High Tech Slant Six Gets Boosted

(Pat)>> You're watching Powernation!

(Frankie)>> When people refer to the slant six as " The Leaning Tower of Power" it's usually kinda tongue and cheek.

(Pat)>> But our turbocharged Chrysler engine is no joke! [ Music ]

(Frankie)>> Hey everyone, welcome back to Engine Power. I'm Frankie Forman, and today we are continuing on our Chrysler 225 slant six, The Leaning Tower of Power. Now this is a project that was directly brought about by you the viewers and your requests. We have done other six cylinder projects in the past, but this one actually took quite a bit more work. We have gotten it to short block status so far, and that involves some unexpected challenges. But in case you don't know how it got to this point here's a quick look.

(Pat)>> Since we needed strong, durable parts in this build a forged crankshaft was mandatory, but getting that early model forged crank to work in a newer cast crank block required some planning. After balancing the crankshaft to perfection in our CWT Industries Multi-Bal 5500 we machined some precision thrust bearing spacers so both the bearing and crankshaft fit properly in the block.

(Frankie)>> The Molnar seven inch, five thousandths forged H-beam rods were mated to Wiseco three-four-sixty bore forged pistons. They received Total Seal gas ported steel rings. A custom ground flat tappet cam shaft from Comp Cams gave us the lift and duration numbers we needed to build reliable power naturally aspirated or turbocharged. That was a ton of great work but in reality that was kind of the easy part because today we're gonna be finishing up this engine, getting it on the dyno, and seeing how much power it makes naturally aspirated and turbocharged. Now that means not only doing all the normal engine building stuff like assembly, fitment, and painting, but a lot more custom work in order to make everything work together. For instance, we have to figure out our mounting for our crank and cam sensors so we have the proper signal for our e-f-i to run the sequential fuel injection and sequential coil near plug ignition. We have to build a custom e-f-i harness because this is a pretty unique application and you can't buy one off the shelf. We have to plumb the entire turbo system, which means oil lines, waste gates, tubing, all of that jazz. And one of the most important ones is we have to do some custom work to the induction system so that this engine can actually make good power.

(Pat)>> We are gonna attempt to do that with a stock cylinder head. Not a lot of performance options for the slant six. So we got us a late model slant six head. This has the smaller size valve. So that's a little bit of a disadvantage but I don't think it's gonna be much of a problem just because this doesn't flow much anyway no matter what you have. The valve size is one-six-twenty on the intake and one-three-sixty on the exhaust. Pretty small but it is a small volume port. We got this up on the SuperFlow SF-750 flow bench before we did anything and the numbers speak for themselves. Pretty much what we expected, but that doesn't mean that we can't improve air flow. We're gonna do some simple things to this cylinder head that you could pretty much do to any cylinder and improve flow. We've already done a little bit of port development before this to see what direction it would lead us, and so far it's going pretty good. So all we've got to do is finish the other three and get it back up on the bench.

(Frankie)>> While Pat works on the cylinder head we'll mockup our stock timing cover, install the o-e replacement damper, and this aluminum puck we'll explain in a second. It's held in place with an ARP big block Mopar balancer bolt. [ drill humming ]

