'91 Dodge Ram 50: A Frankenstein Story

In reply to Left Ventricle :

It's most certainly a thing, it's common in the Evo world as well with 2.1 liter builds which is where I first heard of it.  The short stroke creates more dwell timing essentially for the piston which means you can run more boost/ignition advance per compression ratio.  Plus the rod/stroke ratio is more favorable. It should be a pretty cool engine down the line.

Can't wait to hear how this handles. You've really got me thinking on my Courier and long term plans, suspension wise at least..

In reply to classicJackets :

If it doesn't handle well I only have myself to blame.  Seeing something similar on a Courier would be awesome.

Spent most of Friday afternoon watching the the clock and day dreaming about pulling the bed on the truck.  I had a game plan.  Remove the filler neck cover, disconnect filler neck, remove bed mount bolts, rig the bed and pull it off with the engine hoist.

First roadblock, 4 of the 6 Phillips head screws that hold the filler neck door on won't budge. Time to get the die grinder out.  There's a special place in hell for people that consciously use phillips head hardware, these will be replaced with Torx or allen head cap screws the way god intended.

Also took the ugly and heavy bumper hitch off. Four rusty bolts later the tail end of the truck is roughly 90lbs lighter.  The stock rollpan looks great, this little bitch has a great ass.

I pulled 6 bed mount bolts out and rigged up the straps to pull the bed. I started to jack up the the hoist and the bed didn't really go anywhere. berkeley. I consult the Chilton manual to figure out where the bolts I missed are. Pull the 2 remaining bolts and pop goes the weasel.

Diff clears the gas tank and the batwing lines up perfect with the frame rails *self five*

The frame on the front of the truck was less crusty than the rear.  Still it's not awful, rust converter and some decent enamel paint this should be fine. Here's a general idea of what I'm dealing with.

I need to line up the batwing left/right, front/back and pinion angle.  The rear is looking like it's going to very straight forward.  One of my good friends from engineering school and SAE Baja came over tonight to check out the progress and consult on suspension.  He designed the suspension on the Baja cars while I played with the torch and built the frames.  I picked his brain on shock placement and got a bit of a knowledge download on suspension.  I spent most of today being lazy, installing Euro projector headlights on the Fiesta and shooting the E36 M3 with my buddy.  I already have some plasma cutter and bandsaw action planned for tomorrow.

With the bed off now is the perfect time to investigate and upgrade the fuel system. The sending unit and the level sensor are both pretty crusty so you southern boys should look away now.  I did chisel the flaky stuff off and then spray the remainder with phosphoric acid.

Walbro 450 vs stock Mitsu pump.

I still need to rewire the new pump but it is now mounted on the hanger.  I did spy some sediment in the bottom.  Should I try and drain this even more and try and remove that little bits in there or leave it and let my filter do it's job?

That tiny bit of sediment I'd leave to the pre-filter.

Rear suspension looks easy enough to get mounted. Will you be attaching the batwings to the underside of the frame, or notching it out to fit?

In reply to Mezzanine :

I took the hard rubber body mounts off the top of the batwing which allowed it to slip up an extra inch. Right now I am planning on attaching it underneath the frame this might give me some slight rake but it is the easier path forward. I can always adjust ride height in the rear with changing upper shock mount or adjusting the coilovers.

Note on the hard wear. Id take Phillips over flat heads, just saying, Mine was pop riveted on due to rot. 

Wired the fuel pump up and added zip ties for structural support.  I got ambitious and decided to measure the resistance range of my fuel level sensor while the bed it off.  The ohms readings were not consistent at all I might need to clean the terminals off more they were a bit dirty.  I'm going to try it again before I start googling or say berkeley it that's later's problem.

Did some welding last weekend for a buddy and managed to drop my torch and shatter my cup after I had finished and was cleaning up.  I needed to get some replacements for the amount of plasma cutting and tig welding I have planned in the near future.

I recently saw something in my googling about lower coilover mounts for C4 IRS swaps and issues with loading the shock mount with all of the load. I hadn't thought about this before, the monoleaf helps to distribute the loads the rear suspension experiences and I was planning on taking all of the load and putting it in one spot on the rear knuckle.  I found a couple companies offer a solution to this and make a lower coilover mount bracket that bolts to the trailing rod mounts but they want $250 for something I can design, prototype and weld myself for about $30 in material and a few hours of time.

My original plan.

The consequences.

Expensive things I can make myself.

Ran home on lunch to start a print.

The batwing is basically in place, one of my friends from Baja stopped by the other day.   We jigged the batwing in place and measured everything up. I need to set pinion angle and cut/weld mounts, the 3D printed mounts fit perfect and will make great templates.  He made the remark, "when you think about how we built a chassis from scratch almost every year this isn't really that bad compared to Baja."  

