How to Not Dominate the World With Lots of New Horsepower.

Our faithful and much loved #430 Jeep Cherokee road race car has exceeded pretty much everybody’s expectations, recently being named by Car and Driver as the Greatest Road Racing Cherokee in (LeMons) History. The “in LeMons” caveat was quickly redacted by The 24 Hours of LeMons themselves, meaning we have a lot to live up to. But how do we crack through that glass ceiling that exists for 2WD SUV road race cars? A question that is commonly asked by nobody, anywhere.

We’ve been competing with basically a stock 4.0 for years, and have had a love/hate relationship with it. On one hand, it has six pistons in a straight line, as god intended. The AMC Six is typically reliable despite abuse and neglect, and usually good for 300k miles, but ignore what the Internet tells you; you just can’t make significant horsepower out of them on a LeMons budget (which is to say, basically nothing). We dabbled with the idea of forced induction, but that brought up questions of reliability (which we had *just* conquered) or a stroker 258/242 hybrid which would blow our budget and are fickle by nature. We knew the Jeep had the awesome Falken tires and the brakes to compete with the big dogs, just not the horsepower. The Cherokee’s barn-door-inspired aerodynamics were no help over 50 mph, either, further highlighting the lack of brute power.

So, what to do? It is commonly accepted that the least reliable engine in all of LeMons history is the normally bullet-proof 350ci Small Block Chevy V8 family of engines. So obviously we decided to pursue that route. Actually swapping in a SBC motor is not at all new in the Cherokee world, and the entire time we’d been screwing around with the AMC/Chrysler 4-litre engine, there was this Chevy V8 sitting in the Petty Cash High Technology Centre and Proving Grounds’ shop that had been scavenged and ear-marked for another project. It came from a wrecked ’99 Silverado pick-up that we’d bought and parted out years ago for said other project. The parting out and scrap value of the truck we bought put the last remaining component, the 5.3 liter LM7 V8, at an actual cost to us of about $150…well within our LeMons budget.

Stats for the Silverado truck motor looked encouraging, 270 bhp and 315 lb/ft out of the box compared with 173 hp/220 lb/ft for the AMC 6 cylinder. Also, mated to the power hog of an automatic transmission that we were saddled with in order to stay within our budget, we never saw anything like the advertised hp out of the AMC Six.

Conventional wisdom when doing a Chevy V8 swap is you just toss in the GM transmission that was originally behind the V8. But no, that would be too easy and would blow our $500 budget. Besides, the Aisin-Warner AW4 auto had been supremely reliable, despite an inadvertent 85 mph shift past OD into reverse one time. We also got in touch with some Toyota Supra experts, a car which inexplicably shares basically the same transmission. We mailed Fringe XVO our valve body and they sent us one back that had been tweaked for faster shifts; counter intuitively this actually reduces wear and keeps heat in check. With this mod and a couple coffee table sized trans coolers, we stuck with our trusty slush-o-matic and made an adapter to make it bolt up to the Gen III Chevy V8…how hard could it be? Turns out the answer is “very.”

In the end we used a 4L60E bellhousing from a Chevy Astro, a flex plate from a Camaro with spacers welded to it then bolted to the flex plate from a Cherokee, bolted to a Cherokee torque converter, all held together with an adapter plate that we made with a drill press, band saw and the power of positive thinking. We spent a great deal of time getting this bastardized combination to “kinda-sorta” work. Niggling details and lingering doubts left us with no time to do any real testing of the combination before race day. Knowing that we were venturing into the unknown, we ponied up for a fancy-pants, track-facing paddock/garage rental at Sears Point/Infineon/Race Sonoma/whateverthehell they’re calling it now. Baller status for sure.

We spent so much time fiddling with the transmission adapter (literally over night, through the morning, right up until the green flag dropped) that we neglected to give our new motor much attention. Before even dropping the 5.3 into the Jeep, we’d pulled the oil pan, checked the bearings, compression in all the cylinders, etc and everything looked hunkey-dory. It made great oil pressure (40 lbs at idle when hot) and after a few spirited excursions around the paddock we were fairly confident that this crazy idea would work. We even used a Camaro/Firebird LS1 oil pan with lots of baffling, our Accusump from the 4-litre and AmsOil 20/50 race oil from 4x4Oil.com We finally had the winning combination after 12 races: It was our race to lose.

Here’s our first lap out:

With our uber-conservative exhaust and only one lap to prod the limits, things didn’t really feel all that much faster than before. Hmphf.

After coming into check why the oil pressure was dropping off, the motor seemed to heal itself and regain its previous strong pressure. Faulty gauge? Ghost in the machine? Meh. Back out we went, with all the bugs surely sorted. Ha.

