Crate Engines

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JASPER® has four levels of engine performance for your project vehicle.

Stock Engines
Class I Engines
Class II Engines
Panther Crate Engines

“Stock” is the general production engine offered in a production vehicle. Stock crate engines receive JASPER’s tried and true methods of remanufacturing, including torque plate honing, three-angle valve seat machining, precision crankshaft machining, oil chamfering and polishing, and computer-assisted live-run testing.

A “Class I” engine is the same JASPER general production engine, but with a mild camshaft upgrade. Class I crate engines generally produce up to 10% more horsepower and torque over the standard stock engine.

The next step up is JASPER’s “Panther Crate” Engine. These crate engines utilize a more aggressive camshaft profile compared to the Class I engine. They also receive performance cylinder heads as an upgraded bolt-on part. With performance starting at 300 horsepower, and that fair idle lope street rod & muscle car guys love to hear, the “Panther Crate” engine is regarded as the most economical horsepower build.

Finally, the “Class II” engine is for the serious performance minded person who needs power for a specific application. These crate engines receive additional machining to castings such as align boring, block deck surface machining, and balancing of the rotating assembly.

Special components like performance valves, high performance fasteners, a double roller timing set, and high tension valve springs are selected and matched for most applications to obtain maximum performance.

Visit the Performance sections of our Video Library and our Literature Downloads for more information. The Performance section of our Literature Downloads page provides a number of specification sheets on the various builds we offer.

Stock Replacement Engines

If the gas engine in your car, truck, van or SUV is no longer performing to your expectations, there’s no need to trade for a new or newer used vehicle. After all, if you didn’t intend to replace your vehicle before the engine got tired, why would you now?

What is a long block engine?

A long block generally includes the block, head(s), camshaft, and valvetrain components.

A JASPER® remanufactured gas engine is more complete and is live-run tested to ensure proper oil pressure, vacuum, compression, and proper actuator operation if applicable.

A JASPER remanufactured complete gas engine includes the following additional parts:

  • Oil Pan
  • Timing Cover
  • Finishing Gasket Set

Replacing your engine with a JASPER® stock replacement engine will cost considerably less than replacing the vehicle. You probably have a feeling of comfort with your “ride” because you know where all the buttons and knobs are and, most importantly, you know your vehicle’s maintenance history. Remember why you purchased it in the first place – you liked it – and it was the one you felt would best serve you, your family, or your business. And, don’t forget the “soft” costs associated with the ownership of a vehicle – license, insurance, and, of course, the taxes on the purchase of a different car, truck, van, or SUV. You’ll save on all of these by holding on to your present vehicle and giving it new life with a remanufactured engine. The money you save can be used for the other things that are important to you like saving for college, retirement, that special vacation or adding profit to your business.

Warranty Information

A JASPER remanufactured gas engine includes a 3 Year/100,000 Mile Transferable Nationwide Parts and Labor Warranty (click here for details about the warranty).

Nationwide Availability

JASPER stock replacement gas engines for most applications are available immediately from our huge inventory located at our distribution network across the U.S. This means you can be up and running again in the time it takes to have someone else go through the process of tearing down and rebuilding your engine. So, go to our online catalog to get a price on a stock replacement engine that matches your vehicle and then click on the “Find An Installer” icon to find the JASPER installer that is near to you.

An installation kit is also available for purchase, click here for details.

Class I Engines

The Class I version of the JASPER performance engine is for the individual who wants more performance than stock but nothing too radical in camshaft or engine design.

Our Class I engine does not use a radical camshaft and it’s compatible with today’s computer controlled engines.

Proudly built in the U.S.A.

Class II Engines

JASPER® has been building engines and transmissions since 1942, and in that time we’ve learned a few things… like, how to get every inch of power out of our performance products. Our Class II performance crate engines are designed to bring your vehicle to the next level.

If your passion lies with street rods, muscle cars, racing, or a project vehicle somewhere in between, JASPER has the crate engine, transmission or a combination of both that will give you the performance you need and fit your budget. We will also build custom applications.

Here are some of the attributes of JASPER’s Class II Performance Crate Engines:

Preparation and Machining Specifications

  •     Thorough cleaning
  •     Serdi three angle valve seat machining
  •     Precise surface finish measuring
  •     Machining of block surface
  •     Main saddle align honing
  •     Electronically balanced engine assembly
  •     Torque plate honing
  •     Computerized boring
  •     Precision crankshaft machining, oil hole chamfering and polishing

Part Specifications

  •     New high performance rod bolts and nuts
  •     New high rev lifters and performance valve springs with retainers
  •     New high-volume oil pump
  •     New double roller timing set
  •     New harmonic balancer
  •     New high performance bearings
  •     New flat top hypereutectic pistons

Please visit our Literature Downloads section to get our Performance Brochure and our specification sheets, or Contact Us for pricing or for more information.

Proudly built in the U.S.A.

Panther Crate Engines

If you are looking to improve the performance of your vehicle, look no further.

This package will offer you the performance you are looking for! This engine is ideal for streetrods, Corvettes, Camaros and other performance vehicles. Priced very reasonably, this engine includes the block, Vortec-style heads, oil pump, and timing cover.

Displacement355-358 Cubic Inches (5.7L)
Horsepower333 @ 5400 rmp
Torque374 ft. lbs. @ 3800 rpm
Max. Recommended RPM5500
Compression Ratio9.5:1
Piston MaterialHypereutectic
Connecting RodsStock Remanufactured
Cylinder HeadsNew Aftermarket 64cc Chamber Heads
Valve TrainOverhead Valve w/Pushrod
CamshaftHydraulic Roller Lifter Design
Intake Valve Diameter1.94″
Exhaust Valve Diameter1.50″
Advertised Lift (Intake/Exhaust).443/.465″
Advertised Duration (Intake/Exhaust).288/.298″
Rocker Arm Ratio1.50
Valve LashZero
Engine Idle Speed650 rpm
Spark PlugsRS1YCS
Spark Plug Gap.060
Fuel Pressue Required5 to 8 psi


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