With most classic cars an engine swap will decrease its value and the number of possible buyers significantly, especially when mixing and matching brands. If your swap recipient is a full classic or rare car you might need to seek the services of a witness relocation agency. Where a big V8 lump in a Jaguar XK120 would be considered a bit anti-social, almost no one would have a problem with a adding a couple cylinders to a Triumph TR7. Heck it would probably increase the value for most. Our example today is perhaps a little too far gone though.
The history of Triumph’s slant four cylinder engine is a little convoluted and often misunderstood. Some folks will claim it is “the Saab engine”. Perhaps they are Triumph apologists trying to deflect blame for this head gasket popping wonder but this turkey was definitely Triumph baked. With some rather aged engine designs in the fleet a Triumph team led by Lewis Dawtry and Harry Webster embarked on a project to develop a new, more modern overhead cam engine. Engine displacement was designed to be very flexible so that it could accommodate displacements from as low as 1.2 to over 2 liters. One can speculate that Triumph perhaps also hoped to replace the Spitfire’s engine, whose design dated to the 1953 Stardard 8’s 803cc engine. Pure speculation, but what is quite clear is that they tilted the engine at a 45 degree angle with an eye to make a V8 possible as well.
When the infamous Triumph Stag was developed starting in 1964 it was originally intended to use the straight six engine as fitted to the TR6 and 2000/2500 saloons. When its role moved from sports car to touring car, a larger V8 engine was deemed necessary. As planned, essentially two Triumph slant fours were added together to form this new V8 engine. The initial plan for the Stag’s V8 was a displacement of 2.5L. Coupled with fuel injection, this would have given the Stag the performance it needed. But when the Bosch fuel injection was tossed in favor of twin Zenith-Stromberg carburetors, a last minute boost in displacement to 3.0L was needed to retain adequate performance. Unfortunately the bigger bore needed for the larger displacement cut into the water jackets which contributed to the Stag’s cooling issues.
So where does Saab fit into this story? Saab had their own two stroke motors, and later augmented with the Ford Cologne V4. Neither engine was deemed to be suitable for the upcoming bigger car. Saab had contracted with the well-known UK based engineering firm Ricardo to build them a suitable four cylinder engine.
Unfortunately, Ricardo found themselves in a bit over their head designing an engine from scratch and was unable to deliver. Ricardo also contracted with Triumph regularly (but not on the slant four motor) so they knew of its existence and that it would soon be ready for production. Ricardo then put Saab and Triumph in the same room and a deal was hammered out to use the new engine in 1.7L form for the upcoming Saab 99.
Unlike most engines of the day, the new Triumph SOHC four could be used with an electric rather than crank driven fan, which worked well for Saab’s front wheel drive application. Perhaps to keep the Saab tradition of longitudinally-oriented engines, Saab mounted the Triumph engine “backwards”, with the output shaft and clutch gearbox in front, and with the transmission directly under the engine (the top of the transmission doubles as the engine’s oil sump).
Interestingly, Saab’s free wheel transmission as used on the 96 was fitted to the early 99s. Triumph built the engines initially, but Saab specified a specially tuned Zenith-Stromberg CD carburetor. In 1971 displacement was bumped via a larger bore to 1854cc, but Saab was increasingly unhappy with the quality of the engines delivered and brought the design in house. From 1972 to 1985, the Saab engine increasingly diverged from the Triumph design. Fuel injection and a turbocharger were fitted on some variants. Another interesting fact is Saab briefly considered using the Stag’s V8 engine to power the performance variants of the 99 and even built a few V8 equipped prototypes. Saab eventually settled on turbocharging instead, and probably felt like they had dodged a bullet once the Stag’s issues came to light.
Getting back to the TR7 (CC here): it was launched in 1975 with a 2.0L (1,998 cc) variant of the slant four engine. Horsepower was a competitive 105 for the home market and 92 for North America. Sadly the more powerful 16 valve version from the Dolomite Sprint was never fitted. Given that it had seen duty for a few years in Triumph’s own Dolomite 1850 line one would expect any issues to have been worked out already. As many a TR7 owner knows that is simply not the case. The engine used an iron block with an aluminum head. Not a terribly uncommon thing to do in the 1980s but still somewhat novel for British car at the time.
