How about a 241 red ram, .060 over with a semi-grind cam? In the '53 Coronet Sierra it was a sweet engine. Even through the fully baffled
34 inch shell muffler it advertised it's potential with a beautiful exhaust note at highway speeds. (3 speed O/D tranny too)
There is also the difference between motor octane rating and research octane rating. I forget all the ins and outs but basically the motor octane rating was determined by running the fuel thru a specific motor and seeing at what point it would knock. I assume they would change the spark advance or something to develop the number. The research octane rating is probably what you described. Europe uses/used one and the US used the other for a number of years. Now I think in the US they use the average of the two. I could be wrong on some of this.
There is also the difference between motor octane rating and research octane rating. I forget all the ins and outs but basically the motor octane rating was determined by running the fuel thru a specific motor and seeing at what point it would knock. I assume they would change the spark advance or something to develop the number. The research octane rating is probably what you described. Europe uses/used one and the US used the other for a number of years. Now I think in the US they use the average of the two. I could be wrong on some of this.
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You have it right, except that they vary engine compression, with a screw, rather than spark advance.
Now we're getting way OT of the original post... but I agree with you, and I suspect the reason is actually the same as the reason a Studebaker (bringing us back a few posts) or Caddy V-8 sounds so good too... I think it's that siamesed center exhaust port. It just does something to the exhaust sound that makes it sound so much nastier than more modern head designs as found on a SBC, SBF, or LA engine...
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That's very interesting, but I have no idea.
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(NN)
Now I really am just speculating, I don't know why it is, but tell me that I'm wrong - all three of the old-school engines I mentioned sound fantastic when tuned up and wound out.
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The only one of those I remember is a Caddy-engined dragster from the early '60s, which did sound noticeably different from the Chevy small blocks that were common at the time. I don't know why, but I'll tuck away your theory for examination on a rainy day.
I think later Caddys had modern style heads, I was specifically referring to the 331 and its derivatives (which Studebaker was actually accused of copying, and there is at best a lot of really, really parallel engineering going on there.) But if this was the very early
60's it is quite possible that that's what you're remembering.nate
Eds back?
Welcome home Ed.
Gunner
The methodology of the left has always been:
A few strokes of a file would fit the caddy intake onto the Stude - and before the Stude V8 came out, guys were fitting Caddy engines into Studes - they called them Studilacs.
Oh, no doubt... before the R1 was introduced, putting a Caddy engine in a Studebaker was the easiest way to get some extra power in a light vehicle... which we all know is a recipe for good times.
nate
sorry, but both you and clare are combining and confusing two separate things. compression is what i've described above. but you're including within that, the /charge/, which is a separate matter.
you're right that charge is very important, it is afterall the purpose behind turbo and super charging, and can be improved by good gas flow dynamics in normally aspirated motors, but it's not compression in the cylinder sense.
see above - charge is not compression unless it's achieved by a separate means, like turbo.
right, but that's not increasing the compression ratio, it's increasing the volumetric efficiency!
higher charge efficiency. that's why cam timing is more important.
IF the charge is greater...
assuming the charge is greater...
we are indeed talking past each other, but that's because you're confusing charge with compression. they're NOT the same thing,
no, it's higher on a more aggressively charged engine...
because the charge is different!!!
crazy God-am nnettikketterrs, always trying to bury Moore's God-am law!
No - same charge, higher compression + greater impulse - for several reasons. The pressure produced in the cyl increases by more than the increase in compression when the fuel lights.
No - as I stated before - just assuming the charge is the same. This is because higher compression yeilds higher efficiency - and more power output for the same amount of fuel.
Nope. You are right that a greater charge will do it - but higher compression ratio does the same thing . High compression engines - ALL ELSE REMAINING THE SAME produce more power and provide better fuel economy, within the limits of fuel quality. This is because more pressure is PRODUCED by burning highly compressed fuel, and it also burns faster, meaning you get fully expanded exhaust gas when the valve opens, instead of still burning fuel. The two SOUND different. Fully expanded gas is higher pressure than still burning charge.
sorry, but "same charge, higher compression + greater impulse" is self-contradictory - you can't have same charge and greater impulse. if the impulse is greater, then the charge is greater. by definition. and it's the increase in charge that produces results.
now, if, under strictly controlled experimental conditions, with all other variables being the same, the same charge is compressed more in a higher compression [longer stroke] engine in all other ways identical, and the cylinder head design doesn't create anomalies, /then/ you can say that higher compression helps improve output, but that is entirely /not/ what people are observing when just comparing different engines because they're taking no account of different heads, different cams, and different manifolds.
Nope Jimmy Boy - you are WRONG. A high compression engine does not breath differently - as I said "ALL ELSE BEING EQUAL"
Longer stroke is NOT part of higher compression ratio. It will CAUSE a higher compression ratio - As will an overbore -but either one will also increase displacement. Higher compression ALONE makes a big difference. Same heads, shaved 15 thousanths of an inch - or even 30, increases the compression significantly - and with no other changes increases the torque and horsepower of the engine - which means the pressures in the cyl are increased. No "strictly controlled experimental conditions" required.
By just changing the valve clearance to half the specified clearance, shaving the head twenty thou, rejetting the original 1bbl carb and recurving the distributor on my old (1963) 170 inch Valiant slant six I was putting 206 HP to the rear wheels on the dyno (at 6500RPM). Original cam, heads, and manifolds - 1/2 inch larger exhaust pipes. The ignition recurve was just to optimize the timing for the faster burn and to take advantage of higher octane fuel.
??? dude, sorry, but you're fundamentally underinformed if you genuinely believe that statement.
because here you are contradicting yourself. if you don't understand why, that's the problem you need to address.
right, but displacement is not a measure of compression ratio.
then you don't understand what i'm saying.
this is precisely my point. you're modifying 5 factors, including the "valve clearance, re-jet, distributor curve and exhaust", but attributing the results to just one. and a trivial one at that. no offense, but if you can make such a statement and don't understand why you're simply supporting the point i've been making all along, then this whole conversation has been wasted.
correct - i cited stroke because that is the conventional route to achieve the compression necessary for diesels, but domed pistons can do it too.
the biggest issue creating the need for high octane is that many conventional domestic cylinder heads have all kinds of angular features, sharp points, and areas where, when the piston is close, there is a long slim flame path. all these lead to poor combustion, detonation, or both. the best modern cylinder head designs have their sharp pointy bits smoothed and rounded, and try to keep shallow spots to a minimum. this allows a higher compression ratio to be used successfully with lower octane fuels. domed pistons don't help the combustion chamber issues - in fact, they often exacerbate it.
but you're not keeping everything equal, you've got FIVE variables in your equation but are claiming only one.
sorry, but apparently you don't. unless you're expecting me to disregard all the incorrect statements you've made.
reducing combustion chamber size does increase compression ratio, but as is apparent from your lack of understanding on this point, it can create significant problems, including unmanageable detonation because of sonic compression points and poor flame path propagation.
nope. see above.
no, you rolled five variables into one, just like so many others do when making mistakes on this topic.
sure. but you were trying to say that compression ratio alone made the difference. it doesn't. by your own words - if you understand what you're describing correctly.
by your own words, it wasn't compression ratio - it was cam, ignition, carburetion and exhaust /together/ with compression. if you had /not/ adjusted cam, ignition, carburetion and exhaust, any "improvement" you'd have seen for a mere 0.020" would be more due to better air flow from removing combustion chamber carbon. as an "experienced" mechanic, you'd know that motors run better when the head is simply cleaned. and that's not increasing compression, it's decreasing it.
making mistakes, learning how to be scientifically analytical and figuring out that you can piss some people off by pointing out that even though they may sincerely believe they know what they're talking about, they can still be completely wrong.
from a motor with an output of what? 60hp per liter?
bottom line, that's just lipstick on a pig from a company that won't invest in new technology or undertake proper research programs. or to put it another way, if you're stuck with two [push-rod operated] valves and no budget for proper combustion chamber re-design, that's the cheapest option to "improve" an already pitiful situation.
otoh, you have honda and toyota with nearly a billion dollars in research between them on researching combustion chamber flame propagation, [about $400MM on the original lexus ls400 motor alone iirc] and they have nice rounded chambers with no "clearance" issues. and you have production honda motors with up to 120hp per liter, conventionally aspirated, clean burn, and the ability to run high compression on low octane gas, up to 9krpm. go figure.
i acknowledge that you're not unique in your opinion, and that there are plenty of other "practical" mechanics out there that don't want to be bothered with the science, but 1000 people all sharing the same opinion doesn't mean that a single one of them is correct. and to contend that that kind of mechanic knows more than the phd's that study laser diffraction patterns inside combustion chambers and spend years modeling flame front propagation on super-computers, is simply ridiculous. it's just like a while back when some people here were trying to say that brake lines somehow decay and develop one-way valve "flaps" inside them [yes, there are multiple people on the web that repeat this bizarre myth], and that by sticking multimeter electrodes into antifreeze, you're somehow measuring galvanic corrosion [you can find multiple regurgitations of that flat-out wrong assertion too], corrosion where a zinc anode can "protect" an aluminum head, even though it's got a lower electrode potential.
bottom line, people make stuff up to explain what they see with the knowledge they have available at that time. and if that explanation "works" for a limited set of circumstances, some simply stop and don't look any further. [the earth is flat, right? everyone can see that.] but if that model doesn't explain how ships don't fall off the edge, then what? deny the truth? or start again and figure out a better model, even though it's harder and there might be some math involved? that's the situation you're looking at here. g.m. [and those that follow their thinking] are stuck in the 50's looking at a flat earth, and the japanese have sailed around the globe, not fallen off, and have sat down to do the math on their equivalent of heliocentricity. that's why their cylinder heads are different. and their cars output more per liter.
i acknowledge that you're not unique in your opinion, and that there are plenty of other "practical" mechanics out there that don't want to be bothered with the science, but 1000 people all sharing the same opinion doesn't mean that a single one of them is correct. and to contend that that kind of mechanic knows more than the phd's that study laser diffraction patterns inside combustion chambers and spend years modeling flame front propagation on super-computers, is simply ridiculous. it's just like a while back when some people here were trying to say that brake lines somehow decay and develop one-way valve "flaps" inside them [yes, there are multiple people on the web that repeat this bizarre myth], and that by sticking multimeter electrodes into antifreeze, you're somehow measuring galvanic corrosion [you can find multiple regurgitations of that flat-out wrong assertion too], corrosion where a zinc anode can "protect" an aluminum head, even though it's got a lower electrode potential.
bottom line, people make stuff up to explain what they see with the knowledge they have available at that time. and if that explanation "works" for a limited set of circumstances, some simply stop and don't look any further. [the earth is flat, right? everyone can see that.] but if that model doesn't explain how ships don't fall off the edge, then what? deny the truth? or start again and figure out a better model, even though it's harder and there might be some math involved? that's the situation you're looking at here. g.m. [and those that follow their thinking] are stuck in the 50's looking at a flat earth, and the japanese have sailed around the globe, not fallen off, and have sat down to do the math on their equivalent of heliocentricity. that's why their cylinder heads are different. and their cars output more per liter.
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