Powertec 10 Episode 2 Torque vs Horsepower

hi David Bizon here and you are watching power tech 10 if you care to give me just 5 or 10 minutes of your time then I won't give you the benefit of my 50 years or so of building race winning engines okay it's a starting point I need to show hair torque and horsepower linked well before I get too carried away with the heavily measured torque I think I should point out the torque the torque vigor per cube gives us some valuable insight into how effective our engine is converting fuel into mechanical energy the key here is to not look at the gross torque output ie the whole torque output of the engine because a big variable here is how big the engine is the more cubes it has the more torque it you think that's a natural consequence a bigger motor however to look at how effectively the engine is working we need to look at the foot-pounds per cube with very good efficiency then we will see high torque numbers per cube if it's a bit of a lame thing then we won't see very big tour fingers so let's look at what affects the torque it's directly related to the brake mean effective pressure that's the pressure we'd have to have in the cylinders to equal the torque that we're seeing that the flywheel assuming no losses now the engine does have losses this is what we're trying to fight try to find friction losses we're trying to find losses in in charge trapping efficiency we're trying to find heat losses and the list goes on the question is how do we know if we've met with some success and achieving these goals if we leave friction after the equation in this stage we can say that the torque Ekman of an engine is determined by the compression ratio port flow and velocity and valve event timing to make the maximum torque per cube all of those factors need to be right so let's just look at those for a moment okay what we have here is stop Ford Mustang Sunday that's been fortunate and it's been faced up to get the combustion chamber down the best way to get compression is to first minimize the volume of the chamber if that doesn't get the compression where you want it it's a question of using a domed piston now this has a very high dome life I can't reduce this piston and basically what it is it's an engine builders piston right minimizing the duck the capacity of the chamber they were almost inevitably be too much don't worry the thing is is that could be skimmed until the compression is where it should be however don't Pistons present a problem after they get past a certain height usually about a tenth of an inch they start to impede the flame travel and that makes the compression being used less effective than it could be so our first goal minimize chamber use a piston with a minimum don't want it to get the job done ideally we're look right here like this a flattop piston the only thing in it is valve contacts this is typically the type of piston that I use in my bills I try to target the combustion chamber that is small enough to give the conversion I need with a flat top piston this is another iconic piston here with a curtain skirt okay so we have established that compression and an effective charge burn are the first things to pay attention to when we're attempting to get to work the next thing is the size of the intake port what we're trying to shoot for here is a port that flows well and has good port velocity we need to increase both of these factors over stop when we're dealing with the head like this so we need to up the port velocity and the flow which means that we have to be very careful not to take too much out of the port but at the same time take metal from where it's necessary to increase flow now there's a certain skill in this which comes at a time if you don't have time to acquire that skill by at least five years then it is time for you to invest in my IOB flow mentor program you can see more about that one my channel where is detailed to formas the last degree anyway also note that these ports are not polished anyone that comes into my port and since they were learning how to polish heads I immediately know they have not got a clue right least nothing better than a very basic we do not polish sports here's the exhausted game minimum cross-sectional area to get the flow required so that we have high port velocity and high flow now let's consider the last player in this circuit or that would be the capture what we have here is the flat type of cam that I use in my 289 small-block Ford vintage racer this motor has lots of restrictions on it it's got to use stock iron heads you can port them but they've got to be stopped castings to start with you have to use stock rockers it's got to be a flat top it camp has to be a to plain manifold contact breaker style distributor and a whole host of other things and also a must-read pump gas fuel there it's for a European series so the fuel available there is at 97 octane which allows us to run if we're careful about a 12 to 1 compression now how much torque and the worst practices motor make 411 foot pains and 502 horsepower and the irony here is is still pretty street draggable then 411 foot pegs how does that stack up against other bigger bills well first I've seen 350 ones that did not make 411 pins it was just in the high 3 80s that's a good sign that the engine builder had no idea what to use in the way of Camp Chef right 411 foot pegs from this 289 Works Act over 1.4 foot transfer Cuba that's a good number especially considering their strengths all the build yeah let's consider something else here we've got to build an engine which we can use alternative heads ice start up with some good aluminum heads and we can use roller cams and we don't have to stick with it too plain Apple as this build this then we've got options to move up soon still getting torque is the hardest part I've just done a 427 built Chevy with a friend of mine Terry Walters and the ten point five to one compression that motor made six hundred and sixteen foot pans and 703 horsepower now those foot pans work out to be one point four four seven foot pans per cube that is engine masters build territory you don't know what engine masters this is that yearly competition professional engine builders get together they've probably little teams and they compete to see who could get the best paper per cubic inch of engine and whoever gets the best walks away with the prize now there are no rules in this the limit anything to any great degree gotta use pump fuel so you don't see compression as much over about eleven to one so the bottom line is this get the compression ratio right get poor flow and velocity right get the camshaft album vents right and you will make talk big torque per cube it's very satisfying to have 302 which makes it sort of put pans of torque that have normally seen from a 351 so you may we'll us where does one find out in detail about how to ports on the heads so that they have a good for steam flow and picked the right barb events for the camp well there are para tech 10 videos going up all the time and these will be these subjects will be included however if you find yourself in a position where you simply cannot wait you can always check out my performance seminars which go into far greater detail that we are here by checking at the website shown along the bottom of this screen thank you for watching you

Channel: David Vizard Performance

Views: 35,963

Rating: 4.949791 out of 5

Keywords: David Vizard, performance

Id: 12JDz7mNY1M

Length: 12min 46sec (766 seconds)

Published: Wed Apr 25 2018