(Frankie)>> We're using this Holley EFI 36 minus one crank trigger wheel cause we've used them in the past and they're extremely accurate, which is gonna be great for our e-f-i. This one is for a small block Chevy but we made it work on our Mopar damper by drilling out the three mounting holes a little bit and then building a locator that centers it on damper. Now this kit comes with this cool bracket that mounts the crank sensor. That's not gonna work in our application because we don't have any mounting holes and we need to get the spacing right. So we're gonna use the bracket for the sensor and two five-sixteenths nuts as mounting bosses. We're gonna weld them directly to the timing cover. So we need to get our crank sensor set right on this seventh tooth. This is the seventh one after the missing tooth, and that's what the e-c-u is gonna use to determine where top dead center is. We'll butt it right up against the reluctor, and then we can use our adjustment later to set our air gap. We'll get it lined up, tacked to the timing cover, and then fully welded. For the cam sensor the position of the crankshaft is extremely important. Following Holley's instructions we'll put it at 240 degrees before top dead center of number one on the compression stroke. The next thing we need to do is determine where our cam sensor's gonna go. This is gonna give our e-c-u its cam sync, which will tell it whether we're on top dead center of compression or overlap, which we need for our sequential fuel injection and sequential coil near plug. So we need it to not interfere with our crank sensor. So we need to know where to put it in our timing cover, and we're probably gonna put it right there, which will put it right on this web of the timing gear. And we're gonna be installing a flying magnet trigger into the timing gear to trigger our sensor. We'll mark the center of that web, and then drill and tap a quarter-twenty hole. [ Music ] With the timing set reinstalled we use a threaded punch to mark where our sensor bung needs to go in the timing cover. The flying magnet trigger is bolted into the cam gear with red thread locker. It's torqued to 70-pound inches. With the crank and cam sensor mounts fully welded and the cover painted we'll install everything for real. Then we'll set the air gap on both the crank and cam sensors at 50 thousandths. While we're working on the front of our engine we're gonna go ahead and finish it up, and we can't get an electric water pump for this application. So we're gonna be using a mechanical one, and that is why we decided to use an o-e style damper. We could have used an aftermarket performance damper for a big block Mopar, and it would fit and work, but then we'd have to figure out our pulleys and belt alignment. So to make it easier we're gonna be using an o-e style damper, and it's gonna work great in our application. For a mechanical water pump, because we are starting from scratch we had to find one. So we right to RockAuto dot com. They make it really easy to find parts because they break it down by make, year, and model, and then depending on the part category they break it down even further between economy, daily driver, and professional grade parts. For our slant six that means it was easy to find one because we just picked a Chrysler, picked the same year as our block, and then found a model that had a 225 in it. For our application we picked this AC Delco professional series water pump. This is a really high quality unit. It has a hardened shaft, sealed bearings, and coated seals. So it has extreme longevity. It was thoroughly tested at the factory so that it can be installed leak free. That means it's gonna work great in our application and be just as durable as our notorious durable inline six. Coming up, we give our engine plenty of performance upgrades, and then we put it under pressure in the dyno cell.

(Frankie)>> We're continuing on with our slant six, and the next thing we're gonna be doing is sealing up the bottom end. Before we can do that we need to install our crank scraper. This was made specifically for this engine. It's pretty easy to do. It only takes a couple of hours, a piece of metal, and some cutting and grinding, that this is matched to the profile of the crankshaft. As the crankshaft goes by this is gonna catch any excess oil and keep it in the bottom of the pan. If we didn't have this that oil would be slung around inside the crankcase increasing windage and robbing horsepower. This one was built to be located by the oil pan bolts. So if it is bolted in place it can't move, it can't hit the crankshaft, and it's gonna keep that oil where it needs to be. We made ours from 50 thousandths mild steel. We'll bolt it down after applying a bead of silicone. Once the silicone dries the scraper will stay in place so we can replace the oil pan bolts and finish installing the oil system. [ Music ] [ grinder buzzing ]

(Pat)>> Next is a simple pocket port job on the cylinder head. We're not gonna set any world records for power. So we aren't gonna get too obsessive with our work. We're just going to do the kind of job anyone can do at home with a little bit of care and several hours effort. We'll use several different carbides to reshape the guide boss and clean up the bowl area underneath the valve job. The last thing we want to do is ruin this cylinder head by grinding into a water passage. So we are being very conservative with the amount of material removed. Cast iron does take a little longer to remove than aluminum. So this head is more forgiving because you don't get yourself into trouble as quickly. The same care is taken with both intake and exhaust ports. Once we have the general shape we want for the ports we'll switch to a cartridge roll to finalize both the shape and the surface finishing. This step is more about smoothing the carbide burr finish than it is removing very much material. You can still make minor adjustments, however. The final step, which is purely for aesthetics, involves the use of emory cloth on a split pilot, otherwise known as a flapper wheel. This creates the final shiny finish. Every head porter has their own technique for finishing. Some people focus on the numbers. Some people focus on the looks, but we like a little of both. [ grinder buzzing ]