Unfortunately for TR7 owners there are several factors conspiring against long engine life. First of all many owners (especially in Britain) filled the cooling system with straight water rather than coolant which lead to corrosion with an aluminum head. The quality of the casting on the head itself was not high so they had a tendency to warp if overheated. The timing chains can stretch, the water pumps can die and fans can fail. So all sorts of cooling problem then. Blown head gaskets were a common complaint and to add insult to injury the retaining studs on the head are set at an angle which gives all sorts of grief and complication when replacing the gasket.
The TR7’s problems didn’t end with the engine of course. The early units were fitted with a four speed gearbox shared with the Dolomite but also Morris Marina. It was a rather weak and uninspiring unit. The later cars (optionally starting in 1976 for North American, 1978 for the UK and later made standard) had a fine Rover five speed as well as a stronger rear axle.
Quality issues abound on the early cars with TR7s being a poster child for the results of militant labor relations. The early cars were built in the Speke factory and almost all have a 4-speed manual or a 3-speed automatic gearbox. Visually the early cars have TR7 script at the front on bottom of the bonnet/hood. The rear has Triumph in smaller letters followed by TR7 in large letters on the trunk lip. These are to be avoided as the bottom of barrel build quality wise unless they have been lovingly sorted.
Next up are the Canley built cars which can be identified by the large wreath logo on the slightly revised bonnet/hood with Triumph written in the middle. The long awaited convertible arrived in 1979. Production again moved for 1980 to Rover’s Solihull plant. These cars can be identified by the small raised badge on the hood/bonnet. The Solihull built cars actually have pretty decent build quality but it was too late by then as the TR7’s reputation was cemented in as proved by its common appearance on the worst cars ever lists.
This particular car is an earlier fixed head coupe with its troublesome engine tossed away. A friend of mine owned this very car a number of years ago. It has a Ford 2.8L V6 and C3 automatic swapped in that no doubt provided a healthy boost to both torque and reliability. The story he told me was the car was converted professionally by a local British automotive shop a number of years back (well previous to his ownership). I strongly suspect it would have been sometime in the 1980s as the Buick 3.8L V6 was offered in kit form later and took off as a much more popular swap option.
He only drove it once and that was one the way home from purchasing it. The route took him on the very busy and fast Deerfoot Trail in Calgary. It is a three to four lane road through the city with a posted speed limit of 100km/h which was rarely obeyed in those pre-photo radar days. Why all the back story on the road? Well, to set the scene for what happened next. He was driving it home along the Deerfoot testing out the V6’s improved acceleration when the steering column completely dropped in his lap. The experience was so harrowing that it got towed straight to his storage yard and it hasn’t been driven since.
You can just see the zip ties holding it in place currently.
So there you go – a write up on the TR7 that didn’t include a reference to the famous tag line “The shape of things to come” or moan about the rather subjective area of styling. I happen to like the look of the coupe but there is no accounting for the taste of the majority, I suppose. The engine may have been troublesome as shown by Google’s first suggestion when you type “Triumph TR7 engine” is “Triumph TR7 engine swap”. You may have also hit rock bottom engine wise when you go shopping for a Pinto V6 to source an engine! But I suspect this one was quite a fast and fun little beast back in the day once that V6 was installed. I’d just prefer to take mine with a clutch pedal.
Proof you can’t polish a turd
One of these guys showed up at my father’s scrapyard retrofitted with a Chevrolet 229 V6 with 2bbl carb. The car was junk but the engine looked like it belonged there: it was not rigged-up & probably would have been a fun little ride.
If you could keep the steering column intact you could have the start of a regular college industry. Sort of like the sbc and jag. Had a friend with one of those. He said the only way to keep a jab running was to drop a 350 in it.
Nice British Camaro ya got there…
I’ll bet one of these with a Buick 3.8 would be a lot of fun, although it probably messes with the weight distribution a fair amount. I was never a fan of the TR7, just from its looks. By the time these came out, I had in my mind what a proper British sports car was supposed to look like, and this was not it. The quality issues only added to the styling problem.
