an engine.

However, if you can increase the horsepower of the same engine without reducing the torque, you increase it's capability overall.

Torque is how much strength an engine has, or, in other words, how powerful each explosion in the cylinder is and how long it can apply that power (piston stroke). Horsepower is how often it is applying that strength. That's why the higher the RPMs, the more horsepower. You're applying that torque, say, 4000 times a minute instead of 2000 times a minute. That's why a low revving high torque, low horsepower engine (like the stock 300) will lose speed on a hill. It may have a lot of torque, but it doesn't apply it often enough. But, bring the RPMs up, and you'll fly up that hill no problem.

So, if you can increase your horsepower without reducing your torque, you're just making a better engine.


That's also why those little low torque Honda motors do so amazing. They can rev to 9000 RPMs. They may only make 125 torque, but they apply it 9000 times a minute, which really gets them moving.

 

Now there's some knowledge

 

Never really looked at it that way, awesome learning me some things.

 

If you can boost your engine's horsepower that's a plus. The point I was trying to make was that horsepower on a street engine isn't as valuable as torque is when it comes to pulling. The 300 six is an amazing engine when it comes to stock torque. It'll out pull an FE from a dead stop, it's what makes the big block inline Ford sixes such a versatile engine, unfortunately though in stock form IE castiron combination intake/exhaust manifold 1bbl Carter YF carb, autolite point distributor) leaves a lot to be desired as far as stock HP goes.