(Pat)>> Next we'll move on to the valve job, improving the stock one with a custom three angle job. We'll use our Goodson stone setup for this. The 30-degree top grind is first. Then we'll move on to a 60-degree bottom cut. We'll spray graphite onto the seats so we're able to see where the 45-degree stone contacts the valve seat. The resulting shiny area reveals the seat width. [ grinder buzzing ] [ compressed air hissing ]

(Pat)>> The check our work we'll lap in both valves using fine lapping compound. [ Music ] Looks good! At last we see what improvements our work has done. The cylinder head is set up on our SuperFlow SF-750 flow bench. We'll lift the valve in 100 thousandths increments checking air flow in cubic feet per minute. On the exhaust side peak flow at 600 thousandths valve lift is 140 c-f-m. Then we'll switch over to the intake side, adjust the flow direction of our bench, and repeat the process. Peak air flow on the intake side is reached at 174 c-f-m at 600 thousandths lift. That's a 19 percent gain on the intake side and a 44 percent gain on the exhaust. Exhaust to intake ratio is 80 percent at 600 lift. Coming up, first we lash it. Then we thrash it!

(Pat)>> With our short block all buttoned up it's time to move on to fastening the head down to the block. Now we have already cleaned, painted, and fully assembled our cylinder head using some brand new Comp Cams valve springs. We have set the installed height up at one inch-650 thousandths, and that will give us about 92 pounds of seat and 235 pounds of open pressure. That would be completely sufficient if we were only turning the engine 4,500 r-p-m and under, but we have some big plans for this head and big plans for that engine. So we are gonna break the engine in and run these on the naturally aspirated version, and then change them over to a stiffer set of Comp springs so when we start making the big power and big r-p-m it can control the valve train. To give this head the best chance it can to seal up under all that cylinder pressure we are converting from head bolts to head studs. ARP makes a specific stud kit for our 225 slant six. These are seven-sixteenths in diameter and have a 200,000 p-s-i tensile strength. The kit comes with the studs, parallel ground washers, and the nuts with some ARP Ultra Torque lube. The biggest thing is it comes with a concise set of instructions that have to be followed exactly to get the maximum benefit from these studs. What we love about ARP is they have a commitment to engineering and quality control. So no matter what the application they have a fastener that fits your needs. Before the cylinder head can go on our Comp solid flat tappet lifters are installed. They have a 12 thousandths e-d-m hole in the lifter face for additional lubrication. They are lubed with Comp Cams' included break-in lube on the bottom and regular break in oil on the sides. Don't use a magnet to install them. You might get metal debris stuck to the lifters. Our head gasket is a Fel Pro composite that is 45 thousandths compressed thickness. Calculated static compression ratio is 10.12 to 1. The ARP head studs are torqued in three steps to a final value of 80-pound feet. [ torque wrench beeping ]

(Frankie)>> The Trick Flow pushrods are 9-900 in length with a three-eighths diameter. Because this engine was designed for five-sixteenths pushrods some clearancing was necessary on the cylinder head to make them work. Finally our YellaTerra shaft rocker system gets put in place. These have billet shafts, full roller fulcrums and tips, and they are 1.65 to 1 ratio. Racy! The ARP fasteners are torqued to 30-pound feet, and cold lash is set five thousandths on both the intake and exhaust. [ Music ] Since we're using a late model slant six head we had to make an adapter to run this cool cast aluminum valve cover from our friends at Aussiespeed. Speaking of Aussiespeed, they sent this cast aluminum long runner Hurricane intake that's been converted to port e-f-i by Gil Welding. Next are the Dutra Dual exhaust manifolds. These have to be installed before the wing style washers and nuts are loosely hand tightened. Gil Welding also made this trick alignment bar to make sure the manifolds are in the correct position before we tighten all the fasteners. [ Music ] They also provided this manifold crossover pipe that allows us to mount a T-4 flange turbo. Our engine is coming together and it looks like it's ready to go in the dyno, but there's actually a lot more work we need to do before we can get it running. Like we said, you can't buy an e-f-i harness for a slant six. So we're gonna have to build one, and to do that we're gonna be using all Holley EFI components. Holley has really stepped up to the plate in terms of e-f-i, making it super easy to find the parts you need and converting an engine to fuel injection. Ours is gonna be based around this Holley EFI HP e-c-u, which is gonna control the entire engine, meaning our coil near plug ignition, our fuel injection, and all of our sensor data. We also got all the supporting components we need from Holley in order to complete our e-f-i system. Now it seems like a lot of work building a custom harness, but in the end it's gonna give us a ton of control over our engine, and we'll have a tailor-made e-f-i system for our slant six. The fuel rail is loaded with 76 pound per hour injectors, and our Holley EFI smart coils are mounted on a custom made bracket that bolts to the valve cover. We'll start running all of our wires across the engine to each spot where they need to go. After removing the unneeded wires from the harness it will take several hours to terminate each connection and pin each connector correctly. [ Music ]