It is funny that something as minor as a steering column hanger would sideline the car. I guess your friend was just not cut out for 1970s British car ownership. But then, so few people are. 🙂
I was thinking the same thing: spend all the money and then park it instead of bolting the column back? Must have been traumatic.
Well he owned many, many other cars at the time. Probably 30-40 classic cars all in similar sort of shape. Bought cheap and then stored. His “driver” classic is a big ’59 Cadillac sedan
There were some preproduction TR7 Sprints with the 16V engine — exactly how many is a little unclear (several sources authoritatively claim contradictory figures), but I’d call it “a couple dozen.” The Sprint was fully intended to be a production model, in between the base car and the V-8, but when Michael Edwardes decided to close Speke No. 2 and move production, the project was dropped. Some of the early-build Sprints did escape into the wild and I’m pretty certain some owners have created their own by installing the Dolomite Sprint engine.
It’s a shame the SOHC V-8 wasn’t better sorted by the factory. Setting aside its reliability problems, the Stag engine was really not a bad design. The execution, however…
There was a time when the Ford 2.6 and 2.8 were popular for swapping into all sorts of vehicles that had been powered by 4cyls. There weren’t many other available options for a V6 in the 70’s and early 80’s. Yes there was the Buick V-6 but being a 90 degree unit they were much wider. The Chevy 2.8 did come along but it quickly earned a poor reputation.
I read somewhere that the main problem with the British-built slant 4 engines was that the cylinder heads were too “green” ( fresh) when they were machined. In the same way that when BMW wanted to turn their 4 cylinder production engine into a turbocharghed F1 motor they didn’t use new engines but old “matured” ones that had been returned for re-conditioning.
Ive seen most of this before but how is it possible two 4 cylinder engine blocks of 1850 have capacity problems at 3 litre, I was always told it was a foundry fault and engines were built and installed still with casting sand in the water passages. I see some daily dunger Stags here so the problems can be solved after market. That and the TR7 should have been fitted with the Rover Buick V8 from day one, a great opportunity missed.
There was a TR8 with the Rover/Buick V8 but I think they were all left hookers and went to America
The original plan was for the TR7 to get the Rover V-8 about a year after launch, followed by the 16V Sprint engine. However, the launch was delayed until early 1975, by which British Leyland’s finances were well and truly knackered — the Ryder Report was published between the TR7’s U.S. introduction and the European debut. Since the company didn’t have any money to spare, a lot of projects were pushed back and then the strike and closure of Speke No. 2 delayed thing further. (The same happened with the convertible.)
There were a few right-hand-drive TR8s — something fewer than 60 — with no catalyst and two carburetors instead of fuel injection. However, shortly after the RHD TR8 was announced, BL decided to close Canley and was still trying to decide if there was enough money to facelift the TR7. There wasn’t, TR8 sales weren’t good even in America, and the company decided to pull the plug.
Oh come on… a falling steering column could happen to anyone! What’s the big deal?
I must be the outlier here, as I have always loved the shape of the TR7/TR8. I have seen a number of these things with the Buick V6 swap, I don’t believe I’ve ever seen one with the Ford V6 swap.
Nor have I ever run across one with the 60 degree Chevy V6, but often thought that would be a good swap, too. I wonder what it would take to swap in a later one, like a 3.4L HO (185 HP as fitted to mid 00’s Pontiac Grand Ams) or the 3.9L (200? 210? HP)? I would think the fuel injection system might be a bit of a challenge, but I know there’s aftermarket support for all kinds of set ups…
I guess it’s like so many other things, just add money… Ha!
Everything ya need to know about a GM V6 swap.
http://www.johnscars.com/tr7/tr7new.html
Plus a Google search shows swaps with Mazda rotaries, Toyota I-4 and V-8’s, Saab turbos, chevy, buick, and rover v-8’s of all kinds. The possibilities are limited only by your check book, time, and abilities.
I called them “The shape of things that break” from experiences of owners I knew.
