Can one engine be inherently more powerful than another?

[Whittey]

The topic says it all. This question sparked from a debate on whether or not the 300cid Ford inline six is a good engine or a useless engine, but I figured you'd all have your ideas as well.


-=Whittey=-

 

[evelrod]

Of course some engines are inherently less powerful than others, by design. A sidevalve engine will not make the same numbers as an OHV engine etc. As to whether one engine is 'useless', that is another, more subjective issue.
My opinion is that as long as an engine is operated within its design envelope with few problems and is fullfilling operational requirements, it is NOT useless. It may not be the most daring concept as engine designs go but it is doing its designed job. What more can you ask of a so called 'useless' engine?


Rod

 

[Whittey]

Ok, how 'bout this.... Comparing two motors of similar displacement and similar make (iron block/head(s) and OHV of ~5 liters) can one be inherently more powerful than the other? (specifically comparing the 300 to the 302)


-=Whittey=-

 

[ivymike]

Sure - you can tune/build motors to perform differently. Intake and exhaust runner lengths, rod/stroke ratios, cam lift profiles, etc., all come into play. Is that the answer you're looking for?

 

[GhettoEngineering]

Absolutely - but one thing you have to consider is that you can't just look at one number, such as "peak torque" or "peak hp"... One of the two engines could make twice the peak hp by being tuned for a torque peak at high RPM, and the other engine of physically similar design could be tuned for a low RPM torque peak; the first engine would be "inherently better" in a road racing car, but would be "useless" if you want to unearth large tree stumps or tow that race car on a trailer up a mountain pass.

 

[ivymike]

Or you could have one that's tuned very poorly throughout the running range, and one that at least performs well somewhere...

 

[GregLocock]

Or you could look at the MGB's engine, which was OK (ish) in stock form, but a real pig to improve in any cost effective fashion. An engine of roughly the same vintage designed by a more clueful soul is capable of running at 120 hp / litre, at a price, eh Rod?



Cheers

Greg Locock

 

[buzz41]

A 90 deg V engine can have much lower dynamically loaded main bearings than an inline configuration. Everything else equal, with optimally weighted cranks, the V engine will have less friction than the inline - inherently.

Bore/stroke ratio. A small bore long stroke engine has a smaller combution chamber area, so less heat loss and more torque/power at low speeds. The opposite big bore short stroke , lower piston speed, room for big valves, so, inherently more potential power because of the higher revs possible. Right?

BTW, I have a Ford van to re-engine. I'm told that the 302 will be a better choice than the original 300. There seems to be more 302's around, so that advice is getting some play. dunno.

 

[GregLocock]

Well, practically speaking it isn't difficult to to get the mains right on an I6, and if that really bugs you you should got to a flat four or a flat six, where the crankshaft has a hope of some structural integrity rather than the piece of cooked spaghetti you get in a V6 (exaggerating somewhat). I think you'll find that it is far more difficult to get a good crank design than a good main bearing design.

The real problem with I6s is that the crank gets long very quickly as displacement increases, so larger engines tend to have disproportionately lower redlines. You can see this on BMWs, their 2 and 2.5 litre units are sweet, their 3.5 litre is just OK. Cheers

Greg Locock

 

[buzz41]

Engine design thrills me - not bugged at all, so give it all you got.
I didn't think the thread was about servicing. So, "gettin the mains right" would not be something inherent. A 90 deg V engine can have lower friction than an inline, inherently. So, more output.
Having to deal with an INHERENTLY longer crank on a inline, maybe using larger journals and a large damper, is an additional deficit. This is more in the realm of original design, I think, not mods or service. But both are worthy subjects.
Flat engines also have high dynamic loads on the mains. The center main on a flat four really gets it bad. No frictional advantage there.

The practical aspects of whether a Ford 300 or 302 , pros and cons is very interesting to me all by itself, though.

 

[Whittey]

Well Ford made a factory forged unit (the HD version) used up to (AFAIK) F1000 (known fact in the F700s). I personally know a kid that revs his stocker up to 7k (first gear only, in second thats over 100 and an 82F100 doen't handle well at those speeds) on a relatively stock motor. BTW, the 302 and the 300 have the same bore (4&quot but the 300 has a much longer stroke (3.98&quot.

Here was my point:
Almost any motor can rev if built to handle it. If you can find a factory forged crank, forged pistons and the stock rods (forged since '65) you can build a pretty darn bulletproof bottom end. But what can the valves handle? Can the valvetrain on a 302 handle more rpms than on a 300?

http://www.inliners.org/race/race11.html

Just a link to a guy who does pretty well with the 300's in drag racing. 9.73@135mph isn't bad for a N/A tractor motor.


