Let's face it, as motorheads, we play little head games with each other. Of course, if that head being gamed is Hemi-derived, a simple look under the bonnet will shut up the naysayers. We get a somewhat perverse thrill out of psyching each other out a bit. Take this gem here-looks pretty serious, right? Well, it began life as a two-barrel 318, the most common V-8 in the world of Mopars. So you could tell that inquisitive mind giving it the eyeball that it's a 318, and ya wouldn't be lyin'. Of course, just like Charles Atlas' old ads in the comic books, this former 98-pound weakling is done getting kicked in the face.
As Ken showed us, this is a literal armory of potential Mopar engines, all of which had been given basic approval before being stacked against the wall. Like the Marines, however, not all will make the final cut, as they will be pressure- and sonic-tested for cylinder-wall thickness and core strength before ever being selected for stroker use (or any buildup at Hensley's for that matter).
For starters, it now sports a crank and reciprocating parts that have boosted the internal displacement by over 80 cubes, for a total of 402 inches that will stomp those 5.0 girlie men into the dirt in a heads-up battle. It's topped off with a bunch of tasty goodies, so you might want to think twice before swapping a heavier big-block into your ride.
We first saw this engine in its finished state at Hensley Racing Enterprises, based in Knoxville, Tennessee. Ken and Alice Hensley have run this particular Chrysler-oriented operation since 1996, when they bought out retiring Chrysler maven Herb McCandless. their background in Mopar parts dates back to the '60s with a speed equipment business in their family-owned Dodge dealership. Ken has been a Chrysler loyalist throughout the last 35-plus years, either as a businessman or a racer. Today, the firm's large building, located off the Clinton Highway, features a retail store out front, while son Matt and a crew of talented merry men are in the machine shop massaging parts and building engines for customers. What makes Hensley unique in this particular project is they are building stroker small-block engines as 'crate designs,' which the Hensleys sell under the HRE Blueprint Series.
After the block is pre-tested and bored to spec, it is put on the Sunnen CK-10 mill and honed. The torque plate bolted to the deck will make all the difference in the world when the engine is finally assembled, as the bores will have been honed with the exact stress the head fasteners place on the structure of the block when the head is installed.
"These are not crate motors in the conventional sense," states Ken. "We know each engine application is different, and we really want to find out what the customer wants before we start putting one of these motors together. Basically, what we do is use a select number of parts that have proven to work, and combine them into a specific package that meets the customer's needs. Where we are different from some other engine builders is that we have the hardware here to build the basic package pretty quick. The bottom end is similar across the board, and we change things here and there as the customer's needs dictate."
Hensley Performance offers the engine in a variety of power levels, ranging from a torquey stump-puller for towing, to a roller-cammed bracket engine. So we came to the Volunteer State to get the lowdown on brewing up the 318 stroker 'crate motor.' Since you will probably want to know the pocket wallop before getting started, the price of the basic 402 intake-to-pan stroker is just under $6,500 from Hensley, which is very economical when you realize the pre-use teardown some other crate engines may require is not needed. This package has been built by Mopar-racing guys who take a lot of pride in doing it right-period. It uses name-brand parts and high-quality machine work for a butt-kicking final combination. The version shown here will cost a little more, since we utilized the Edelbrock head option.
Of course, you could certainly do this buildup at home. you can also call the Hensley's shop at 865/947-0426 and talk to someone about your specific application, and they'll either put one together for you or sell you all the parts you need. Regardless of the method that works best for you, here's how it's done
Here are the other parts that make the bottom end work-Eagle H-beam rods and lightweight alloy pistons from Ross, custom-made for the 4.00-bore 318. Compression ratio is determined by a number of factors: the planned use of the engine, camshaft type and design, and cylinder-head configuration among others. This is why the Hensley crew prefers to talk with you before they begin the process of actually building this crate package. Moly rings will be used to seal it all up.
