Steve Morris Engines has been at it again with a supercharged big block to shake the wheels off a customer’s Top Sportsman drag car. This 540 cubic inch engine was built to some uncommon goals — specifically, reigning in the horsepower to the customer’s preference. The mechanicals include Brodix cylinder heads ported by Morris, a custom ground camshaft, and Diamond pistons. Controlling the fuel delivery is Holley EFI, managing the flow of methanol through the Billet Atomizer 700 lb/hour injectors.
“That is our conventional-headed program, we know what that does with F2s, F3s, now Vortech 123s, Xi, and have a pretty good idea of what it would do with some of the different blowers in between,” Steve Morris announced.
Going into this process Morris had to take a slightly different mindset, one that tends to be counter-intuitive when a customer puts a ceiling on the horsepower number.
“We had three things that were holding us back from testing it at higher power levels, one is that it’s our 2,500 horsepower platform — we’ve shown that we continuously under-promise and over-deliver. We rate it there, but they do make upwards of 3,000 horsepower if somebody really wants to lean on them,” Morris continued.
The initial power adder came in the form of a Vortech 123 mm supercharger. “Our race-series superchargers feature Vortech’s patented diverging diffusion technology, all out compressor stages are developed and tested using the only SAE-compliant test cell,” said Jimmy Martz of Vortech.
The first pull yielded a peak horsepower of 2545.69 at 7,200 rpm, and 1864.77 lb/ft of torque at 7,100 rpm and 30 pounds of boost. Limiting the engine down the to customer’s requested mark of 2,000 horsepower and still retaining the option to go even lower to 1,500 until the learning curve is on the downswing.
Morris found it difficult to de-tune the engine for his customer’s desires, a testament to his methodology. “You usually don’t have too many people that want us to take the bigger blower off because it makes too much horsepower, ” said Morris. Because this is a methanol-fueled engine the conventional methods to soften up the power just didn’t have the expected effect.
“That’s one difference with methanol — to soften up the motor we’d pull timing out and make it richer, but by doing those things it just didn’t lose the kind of horsepower we would have lost with gasoline, we just could not get the thing to lose horsepower so we just had to knock all the boost out of it,” explained Morris.
By changing to different gearing they slowed down the blower and dropped the boost to around 19 pounds — netting 2059.37 hp and 1508.95 lb/ft. Still above and beyond the desired number, Morris’ next course of action was to take the blower down to the slowest gearing he had available for the 123 mm Vortech — still north of the 1,500 hp mark, it was time to downsize.
“The one thing about the Xi on that motor is — it got them to where they wanted to be from a power perspective but that blower is probably too small. It certainly gives them options — but what happens is, it starts to run over to the right (if you look at a compressor map) and could be potentially be running in an area called choke,” warned Lance Keck or Vortech.
The Vortech Xi blower — admittedly a small supercharger for an engine of this size, but in the name of restraining the big block, it put Morris’ engine right in the ballpark. On 10 pounds of boost the 540 generated 1490.05 hp. Morris was surprised at the linear power curve the Xi helped produce, “The small blower was surprisingly good on that larger motor, I really felt it was going to be too small a blower but it really hung in there and I was surprised. Some other brands of supercharger act like a two-stroke motorcycle, they’re either off or way-on!”
Morris was enthused with the predictable ramp-up of power Vortech’s blowers offered. “It has a lot to do with impeller design, as well as diffuser area. You get into a whole bunch of stuff like tip-height, what we call a B5 area of the blower’s diffuser — all that plays into the blower’s efficiency and it’s performance. All that stuff has to be a consideration when you model the compressor stage,” explained Keck.
Morris explained that his approach to engine building and tuning is very reactionary, while it is important to be proactive and have a plan, sometimes that notion can mislead what an engine actually needs to perform.
“It was interesting doing the testing with the methanol, single-injector, and the different blowers. I think it’s been a little bit easier than what we’ve been trying to do with it. I’m a big believer in giving the motor what it wants — and that’s why our tune-ups are different than other people’s tune-ups, and I approach engine building a different way than other people do,” Morris explained.
“I don’t come into it with a preconceived notion of this is what its got to do, and then tailor everything around what my idea is — my idea doesn’t matter. What matters is, what does the motor want? What does it respond to, what makes it happy,” he continued.
In the case of tuning a methanol engine, Morris has found there to be a large range in which to tweak and fiddle with parameters, but be careful he warned, because there is a limit, “My experience with the methanol stuff is that it has a fairly wide tuning window if your air temps are not excessive. Once you get outside that tuning window with methanol there is no forgiveness,” Morris concluded.
“We don’t tend to match stuff like that because once you start getting over close to the right in regards to choke, bad things start to happen — efficiencies drop. Once efficiencies drop you start to see an increase in discharge temperatures — and the temperatures tend to escalate quickly. But since they are running methanol they should be ok,” Keck added.
A build of this nature displays both the skills and experience of Morris but also the extent to which Vortech knows their market. Applications for these superchargers “run the gambit,” said Keck. “For the Xi, we’ve got a 1,000 cubic inch, 12-cylinder boat engine two of those are going to go on. From X275 racing, to outlaw 8.5 stuff that these work really well on.”
They have gone to great lengths to exploit materials and design to offer some of the best products. “We have a proprietary material that we use for the impellers. It’s something that we’ve come up with that works extremely well and is beyond durable. We were shooting for a specific rockwell hardness at a given temperature.”
If you would like more information reach out to Steve Morris Engines or Vortech Superchargers through the box below.