okay, with 92 leaded, i’m running slightly richer vs very lean 98 leaded, it’s only a difference of $75-ish, with the 98 leaded having almost an extra 5 hp even when running significantly leaner. slightly more expensive, but i found it to be worth it.
it also has better throttle response, not that it’s being taken into account though.
but then again my(our) car is essentially “oh, it’s only slightly more, why not?” being piled up.
how much you getting out of it? i got 55 out of it without going full on idiot mode, but i’m still debating on what carb to use. 4 tub or Weber?
going bonkers? up to almost 80hp. but i’m not going that high. because fuel economy.
but i’m not revealing it yet until the ads are finished.
i think i can get 80 out of it IF i change the crank and run it much richer, but 55 fully lean i’m happy with, just mine costs ALOT 
Wow, you guys really are firing the parts cannon at that little engine. I went minimalistic, aimed for a reasonable increase in power, kept things simple. Gave it two carbs to breathe in better and a slightly better exhaust. Even at that, I kept it with eco carbs and only went up one exhaust type from stock. Then it’s just tweaking cam and timing to get what I wanted and still remain efficient.
Granted, can’t blame anyone for using the old “Engine’s crap, blast it with the parts cannon” trick. I was tempted, but chose to keep costs down.
i don’t think i even used tubular exhaust… but i can’t recall.
though i did go for bust on the bottom end stuff, and i also stuck 2 carbs on it.
but as i said, i’m not revealing any numbers just yet. i don’t think it’s as high as you think.
I threw out the cast log and went for short cast. When the exhaust header’s in the way for making power, it has to go.
Short cast headers and a two barrel carb. It’s not the most powerful thing I could do with that engine but I think it’s a good step in between increasing power and maintaining economy.
i need to, mine’s a fat little fucker.
If anyone thinks it really is necessary then go ahead and send in a revision. I don’t think I added any information to my original post (no heay duty offroader needed, runnibg cost does matter) but well:
so which is more “penalty-heavy” though?
slightly higher running cost, or more expensive fuel.
since i found better fuel gets slightly better mileage, but also increases the running cost a little bit
so my engine is simple with a single dcoe and 98super…why? Because I found in testing that twin (single barrel) carbs increasing the build/running cost far too much, I could get better economy (by over 1L/100km) and running cost’s using 98super and it is 1967 there’s plenty of fuel. Also it’s a Dune Buggy a chrome engine with fancy exhaust pipes and air intake were a must to keep my build within my own set (DSD’s) of standards
Torque not power is what matters I believe.
if you’ve watched killrob’s video about this. this is not right, not incorrect either.
simply, in my own words, torque matters, inderectly. power matters, directly.
because torque is what ‘produces’ power, and power is the important thing here. but without torque, there’s no power either.
if you get that…
but by the context, you wanted to say that, a wider power band with the torque peak in the middle range is better… right?
What I was trying to say was that you can have large peak power numbers but without the turning force (torque) power is meaningless.
I am talking real world here from a mechanical and drag racing background.
For example I will use superchargers.
you have positive displacement where torque is delivered in one big push from the moment you put your foot on the gas. Centrifugal superchargers require time to spin up to an RPM that allows positive boost to start being made. On paper most side mount superchargers will produce huge power and torque numbers but they are all in the last few 1000RPMs so on the track instead of having a full rev range that you can use only the top end produces enough turning force to be usable. A positive blower however produces a flat torque curve from idle and (if appropriately sized) will not run out of puff and can use all of the rev range if needed.
I claim no ownership of the next info which I have pulled from the net to put my point across
Torque
Before you even can consider horsepower you have to work your way through torque. Literally. Edmunds did a great write-up on the importance of torques a few years back, and an excerpt from these writings sums-up this power source perfectly: “The measurement of torque is stated as pound-feet and represents how much twisting force is at work. If you can imagine a plumber’s pipe wrench attached to a rusty drainpipe, torque is the force required to twist that pipe. If the wrench is two feet long, and the plumber pushes with 50 pounds of pressure, he is applying 100 pound-feet of torque (50 pounds x 2 feet) to turn the pipe.”
Torque is also is what moves you at lower speeds, so a car’s ability to jump off the line from a complete standstill all depends on how much torque it has, and to quote auto enthusiast extraordinaire Jay Leno, “Horsepower sells cars, torque wins races.” However, once you get moving it is important to have less torque and more horsepower to maintain a high speed, which is why there is a huge differentiation between bottom-end and top-end power.
