Project Madera: A Jimmy GT

[skorpioskorpio]

I've actually been in parts collection mode for a month or so now, but my new, to me, Jimmy is officially, well at the body shop, here. Now the project begins. Here she is:

[skorpioskorpio]

...and here is her new heart:

[skorpioskorpio]

...and her new shoes:

[skorpioskorpio]

So it'll be in the body shop to replace the rockers, which have some bubbles in them, other than that a pretty rust free tub. Also going to fill all the usual piercings, mirror holes, antenna spring mount holes, boat cleat holes, body molding holes, spare tire carrier holes, roll bar holes, <sigh> trailer brake holes in the dash, aftermarket underdash aircon mounting holes, etc... Hmm It's a lot of holes.

Then it'll be off to the disassembly party, then to the blaster.

In the end it'll be a 2WD, 4 corner coil over, trailing armed, wide tracked, Vette braked, 6 stack ITB 6, Le Mans inspired GT Jimmy. Made to comfortably haul my girlfriend, my equally oddly conceived canyon carving vintage dualsports, and my neurotic German Shepherds. Should be interesting.

[bouncytruck]

Sounds cool. I like the wheels. Do you have renderings of what you want it to look like?

[skorpioskorpio]

I don't, I've thought many times about trying to photoshop something up, but given that I plan on putting a 67-68 cowl hood on it, I know that photoshopping just that is probably beyond my skill level...and I have pretty decent photoshop skills.

But here are some details...

The wheels are from an inventory of wheels created for the Super Performance Shelby Daytona Coupe reproduction. They are pin mount wheels and have no lug nuts, just one giant 3" nut in the middle to hold them on. They are 18x10"s with kind of crazy back spacing of 7.2" which after the hub pin adapter for the center lug nets out to about 6.8". The tires on them are Diamond Backs, which are actually Nitto 555s, 295-45-18s. I'll be using these all the way around.

The chassis is going to be a Porterbuilt DM Mild Drop setup, chassis work is going to be done by Delmo. I'm only keeping the outer frame rails, everything else is going, replaced with all tubular cross members, outboard shock mounting on the rear. I'm going to be stretching the track width with extended control arms in front by probably 2 inches a side to compensate for the huge backspacing, this is good, it puts the steering pivot point out into the rim and shortens the front to rear movement of the steering. Should quicken up the steering quite a bit without being twitchy. To put it in perspective, the steering lever part of the spindle (I'll be using CPP 2" modulars) should actually be about 1.5 to 2 inches inside the rim on the back.

Kore3 is making the custom hubs for me that are made to clearance the pin mount center lug adapter and mount up the stock 13" Heavy duty '96 Corvette rotors. I'll be running the Z51 sliding calipers simply because I'm building this as a driver and it's a whole lot cheaper and easier to change than getting into the opposing piston Brembos or single source Wilwoods or Baers. In the end it's being built for a long and serviceable life.

To round out the front suspension I'll be running the Ridetech Select coilovers which are electronically controlled dual dampened shock cores that have a selectable tour and sport mode. I plan on running them independently selectable front and rear so that there is a soft daily driver mode with all four in the softer position, a have some fun mode with all four stiff, and a cargo-tow mode with the front soft and the rear stiff.

The rear end is going to be a custom Moser 12 bolt, which will probably end up being almost 6 inches wider than stock with a Wavetrac differential the corresponding 13" Vette brakes with internal parking drum will be used in the back.

[skorpioskorpio]

Here is the CAD rendering of the hubs Kore3 is milling up for me, it also shows the center adapter for the center lug with the rotor sandwiched inbetween:

[skorpioskorpio]

Here are pictures of one of the adapters itself along with one of the pins and the center lug. Next photo is of the comically large lug wrench for the center lug pictured along side a 1/2" drive ratchet for perspective.

[skorpioskorpio]

The engine is an all aluminum 4.2 Liter 24 valve double overhead cam straight 6. This engine came in Chevy Trailblazers, GMC Envoys, Buick Rainiers, Isuzu Asenders and Saab 9-7xs from 2002 through 2009. Mine is a 2008 version which put out 290hp stock, with the individual throttle bodies, more engine control via the new AEM ECU and free flowing exhaust, I should be seeing probably around 325hp from this engine to start which is close to triple the output of the std Jimmy 250 I6 and nearly double the Jimmy 350 small block from 1970. The engine has 10,000 miles on it. With some port work on the exhaust side and cams these engines are pushing past 400hp and with boost well past 700.

