302 vs. 305 Round 2

[Frankie] You're watching Powernation!

[Pat] This time on Engine Power. [Frankie] This is kinda the moment of truth. [Pat] I already know what the truth is. We continue testing our 302 small block Ford and 305 small block Chevy in our small displacement showdown with budget upgrades that were picked by you. [Frankie] We're going to put the most popular and supposedly best production heads for each engine against each other, and at the end of the day the data will tell the truth. [ Music ] Hey everyone, welcome to another episode of Engine Power. Today we're gonna learn together. We're gonna have some fun with some junk yard engines, and we're gonna do it on a budget. This is round two of our small displacement showdown with our small block Chevy and small block Ford. [Pat] In round one we took our 302 and 305 and put them on the dyno to get some baseline numbers. Then we put similarly spec'ed parts on them and ran them again. Low and behold they made similar power numbers. So we took your suggestions and got some more parts that are economically priced and we're gonna run them again on the dyno to see what it made. To see where these engines are right now, what they made, and what got everybody all fired up check this out. We wanted to put some real data behind the classic small block Ford versus small block Chevy debate that still rages to this day. And we picked up a bone stock 302 and 305 since they are the most common and affordable engine for each. The baseline dyno numbers aren't what we were focusing on but we had to start from somewhere and the 1990 302 came in at a strong 251 horsepower and 303 pound feet of torque. Once we got the stock 1984 305 on the dyno it definitely lacked some luster in the power department compared to the Ford mostly due to the factory flat tappet cam and only made 209 horsepower but it was close on torque at 301 pound feet. With baselines established it was time to tear into each of the engines in order to give them a reliable budget minded upgrades and we gave them each a quick and dirty cleaning to remove as much gunk as we could. We tried to use as similar of parts as possible and we didn't even crack the heads off of them. [Frankie] The 305's cam had specs of 218 and 224 at 50 thousandths lift for duration, an l-s-a of 110, and valve lifts of 495 on the intake and 502 on the exhaust. It was followed by a set of new retrofit hydraulic roller lifters, new hydraulic roller valve springs, the stock rockers, and then the engine was topped with an Edelbrock Torquer-2 intake manifold. The 302's cam specs were also 218-224 at 50 with a 110 l-s-a and had a close 514 thousandths valve lift on the intake and exhaust. It was wrapped up with stock replacement roller lifters, similarly spec'ed valve springs, stock rockers again, and the same Edelbrock Torquer-2 intake manifold. We ran both engines with FiTech's Ready to Run ignition system and an Edelbrock 650 c-f-m VRS 41-50 carburetor for our comparison test back in the dyno cell. It's no surprise given their similar displacement, head flow, and cam specs that the engines laid down almost identical power curves with both making 302 horsepower and 328 pound feet. We got a ton of great feedback from those tests and the big thing that we heard was that we should have used the later model Vortec heads for the 305 and on the 302 we should have got a set of GT-40-P heads cause these are supposedly the best production heads you can get for these engines. So that's what we're gonna do today. [Pat] We're gonna stick them on the engines along with matching new single plane intakes and we're even gonna throw in some higher ratio rockers, but first we have to baseline these again because we have a new setup on the dyno and we want accurate numbers. How are we gonna determine this? [Frankie] Which one goes first? We can flip a coin. [Pat] Ford, heads! [Frankie] Ford first. [Pat] Ford it is. The only slight change we'll be making is switching from Edelbrock's 650 c-f-m VRS 41-50 carb to their 850 c-f-m version that has annular boosters to test it out in anticipation of our upgrades. [Frankie] Made a few runs just to get some heat into the engine and get some averaging data. I think we're ready for the last one. [Pat] We have new data, different gasoline. There's a whole bunch of different factors but baseline is baseline. This is where we're gonna measure all of our changes off of. [Frankie] Same r-p-m range, 2,000 to 6,000. Let's see what she does. [ engine revving ] [Pat] That's gonna be very close. [Frankie] I'll take that. 323 pound feet. [Pat] So it is 306.9 horsepower. The curve is in the same area. I think that's a great baseline. [Frankie] I think that's solid and now we just have to get this one off and get that Chevy on. [Pat] Put that Chevrolet on. [Frankie] The dyno water hasn't even cooled. In less than 30 minutes we got our blue oval off and our bowtie on and running. [Pat] We got our 305 on. It runs. It's just like it was when it came off. You don't touch the distributor. You just hook up power, water, and fuel to it and light it. [Frankie] Did not touch the distributor. All we had to do was slap a carburetor on it and run it. 2,000 to 6,000 just like the Ford. We know they're very, very close from last time. So we'll see how close they are again and go from there. [Pat] Let's start and away we go. [ engine revving ]

