During an engine swap, sometimes your plan takes a detour…
This week, I’m going to review the two major issues I encountered while installing the fuel injected Scorpio engine into my Mustang II, but before that, let’s cover the (mostly straightforward) modifications I made to the charging and starting system.
The engine block matches up- The accessory drive not so much…
I had hoped to use the Scorpio alternator mounting brackets in the Mustang, since I wanted to keep all the Scorpio accessories, including the power steering pump. The Soul Survivor had been equipped with power steering when new, but a previous owner installed a manual rack. I wanted to restore the power steering, but to do so I needed hydraulic pressure.
Alternator mounted to the 2.9 V-6 using the Ranger brackets.
However, this was not to be. The passenger side frame rail interfered with the alternator when mounted to the Scorpio bracket. The fix was pretty straightforward- I found a bracket and alternator off a 2.9 V-6 which moved the alternator up. The “new” alternator also included an internal regulator, so I bypassed the fender well mounted regulator.
Nothing very complicated- The factory solenoid becomes a control device for the new starter.
The 2.9 engine also included a starter mounted solenoid, instead of Ford’s system using a remote mounted solenoid. Rather than rewiring the existing starting system, I ran battery power directly to the starter solenoid, and then connected the starter’s control terminal to the remote solenoid.
Braille battery- Note the clearance between the battery and the exhaust manifold.
Finally, I used a Braille battery in to replace the Mustang’s Group 26-R battery. Due to the tight confines of the engine compartment, the factory battery sat right on top of the exhaust manifold. The smaller Braille battery still handled the starting duties, but allowed air space between the battery and exhaust manifold, and also allowed better access to the back cylinders on the passenger side.
The 2.8 manifolds (top) had 2 common ports and a different bolt pattern .
Speaking of exhaust manifolds, the exhaust system for this exchange ended up being the most expensive part of the project. As I wrapped up the project, I wanted to drive the Soul Survivor to the Mustang’s 50th anniversary celebration in Las Vegas. As often happens, I was under a considerable time crunch and could not use the original manifolds on the 2.9, since Ford modified the exhaust outlet spacing on the newer motor.
As you can see, the steering U-Joint has a smaller diameter than the factory joint.
On the right side, the Scorpio manifold almost cleared the frame rail, and I only had to grind a little material off the manifold flange. On the left side, the Scorpio manifold interfered with the steering column. To address this, I acquired a manifold out of a Ranger pickup. The manifold cleared the steering column, but the isolator (rag joint) rubbed against it. A smaller universal joint for an aftermarket Mustang II rack solved that clearance problem.
Whoops- There goes my budget! When dealing with fabrication projects, never tell a shop you’re working on a critical deadline
With the exhaust manifolds in place, I took it to a muffler shop for a custom exhaust system. I should have shopped the job around, and I made the additional mistake of mentioning my time crunch. All told, the exhaust ended up costing me more than the donor car (to be fair, I did get that car for a song…)
An example image showing the difference between Front and Rear sumps
The last system I’ll cover is the oiling system. It was a major pain, mostly because the Scorpio engine used a rear sump while the Mustang II came with a front sump.
Same basic block, two different cam drives….
In addition, the 2.9 engine used a roller chain camshaft with hydraulic lifters, instead of the gear driven solid lifter cam in the 2.8. You wouldn’t think the camshaft drive would affect the oil pump but life is a learning experience…
During the swap, we pulled the 2.8 engine and stripped off the parts we planned to re-use. This included the oil pickup tube and oil pan, but not the oil pump.
Similar but different. The 2.8 pump has the smaller intake port.
However, when I tried to mount the pick up tube to the 2.9 pump, I discovered the pump inlet did not match the tube. As this picture shows, the 2.9 pump inlet uses a three bolt flange with a larger inlet (compare it to the 2.8 pump with it’s smaller inlet and two bolt flange design). Also, the 2.9 pump was slightly taller and interfered with the Mustang oil pan.
More differences- The 2.8 shaft is on top, 2.9 shaft below.
Engine swaps are not for the faint of heart- The 2.8 pump bolted up to the 2.9 block so I swapped over to the old style pump and discovered the 2.8 pump used a hex driveshaft while the 2.9 used splines. Therefore, the Scorpio distributor could not drive the Mustang oil pump.
