We recently had the chance to spend some time with one of the coolest Jaguars in the world, and in addition to having Mr. Larry Chen point his lenses at the V8-powered, manually-shifted XJ8 L, we also talked to its owner and builder to get a better idea of how this project originated and what makes it so special.
So without further ado, here’s Karl T. Muth to tell us more about his stunning Jag…
I’ve always liked this shape and generation of Jaguar XJ and I really think the newer cars have lost the nostalgia and Britishness that made these cars great. I wanted the last generation of steel car for the project, which is this generation (X308).
I found a car that was almost exactly what I wanted as a starting point for the project, except it had a sunroof (the car has since been swapped to a non-sunroof roof). I paid $1,201 for the XJ on eBay and picked it up from an elderly man who was the first owner and very apologetic that the fore-aft power adjust on the driver’s seat did not work.
The car had 72,000 miles and poor compression on cylinder #3; it was ripe for an engine rebuild, so I didn’t feel bad about my plan to get rid of the Jaguar’s 4-liter stock engine.
LS Power
I bought the car intending to do a swap and I was originally going to use a GM Performance LS3 376/525 crate motor, offering a reliable 525 horsepower out of the box.
I ended up modifying this engine with various Lingenfelter parts. Everything above (and including) the head gasket is ZR1, meaning the heads are LS9 items re-machined (three-angle valve job) for normally-aspirated performance (the LS9 is supercharged).
The engine also runs Lingenfelter’s GT 1-1 camshaft, titanium intake valves, sodium-filled exhaust valves, and lots of other upgraded hardware, reaching 575 horsepower on the bench normally-aspirated.
In the process of the swap, the car became significantly lighter (the Jaguar motor and ZF transmission were heavier than the LS3 and Tremec 6-speed), and the weight distribution also improved.
The LS sits nearly three inches back from where the Jaguar engine sat (block center to block center) and substantially lower.
Also, pushrod engines carry their weight far lower in the block (versus overhead cam designs), so the weight in the engine bay is located more advantageously. In a big sedan like this, every bit of weight savings and weight redistribution helps.
The engine is mated to a T-56 Magnum transmission with the shorter ‘road race’ gearing and an exposed shift gate.
Leather & Walnut
The engine’s vital signs are monitored through a Racepak digital unit set into the walnut dash.
I also replaced the front seats with Audi items and the entire interior was re-trimmed by Alea Leather, with diamond-quilted Alcantara centers.
However, the parts I love most about the car are the little touches.
The carbon fiber bullet mirrors from a Japanese-market Mazda MX-5 race car; the Aston Martin-style flush door handles; the motorcycle-style fuel filler cap and so forth.
The main use of the car is picking up clients at the airport, taking colleagues to meetings, and so on. It’s the first thing in my garage with four doors in a while.
Everyone who rides in it enjoys it immensely; even people who are not car enthusiasts know it’s something special.
For more on Karl’s build, and to get a glimpse of the car in action make sure check out this Smoking Tire video where Matt Farah and Karl take the beast for a spin through the canyons. It’s worth the watch for the sound alone.
Karl T. Muth
Photos by Larry Chen
Instagram: larry_chen_foto
larry@speedhunters.com
Karl T. Muth’s LS3-Powered Jaguar XJ8 L
Engine
LS3 aluminum engine block, Lingenfelter LS9 L150026109 ported heads, Lingenfelter 3-angle valve job, GM Performance valve locks, ZR1 valve seals, titanium valve spring retainers, Comp Cams 26926-16 dual valve spring kit, ARP 234-4317 adapter head studs, ZR1 lash caps, sodium-filled 1.59” exhaust valves, Lingenfelter L300025297 oil cooler adapter with external 13-row single-pass oil cooler, Comp Cams Ultra Gold (1.65-inch) rocker arms, Lingenfelter GT1-1 camshaft, Manley Performance single-piece chromoly pushrods, Pankl 12624231 titanium connecting rods, Wiseco forged 11.8:1 pistons, custom exhaust with 4-2-1 headers and an X-pipe layout
Driveline
Tremec T-56 Magnum transmission with close ratios, custom driveshaft, lightweight GM Performance flywheel, SL63 AMG intermediate crossmember & driveshaft loop, finned (for cooling) Salisbury HU 8.8-inch rear differential cover
Suspension
XJR Arden suspension with modified lower control arms (deep perches)
Wheels/Tires
Fifteen52 Tarmac R40 multi-piece forged wheels 18×8-inch (front) 18×9.5-inch (rear), Yokohama Advan tires
Exterior
BMW X6 side marker lamps, motorcycle-style locking fuel filler door, Kindig smooth door handles, bullet-style carbon fiber door mirrors, Lexan clear wheelwell flaps, chrome re-painted body color
Interior
Audi A4 front seats & stock Jaguar rear seat retrimmed by Alea Leather, custom headliner, custom trim panels to match factory walnut dash pieces
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Cutting Room Floor