This time it was something stupid on our part, a coolant line that needed to go to the overflow tank and not be plugged with a screw like it was. So once more back in we came for a quick fix; by this time any hope of a class win was gone. You just can’t spend that much time in the pits and have any chance in the hyper competitive California races with 175 other race cars. So with a more relaxed pace we went back out…and had the same mysterious loss of oil pressure after 2 laps. Okay, fine..we’ll do it right and try to get the car back on track, but do it with an eye on actually fixing the problem, not just a slapped together short term solution. We decided to pull the oil pan and check the oil pick-up to see if it might be clogged.

It was…a lot. And there was also a great deal of metallic debris that looked remarkably like the bearings were tearing themselves apart. In 5 laps.

Hey, no biggie…we’ve swapped an engine every time we’ve raced at Sears Point, just never this early on. Par for the course, Semper Gumby and all that. The local generic parts store had rod bearings in stock for a 5.3 V8 (no surprise, GM has been churning them out by the millions for nigh on 15 years) for almost free. We decided that in addition to cleaning out the oil pick-up we’d throw in some new bearings for added insurance. With a couple hours to spare in Saturday’s session, the Jeep made a triumphant return to the track.

For two laps, then good bye oil pressure. We were officially flummoxed and out of ideas. Back into the engine we tore. We called LSx experts. We went from team to team to see if they’d ever heard of anything like this. We called Miss Cleo the Psychic. No help. In the end we put everything back together and changed the oil again, with a fresh filter hoping we might be able to get rid of the sludge that was giving us so much grief. Nope.

With no time left to source a junkyard motor at a reasonable price, we decided to pack it in, start drinking and save what was left of the motor and at least take the checkered flag.

Not a totally hollow victory, but also not very satisfying considering the staggering number of hours we’d spent in the shop putting the puzzle together. There is one ray of sunshine, a silver lining of sorts: The basic concept of a much more powerful motor in the old XJ chassis actually felt pretty composed and controllable. Of all things, the one-off trans adapter seems to work, and the tranny itself appears to be up to the task. There are some things to be addressed and sorted, but as a testing/proof of concept the weekend was a success, albeit a very expensive one. But hey, that’s racing and we had to pay the piper eventually. Hopefully this means our next event (Buttonwillow Raceway Park, June 29-30) will be trouble free. Hey, we can dream, can’t we?

How to Make a 4-Litre Survive Road Racing

The AMC/Jeep 4.0 liter inline-six: Synonymous with reliability, these engines are well known to easily last to 300,000 miles or more. They endure torture in off-road applications, overheating, water ingestion, low oil pressure from extreme angles and shrug it off like it never happened. They make decent power (ranging from 173hp-190 hp) and gobs of torque. What better possible endurance racing engine? That’s what I thought when I selected the Jeep Cherokee as the platform for the Petty Cash Racing 24 Hours of LeMons racer.

Before I explain how terribly misguided this assumption was, a little history is in order. In 1964, AMC replaced their previous Nash derived OHV I-6 with the basic foundation that survived until 2006 in continuous production. So this lump of iron has been around the block more than a few times, and like I mention, earned a sterling reputation for reliability, especially in its final iteration, the Chrysler influenced 242 ci/4.0 liter version. At first the team had very good luck with the 4.0. Our first race was Thunderhill in 2009, and the Jeep surprised a LOT of people that first outing. We actually had to get a special exemption from organizer and self-proclaimed “Chief Perpetrator”, Jay Lamm, just to enter the event. People were convinced we were going to roll over on the first corner.

Instead, we finished 63rd out of 156 entries, a convincing result considering none of the team had ever been on a race track in competition before. The motor did great, didn’t use oil and even sounded mean with our Cherry Bomb muffler and side exit exhaust. We thought we were pretty clever.

All clean ans shiney at out very first race in ’09 at Thunderhill Raceway.

Things had gone so swimmingly at our first race, we decided to not change a thing and raced at what was then called Infineon Raceway, aka Sears Point. We finished mid-pack due to some unscheduled trips to the penalty box for contact with other cars. Up until this point, all we’d done to the Jeep was change the oil and brake pads. So far so good. In fact, things were going so well that we decided to leave it mostly alone for our next race at Buttonwillow Raceway near Bakersfield in December of 2010. We were baffled when we developed a pretty serious case of blow-by, and enough crank case over-pressure to blow out the dipstick out of its tube (enter zip-ties). Despite the slightly wounded engine, we took home a trophy, first place in Class C, this time 32nd/173 entries.

Buttonwillow ’10 on our way to a class victory.

Our next race was at Sears Point again, and we were looking forward to redeeming ourselves. That lasted 3 hours and then a piston exited block-left. We were baffled. 4.0s are supposed to last forever! No matter that we bought ours with 201k miles and had proceeded to put about 3500 racing miles on it. We scrambled all night and swapped in a junk yard motor that we found that night and finished the race, but we were now a little suspicious of our old friend the 242 straight six.

