Why Ford’s Flathead V8 Engine Died


Hello everyone and welcome in this video we are talking about the Ford Flathead V8 engine and it’s a pretty neat engine we’re gonna be getting into a bit of how it works and ultimately why it died off in the year I was born 1953 Now this is a super cool engine it was introduced in America in 1932 in the Ford model 18 and it was really the first mass-produced V8 engine entering the market so you could say it started our obsession in America with v8 engines which that lust has certainly never died still super passionate about v8 engines though the style has changed quite a bit now. This is a later model Ford flathead v8 engine it’s a bit larger than the original the original was a 3.6 Liter v8 and it had a compression ratio of just 5.5:1 and produced 65 horsepower which you know you may think is a bit embarrassing out of a 3.6 liter v8 but you know this is back in the day 90 years ago when they didn’t even have computers so it’s pretty wild how sophisticated this engine actually is for its time it’s pretty cool, and I had a lot of advantages especially from a cost perspective that allowed it to enter the mass market, okay so let’s get into how this engine works first and we’ll just start disassembling it and kind of dive into it so up top we have the air filter fed through the carburetors into the intake which then passes into the engine and then out the exhaust you can see those middle two cylinders share an exhaust exit whereas each of the outside cylinders have their own individual exit so we’ll go ahead and take these wires off which are igniting those spark plug, you can see the four spark plugs right there, and so why I’ve gotten the Flathead name here’s the engine cylinder head so extremely simple basically just one piece of metal and that really helped with the cost of it because the cylinder head was not complicated at all all of it could be cast into a single block where you have your intake and exhaust valves as well as your pistons in front we of course have this cooling fan you’ve got a generator, and then the distributor right here in red which is going to be sending the ignition to each individual spark go ahead and turn this off and remove our intake so there’s our air filters here we have the intake pull that off so pretty fascinating looking at the actual operation of the intake and exhaust valves as well as the Pistons so you’ve got a single camshaft located in the center of the V which is operated by the crankshaft geared of course two to one so two rotations of the crankshaft for every rotation of that camshaft, which is opening these intake and exhaust valves now you’ve got the same basic four strokes as any other engine so there was your intake stroke pulling down compressing that air & fuel mixture power stroke is that piston goes back down and then pushing out through the exhaust now you can see that exhaust valve opening up there, and then the cycle repeats itself so pretty cool you can actually see the operation of those valves by the camshaft here within the engine and you’ve got those two exhaust valves shared in the center there which port out through that Center exhaust and then these will actually come down the sides and through the exhaust versus your two intake ports right here you know so it’s actually shortening making that path simpler, and you’ve got these cylinders offset a little bit so that single camshaft can operate each individual valve so none of the two valves actually line up directly so perhaps it’s a bit obvious looking at it now but it’s a real simple design and part of that simplicity is beautiful leads to reliability and you know helps this engine come in at an affordable price point where it can be marketed in a mass production vehicle and actually you know sold out to the everyday common person and so that’s really the beauty of this engine is that it can bring the V8 to everyone not just you know really expensive performance cars, so so that’s really the advantage of it and it actually did have decent low-end you know lower rpm power, but as you might imagine, the downfall of this really comes down to airflow and efficiency because it isn’t reall y optimized for good airflow or good efficiency and so we’re gonna get into the reasons for both of those, okay, so first let’s just get into the air flow and the air flow path is not ideal in this situation, so you’ve got your air it’s going to be coming in right here, then feeding up, so it’s going to go up this direction then it has to chain change 90 degrees and then it has to change another 90 degrees and go down into the cylinder rather than you know on today’s engines the airflow goes towards the piston out around it and then down into the cylinder rather than making 180-degree turn now it has to do the exact same thing when that airs on its way back up so it comes up the cylinder goes that 90 degree angle and then out the exhaust so again the airflow situation here is not ideal just based on the path that the air has to travel versus today’s modern engines the other challenge with air flow is that your intake and your exhaust flow is in opposite directions, so after your power stroke you’re pushing that air out the exhaust and your air flow is traveling this direction so that exhaust valve starts to close and your airflow is going in this direction then your intake valve opens and suddenly you’re reversing that air flow into the cylinder versus in today’s modern engines that air flow is in the same direction so the intake air comes in and then as it exits the exhaust the exhaust air is traveling in the exact direction that the intake air is going to be entering in and so you have that nice scavenging that nice air flow exit where it’s a smooth transition from exhaust to intake rather than having them collide with one another and act in opposite directions now the air flow challenges don’t end there because as you can see if the air is coming in from this intake valve right here and it all needs to travel this direction the air that comes in on this side of the valve on the top there has to completely change around so it’s kind of ideal from this end where it can just come right out and then go into the cylinder but really that’s the face where all of that air flow has to flow in on this side of the valve on this top portion here if it were to come out there then it’s got to go up around the side of the valve and then back down into the cylinder so it’s very challenging from a design standpoint it’s much more ideal in today’s engines to have that valve over the cylinder where the air flow can go completely around the valve and into the cylinder rather than you know just having a portion of it where the air flow is ideal. Okay well, if air flow isn’t great then why don’t we just open these intake and exhaust? valves more just push them open more so that you can have more flow in well the challenge with that is is it means you have to dig out more of this cylinder-head so the more of this cylinder head that you remove to allow for space for these valves to have clearance and open up and provide airflow then the lower your compression ratio is going to be because this is to the side of your piston so the larger this volume here to the side of your piston the less you can compress the overall volume of that cylinder because you’ve got this big volume above the valves so if you want to improve the compression ratio it often means you’re reducing the amount of clearance that your valves have to open and close so you’re further impeding air flow at high rpm so really you know the battle to make this thing efficient and flow well is a losing fight because you can’t have a high compression ratio and high rpm air flow and you can’t have high airflow with a high compression ratio both of them fight against each other so one of the final versions of the Ford flathead v8 was a 3.9L very similar to what you see here, and had a compression ratio of 7.2 to 1 and produced 110 horsepower but how do you improve how much power this engine makes? Well you get rid of it, and you switch to an overhead valve design, and that is what Ford did in 1954 so this thing died out in 1953 producing about 110 horsepower and then the next year with their overhead valve design with the same displacement they were able to improve how much power the engine created so huge shout-out to Erik Harrell for lending me this beautiful 3D printed engine I will include links to this in the video description and thank you all for watching if you have any questions or comments of course feel free to leave those below and I’ll include some relevant links to other videos you may find interesting if you enjoyed this one.