(Pat)>> Up next!

(Frankie)>> Oh wow!

(Frankie)>> We've got our slant six running on the dyno. We've broken it in, changed our valve springs to our stiffer set, and we've been making dyno pulls at operating temperature. This thing is making mid 220s for power and high 270s for torque. So what we're gonna do is cool it down like we would at the dragstrip and make a hero run and see what this thing will make. [ engine revving ]

(Pat)>> Loads in nice. [ engine revving ]

(Pat)>> Stacks it in there nice, doesn't it?

(Frankie)>> That thing sounds awesome. Oh snap!

(Pat)>> 230 horse, almost 288-pound feet of torque.

(Frankie)>> 230 horse out of a slant six, that's awesome!

(Pat)>> This was just the icing on the cake. We've got to set up for some turbo stuff now.

(Frankie)>> Using our Forney tig welder, along with stainless tubing and 45-millimeter Turbosmart wastegates we got from Summit Racing Equipment, we'll modify our exhaust for turbocharging. We're using an STS 59-millimeter turbocharger, and both the oil and waste gate lines are made with Earls fittings and hoses. [ drill humming ]

(Pat)>> Finally what we've all been waiting for. We're gonna start making some boosted runs. We're gonna be a little conservative at the front. Probably around five or six pounds of boost to see how it reacts. Frankie has done 100 percent of the programming. He has done the wiring. He has done all of the fuel and timing maps. So whatever happens it's all on him.

(Frankie)>> I'm like, this is a set up. I think we're gonna be good and hopefully see some good numbers.

(Pat)>> Let her rip! Look at that, glassy smooth!

(Frankie)>> Oh yeah! [ engine revving ]

(Pat)>> Slanty six, I love you! Not only does it look good, it runs good.

(Pat)>> 325 horse, 400.0-pound feet of torque. So we have a really, really nice running... We could stop right there.

(Frankie)>> You're making over 300-pound feet at 2,200. In a car that would be 10 times better than what'll come in a slant six car.

(Pat)>> This particular engine made 90 horse stock from the factory. Now is the question. How hard do you want to push it because this is your call. Whatever you want to do I fully support.

(Frankie)>> I don't want to get too crazy with it. We have good parts but we're still on pump gas. Don't want to get too crazy with it, but I would like to get it over 10. So say 11 p-s-i.

(Pat)>> I would like to see the boost in the double digits. I respect that you don't want to get too crazy with it. [ Music ] [ engine revving ]

(Pat)>> Spicy meatball! [ engine revving ]

(Pat)>> That made some very nice power!

(Frankie)>> Wow!

(Pat)>> 402 horse, look at the torque.

(Frankie)>> 517.6-pound feet.

(Pat)>> How much boost was that?

(Frankie)>> Got a little bit above 11.5, 11.6, but average it's about 11. That is awesome!

(Pat)>> We have a 232-inch engine making 517-pound feet.

(Frankie)>> At 3,200 r-p-m. This would still live for a long time. We're really conservative on the tune-up and having the control of the Holley EFI, the coil near plug ignition for strong spark, and the boost control makes it really easy to do.

(Pat)>> You could take the Holley and put a low boost and a high boost switch on your Pro dash.

(Frankie)>> Do a boost scramble.

(Pat)>> It has to go into something.

(Frankie)>> This is a dream build for us, and hopefully we'll find something to put it in.

(Pat)>> I got some ideas. If you want to see more custom engine builds check out Engine Power on Powernation. [ engine revving ]