Tackling The Block
Why the 318? Simple, they're solid, readily available, and cheap. Unlike a 340 or 360, there are literally hundreds of thousands of 318 cores still available. Ken has a number of things he looks for when selecting a block for the stroker process. These include taking basic measurements-which determine what has been done (if anything) to the block in the past, and any potential danger spots that might reveal excessive wear or cracking. He also looks for a pre-'76 casting date. Most 318s are durable engines that can withstand a lot of abuse, but there is no use wasting time on one that might be useless for anything but anchoring a boat.
The first step after the disassembled block is visually examined is to pressure-test it. This is done by using metal plates to cover vital areas, checking and reinstalling freeze plugs, and making sure nothing leaks where it shouldn't. Next comes sonic testing for cylinder-wall thickness-if the block is going to be punched out, this is critical before ever cutting the metal. Like the pinging heard in submarine movies, a sonic test uses sound waves to determine material thickness. Ken especially notes that two blocks cast sequentially can vary immensely. Like the pressure testing, this is very cheap insurance before machine work begins. thorough checks at this juncture will help ensure the final engine both seals well and makes its maximum potential horsepower. these two tests are integral to any engine buildup done at the Hensley shop.
Engine balancing is critical, and here Matt Hensley is using a digital scale to make sure the new rods are within balance tolerances. The lightest of the eight rods will be the baseline, and the others will be massaged carefully to meet that number. All tolerances stated for the products are also double-checked. This is becoming more critical in the speed industry, which is importing quite a bit of hardware these days. Matt and the Hensley crew try to take nothing for granted, summed up in their motto, 'Know, Don't Blow.'
Since the stroker crank will be bringing the rods and pistons where no reciprocating assembly has ever been before, this is followed by clearancing to the bottom edges of the bores. Also at this time, the surfaces inside the engine that might have casting slag or roughness are also cleaned up to ensure good oil return. in race applications, oiling changes will be made now, as well.
After this, the block goes through the machining process. This includes boring and honing using torque plates that are bolted to spec tightness, as well as deck squaring as needed. As with all engine builds, some machine work will be determined by the final horsepower range desired, but Ken believes that boring, honing with a torque plate, and main-bearing clearance clean-up are all necessary, regardless of what the final level of modifications are. Main caps from the stock 318 will be capable in some applications, but HRE uses aftermarket caps when needs dictate them.
Oiling Tricks
To ensure good lubrication for your engine, there are a few upgrades that are well known in the world of high-performance small-block Mopars. For race engines, these mods include opening up the passages between the main bearing saddles and the lifter galley to 9/32 inch in mains 1,2,3, and 4. Also, the area between the rear main, galley, and oil filter area needs to be opened up to 1/2 inch. A crossover tube is also fabb'ed for upper oil flow. Need directions for all this? Hensley Performance has instructions on both LA-series (273-318-340-360) and B/RB (361/383/400/413/426/440) oiling modifications in their 88-page catalog, as well as other technical tips. The primary thing to remember is it will be a lot harder to remove a bit that has broken off inside an oil passage than you might think, so take your time. Once done, take every possible step to ensure the block is completely clean of any fragments. While cleanliness is critical, passage size and changes are not as critical for hydraulic-cammed street applications like ours, so we bypassed that step.
Heads Of State
Cylinder heads are one area that will make a difference in both the final cost and the final power your engine makes. Contingent on how you plan to use your engine, you can go with a set of Hensley's custom-reworked stockers, or go with a flat-out big rpm set that will send a small-block powered 3,000-pound drag car below the 10-second zone.
Making It All Work
We left a few things, such as headers, off the engine, since they will be up to the end user. Ken himself recommends a primary length of 34 inches, and 1 5/8-inch diameter primary tubes. Final selection will be made based on body type and final application. Here are a few other items to consider when building a stroker 318 that won't be bullied around any longer.
The Cost Of Power
So you want to get your grimy little mitts on one of these stealth bombers? There are a few things to consider, like how do you want it built? That's right, you can have it your way, to an extent. Ken gave a couple options you can get with the approximate price.
Street Rods and mild street performance $6,495
Bracket Buster $7,895
