Return Of The Rocket — A New-School 560-Inch Olds For The Street

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Return Of The Rocket — A New-School 560-Inch Olds For The Street


Let’s be honest- you just don’t hear much about traditional Oldsmobile V8s anymore. Once a staple of the muscle car era, and then enhanced with the development of aftermarket cylinder heads, the traditional Olds V8 brings a storied history and a long list of accomplishments with it. Who could forget the Hurst/Olds, and how many flat bottom ski boats were outfitted with torquey 455 Olds engines?

Olds guru C.J. Batten developed the first aftermarket heads for the engine, but they were pricey and not many sets were made. They were among the very first of the aftermarket heads made for American V8 engines without any assistance from the factory. The heads worked great and were well-known, but limited production capabilities meant they were relatively rare. Rarity meant they were also expensive to produce.

Once Edelbrock started producing aluminum versions of the Olds head, many more enthusiasts were able to lose weight and gain performance by adding them. While many enthusiasts were able to order finished sets and bolt them on right out of the box, Olds specialists began ordering unfinished sets and accomplishing specialized port work, custom chambers, and trick valves to take the Edelbrock castings to the next level. The power gains justified the effort, and they were readily-available to Olds fans who wanted them.

But lately, it has seemed that things were getting quiet in the traditional  Olds camp. Muscle car enthusiasts have embraced the potent GM LS-series engines and they’ve stolen the spotlight. Only the hardcore Olds fans keep wanting more and more from the only “correct” engine that should be under the hood of a proper 442. Fortunately, there are enough of them to justify the continued development of more serious hardware. The addition of modern casting and machining technology hasn’t hurt either.

Entering the 21st Century

The greatest example of this development can be seen in the Rocket Racing block. We showed it to you in 2018 and told the story of how it’s been beefed up to handle long stroke cranks and crazy power levels. The block has high nickel content (so much that it’s actually tough to hone) and can handle 800 horses with ease. Now, it’s time to put one together and show what this new-school Olds is capable of.

This engine was designed and built by Bill Trovato. Olds fans will recognize him as one of the few remaining Oldsmobile gurus in the racing market. Trovato gained fame among enthusiasts back in the NMCA/NSCA days by beating all the other makes with his Olds-powered Starfire. Engine enthusiasts will remember the Bill Trovato Racing (BTR) entry scoring in the top 10 among the best engine builders in the country.

We have covered the Rocket Racing block in the past, and it’s an incredibly stout piece. Besides being able to handle a ton of bore and stroke, it can also handle all of the power that can be made with such a combination.

So, what happens when we give Bill Trovato a Rocket Racing block? We get 560 cubic inches of angry Oldsmobile. Bill started with a 4.400-inch bore and teamed it with a 4.600-inch billet crank from Sonny Bryant. He shared with us that the center counterweight is the key to this long-stroke crank not beating up the Swaintech-coated bearings.

Since this engine is designed for a street/strip car on race gas, Trovato turned up the compression ratio on the CP Pistons to 15.2:1, with steel H-beam rods and a very custom cam to make it all work.  The camshaft is a custom COMP Cams solid-roller, boasting a full .760 inch lift on both intake and exhaust, 112 degrees of lobe separation, and aggressive 276 intake/288 exhaust at .050-inch lift, with 312/324 advertised duration.

A billet crank secured by billet main caps is an awesome combination for strength. The 4.600-inch stroke Sonny Bryant crank combined with 4.400-inch CP pistons produces big cubes and is unphased by big power on the street.

Riding the lobes are BAM Products lifters, which you might not have heard of yet, but we’re betting you will. Trovato claims they are outstanding, available, and consistently high quality, which seems to be a rarity in the lifter market lately. Joe Hornick Enterprises supplied the PSI valve springs, retainer, and keepers- which are their high endurance units. The lifters are connected to the 1.8:1 ratio T&D shaft rockers by custom-length Manton pushrods.

Top End Transformation

The heads started life as previously-mentioned Edelbrock units that have received a max-effort porting job at BTR. Then, the heavily-reworked chambers were filled with stainless valves measuring 2.165-inch on the intake side and 1.680-inch on the exhaust. The ports are fed by a much-modified Edelbrock 2810 Victor intake manifold, with a 4150 flange. The work was done by Marty Zimmerman, who was the director of cylinder head services at Ray Evernham Racing at one time.

The intake now has Dominator flange and has been welded up for increased flow, the ports were moved, some port taper was added, the plenum floor was lowered, and more. Because it’s an Olds application, this custom intake was developed exclusively with BTR.

Trovato gave the Edelbrock casting his “max-effort” once-over in order to transform them from good to great.

The carburetor had to be special too. Bill worked directly with Dale Cubic of CFM Carbs to develop the carburetor. It’s a 1,150 cfm Dominator with reliable street manners, which is nothing simple to accomplish. Ignition duties are trusted to proven MSD components. A new Power Grid Pro-Billet distributor was used, but a crank trigger upgrade will probably happen.

This engine is headed into a racy ‘66 Cutlass. Owner Joe Jankowski wanted his portly blue hustler to overpower modern machinery with brute power. The 560-inch Olds will surely deliver. A full-boogie Turbo 400 transmission is being readied to back it, and we’re anxious to see what kind of drag strip performance the car is capable of once it’s all dialed in. A round of rear suspension updates and a ]air of sticky tires are sure to find their way under the tail of this classic Cutlass.

This manifold is about as far from off-the-shelf as you can get in a cast manifold. The only way to be any more custom would be to make it out of sheet metal.

Trovato assured us that this is not too radical of a build for a Rocket Racing block, and shouldn’t require any extensive maintenance while making insane power — 840 horses at 6,900 rpm, and 735 ft-lbs. of torque at 5,200 rpm — all the way up to 7,200 rpm. The great thing about big-displacement engines is that they don’t have to work too hard to deliver big power. We doubt Jankowski will be bragging about fuel mileage, but he’ll have plenty of other attributes to discuss.

As you can see in the dyno chart, the engine pulls right up to that 7,200 redline, still making 837 horses way up there. Typically big-inch engines don’t sing past 7,000 with ease, and few keep making power up there. This one is very comfortable in the higher ranges, power-wise. We’re wondering how the suspension under that Cutlass will like that 735 lb-ft at launch.

 



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