Pete Trasborg
Brand Manager, Jp
693HP! Last month we revisited the Insane Inline idea-for those of you playing catch-up, the idea is pretty simple. The six-cylinder Jeep engine is one of the stoutest factory engines out there, and it should be possible to build big power without the motor going pop.
So, we got together with 505 Performance and assembled a 5.0L inline-six Jeep engine. We started with an '04 block that had been hydrolocked, bored it out 0.060 over, and threw 505's 5.0L stroker kit at it. While bench racing, we came up with 600hp as our goal. We'd heard of Jeep engines that put down high 500hp figures, and we figured that three times the stock output would be something to brag about. Our first dyno pull at Westech Performance netted us 558hp/674 lb-ft without tuning, so we knew we were going to be close to our goals.
To get up to the numbers we were looking for we were prepared to go up to 30lbs of boost. At those boost levels, detonation can quickly kill an engine. In an effort to eliminate detonation, we coated the turbo with a C-186 coating from Streamline Custom Coatings to keep heat down, and ran a water-to-air intercooler to further reduce the temperature of the intake charge.
We hit a couple of snags along the way, but still blew the previous Jeep inline-six power levels out of the water. Not only that, but we are thinking of towing with this motor, thanks to its awesome torque down low and diesel-bashing power numbers. Follow along to see how we got 692hp and 777 lb-ft out of a regular Jeep engine.
Aftermath
After 40 dyno pulls and completely blowing through our power numbers, we decided at the end of the second day that we were happy. We had used 48 lb/hr injectors, which were running at 100% duty cycle at 570hp. To get to 693hp, we had to bump the fuel pressure way up (fortunately for Westech's dyno that wasn't a problem). However, we'd made a ton of pulls on the motor, and we just weren't sure how it would hold up to more. As it turns out, we needn't have worried. We took the motor back to 505 for an autopsy, and we could still see the crosshatching in the cylinder walls. Maybe with bigger injectors we could hit 800hp with this thing.
PhotosView Slideshow