Anyway, progress today, Cleaned up a few areas on the top and brackets, changed out plugs for new and got the coils mounted. Started unweaving the wiring harness to pull out the individual pigtails I'll need for the new ECU. Attached are some pics with the coils, then the next pic is with the pigtails for the coils, fuel-rail, and water temp sensor although I think I'm going run the new harness towards the back and not towards the front as shown and how stock harness runs.

[Wasted Income]

Nice! I've been wanting to turbo the hell out of one of these and put it in something.

[skorpioskorpio]

Funny, your "Family Truckster" build is going through a lot of the same sort of things I'll be doing on mine, it's practically my reference manual. 2WD conversion, hydroboost, aftermarket ECU, etc...

There are several guys running turboed 4.2, and they are getting crazy numbers out of them. One guy is running one in a Chevy Nova running low 9s, there is even a dragster or two.

Here's one guy who put a DCOE patterned 4.2 in, mine will be similar, but I'm actually trying to get the CAD done for the manifold, do a model on a 3D printer and have it cast, this one is fabricated.

[Wasted Income]

Yea I've seen the nova. Pretty awesome putting a wagon on the bumper like that.

[skorpioskorpio]

I passed the torch (code for keys and money) to the body god at B & E Custom to de-perferate my Jimmy and had time to do some measuring. Since all the 2WD guys like to talk about 3" and 4" drops and such I figured I'd measure out what my "drop" will be, works out to about a 10" drop

What I did figure out, useful, is that I should still be able to get a NWMP tank under it. They will make me a modified one that is 3 inches shallower than their 37 Gal tank, works out to 27 or 29 Gal I forget which. But it should be 2 inches higher than the frame mid point, which should be at about 8 inches, so 10 inches, I'm ok with that.

Also for future reference I was checking that if I fill the cowl (I'll be doing Vintage Air so the cowl vents no longer serve a purpose) could I extend a cowl induction hood all the way to the windshield and have it clear when you pop the hood, looks like you can

Also gave Porterbuilt their deposit and that work is under way.

[NTR72GMC]

Cool build! I've thought about finding a trailblazer motor for my blazer a few times.

[skorpioskorpio]

I went and visited the truck today, and the total is, 95 holes being patched in the body with all the trim and accessories removed. Also got the 67 grill which I'm just using the grill top filler panel from and a 67 latch assembly, so I can fit the slant nose cowl hood on. I actually went to test mirror placement but unfortunately I arrived apparently 15 minutes too late and the passenger door was already off . I am putting bullet mirrors on it and wanted to see how that all works out with the wing windows. The drivers side is not a problem it's the passenger side I was worried about and no passenger door means no test. Mirrors are late 60s square head Talbot Berlin 333 racing mirrors from a GT40. Here's a pic:

[skorpioskorpio]

Also made some progress on getting the Solidworks design for the intake manifold. Been going back and forth with the design, but probably have that ready to print in a week or so, then it's off to the foundry. Also got good news on the cast oil pan to convert the 4200 from front sump to rear sump, looks like my lead time will be a more reasonable month instead of 3 now.

The rockers look a bit worse than I originally thought, so I'll need to go in a bit on those past simply the rockers alone. What panels are needed to replace them into the floor? Is it just this panel or is there stuff inbetween?

[gringoloco]

Wow, just wow. Outside the norm, but in a good way. That piece will repair the outside edge of the floor, behind the outer rocker. Looking forward to progress and it looks like you're moving fast!

[skorpioskorpio]

Look sir, look sir, Mr. Knox sir, lets do tricks with stacks and socks sir...

[RED 1970]

Curious on what the budget is for this build.
Lots of very innovative (expensive) mods going on!

[skorpioskorpio]

Oh, lots!

[hgs_notes]

Definitely going to keep an eye on this build. Sounds like a ton of fun.

[skorpioskorpio]

So a little background on the name "Madera", My projects are named after where they came from, the Jimmy came from Madera, CA just North of Fresno. The truck is being built as a canyon carver but also as a hauler for the bikes I restore, err mod, which are overhead cam, 4 valve Honda singles. The 2 twin '72 XL250s that will be in the back I call "Monterey" and "Mohave" after where they are from. The bikes, which started out as dual sports now look fairly original at casual glance but are in reality pretty modified machines and themselves built for canyon carving. After this project is done I plan on also doing a fairly radical Honda single Café Racer. Anyway, all early '70s, all 4 valve per cylinder, all silver with black and red accents, all done with respect to the period they are from for the most part, you get the idea. Here's the bikes:

[Splash4195]

Nice build!

[warbucket]

Cool, I wish I still had my 75 XL350, what a great bike.

[sixtyeightchevykid]

very cool build.