Not long ago, I leaned over the wing, looked into the Stag’s engine bay and all I saw was an abyss.
Nothing lined up.
Installing the proven and reliable Triumph 2.5-litre six into the Stag was the easy part of my summer Stag project. And it is where my good luck ended. Because just about everything since then has been a struggle.
I knew already the 2.5‘s starter and alternator were on opposite sides as the Stag V8, so wiring would have to be fabricated. However, I expected no major problems from the clutch hydraulics, power steering system, throttle cable, radiator and hoses, cooling fan — but all of that and more needed major sorting.
Further complicating matters were the tubular exhaust and my special triple carburetor set up. After a solid week of slow or no progress, I contemplated removing the 2.5 engine and just using a rebuilt Stag V8 I have in another car. But slowly, I began to score small victories and get the project moving again.
One thing I’ve learned about Stag restorations is that the more components you install, the more difficult the car is to work on. Room for wrenches and access to parts disappears quickly. And that’s certainly what happened when the engine and ‘box were installed. That part of the job was easy.
In fact, of all the engine installations I have ever done, none went faster or smoother than mating Triumph 2.5-liter six to the Stag. The engine and manual gearbox were placed on a wheeled dolly. I put jack stands under the car, removed the front suspension, and, after undoing the oil filler cap, the powertrain just cleared the Stag’s front apron and slid directly under the mounting holes in the frame rails.
Then I attached chains to the lifting eyes and connected up the engine to a hydraulic hoist. In less than 15 minutes the engine and box were raised into place and bolted in. I used the front and rear engine mountings from a 2500S and was astounded at how nicely everything fit together in the Stag. All the holes in the frame rails were there and in the exact places. Same with the rear mounts. Two hours later, the Stag was back on all four wheels with its new smaller, but more reliable engine and rebuilt overdrive gearbox in place.
Starting, then, with the power steering system I had to solve numerous problems. The Stag power steering hoses available from Rimmers and others are too long and not shaped properly. I could find no LHD Triumph 2500 hoses, so I had to modify the Stag hoses. My first attempt ended in disaster and I ruined both hoses, an expensive lesson. I got it right with the next set. But the PAS pump is sitting about 2mm off the frame rail and hopefully won’t touch when the engine is running.
Progress came by figuring things out and trying different combination of parts, new, used or from other vehicles to determine what works best and looks professional I dug deeply into my store of spares collected over a decade.
If I just wanted to put the 2.5 in the Stag and get it going with no regard to appearance, I could be done by now. But from the start of the project, the one goal was to make the car not only function well, but have all the mechanical bits really buttoned down and factory looking.
The cooling system, for example, uses TR7 parts that look like they belong in the Stag engine bay. From a 1980 TR7, I used the overflow tank and mount, which fit the Stag’s inner fender well perfectly and look like Triumph put it there. The fan blades are TR7, too. They nicked the nose of the 2.5‘s water pump — until the blades visited the business end of a bench grinder and were shortened about 1/4 inch. The top hose comes from a 1992 Plymouth Laser.
The three-carb set up uses a mechanical linkage from a Federal spec TR6. But the Stag has an accelerator cable. A combination of an adjustable TR3 choke turnbuckle, a Rover 827 throttle cable, and Mini Cooper linkage worked a charm to meld the two systems.
The GM alternator would not fit due to interference with the top of the front engine plate. A high-revving Dremel swooped in and solved the clearance problem. A standard Stag alternator arm worked perfectly with the GM alternator. And it looks great in the Stag engine bay.
Despite some morale crushing setbacks, re-assembling the Stag has been the most fun old-car adventure I have ever had. Some days, everything you touch is magic. Other days, you spend hours fiddling with something like a clip on weatherstrip on the door or the chrome windscreen trim.
It was joy trimming and installing the carpet and installing the rebuilt seats and the rest of interior trim. With the entire dash board assembly out of the car, it was easy to not only fit the carpet, but attach it so that it is tight and stays in place. The key is to place the edges behind and underneath things and use the odd snap and velcro strip. Reproduction carpet kits are not the best fitting, so a tape measure and sharp razor blades, strong glue, and plenty patience is necessary to do a good job.
And so it goes. Each week the list of problems grows smaller and the Stag inches closer to being ready for testing. The lesson here is that when swapping engines, the most difficult part of the job may not be bolting the engine to the car, but connecting up all the plumbing and electrical items so that they look factory installed and are safe, reliable and durable.
Is the Editor of the Parkers website and price guide, formerly editor of Classic Car Weekly, and launch editor/creator of Modern Classics magazine. Has contributed to various motoring titles including Octane, Practical Classics, Evo, Honest John, CAR magazine, Autocar, Pistonheads, Diesel Car, Practical Performance Car, Performance French Car, Car Mechanics, Jaguar World Monthly, MG Enthusiast, Modern MINI, Practical Classics, Fifth Gear Website, Radio 4, and the the Motoring Independent...
Likes 'conditionally challenged' motors and taking them on unfeasible adventures all across Europe.