[Frankie] 323 pound feet. [Pat] It's literally the same pull. That's about as good as we're gonna get. [Frankie] Now we just have to do all the work and change all the parts. [Pat] We definitely got a good baseline. On to the work. Up next, we show you our plans for testing before we dig into our blue oval, getting our first look at this 35 year old engine.

[Frankie] Now that we have solid baseline numbers on our 302 and our 305 we can start tearing into them to do our upgrades. Like we said before, we're gonna do a head, rocker, and intake swap and we are only going to tear them down enough to do those upgrades. We're not gonna take anything else off of them. Speaking of upgrades let's show you what we got. We wanted to keep these projects relatively relatable and affordable. So we set an arbitrary budget for each engine of $1,500 dollars. That's what we could save up in about six months if we ate ramen noodles, cashed in pop cans, and sold our plasma. This is what we can get for that amount of money, and this is parts, and gaskets, and everything all included. For the Chevy we have a set of 059 reproduction castings. These are supposed to be the best production 305 head that you can get. They have a 1-9-40 intake valve, a 1-500 exhaust. They are housed in a 58cc chamber, and it has 170cc intake runner. These were $850 dollars for the pair for a brand new reproduction head shipped to our door in two days. Now we're gonna take both engines and up the rocker ratio by a tenth. So we have a 1.6 ratio set of Proform rockers from Summit Racing Equipment. These were $226 dollars. Now because the Vortecs use a different style intake manifold. It has a vertical bolt pattern instead of the angled we did get a new manifold. This is a Holley 41-50 series manifold. So it was $378 dollars and will allow us to run our carburetor with the 305. [Pat] Moving over to the Ford side of things we did the same thing. We sourced what the internet says is the best flowing o-e-m iron head for the five liter. These are a GT-40-P casting. So they come with a 1-8-40 intake valve, 1-4-60 exhaust valve housed in a 58cc chamber. These have 145cc runner. Our rockers are also an increased ratio. They're 1.7 to keep the playing field even. That goes with a new single plane intake for the Ford, which has a comparable plenum depth and runner length as the Chevy. All this stuff still under our budget. A completely redone set of heads $700 dollars. How much were these rockers? [Frankie] $228. [Pat] And under $400 dollars for the manifold. We're gonna put all this stuff on and we're gonna see how this stuff effects our power. We are gonna reuse all the parts that we can on these engines like the headers, distributors, spark plug wires, and such. Everything is carefully inspected and organized during disassembly, and we can tell by the condition of the spark plugs how good the tune up is and how good the cylinders are sealing. With the small single plane unbolted and wedged free we can start removing the rocker arms and push rods at t-d-c compression stroke in the firing order. The head bolts are broken loose for the first time in 35 years, and with them out we get the first look inside the cylinders once we pull the heads off. [Frankie] It was running really nicely. It wasn't burning oil or anything crazy. All of our upgrades are based on data. So we flow tested our new GT-40-P and 059 Vortec heads on our SuperFlow SF-750 flow bench. Now that our Ford's E-7-TE heads are off we can see how they compare with our new setup. The GT-40-Ps show gains at every lift point between 100 and 600 thousandths of an inch with a peak c-f-m gain of 26 and average gains of 17 c-f-m. Now that we have flow numbers on our GT-40-P heads we need to get them reassembled before we can get them on. We're gonna take our valvetrain off our first iteration and put them on these heads. We've already gone ahead and measured everything and set them up with all the same hardware. So we're at 135 pounds of seat pressure and 380 pounds of open pressure. We just need to get those springs on here and then we can bolt our heads on. [Pat] We already cleaned the gasket surfaces on the block and the new composite style head gaskets with a 4-100 bore and 40 thousandths compressed thickness go on in the proper orientation with the coolant passages open in the back. With a tighter 58cc combustion chamber on our new heads we have an increased static compression ratio on the factory 9.02-to-1 to 9.56-to-1. [Frankie] Following our budget we are reusing the stock head bolts, and since the bottom holes go into the coolant passages all the fasteners receive thread sealant before installation. They are torqued in three stages to a final value of 70 pound feet. Because we are changing the rocker arm we did check rocker geometry and measure for push rod length and we were actually able to reuse our Comp 6-400 long five-sixteenths diameter chromoly pushrods in this build. [Pat] Each pair of rocker arms can be installed and torqued to 30 pound feet at top dead center on the compression stroke of each cylinder in the firing order, which on this engine is 1-3-7-2-6-5-4-8. With new Fel Pro 12-50 intake gaskets and beads of silicone laid down our new Holley single plane intake manifold can be set on the factory intake bolts reused. They all have thread sealer applied and are tightened down evenly to 24 pound feet. Because of our new pedestal rocker setup the factory valve covers will not clear. So we pulled these cheap stamped steel chromies off the shelf to wrap up this blue oval. [Frankie] Up next, we tear into our 305 and find out if that Vortec hype is real. [Pat] What he said.