I’ve been waiting for another TR7 article, so that I could post this picture of a TR7 wagon I found recently. Apparently it’s a TR7 Tracer, modified by the team at Crayford. It makes the standard TR7 look rather like a ravishing beauty by comnparison:
TR7, Well we love our 7. bought it over 15 years ago from a fellow in Seattle. It sat for like 8 years in a field with horses in Enumclaw Washington. The streering was frozen and this made an experience towing it out of Seattle, which require us to rent a dolly, rather then use a tow bar.
It did not take long to start car, I soon repaired the diaphrams and made adjustment to the Carbs. I put Power steering fluid in the rack and freed up the steering and we were off and running. The motor sings along on the freeway, in fact I have driven it three times to Seattle from Grand Forks N.D. without difficulty. Sorting out the clutch fluid boiling took some time to figure out. After replacing all compnents with new, the solution was to wrap the exhaust with fiberglass.
We drive the car in summer and even though it needs paint, rust is not a problem on this car, we have taken it to a few car shows and people seem to like it well enough. Its really been a good experience and did I say i paid like $250.00 for the wee beast? Somebody must have done a lot of work on the engine as it has performed trouble free since we purchased it. It always starts and is a blast to drive.
It realy deserves a paint job,its been kind to us and after 15 or so years of driving we would buy another should we find one cheap.
Ebay has brought us another TR7 drop top this time without an engine? Price $200.00 So, what engine should I put in the beast? I think a US or Japan brand. We have Toyota 22R motors waiting for rebuilds and A COUPLE of AMC six cyl.One 350 Olds and a Cadillac 500 🙂 Anyone got experience with this
Hey Michael; I bumped into your post after stumbling into C C. How are you , and the 7?
Having owned a few of these I can say that a lot of this little car’s bad image is to be blamed on the early examples. I presently own two of the 80′ model Spider editions. Both are roadworthy but I can almost guarantee that if I wanted to drive either one this weekend, I had better be prepared to fix something before I leave the driveway. I would probably get back home without any repairs on the road but would expect to work on it again before the next trip. Never anything major but always something. Typical British car in other words.
If you are looking for a 7 to buy, stay clear of all models except the one’s built in 1980 with a vin number starting with TPV. Also check that the overflow bottle is on the drivers side (US models) and that the ignition system is made by DelcoRemy. If the odometer is at a multiple of 60 thousand, get ready to change a head gasket. Trust me on that one. Another thing, if the Zienth carbs are not working really well, get ready to replace them with a couple of Webber down drafts. One of my Spiders still has the original carbs and they run rather well but not near as smooth as the other with the Webers.
I did a motor swap in an older 7 once. I slid in a Nissan V6 with a 5 speed from a 300Z. I used a 1987 VG30 but the upper plenum caused me to have to relocate the hood latch. I never finished this project because of a divorce, sold it to help pay the lawyer, so I can’t say how it turned out. I do have another VG30 from a 1988 200SX (yes, a few 88 200SX’s came with the V6) that I plan to use in one of the Spiders at the next head gasket change interval. The SX upper plenum is much smaller than the Z’s.
A coworker of mine had a TR7 roadster. He noticed that when he cornered, there was a loud bang in the left rear of the car. The dealer said everything normal. Gary started pulling down the interior trim behind the seat and made a discovery: the wheelwell stamping and the fender wheelwell arch had never been welded together and it was these two parts shifting that was producing the bang. Took the car back to the dealer, and was told “that is not a defect in materials or workmanship” He had to go to Triumph to make his point that a car not entirely welded together was indeed a defect in workmanship, and finally succeded in getting the welding done.
Last time I talked with him, in the early 90s, he still had that TR7, and it had been joined by a TR7 coupe and a TR8.
Does the sub frame have to be removed to pull a buick 231 v6 out of the TR7? Thanks
i have a 76 TR7 my older brother built and it has a 350 400hp chevy with 4 speed automatic
And its a wild child and great fun to drive and everyone that sees it loves it
You never know that engine is under the hood if a little of the air cleaner sticks,paintec same color so really dont even notice it
i have a 76 TR7 my older brother built and it has a 350 400hp chevy with 4 speed automatic
And its a wild child and great fun to drive and everyone that sees it loves it
You never know that engine is under the hood if a little of the air cleaner sticks
out,painted the same color of the car,the entire car is white so really dont even notice it