My Hesco Motor

My Stroker motor

My ’98 TJ needed a new motor and after considering all my options I decided to get the Hesco 4.6L stroker motor for a number of reasons (see article on stroker motors). Hesco is a very well known company that has an excellent reputation for high performance motors for Jeeps and many other makes as well. Their in house dyno facility tells me they know what will work for bringing out the horsepower and torque.

What is a stroker motor and how does it work? The stroker motor name comes from the fact a stock engine crank has been replaced with a crank that uses a longer throw or stroke. The longer stroke means that there will be more travel for the piston and more volume in each cylinder. The crank change combined with a little boring on the cylinders and some new parts and we will have an awesome motor that all fits in the same engine block of a 4.0L.

My motor was built up by Hesco and I considered building up my own motor until I looked at my calendar of things to do. I just didn’t have the time to build up my own motor anymore and with all my welding and grinding jobs going on in my garage, it was not the environment I wanted to build up a motor in. If you do have the space and time, Hesco does offer a full stroker kit and with a little machine work you will be able to put together your own motor or if you are lazy like me, just let the Hesco boys build one up for you.

The Parts

My stroker motor uses a 4.2L (258) crank shaft in a 4.0L block with custom ceramic coated pistons with moly coating on the skirts, custom rods with fitted wrist pins. The motor also has CNC machined heads with a 5 angle valve job with high performance valve springs and valve guides. The cam is a H264 for lots of torque and a double roller timing chain makes sure it turns the cam. To keep things properly oiled there is also a high volume oil pump and a high performance water pump to keep everything cool. Larger fuel injectors will be required to make sure this motor gets enough fuel and I am also using a ’02 intake manifold for a little more performance. This set up with Hesco’s machining work produced a 4.6L motor with 269 HP and a whooping 339 ft/lbs @3200 RPM on their dyno and its smog legal. The stock computer is kept and it will work fine on regular unleaded fuel.

The Install

The install was a remove and replace job. For all outside appearances we are replacing a 4.0L with a 4.0L. All the brackets and engine mounts will fit perfectly as well as the electrical sensors and even hoses. It took friend and I about 10 hours for the swap with air tools, an engine hoist, one large pepperoni pizza and two orders of ravioli. It was a very smooth install and everything fits like a glove.

The Seat Time

The motor started up perfectly and the growl at idle was very nice. We let the motor warm up and checked for leaks. When all the hatches were secured I went for the test spin. It was a night and day difference. When the gas pedal was press the Jeep pushed back. The motor had plenty of torque at idle and it wanted to move even at idle. On a level surface I can ease out the clutch and get my jeep moving without killing the motor. On grades I can easily maintain my speed without having to downshift and my cruise control can keep up on the freeway now. One can easily exceed the speed limit without much effort and acceleration is a lot of fun. Off roading is now a lot easier because there is so much low end torque and it makes climbs easier and more controllable because of the gobs of torque without the higher RPM. It is very entertaining to have a fast TJ because speed and Jeeps is not something that most people think of.

Overall Evaluation

This motor is a dream come true, lots of horsepower, lots and lots of torque and I’m still running regular unleaded fuel. There is no check engine light, I passed my smog check fine and I have a smile every time I drive my TJ. Fuel consumption is about the same but there is a noticeable difference when I play Sunday school bus driver or if I play throttle monkey. I enjoy not noticing grades as much and it is very nice to know the motor has some punch left in it when I’m on the freeway. In my opinion the true test of how much you like something is would you do it again and that answer is a big YES with out a doubt.

I you have any questions or comments on this motor or any Jeep stuff, please feel free to email me.

Thanks to:

Bennie at Hesco for answering all my questions and the Hesco boys for a first rate job and service.

Tom at Jeep Specialist in San Francisco for all the last minute parts.

Mark Perez for the help with the install.

Duke Dog and Elsa Dog for the guard duty and food begging.

Contacts and info

Hesco

1200 2nd Avenue South, Birmingham, Al, 35233

205-251-1472

Ask for Bennie the Jeep motor guru.

Jeep Specialist