-=Whittey=-

 

[TheBlacksmith]

I put over 125,000 miles on a F250 with 300 inch six and C-6 automatic before trading it for a 99 F150 (smoother ride) Supercab. I considered the drivetrain near bulletproof. I used it to trailor a 24 foot cabin cruiser. Due to a military move, I had to weigh this combination once, it was 10,600 pounds GVCW. It felt a little choked at about 4000 RPM, stock cast iron exhaust and Carter YF1 single barrel. I think tri-Y headers and a nice 360 CFM Holley would have made it real sweet. It was very smooth and reliable, always pulled the load albeit not too fast sometimes. If it had been a supercab, I might have kept it and done the carb and headers.

Blacksmith

 

[Whittey]

A 309 holley, single or dual header, Offenhauser C-series intake and a RV cam (with a bump in compression if you're so inclined) should easily put you over 200hp.
The stock motor was a horrible setup. Log intake, log exhaust, 230cfm 1bbl. It draws 8" of vacuum at 1500rpm WOT. Tiny valves, smaller ports. And it still performed within 95% of the 302 yet at much lower rpm's. I would have loved to see what the 300 could do with a 4bbl and cast headers from the factory.


-=Whittey=-

 

[evelrod]

Two V8 engines, Ford and Chevrolet, taken to their output limits in NA form---Re. NASCAR. It is very difficult to tell the difference in the two engines in practice. Both have virtually the same output and rev range. Both weigh about the same. Both have about the same life expectancy in combat. The question was , is their an inherant differance in output in differing designs. YES,---BUT---as Greg pointed out with the MGB (and I might add the A and the XPAG) were all pigs to get reliable power at a reasonable cost (You can fix ANYTHING if you throw enough $$$$ at it---Reaganism). An 1800 MGB 5 main engine could make 185 bhp at a cost of major $$$ while a 1558cc Ford Twincam with little more than a mild port job and a set of aggressive camshafts could equal that figure and with equal $$$ output could see 205bhp with ease! Versions of the original 105E are running in the 250 to 285 range, not bad for what started as a 900cc economy engine design.
My point is (I am getting to it) that some engines by design or by good fortune have been great for modifications toward power increases while other have not. However, most all the engines in use today fullfill their design requirements even though the designs are INHERENTLY different(better/worse?). There is good and bad in people, not things and certainly not engines. Just some better than others.(My Model A Ford engine is a great little four banger, but it redlines at 3000rpm!!!)


Rod

 

[carnage]

one point noone has mentioned yet in the 302 vs 300 is that the 302 will never give the same amouunt of torque at low engine speeds that the 300 can, because inline engines produce more torque (everything being equal) than v engines. In a car as a "hot rod" motor the 302 will work "better" because it can be more eisiely modified to produce high hp at high rpm. In a heavy vehicle the 300 will be much better because it produces much more torque. I've seen inline sixes in three ton trucks they work because they can put out the necessary torque. If you are looking for performance parts for inline engines then clifford performance is a good place to start.

http://www.clifford.com

they are out of ponoma california and specialise in inline engines

 

[Whittey]

"because inline engines produce more torque (everything being equal) than v engines"

Why is that? In this instance we're comparing a 302 versus a 300, but lets say there was a 300cid V6 out there. Would the inline produce more torque?

Why can't the 300 be used for high rpms? Building it with the factory forged items you'll be limited by the valvetrain same as the 302 would.

Clifford Performance isn't a very good company. There are alot of people that are unhappy with the fitment of their products, they are expensive, and their customer service is bad. Anything you can get from cliffords you can get from elsewhere cheaper. Schneider makes cams up to 320M, Offenhauser makes intakes (and i'm bidding on a Holman Moody intake on Ebay right now) everyone makes headers, bumped compression, SBC valves are a simple swap, its got a 4" bore so you can put hundreds if different pistons in there... It really isn't that expensive to build one of these unless you get it from a specialty place like Clifford. Dual quad intakes, tripple 2bbl intakes, tripple 1bbl intakes, all can be had.


-=Whittey=-

 

[carnage]

that is true for the 300 ford but not many people make stuff for the 225 slant six i'm building.
the reson the inline motors make more torque has to do with the pistons all being lined up instead of at offset angles.
the reson that the 302 can spin beter is that it has a shorter stroke meaning the piston is not traveling as fast so there is less force lost to the piston having to stop and change direction.

 

[Whittey]

Ma Mopar still makes quite a bit of stuff for the slant that i'm aware of. Doug Dutra does alot of work with the slant as well.

http://www.allpar.com/racing/slant-six.html

-=Whittey=-

 

[ivymike]

"the reson the inline motors make more torque has to do with the pistons all being lined up instead of at offset angles."

Care to go into more detail? I'm still wondering what you're getting at.

 

[Whittey]

Also note that the 300 uses an offset piston (well, the replacement pistons from KB/Silvolite say they are).


-=Whittey=-