My printed brackets didn't come out perfect but they were a great visual aid which is what I needed.  Rushed setup on the lunchtime print job yielded some curled edges and a warped piece.  More fiddling to be had with printer #1 this week I suppose.

Fits up well for the most part but I managed to size the holes too small to bolt it on. This is why we prototype.

Some batman-esque tabs to hold the batwing in its new home.

Final checks.

First welds. Rechecked everything twice before welding further, everything appeared to be in order so it got burned in.

Since I have no intention of using a horrible device like a C frame or torque arm on this truck I mounted the nose of the third member to the existing cross member that supports the rear of the gas tank.

Put the nut on the plate, weld the nut to the plate, make a tube attached the plate to the cross member. bada-bing bada-boom It's done.

I also added some bracing to the batwing tabs.

The C4 IRS is now 80% attached to the truck.  I still need to make coilover mounts and attach the forward points of the trailing rods but the big stuff is done with the suspension swap now.  I need to keep this momentum going if I have any hope of driving it to the show I plan on attending in 2 months.

Holy E36 M3 is this cool though.  I can't wait to see it back on the ground.  The truck always looks so foreign to me when is in on the ground and not elevated on cribbing.  That's when I realize just how little it is and how much a monster this thing is going to be, like a friggin' Tasmanian Devil.

Fantastic cool build.  I just started reading it today and I find myself bummed out that I hit the current end.  I look forward to more.

Great progress!

how far forward would that center diff mount normally go?   the center mount is designed to react all the driveline torque (max engine torque * max trans gear ratio * ring:pinion ratio) in both forward and reverse directions. 

In reply to AngryCorvair :

The C4 C frame mounts the tail of the transmission to the nose of the diff and ties the whole drivetrain together. I am hard mounting the trans and the diff so they are both not moving. Not something I'm really worried about.

In reply to preach :

Thanks man, I appreciate it! I have plenty more planned.

You might want to consider the stock spring setup.  It seems that everyone thinks that coilovers are a great upgrade, but in many cases, they ruin many qualities of the C4 setup, then break at the mounts.  If your overall weight outlook is somewhere around 3k, you can easily use the stock setup with success (it weighs like eight pounds on each end--light and cheap are both good, no?).  It is also height adjustable, so torquing coil springs should not be seen as the only route to height adjustability (and ride destruction).  Your rear batwing mounts look great!

Note my own application of what used to be a 1992 C4:

In reply to rustomatic :

Thanks for the advice. I may end up back with stock damping and spring later on but I have to make upper mounts for shocks/coilovers regardless and I already bought the coilovers.  If they end up not working out I'll still have the stock monoleaf sitting on the shelf to reinstall.  I'm shooting for 2600 curb weight which may be a bit ambitious but it is about what the stripper models of these trucks weighed. 

By the way that Falcon is badass.

I was in a bit of a slump this weekend and working slowly but I still managed to make brackets for the trailing rods and mount them to the frame.

I cut up more beer boxes to make a template for some gussets for the trailing rod mount. 

I couldn't sleep Friday night and didn't want to wake the neighbors up with the angle grinder and bandsaw so decided to play with the belt routing and throttle body on the engine.

I want to use the Camaro throttle body (red) since it has what is supposed to be a more linear throttle cam than the truck throttle body.  You can see the difference.

There is a clearance issue with the Camaro tb and the water pump outlet.  Most guys run the truck throttle body or get a Camaro pump (water pump outlet comes straight forward rather than up) and put a truck pulley on it.  I have a couple of truck pumps lying around so I'm going to cap the top and run a piece of tube out the front of the pump.

Trying to formulate a gameplan for engine mounts again since I cut the other ones off  with the frame when I sectioned it.

Also came up with a template trick this weekend. I printed this bracket for verification before cutting steel, traced it and then plasma cut a little larger than the template.  Clamp the template to the steel and then you have a perfect guide for grinding/sanding the edge.  No issues with this plastic melting from the heat, this is PETG which melts on my printer around 220* C.

I'm hoping to have the truck back on it's wheels this week, most of the bracketry has been cut and just needs to be finished, drilled and welded.

Cool idea on the 3D printed sanding/grinding guide.  With another print (with dimensions offset for cutter cup radius) you could probably do a plasma cutter guide, no?  That would be slick, too.

In reply to ClemSparks :

It might be worth a try, I'll have to look into it.  The plasma cutter tends to generate quite a bit more heat so I think that might be an issue for PETG or ABS plastics even.

Nice work! Keep chipping away - watching this move on has kicked my butt into gear on my own project!

In reply to classicJackets :

Glad I could be an inspiration. I've gotten into a rhythm and I'm starting to see the light the end of the tunnel.

Very nice- looking forward to seeing this in action.