[Pat] With the Ford all ready to go it is the Chevy's turn to get some parts put on it. All this is gonna look very similar because essentially we're doing the same thing. [Frankie] After getting the spark plug wires and valve covers off the distributor can pop out and the headers can be unbolted from the engine. The Chevy intake comes off and the lifter valley looks just as clean as we left it. [Pat] The locking rocker nuts are unthreaded by hand to remove the rockers in pairs at t-d-c compression stroke so there's no spring load on them. Unsure whether or not this engine has ever been apart we can break each head bolt loose and remove the heads to find out. [Frankie] OG, and it looks good. [Pat] From the condition of the rest of the engine I thought it was gonna be way worse. [Frankie] I think this thing, probably not as many miles as we thought but probably not as well maintenanced as it could have been. Comparing the original 601 305 heads to our new 059 castings we are looking at serious gains everywhere in the flow department. Peak gains happen at 500 thousandths inch of lift with 35 c-f-m and the average c-f-m increase is 24. [Pat] Just like the Ford all of our springs and hardware can be swapped right over to the new head and we have already checked our installed height and spring pressures to make sure they are the same as before. These springs are set up at 135 pounds of seat pressure and 385 pounds of open pressure, very similar to our 302. [Frankie] The 059 heads still have a 58cc combustion chamber, but since the new composite stock replacement gasket is thicker than the o-e one the engine now has a lower static compression ratio down from 9.03 to 8.56-to-1. The original head bolts were cleaned and are reused with non-hardening sealer on the threads. They are torqued in three equal stages to a final value of 65 pound feet. Our reproduction heads came with new thread-in three-eighths rocker studs, and since some protrude in the intake ports they all receive sealer and are torqued to 50 pound feet. [Pat] Just like the Ford we were able to reuse our Trick Flow seven inch 300 long five-sixteenths pushrods after checking valvetrain geometry and they receive extreme pressure lube on both ends. The Proform roller rockers are installed in pairs at t-d-c compression stroke in the firing order, which is 1-8-4-3-6-5-7-2. You can see how the roller tip has guides on it that keep it centered on the valve stem, which eliminates the need for pushrod guide plates on these heads. Pre-load on each is set at one half turn past zero lash. With beads of r-t-v laid down on the China walls and a new set of Vortec style intake gaskets laid down the matching 41-50 Holley intake can be dropped on and the intake bolts torqued with thread sealer to 25 pound feet. [Frankie] With our new heads we have to switch to a center bolt valve cover. So we pulled these cast aluminum ones off the shelf to seal up our 305. To the dyno! [Pat] Coming up, with this round of mods done we're taking both of these engines to the lie detector. [Frankie] It's Ford versus Chevy and I have a feeling at the end of this one of you might be disappointed but remember, you asked for it.