They sure LOOK the same…
To solve this problem, I sourced a Ford TFI distributor out of an early eighties 2.8 Ranger pickup. The distributor control module matched up to the the Scorpio wire harness, and the distributor drive mated to the hex shaft. The housing was identical to the 2.9 housing, so I expected it to drop right into the block, but after twenty minutes of effort, it appeared I was wrong.
Over the span of time, I’ve learned to walk away when things don’t come together. The problem is typically some factor I’d neglected to consider, and until I identify that element, further effort will not generate any positive results.
Mentally chewing on the problem during my drive home, I suddenly realized root cause lay in the updated camshaft drive. You see, a gear drive spins the camshaft in the opposite direction of a chain drive, and as I showed you, Ford changed the camshaft drive for the 2.9.
Eureka!
Sure enough, comparing the 2.8 and 2.9 distributors, the drive gear tooth angle did not match up. I swapped the 2.9 gear onto the 2.8 distributor, and it dropped right into the engine.
Sigh…
Once I bolted everything up the car fired up and drove quite nicely EXCEPT… During sustained operation above 2,000 RPM, the valve train stated clattering like a Model T. It seems the hydraulic lifters in the 2.9 required more oil flow than the 2.8 pump could provide. The pressure gauge showed OK pressure, so I drove up to the Mustang 50th Anniversary celebration with my fingers crossed.
Sorry- No pictures. I may have been a bit aggravated at this point ;-), and did not break out the camera.
The engine survived the trip without damage, but once I got back home pulled the motor, modified the oil pan for pump clearance, and fabricate an oil pickup tube.
That wraps up the engine swap on the Soul Survivor. As I noted earlier, despite these issues I’m very satisfied with the final product. Next week, we’ll take a look at adding cruise control to a car without this option.
Wow, you drive home how much driveway engineering is required for a swap, even one that involves the same manufacturer and engine family. No wonder the 350 swaps are so popular, as pretty much all of the hard work has been done by others.
Isn’t that the truth about stopping when things hit a wall. I cannot remember the number of problems I have solved when I was supposed to be thinking about other things.
The phrase “Sleep on it” is a good one.
I learned that after half a century of wanting the answer right damn now.
While the 2.6/2.8 and 2.9/4.0 are technically the same family the 2.9 stopped short of a clean sheet design but as shown very little was the same. The SOHC 4.0 was even less related to the original.
It’s always the details that end up biting you in the rear. But sometimes you do get lucky. When I did the 302 swap in my Ranger, I found I could use ’79 Fox body engine mounts by merely swapping them side to side and drilling new holes in the crossmember. On a 4×4 swap, some of the biggest expense can be the transfer case adapter. Not here. My truck had a 4 speed, which is the same length as the C4/C5. I went to Ford and bought the output shaft and tail housing for the C5 and put them in the C4. The cost? Less than $200 for both! And OEM quality to boot. At the time, Advance Adapters selling their adapter kit for $500. T-case is in stock location. Pays to research. And I thought just the 4.0L had a timing chain.
Well, there’s a 4.0 push rod motor and a 4.0 SOHC motor.The push rod motor uses the same camshaft drive as the 2.9, but…
The SOHC motor uses a traditional timing chain to turn a jack-shaft mounted in the original camshaft location, and then uses a secondary chain at the front of the engine to drive the camshaft in one head, and a chain at the BACK of the engine for the other camshaft.
The SOHC setup has gotten some bad press for timing chain issues, partly because the original chain tensioner design had issues, and partly because this work pretty much requires engine removal.
Hope you keep that car forever. An old Ford parts guy I know calls many a 61-66 F-100 Frankenstein trucks because they have so many non-original parts on them. From doors with incorrect VINs, to dash, to engine and so forth. Well this is certainly a Frankenstein engine and whoa to someone who could acquire this later and needs to work on the engine not understanding what they have and from where. They will need a complete diagram with parts numbers so they don’t confuse the hell out of any ordinary parts counter guy and that can easy to do today.
“whoa to someone who could acquire this later and needs to work on the engine not understanding what they have and from where.”
