Awww, shucks, Joe. I'm just having fun with junk....
Much to catch up on. Axles, paint, and forced induction.
Rear axle is an Explorer Sport Trac 8.8 rear (31 spline) and front axle is Explorer Dana 35 TTB.
Ratios are 3.73:1. Needs to be ~4.88-5.13:1 to make 5th gear useable. I'm waiting for the turbo installation to chose ratios.
I'm hoping the disc brakes will hold the axles in in the event I break an axle 'C' clip hat.
bigger components for a turbo I assume.
more off rd? Tow? Haul? Any change?
If turbo which size...
I decided on two-tone Rustoleum/bedliner. The Rustoleum will make scratch repair a cinch, and the bedliner on the sides helps prevent it.
The bedliner is Brick Red Durabak and I highly recommend it. Rolls on with a 4" roller.
WoW, nu car !
I think I've mentioned before that I'm not thrilled with the power output of the 4 cylinder in this application (3600 lbs with me in it). I'm getting 19 mpg in mixed driving. Straight highway it gets low 20's. It's not bad, but I'm pretty sure a 5.0L M5OD would not be far off of those numbers.
"...you must be a psychic..."
and chunk gear...now, which transmis.
BTW: I want that paint scheme on mine now..
(I wuz thinkin that silver w/florescent lime or green or whatever the hwy dept guys shirts are).
ALSO BTW I C frame stiffiners in ur future (plus...um...er...ahhh, better stop here).
The biggest problem is the massive jump from first gear to second gear in the Toyo-Kogyo 5 speed (3.96 to 2.08).
The 2.3L doesn't make decent torque until 2500 RPM. Because of that, you have to rev the engine to 4000 RPM when taking off in 1st gear, or the shift to second bogs horribly.
Gears will help, but what it really needs is a low RPM torque boost. The turbo should fix that. If not, and if I don't get the expected MPG boost with the turbo, the 5.0L is waiting patiently.
I rebuilt the turbo. It took two tries at getting the correct bushings. The housing was machined oversize during a past rebuild.
-It's a generic Garrett T3 off a Turbo Coupe.
The 2" body lift helps, but the stock Turbo Coupe exhaust manifold places the turbo where the evaporator housing is.
I will have to scratch build an exhaust manifold.
Manifold will be mild steel to start with. Yes, I know it may crack. This is proof of concept, if I'm happy with the result, stainless/schedule pipe is in the future.
Last edited by MechRick on Mon Apr 20, 2020 3:21 pm, edited 1 time in total.
Hi MechRick, it's great to see the Bronco II getting some more upgrades been following it from the start of your build.
Thanks, Bubba. I've put about 20,000 miles on it since the Sept 2018 post. I really enjoy driving it.
One of the cons of turbos is the requirement for good, detonation-resistant fuel. One of my goals is better MPG, so forcing me to use premium fuel defeats the goal. I'm going to try to run 87 octane. I may need to lower compression, add aftercooling, and add knock-sensing.
To start with, I'm going to lower boost.
The stock wastegate is set at 10 psi. Wastegate-controlled boost pressure is set by the tension of the wastegate spring. Fancy wastegates allow the spring to be changed, I chose to oppose the internal spring with an external one.
Rig for checking wastegate opening pressure...
Hoping for 6-7 psi when I'm done. That should be good for at least 35 HP/45 ft-lbs, hopefully on 87 octane.
I almost cut the top off last summer. That would have required a custom soft top, out of the budget. I decided to get rid of the leaky sunroof and add some open air ability by installing a canvas roof.
I supplement it in the winter with hardboard under the canvas, but even with the canvas only, it's leak-free.
Down here, the 4 cylinder SUV revolution started right when the US started making the Mazda Pickup based Ford Courier. So the problem with four by Four 4 cylinder engines was pushed back to the Tojo Jap imports to fix. The answer was the Naps Z 2.4 Liter, the SR5 2366 Toyota Surf, the 2555 Astron 90 Silent Shaft Hemi, whic was also used by Mazda before the similar sized 2555 cc 2600 Mazda export engine was made.
Ford kept out of the growing Chevy Luv SUV business and actually backed out of the SUV in 1977 when the Early Bronc made a transition to the emerging F150 platform after a gap year.
Your Bronco II is the Jurasic Park Explorer SUV base that Edsel Ford II felt the little Early Bronco should have become...a Range Rover!
The Land Rover was engineered off the 1941 GP, the CJ Jeep.
The 1968 Range Rover was then a response to emergency services, and took elements of the Austin Gyspy 4 lit{re} with the Buick Olds Pontiac 215 V8 to make it light weight. And that's were Ford always had problems until the 4 liter Cologne V6....a total lack of cubic inches to propel the increasingly heavy roller over and crash worthy U series Sport Utility Vehicles.
The Ranger based Bronco II is an absolute honey of a platform, but weight and appointments needed for off terrain work means a minimum of 2.5 liters just to get a 3600 pound vehicle off the mark. With the old 1.4 turbo to normally aspirated conversion, a turbo 2.5 is a 3.5 liter engine for all intents and purposes if geared right.