Horsepower
On the high-end of the spectrum is horsepower, which is typically what people think of when they hear the phrase “performance vehicle.” Images of horses galloping across windswept plains, and a Ferrari stallion rearing its legs in defiance of all things commuter car-related come to mind, but when in reality this is nothing more than one giant marketing ploy. Horsepower is just as mathematical in nature as torque when you break it down to its fundamental design and execution, and horsepower basically picks up where torque leaves off.
At its very simplest, one horsepower equals the amount of power it takes to perform 33,000 foot-pounds of work in one minute. According to an article in Hot Rod Magazine, this measurement of force was first discovered by an engineer in the 18th century by the name of James Watt, who observed that the amount of work performed by a horse that was operating a gear-driven mine pump could indeed be measured. Centuries later, we still use this same equation to measure an engine’s ability to create power at higher speeds, and is the surge in power we feel under throttle at increased velocity.
So without torque in the right places a 10hp difference to the same engine may mean sweet FA
that’s what I was trying to point out lol. what a rabble.
And finally to point out that is what I believe works with small engines, everyone is entitled to their opinions as longs as not a dick lol
some bedtime reading lol
Although revisions are now allowed, I am happy with my car as it is right now, since the engine variant it uses is as cost-effective as its running gear, while all that offroad gear makes it more competitive in the offroad categories. And even though my car is not the most economical machine in this round, as previously stated, its engine used cheaper and more commonly available regular leaded fuel (and in the 21st century, would only require 95RON unleaded). The torque and power curves are also quite consistent throughout the rev range, although with a redline of 5500 rpm and a power peak just 200 rpm before it, waiting too long after the revs pass peak power is not a good idea. I could have extended the redline by 100 rpm, but this would have reduced the engine’s reliability slightly; keeping the redline where it was could turn out to be the right decision in the final results.
okay, disclaime: i’m even that good in physics, nor am i an engineer, nor do i have real life experience with this.
the only ‘complete’ knowledge i have, is from this video
but what you said. contradicts what is explained in the video. and also… the article kinda contradicts itself… at least from what i understand. although, at the end, i did get the point across, but takes the long way around to get there.
“the defendant would like to call @Killrob to the court your majesty” that is, if he has the time. if not, disregard this line.
but
here’s some point from the article that contradicts the video killrob’s made
Horsepower sells engines and cars. But torque moves the car
torque doesn’t move anything. power does. but then later it said
build for torque, and horsepower will take care of itself
which i’m assuming means, they recognised that actually power moves the car.
it’s obvious that at 5,252 rpm, the horsepower and torque values are always equal. That’s why an engine’s torque and horsepower curves always cross at 5,252
The forumla HP = T x RPM / 5252 are in the units hp and lb-ft respectively, so just convert for units and you’ll get the correct coefficient.
To clear up the seeming confusion on the relationship of torque and power, first, you can’t have power without torque. Torque is the force applied to rotate the shaft. Power is the product of that force and the rotational velocity of the shaft. Rotational velocity of the shaft is what directly relates to motion of the wheels (minus frictional losses and inefficiencies in the drivetrain). High torque at low RPM still yields more power than low torque at low RPM.
So there’s a few necessary conditions: in order to attain a high rotational velocity (expressed as higher RPM), you need a) sufficient torque b) low enough resistance to work through the lower RPMs. The heavier and more inefficient and “frictiony” your system is, the more low-end torque you’ll need to get moving in the first place. That’s just to get moving. If you have huge amounts of torque but your system is so heavy duty that the part speeds are limited, then you won’t get much high end power out of it.
This assumes that your drivetrain ratios are the same. You could theoretically attempt to use a small engine in a large heavy vehicle by making the diff and ratios extremely short, but practically that won’t work as well as a low revving engine with huge amounts of torque because the higher RPM working against a larger load puts more strain on the parts and the supposed efficiency in the parts would be completely lost, besides, using a heavy duty vehicle for heavy duty things like carrying loads of shit or towing etc. will easily overwhelm your puny engine because the extra load is so high relative to your engine’s ability. Conversely, you could put a damn truck engine in a sports car and have long ratios, then you’d get an early model Dodge Viper 
Another practical reality is that internal combustion systems by definition don’t produce uniform torque for all rpm (unlike electric motors, theoretically), and different types of parts have different limitations. The challenge with this engine is that it’s a small displacement, freaking pushrod system. This means low torque and low max RPM, so you have to figure out how to make the most of it, or whether to break the natural limitations by pouring money into better parts. And making the car as light as is practically possible, as I have no doubt all of the entrants so far have tried to do (to yield an average dry weight of, say, 630kg).
^^^^^^that’s what I was trying to say
okay then. i get it. that was a whole misunderstanding on my part i guess…
sorry about that 
Well put, I’d just note that torque from your basic DC electric motor drops off as RPM increases.