Once I take a project of this magnitude, it’s a given I’ll keep it for life. Not only are the parts all vehicle specific, there’s no service info identifying electrical harness wire color or engine control component locations. Jay Leno’s shop could keep it going, but I doubt Jay wants a ’74 Mustang II.
Truth. When I start to get frustrated because a project’s not going right, that’s when to figuratively kick the clutch pedal to the floor: put down the tools, walk away, wash up, and go do something else awhile. Otherwise stuff’s going to break.
Who makes those green(!) belts we see driving the alternator?
“Otherwise stuff’s going to break.”
Exactly right.
“Who makes those green(!) belts we see driving the alternator”
Gates- They call their top products “Green Top” or “Green Stripe.”
Huh. Guess it’s been awhile since I bought V-belts; last time I looked at a Gates Green Stripe belt it had a few green stripes, but aside from the letters and numbers the rest of the belt was black.
I admire your ability to stick with this project despite all of the pitfalls discovered along the way. I was part of several engine swaps back in the day and things were much simpler before all the electronics and other assorted advances became a standard part of every vehicle. One could swap out the engine on cars from the fifties/early sixties pretty simply, one just removed the hood, took off as much of the grill work as seemed necessary, unhooked the wiring and removed the appropriate bolts, and then sourced some logging chain and a strong branch on a nearby tree. Putting the replacement engine was a little harder because you had to make sure everything fit and lined up properly but the whole process seldom took more than a day, at most a long weekend. Obviously some engine swaps were more complicated than others but as long as the replacement engine was from the same brand it didn’t take much effort to get it in place and make it work.
Dave Skinner, my continued admiration to you for your accomplishment, and your unselfish sharing of problems solved along the way.
And I’ve gotta tell you again how amazing “factory” it looks. And I see you’re gonna stick with the car—great!
I am afraid to keep reading this.
I’m more and more impressed after each installment of this saga. The idea itself impressed me at the beginning and then how you managed to make it all work and engineer around every roadblock after initially sort of giving the impression that it shouldn’t be too difficult…Very nice work and an excellent chronicle of the task!
I am always impressed with folks who not only do their own wrenching but also modify and make parts to fit their needs. I’ve done that exactly one time I can think of, when I fabricated a wood piece in the shape of a broken plastic piece that connected the HVAC temperature control lever to the door that opened and closed to allow heat in the cabin. Perhaps I should also count the time I changed the dash lighting from pale GM green to red. Since then I’ve changed spark plugs, packed wheel bearings, and other basic DIY jobs, though I’ve mostly stopped doing even those as I get older and cars get more complex. Mixing and matching alternators and timing chains is way beyond my skill set.
I sure hope all this is worth it! The continuing saga makes VW engine swaps like the 1300 in my ’66 Bug to a 1600 single port seem simple!
Always fun swapping stuff around, and it rarely goes to plan, manufactuers make small changes here and there and you have to work around them, you know your car inside out anyone else sourcing parts for it would run into major problems,
My pet car has the same issue I know what everything came from and why but it isnt obvious just looking at it, the body shell rear axle housing and brakes are true to label but nothing else if I sell it I’ll need to provide a detailed list.
Love reading these articles! Very impressed with your perseverance and problem solving. I’ve just finished changing out the front suspension in my Ghia to a 2” narrowed beam including narrowed torsion leaves, track rods and sway bar and replacing all the bushes, bearings and ball joints. New dropped spindles and conversion from 4 lug to 5 lug bolt pattern, too. As all these pieces are available from the aftermarket it’s nothing like as difficult as the reengineering job you have accomplished- that’s a whole other level of wrenching! Taking something apart and putting it back together again teaches so much about how various systems work and as a VW “virgin” I learned hugely about how the car works. The British, American, Italian and German vehicles I have worked on each have their own “flavors” in terms of construction and air cooled VWs confirm this with a logic of their own. I am understanding and bonding ever more with this strange little car the more I work on it.
I love the sense of satisfaction that results from working on a machine and improving it (when the result is successful!)….
I’d love to see more “hands on” articles like Dave’s n CC.
Hats off to you Dave and many happy years of motoring with your Frankenstang!