Those mentioned Big Fours were the pre V6 Isuzu Trooper or whatever and Mitsubishi Monterreo, Triton and Mazda B2600 based Ford Ranger 4WD. Down here, the Mazda based Ranger got the 3.81" bore spacing Magnum 2 liter Mazda 626 and 2200 engine stretched out to the Silent Shaft Mitsubishi and the stroked Chrysler K engine size...about 2555 cc is where it needed to be for those four cylinder SUV's to work offroad with the 4 X 4 option.
The 5.0 is a great economy engine with light weight and power. Aluminum heads bring it down to under 400 pounds compared to 336 pounds for the turbo equipped 2300.
But just a few hours down hand welding a 3.401 2.5 small journal crank back to 2.3 bearing size and a re-machine and tuft-ridding allows you to drop in another few 9% cubic inches, which is always 9% more torque from idle to maximum torque at about 3000 rpm. With a turbo, its a slam dunk.
Yes, the stock 5.0 has to be the better economy to weight and power option than any other, but the 3.3 alloy head with the right induction weighed just 346 pounds and fits the little Bronco II chassis well, with just an adapter to suit the 5 speed transmission.
Good fortune with your choices.
If you look at the specs of the 2.3L it's easy to see why it works great in lightweight cars, but horribly in heavier trucks and SUV's.
The oversquare design (~3.8" bore, ~3.1" stroke), will let it rev, as long as the cylinder head is dealt with. It's not great for low end torque however.
Someone (Scat, Eagle, etc.) needs to make an inexpensive nodular cast ~3.7" stroke crankshaft in both main journal sizes to fit stock blocks.
The result would be a ~2800cc square design much like the big six.
The problem would be piston ring packaging and rod/stroke ratio with the short deck.
The aftermarket has stepped up to the plate, offering main bearing spacers to drop a small journal crank in a large journal block, just like the small block Chevies.
I always chose to start a 2.5L build with a small main block of early '90's vintage. All of the 2.5 Lima engines ('98-on) were distributorless with the oil pump in the distributor shaft location, but the switch to small main journals took place in the early '90's. There are a few hitches. The power steering pump bracket is missing one machined hole in the block (easy fix with a drill and tap), and the stock pistons are pretty fragile.
Speaking of pistons, I have a 2.5L crank stripped out of an engine that cracked a piston. When Ford created the 2.5L, they switched to a connecting rod that was a bit longer (5.457"). Piston compression shrank to 1.211". When I built my Mustang I used Wisecos, and at the time they were pricey. I used them with the 2.3L 5.205" rod, actually reducing rod/stroke ratio, but the piston and ring pack was stronger as a result.
I think the 200 would be a great engine for the BII. It has the torque characteristics needed for a SUV. I would love to build one with the Offy tri-power setup someday.
Last edited by MechRick on Tue Apr 21, 2020 2:06 pm, edited 1 time in total.
The 5.0L in a truck application needs more stroke.
It's possible to cram a 351 Cleveland crank in a 5.0L block, with a bunch of machine work.
Nowadays, the common 3.4" stroke aftermarket cranks are a simpler option.
A Bronco in it's habitat, miles from asphalt...
swapped ina TTB & 8.8?
What gear in the "end(s)" ?
B) If it doesn't meet my goals and I swap a V8 in, the 3.73 set will work ok.
The right side engine mount interfered with the wastegate of the turbo. The fluid-filled mounts and brackets set farther rearward than the older-style mounts, so I made a switch. I incorporated the mount bracket into the A/C compressor bracket.
The A/C bracket had developed a crack. I welded it up and added an attachment point.
The drain is 1/4" off the manifold, which worries me. I may have to slide insulation over it.
The turbo is about an inch below the plastic evaporator housing. A heat shield is necessary to prevent melting the plastic.
Started it up to check for leaks. There is no downpipe attached yet, it's amazing how quiet the turbo makes it.
cast pieces from plumbing for the red header?
Sounds like our shop...
The head flanges are scavenged from a Ranger tubular factory manifold. They are not quite 3/8" in thickness (metric?). I like the bolt spacers. Allows a longer bolt for more stretch, keeps them from loosening up over time.
The T3 turbo flange is 3/8" steel.
The tubing is 16 gauge 1 1/2" mandrel bent exhaust tubing.
I installed the factory turbo brace under the turbo down to the block. Hopefully that will keep it from cracking.
Joined this forum just for this thread.... Any updates?
Very interested in this project as a B2 owner too!
ford4wd08 wrote: Joined this forum just for this thread....
think that;s enuff. The turbo's just gravy...
Indeed. MechRick is truly one of the best, and his posting/photography is exemplary.
I would love to squeeze a straight 6 into a B2, but feel like that would be ALOT of work....
Y is it all ways so hard to get what U want?
Love the BII w/that 200/250, an AOD and nice 6:1 1st gear in the x-fer.
(B bout 60 or 80:1 which would B quite the off-rder but still a nice st mo`chine).
I bet U could get a good kit for the AOD so it would hassle the multipurpose, I like them, just don't now them well...
Rick has it dwn! Let's watch...