Chunks of engine and block at the bottom of the oil pan. Ew.

Cut to 2011. We knew the Jeep was capable of some pretty decent finishes, and I’d been bitten by the racing bug. 2011 was going to be our year, an all out assault on some serious results. I broke out my Sponsorship Knee Pads and went to work: We got a set of massive brakes from Savvy Off-Road loaded with Black Magic pads. We added 2 degrees of negative camber on each front ball joint. Perhaps the biggest improvement was the selection of new 17″ Raceline Wheels wrapped in the new Falken Azenis RT-615Ks in lieu of the 340 TW Mud & Snow rated garbage we had . Disc brakes, limited slip differential and shorter gears in back courtesy of a Ford Explorer rounded out the package. It was a different car.

We went back to Sears Point with high hopes; now we would have the handling to match the reliability and relative speed we’d been enjoying for the last year. And blew a motor 3 hours in, just like last time. It’s almost like there’s something about this track…like a specific corner that robs the motor of oil pressure. Like maybe the long, downhill, off-camber sweeper called the Carousel. Hmmm.

Not what the oil pan is supposed to look like.

We thought about mixing and matching bearings, but the crank was too scored to bother.

Luckily, by this time we were wise to the 4.0s proclivity to eat it’s own bottom end (insert joke here) and brought a spare.

Dan Witte (from JudgeBusters BMW team) looks on and enjoys an adult beverage as we swap in our spare motor.

We took the checkered flag for that race, but it was a not one of our more fun events. Lots of time spent in the pits, not much time actually on track. I swore that we would not return until we had solved our engine issues. Post race video shows our oil pressure dropping dramatically through The Carousel. You can hear the motor getting worse and worse in this video:

Clue #1. Maybe our increased grip and higher lateral Gs due to our upgrades have made oil slosh in the pan the problem. But that can’t be! I’ve run 4-liters their sides’ for minutes at a time in off-roading with nary a problem.

But then it struck me…I was idling at those angles, not running an engine designed with a 5000 RPM redline at 4600. So what to do? I put out a plea on our Facebook page and was flooded with suggestions: “Run 2-stroke oil!” “Add saw dust!” “Put no oil in at all!” “Make your roll cage part of the oiling system!” “90 Weight gear oil!” Out of all these terrible ideas, a couple floated their way to the surface. First, add baffles to the oil pan to keep oil from sloshing around under high load corners. Some CAD (Cardboard Aided Design) later, and we had a partial solution:

Simple, yet effective. CAD to the rescue.

How we really felt.

Welding in some light metal scraps to keep the oil from sloshing away from the pick-up.

Poor man’s windage tray.

Another idea that some old dirt track guys suggested was an Accusump. Basically, it’s a reserve tank of oil that is forced into the engine when it senses low oil pressure. These are surprisingly cheap, and we found a used one in the 2-qt flavor on Craigslist for $85: Insurance plan #2.

Our 2 qt Accusump lives under the dash and keeps us from starving the motor of oil.

We also added a mechanical oil pressure gauge and an oil temp gauge so we could keep better track of what was going on under the hood, hopefully before parts tear an inspection port in the side of the block.

Of course this meant rebuilding our entire “dash.”

While the motor was apart, we tossed in a new set of rod bearings to further bolster our chances of making it through our next race, appropriately enough at Sears Point. Thanks to Eastside Auto Care for helping us out on the parts.

Perhaps the most contentious question ever asked is “What kind of oil should we be using?” We got another onslaught of suggestions: “The thinner the better!” The Heavier the better!” “Distilled baby seal fat is the only way to go!” “Make sure you over fill it by 2 quarts!” Whatever you do, don’t over fill it! You’ll blow up!” We got 81 answers on our Facebook page in an hour. It was pandemonium. One person stood out of the crowd, however, and offered up some very constructive and well thought-out ideas. Turns out the guy, Dirk Werning, is not only a Jeep Cherokee geek, he also runs 4x4Oil.com, an AmsOil dealer. It turns out the Mobil 1 Synthetic we’d been running really wasn’t the right solution for us.

Apparently motors with flat tappet valvetrains need something called ZDDP (Zinc dialkyldithiophosphate), basically a zinc additive to keep the engine from chewing itself up. Dirk advised us that with the high miles our crappy motors had, something a little heavier would be the way to go and shipped us a case (along with a couple AmsOil filters) of AmsOil 20/50 Synthetic Z-Rod. You can read more about ZDDP on their site. Interesting stuff.

So, with seemingly all our bases covered, we loaded up for our next race at Sears Point.