[ engine starting ] [ engine revving ] [Pat] Our small block Ford is on and running. We've made some preliminary pulls getting our timing and fuel where it was supposed to be and it is running really nice. Now time to get some data numbers on this. We've made some changes. It's going to respond just like anything else that you increase air flow with. [Frankie] We have higher c-f-m in the heads. We have a slightly larger intake manifold. Other than that the setup is pretty much the same. Same dyno headers. GT-40-P heads have the weird spark plug angle and you've got to get different headers. These actually work perfectly. Just put 90 degree boots on them. I guess lucked out there maybe. And we put a one inch four hole tapered Wilson spacer on it. We're gonna do that on both. 850 carb, same. 38 degrees of timing is kinda where we landed. I think we're ready to get some numbers. [Pat] Let's see if we can hurt some feelings here.

[ engine revving ]

[Frankie] I'll take that. 339 pound feet and 343 horsepower. Big gains I would say. [Pat] We'll have to overlay that graph. [Frankie] Back it up real quick. I'm super happy with that. [ engine revving ] [Pat] Oil pressure is good. [ engine revving ]

[Pat] That's an overlay. [Frankie] 339.5 and 344.5. [Pat] It squeaked out another horse pressure up top. We'll have to overlay that graph. [Frankie] The way it carries is awesome. [Pat] It carries past 3,800 really well and didn't lose essentially anything down low. [Frankie] At 6,000, peak r-p-m, oh my gosh we're up 41 pound feet and we're up 46 horsepower. That's big numbers! [Pat] That's a huge amount of power for an iron head factory deal. [Frankie] So we have solid numbers on our 302. Now it's time to see how it stacks up. [Pat] See if the Chevrolet is going to do any better. [Frankie] The Ford is quickly disconnected from the dyno and rolled out of the cell to make room for our 305. All the parts to make it run and keep the testing consistent are swapped over from the Ford, and then in under 20 minutes we are ready to hit the key. [ engine starting ] [Frankie] Alright, got our 305 running. Got all our values changed over. Made a couple of test runs just to get some heat in the engine and figure out timing for our new heads and all that stuff. Now's the moment of truth. 2,000 to 6,000 just like the Ford, ready? [Pat] Oh I'm ready. [ engine revving ] [Pat] Oh that's nice. [ engine revving ]

[Frankie] You know, kinda expected. Let's see what we got here. 318 for torque and 326 for power. Let's make a backup run. We'll see if it prints the same numbers. Then we'll overlay and compare it. [ engine revving ]

[Pat] That is gonna be essentially an overlay. [Frankie] 327 horsepower, 317 pound feet. We have good consistent temperatures. Everything's the same. [Pat] It's down a little bit on torque. It makes more power up top. That's what more air flow should, but the obvious elephant in the room is the compression is different. That is a completely great illustration of what that does. Going through the bottom with the mid-range very, very prevalent. On the top though more air flow, more power. [Frankie] It debunks the myth of valve shrouding, cylinder shrouding on 305s cause that's what everybody's gonna say. The better heads weren't a benefit because the cylinder's so small but this clearly shows contrary to that. [Pat] The overlay versus the Ford now is the big concern right. [Frankie] There's the difference between our Ford and our Chevy in their current state. If you look at mid-range torque Ford's killing it. Beating it by a respectable margin. [Pat] This is a fantastic illustration from a data standpoint of what compression does in an engine. [Frankie] We had a budget. We stuck to it. Both engines used a stock replacement gasket that you would get from the store, but because that GT-40-P head has a 58cc chamber it bumped up half a point of compression and the Chevy actually lost half a point because that stock steel shim gasket was so small. Now we have a separation of a whole point of compression and clearly you can't make up for that with head flow. [Pat] We're not trying to stack the deck for the Ford or make the Chevy look bad. This is strictly a bunch of data points from our part selection. But that's gonna get everybody fired up about it and the nice thing about that is we can keep going with this and there's more to do. Know what I call this? Great success!