OK, if there has one thing that being a forum surfer has taught me over my brief tenure of being such, is there are a lot of things that affect, generate, hinder and enhance engine performance that are not understood or simply just ignored.
Most of this stuff is simply just not shared, be it that they are considered speed secrets or the lay person simply does not understand it, whatever.
I wanted to start a thread to discuss some factors that affect engine performance and the parameters that performance engines live within. Read, argue, whine or cry, this is the truth. And as Jack Nicholson said in "A Few Good Men"- "you can't handle the truth". Well, maybe you can, let's find out.
Get your calculators ready, over the next few weeks, you will need them.
Now, with all of that out of the way, let's start by nailing down the first thing we need to consider when wanting to build a new engine and get the maximum performance out of it. Knowing what we want to use it for will deliver the best possible results. Building a high strung engine to take the family to picnics on Sundays will probably not deliver the experience you are after. Well, maybe the experience you are after, but probably not everyone else in the car.
The best place to build a starting point is to determine intended purpose of our engine and then correlate this to a range of piston speeds.
Piston speed will have a crazy-huge effect on how the engine performs.
I am going to break this down into different categories. For those of you playing along at home, I will give you several examples to experiment with, I am not going to lead you down a primrose path to a result that I have predetermined. Your rules, build what you want without spending a dime.
OK, the categories are:
Street engines (stock)
Mild performance or street/strip
Endurance/NASCAR/Road Race
Maximum effort (Mileage limited/drag race)
AYFKM effort (Component failure limited)
Now, the classification for each of these categories are split by how fast we fling the piston. But first, I guess we need to know how to determine piston speed so we can then determine which category we belong in, or vice versa.
The formula for Mean Piston Speed (MPS) is MPS in ft per minute=(inches of crankshaft stroke x (engine RPM/6))
Depending on the stroke of the crankshaft, and the RPM you expect to see, we can categorize our engine. This will affect our pocketbook, because it will directly affect the type and quality of parts we need to buy to support our performance objectives.
Now let's put these categories in a manner where piston speed can help us determine what we are building. Or, what we need to build to fit into a certain performance category.
Street engines (stock) 2000 to 3000 ft/min
Mild performance or street/strip 3000 to 4000 ft/min
Endurance/NASCAR/Road Race 4000 to 5000 ft/min
Maximum effort (Mileage limited/pro class drag race) 5000 to 6000 ft/min
AYFKM effort (Component failure limited) 6000 to 7500+ ft/min
OK, so if you tried a few different combinations, you probably realize we can change the category by solely changing the stroke, changing our RPM, or both. So great, wow, what a speed secret. Thanks a whole pantload Parker, I read through all of this for that? You're an asshole. Yeah, I know I am, thanks. But the thing that we need to understand about the formula is you need to understand engine speed (RPM) is power. Let's take a look at two theoretical engines and another formula, this one you have probably seen.
Horsepower = (Torque x RPM)/5252
By solely changing RPM, I can make one of these engines a grocery getter and the other, an F1 contender.
Two little six cylinders; both make an eyeball popping 246 pound feet of torque :lol
In the first one, my maximum usable RPM is 4500, and when plugged into the above formula (go ahead and do it, doofus), we see the engine is capable of making about 210 horsepower. :facepalm:
Now we will leave everything the same as far as torque, but let's give the engine an F1 race car caliber RPM of 19,250. After you do the math (I don't have to call you doofus this time, do I?) we see that though my torque stayed 246 lb/ft, my horsepower climbed to a panty-dropping 910! :willy
RPM is power folks, RPM is the shit. RPM can also stand for "Ruins People's Motors" if you don't know how to handle your newfound knowledge.
Piston action has a dramatic effect in the way air and fuel enter, and exhaust leaves the engine. Going back to our categories, we are going to relate the effectiveness of this piston action with our engine and piston speed categories. We do this using something called Volumetric Efficiency, or VE. VE simply put is; if I have a 100 cubic inch engine, and that engine can breathe in and expel 100 cubic inches of air for every camshaft (two crankshaft) revolution(s), it is 100 percent volumetric efficient. If the design of the heads, intake and exhaust only allow 85 cubic inches of airflow through the engine, it is 85% volumetric efficient. If it can move 110 cubic inches of air flow, then it is 110% volumetric efficient. Are engines over 100% VE possible? Why yes, yes they are, and I am going to show you how to build one. Wow, a 350 cubic inch engine that can move 385 cubic inches worth of airflow? Oh yes, yes indeed.
But that will wait until the next installment, for now, let this digest.
Street engines (stock) 2000 to 3000 ft/min 80-90% VE
Mild performance or street/strip 3000 to 4000 ft/min 90-110% VE
Endurance/NASCAR/Road Race 4000 to 5000 ft/min 110-120% VE
Maximum effort (Mileage limited/pro class drag race) 5000 to 6000 ft/min 120 to 127% VE
AYFKM effort (Component failure limited) 6000 to 7500+ ft/min 125 to 128% VE
So we have learned that how fast the piston moves has a great affect on the performance I can expect. And we also learned that piston speed is primarily controlled by the stroke of the crankshaft and the RPM of the engine. We also see how changing piston speed makes my engine fall into different performance categories.
Next time I will give you some real world examples I have tuned on the engine dyno and tested on the drag strip, as well as begin to talk about hw we get the air into the engine to take advantage of all of this piston speed we just talked about.
Cheers, Parker
1976 I was a senior in high school, that was the year I had my first tasting of racing – not legal. My ’66 Impala against a Mustang ( a 1973 Mach I) and I got dusted, well almost, the knuckle head (he was a friend) stopped for a red light, I didn’t. My little 283, 2bbl engine (about 195 hp) was hauling about the same curb weight as the Mach I with its 351 CJ engine (about 266 hp) the outcome was certain. But traffic lights are the great equalizer!!!
But would it have had a different outcome if I was racing the new’s Mustang offering for 1976? Let’s see.
If looks were matched with speed, the 1976 Mustang would open of a can of whoop a$$ on my plain jane Impala. With the look of the Stallion Trim or the Cobra II you’d think they were carrying a no less than a V6 and hopefully a V8.
Cobra II
A spin on the original Hurtz rental Mustang.
Cobra II in Blue
Stallion Trim Package for 1976 (I’ve seen this paint job on a couple of Pintos too.)
But underneath the Shelby type exterior or the Hurtz type color palate the cool exterior lay a 4 cylinder engine, nothing special. But with Carrol Shelby’s endorsements and Farrah Fawcett driving one on TV the Cobra II (which was intended to be limited to only 5,000 units) sold over 25k units.
But with the best engine you could shove under the hood, my 283 would’ve made pretty easy work of the 1976 Mustang.
If there is one challenge to the beehive revolution, it’s the perception of the masses. While most engine builders and performance enthusiasts know that the beehive works to improve their engines, many don’t realize the true benefits. Some established enthusiasts are confused and concerned that the smaller valve retainer and single spring used in the beehive system are capable of handling the same high performance loads carried by the conventional spring with two coils.
Beehive springs are a precision component just like any part you select for your engine. Using a tech line expert to help find just the right Beehive springs is critical to your engine’s ultimate performance and durability.
“There are some very knowledgeable engine builders who don’t understand how a single coil spring can be better than a dual conventional spring,” stated Thomas Griffin Head valve spring engineer for COMP Cams.
“The fact is the beehive springs, by virtue of the ovate spring shape and a variety of internal upgrades is compatible with virtually any application where a dual spring is used. That includes some engines with mechanical roller camshafts. The key is to review the required camshaft load and assess the aggressiveness of the camshaft.”
The key profile consideration of a camshaft can be denoted in the camshaft profile section. By reviewing the duration specs for your potential camshaft at 0.050-inch lift and again at 0.200-inch lift, the shape of the lobe can be projected. These are the key figures engineers use to determine beehive spring compatibility. Currently beehive springs for camshafts measuring up to 0.750-inch lift are available.
COMP Cams engineers used a Spintron machine to determine exactly what happens with valve spring dynamics at all levels of engine rpm. This high tech sensor was installed after cutting the cylinder head to make room. The Spintron data noted improved performance at reduced valve seat pressures, among other benefits previously mentioned.
I have a Ford and as I’ve said before, though the years (ok….40’s, 50’s and 60’s) they produced some of the more interesting cars with some of the most powerful engines. Of those engines the Cleveland and the Windsor were major players.
I’m not alone thinking that the only real difference between the two were the names each being made in the plant they were named after. The Windsor was named after the Essex Engine plant in Windsor, Ontario and the Cleveland Engine Plant in Ohio.
1914 Photo of the Essex Engine plant in Windsor, Ontario
Cleveland Casting Plant where the Cleveland engines started.
Totally different plants and countries about the only they had in common was displacement.
The engines for the 1973 Mustangs pretty well with the rest of the matched up the other models engines, but with some minor “tweaks”.
You couldn’t get a Mustang with a 4 cylinder (yet) but you could get with the standard 6. This was the 250 version, (250 cubic inches of displacement) the bore and stroke was 3.68 x 3.91 also used in the Torino. Topping it with a single barrel Motocraft carb and coupled with a compression ratio of 8.0:1 gave it a ground pounding horse power rating of 88 (Oh don’t worry, it gets worse in 1974).
302 remained the same for the Mustang and was the standard for the Mach 1. The 351’s (Cleveland and Windsor were available and they really remained the same as those for the other models.
Now you might be saying, ‘Well Tim, seems like you typed yourself in to a corner here. Those engines are the same.” But here is what made the differences – options!!!
With special intakes, valve springs, dampers, large 4300 D carbs, 2.5 inch diameter dual exhaust outlets and modified cam, you now talking increased breathing and exhaling capacity. Which we all know means…say it with me…..”MORE HORSE POWER!!!!!” But how much? I’m glad you asked.
The 351 with these types of option produced between 246 and 266 horse power. The 302 doesn’t show being configured with anything other than the stock options.
There has been a lot of parking garage incidents lately but I think this one takes the cake. This isn’t some guy losing control on the nearby road and landing IN the parking garage. Not this time. This time the driver apparently went through the concrete wall of the third story of the parking garage in Lugano, Switzerland, and fell all the way down upon some parked mopeds and a tree. The 24-year old driver was only injured slightly after flying off of the third floor. You can say that this brand new 5.0 suffered a tragic death, though.
If you look up into the parking garage, you see exactly where he fell from as there is a guy looking down and a nice chunk of wall missing. It gives you a good perspective of how far this car actually fell!
People love to talk about car sounds. We even mimic them. They can bring back memories of a car you or a family member owned. They can refresh visual memories of a race you attended or even participated in. They also bring back memories of a not so nice incident.
I can recall each sound in separate wave lengths in my first car accident, I was actually on my way to take my drivers test. I was driving my father’s brand new Ford Granada (he worked at a Ford dealership as body shop manager). The car was totaled, the other driver ticketed. A quick car swap and I went on to pass my test.
There are a few more sounds I remember. I remember my high school buddy’s 1973 Mach I, normally as he dusted me in my ’66 Chevy Impala an awesome noise that Mustang made. There was there the sound of the V8 under the hood of my Chevy – smooth but still throaty. (I don’t know if that’s even a work..but I’ll hustle over to Wikipedia and add it.)
But the other day was watching one of the Jason Borne movies and of course the there are the normal car chases. He was driving a little mini cooper and within all the metal crunching and tire squealing, there was one sound, at pause in the chase when he shifted that Mini and the sound the transmission made, triggered a memory.
In 1982 I was stationed in Germany and when I eventual got my European drivers license, the first car I could afford was a 1970 European Ford Escort. It was a 3 speed manual, shift on the flour and the sound of the transmission shifting in Jason’s Mini Cooper brought back that memory of my first European car.
My First European Car
Of course it didn’t have the pep that the Borne Cooper had, but it got me around.
Post up a note about a car sound that sparks a memory for you. Best one wins a free gift.
The Edsel. Name sake for Henry’s son. Touted as “ugly” and a failure. I disagree.
I think they were great and I plan on own one at some point. ( I was pretty close earlier this year – just missed one at an auction.) There is just something about tooling around in one of those large and long 4 door land yacht. Anyway..one day I will, if I just borrow one for a week.
So in the last year of the Edsel what engines were available?
The car came in 4 configuration, body-wise. A 2 door sedan, a 2 door convertible; a 4 door sedan and 5 door wagon, but only two engine options.
Your two choices were of the V8 and straight six variety.
Ford‘s 292 was the V8 power plant . It sported overhead valves, an iron block and hydraulic lifters. The compression was ratio 8.8:1 and with a bore and stroke of 3.75 x 3.60. It came with a 2 barrel carb – model B9A9510-A. Interesting the block and heads were painted black and the value covers and air cleaner were red.
There was the option inline (straight) 6 cylinder. That too had overhead valves and an iron block. Bore and stroke was 3.62 x 3.60 and compression ratio 8.4:1. It displayed 223 cubic inches with 145 horse power. It was topped with a 1 barrel carb, model B9A9510F. It had the same paint scheme as the V8 but was considered a “delete” option in the Rangers series.
223 Straight (Inline) 6 cylinder with the proper paint scheme
Add 2 more cylinder and buy an extra can of paint for additional valve cover and you'll have this 292 with the proper paint.
One of my regular readers, Bill, posted the following question in response to the piece I wrote on Chevy engines. Bill asked…
“No 454 V8 in 1971? I guess that motor came later. ..”
That get me to thinking so I did a little more research. The references I’m use are “Ultimate AmericanV-8 Engine Data Book” by Peter Sessler; “Standard catalog of American Cars” by John Gunnel and “110 years of the American Auto” by James Flammang and Auto Editors of Consumer Guide. I try not to get too much from the Internet at large.
Interestingly enough the 454 is briefly mentioned in the Ultimate American V-8 Engine Data Book, but there aren’t many details. That reference shows that the 454 was available in 1971 as a 4V producing 365 horse power. It doesn’t show under any model just as a general option for Chevy’s. I’m assuming it was just a 400 block with a different bore and stroke.
The 454 was developed by 1970. It’s bore was 4.251 in and had a 4 inch stroke (where as the 400 had 4.251 in bore and a 3.75 stroke). There were other version in 1970 and 1971, designated as the LS5. This version of the 454 was used in the 1970 and beyond in Corvette for one instance and was used in Chevelle.
Interesting that it isn’t referred to in the mentioned references for 1971 year.
Hold the presses!!!!!
It appears that in the reference “Standard catalog of American Cars” by John Gunnel that the 454 was left out off the comprehensive listing of engines for 1971. However, the 454 was use in the SS version of the Monte Carlo – 1,919 were produced. For the Chevelle 80,000 were sold with the SS badge of those only 19,992 were with the 454.
1917 Chevelle SS 454
1971 Monte Carlo SS 454
And in this reference I found the answer to a question I’ve had for some time. About 5 years agoing I was at a car show and ended up talking to a guy with a 1971 Nova SS. It had a 454 as the power plant between the shock towers. However there were 7,015 Nova SS packages sold, none had the 454 as the option.