Top of turn 2 at Infineon/Sears Point/Sonoma/Whatever.

Success! We finished a race at Sears Point without having to do a motor swap! I can already hear you saying it: “One race? That’s hardly conclusive.” Agreed; we decided to put the AmsOil to the ultimate test. A normal LeMons race weekend is about 15 hours of racing broken up over 2 days for a total of about 800 miles. Once a year, however, they do a true 24 hour enduro, straight through the night. You may remember that we won last year’s event in Reno. This year’s full 24 was going to be at Buttonwillow, near Bakersfield, California. Temps were predicted to be above 100 degrees. Perfect torture test.

An extra pair of IPF lights to guide us in the inky blackness of Buttonwillow’s unlighted back stretches, also gives a touch of Jeep Cherokee Wagoneer.

Even with engine coolant temps soaring into the 250+ range and over heating, oil temps never got higher than 280 and we never once saw low oil pressure. That’s on the same oil and filter from the previous race, for a total of 2300 race miles. Okay, we’re officially drinking the cool-aid.

2012 King of the Hammers lives up to its name and reputation

On the 5th of February the Petty Cash/Team NAXJA Jeep Cherokee lined up at the start line for the inaugural SmittyBilt Every Man Challenge leading up to the Griffin King of the Hammers. And we sat there while the rest of the field took off in an angry rush for position. In fact we sat there while our crew raced back to our pits and scavenged an alternator off an innocent Cherokee and installed it in the race car. In 13 minutes. It was that kind of week, full of New Car Blues, a term often muttered in the pits on Means Dry Lakebed where the event is held.

The whole team scrambling to install an alternator and jump start it to take the Green Flag.

Between parts shipments being delayed to family crises, every step of the way forward was after taking two back. As you learned in our last blog entry, we weren’t sure if the car would even make it to the start line. Through the hard work and perseverance of several key players, sponsors and scores of volunteers, somehow we made it.

Paint drying on the drive home from the paint shop.

Exciting New Chapter…4 Wheel Drive!

Now, this might not seem like news to most people, (that a Jeep racing team is adding Four Wheel Drive), but we went about it backwards from what most people would do. We started the team with a 2WD Jeep (gasp!) and now, after three years, we are adding a 4WD Cherokee to the stable. It all started last year when sometimes Petty Cash driver and full-time race promoter Dave Cole announced a new racing class at his rapidly growing Griffin King of the Hammers Ultra4 race series (KOH for short). It was to be an alternative to the now mega buck Unlimited Ultra4 KOH race that takes place on the trails of Johnson Valley, California every February.

KOH wasn’t a new concept to us, as most of the team has been attending in one capacity or another, including racing in the event. In 2008 Petty Cash Racing member Richard “Goatman” Gauthier drove his trail-rig turned race-Cherokee to an astonishing 7th overall in the punishing 100+ mile endurance rock/desert race. Team NAXJA returned in ’09 and finished the grueling event, but lower in the standings than hoped. It was clear that the state of the art had left Richard’s NAXJA sponsored Cherokee “Truggy” outclassed. The next two races, Richard was the Crew Chief and back-up driver for the team that would finish as high as second overall.

Project Widebody XJ- Part 1

At our last event at Reno-Fernley Raceway, we were informed by John Pagel of Evil Genius Racing (and the Chief Tech guy for LeMons) that our wheels and tires stuck out too far from our fenders. I could see what he meant, the Jeep did sort have a 1920s roller skate stance, and I recognize that if somebody was dumb enough to run into us and lock tires, it could end badly. John told us that we could race at Reno, but we’d have to address it before our next race. One option would be to get different offset wheels, but we had JUST gotten this new set of 17″ Racelines to fit our Falkens. We discussed running big offroad fender flares, but that would have looked quite out of place with our 26″ tall tires. So here’s how we built a Widebody XJ:

First step was to pull the curtain back and see what we were dealing with. The Jeep being of unibody construction, our options were limited; the most attractive option was simply to bump out the stock fenders by three inches on both sides. We retained the stock mounting points so that the entire fender could be removed should we need to replace them down the road.

Project Widebody XJ- Part 2

At our last event at Reno-Fernley Raceway, we were informed by John Pagel of Evil Genius Racing (and the Chief Tech guy for LeMons) that our wheels and tires stuck out too far from our fenders. I could see what he meant, the Jeep did sort have a 1920s roller skate stance, and I recognize that if somebody was dumb enough to run into us and lock tires, it could end badly. John told us that we could race at Reno, but we’d have to address it before our next race. One option would be to get different offset wheels, but we had JUST gotten this new set of 17″ Racelines to fit our Falkens. We discussed running big offroad fender flares, but that would have looked quite out of place with our 26″ tall tires. Here’s what we ended up with: