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4 seater TR7

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This is a new one on me.

 

Was it ever a factory option?

 

TR7

 

Regards

 

Peter

No but I seem to remember someone in the register doing something similar many years ago to accomodate his kids. I think you can only do it on a convertible, Im sure it was in the magazine. Alec would probably know.

Stuart.

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Not a very good idea : the body lost his integrity, and the fuel tank is now in the boot, ie less luggages space.

Not even thinking of the wind for the rear passengers (who have no legs, I presume :lol: )...

 

I know it has been made several time, and as Stuart, I remember also an article in TR Action about this modification.

 

Chris.

Edited by Chris59

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Guest Wayne S

Never a factory option but Mark Grinnall made a fair few of these 2+2 conversions back in the day.

 

Many of the home brew ones seem to copy the basic idea.

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As Wayne correctly notes, Grinnall produced quite a number of 2+2 TR7s, in both 4 and 8 cylinder format.

 

An expensive conversion at the time, but well thought-out and comprehensively engineered. Contrary to Chris' suggestions, the body did not lose much, if any, structural integrity - and not much boot space was sacrificed either. Rear leg room of course was minimal, but the rear seats were intended purely for small children - at a time when 2+2 convertibles were few and far between. Wind factor in the back was quite acceptable for kids, an adult would have been buffeted a bit though. As a weekend roadster, or an everyday shopper, a lot of fun - just not enough space for holiday touring. You can't have everything in one modest-size package !

 

In contrast, I've seen a couple of home-brewed 2+2 Wedges that should have been sent straight to the scrappie, more than justifying Chris' adverse observations. Built by morons with no common sense and even less engineering nouse.

 

Anyone looking for a 2+2 TR7 would be well advised to check its origins and documentation carefully, and to inspect with the proverbial toothcomb those structural areas amended in the conversion, as well as all the usual Wedge rot spots . . . . bearing in mind that many Grinnall conversions were 'dipped and stripped', and at least some seem to have suffered from subsequent internal metal seam deterioration.

 

Cheers,

 

Alec

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Interesting replies from Wayne and Alec, thanks guys ;) : I nearly know nothing about "Grinnall", thinking it was only a rear light conversion (lol..) !

 

Do you know a web link to learn a bit more on these cars and their differences with "standard" TR7, thanks ?

 

Chris.

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Guest Wayne S

Hi Chris,

 

I wrote a little introduction to Grinnall on another forum some time ago. Essentially he was a custom car builder specialising in the customisation of TR7s resulting eventually in them creating their own vehicle, the Ramestein. He now makes 3 wheeled motorbikes called the Scorpion.

 

Mark Grinnall converted in excess of 350 vehicles. The idea was that customers brought him there old rusty TR7s and he transformed them into fire breathing monsters, modernised for the early 1990's. The TR7 was an ageing car, already 10-15 years old when Grinnall conversions were at their peak (although some were converedt as early as 1983 when the cars were still under warranty from BL) his customers were enthusiasts that wanted to breathe new life into their wedges to make them TVR beating, fire breathing current sports cars.

Its generally understood from Mark that his first customer conversion rolled out in 1985. In 1982 he was a 20 year old, just sold his first FHC done up after buying from a mates crash damage salvage yard and had just begun his first experiment at putting a V8 into his own DHC at great expense which he later sold to start the business. The 2+2 conversion we have mentioned above started very early on in Grinnalls history and were some of the very first customer conversions he did.

 

No two Grinnalls are alike as the conversion was done to the specification of what the customer wanted and could afford. Some just got upgraded brakes and the V8 engine with no body modifications. 2 of his customers kept the 2 litre engine, but tuned it and had the bodywork modifications made, my purple one was one of those 2.

 

Grinnall’s most famous conversions however combined body modifications: oversized wheel arches, boxed oversized sills, front aprons, Rover SD1 tail lights and colour coded bumpers. He also put in bespoke interior trim, velour or leather with carpeted door cards and vinyl trim on centre cubby box and dash board. Again, there are exceptions to the rule depending on the customers tastes, there are a couple of Grinnalls that used the Morris Ital tail-lights instead and some that stuck with the original configuration.

 

Interestingly my purple 2 litre one also features orange dash lights and electric mirrors...

 

All body modifications are proper rolled steel, welded into acid dipped restored body shells. They are no "bolt on" body kit as they are integral to the strengthening of the car. All panels are blended and de-seamed with fillers to smooth in the lines.

 

Its a mis-conception that Grinnall only did convertible cars. They converted many fixed heads as well.

 

There are no Grinnall "parts" as such as these weren't stock models, they were customised cars to individual tastes. But Grinnall used existing parts from other cars to upgrade. Some basic conversions use most of the TR7 running gear and don’t look dissimilar underneath to a factory TR8. Other more involved conversions such as my red one replaced the front struts with those from a Rover SD1 giving you 5 stud hubs and the SD1 4-pot calipers. Strengthening braces are welded in between strut and inner wing and the sub frame is lowered and used a thicker heavy duty anti-roll bar sourced form either Rover SD1 or Sierra Cosworth.

 

The cars often featured SD1 power steering racks cleverly modified to fit the TR7 sub frame which was bespoke made to Grinnall spec for the V8. The rear end runs a Rover SD1 axle that widens the track, 5-stud hubs again and increases braking power by using Rover SD1 rear drums and handbrake arrangement. There is a Rover SD1 watts linkage at on the back of the axle and the original trailing arm mounts, spring seat and shock absorber mounting are redundant and un-used. Instead Grinnall used thinner trailing links from the Rover SD1 to compliment the watts linkage and fabricated a coil-over damper arrangement (where the shocker sits inside the spring as with modern cars) and this fits between the axle and strengthened inner wheel arch. This is a custom built shocker from Spax and they still have the original drawings from Grinnall to construct these, I know I just bought some.

 

Compomotive wheels were standard either lattice or 5-spoke type and were 15" to fit in the bigger brakes and fill the arches.

 

Engines were anything from tuned standard 8V with gas-flowed heads, inlet manifolds and high lift cam's with sports exhaust and filters (although only two 2 litre cars exist) to standard 3.5 litre V8 from Rover SD1. Some cars were fitted with Rover Vitesse EFI but not many. Usually the 3.5 litre was uprated with blueprinted and flowed heads and high-lift cam on SU's. In my case they also lengthened the stroke and bored the block out to 4 litres and fitted a Holley 390CFM carb. Some later conversions went up to 4.5 litres and beyond.

 

The conversions were n't cheap, the full body modifications could set you back £10,000 and add the V8 engine to that and the bill gets bigger. My red V8 cost £14,500 in 1993 and is a testament to the TR7 that people were willing to spend that kind of money modernising and improving what by then was an old Triumph. For that though you got the car stripped back to a bare-shell, restored and built back up from scratch.

 

Other things to know are that Grinnall were a recognised BL constructor and in their very early days meant that any dealer services and warranties were valid right into the BL Rover and then MG Rover days. Its this fact that makes the Grinnall stand out to many as a TR7 derivative or marque in its own right rather than a "kit - car."

 

In the later days when Grinnall developed the most highly modified of his cars, the Ramestein bodied cars, he was able to obtain from BL a number of original bodyshells. These cars are considered “true” Grinnalls in the sense that they were never TR7s before, they were built and designed from scratch. They were Grinnall’s most heavily modified cars, featuring Volvo 480 front lights and rear lights from a Ford Orion. They even carry a unique Grinnall Cars VIN Number and plate. http://www.grinnall-register.fotopic.net/p50108775.html. Some of these later cars also featured a fabricated fron suspension system that combined the front struts with a reinforcement between the sub-frame creating a wishbone like front suspension setup.

 

The most extreme car was the Grinnall TR-12. This project is detailed on the Grinnall register site but basically entailed using running gear from a Jaguar XJS. The shoe-horned in a race tuned 5.7 litre Jaguar V12 into a fixed head Grinnall. The engine was so large that substantial modifications to the bulkhead were made and the gearstick was actually positioned behind the driver! This car ended its days when it became clear the car was too powerful. Mark Grinnall crashed it into a tree and thus converted it back to a Rover V8. However the car is still in existence albeit in bad condition and has just gone abroad to be a race car. It still has the Jaguar running gear but has a Ramestein front end: http://www.grinnall-register.fotopic.net/c1495101.html

 

Grinnall cars are not known for their detailed records, the most the majority of owners have on their cars are hand scrawled receipts and diagrams. Mark Grinnall no longer has any build records and the tooling for the cars is still rotting away somewhere in Worcestershire. The TR Register now has most of the remaining documents relating to the 350 or so Grinnall TR8s.

 

 

Hope that gives more of an insight

 

Further info and pics on these links:

 

http://www.grinnall-register.fotopic.net/

 

http://www.grinnallcars.com/content/grinnall/ourhistory.html

 

http://www.ss-preparations.co.uk/grin.htm

 

http://en.wikipedia.org/wiki/Grinnall_Specialist_Cars

Edited by Wayne S

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Wayne, what can I say :blink: ?

 

Many, many thanks for this, I learn a LOT about Grinnal.

 

I was VERY far from reality, thinking of only superficial mods :rolleyes: !!

 

Chris;

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I converted my 1st fixed head to have a back seat for the girls when they were Small, used it right up until Layla was eight, floors gave up before they out grew it, just! I did not loose any boot space as a Mini traveler tank on the bulkhead top and even filler lines up, down side it only takes 5.5 gallons :( The other down side was that when they fell asleep you could hear a dunk dunk as you accelerated :D

Andy

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On 9/19/2009 at 4:22 PM, stuart said:

No but I seem to remember someone in the register doing something similar many years ago to accomodate his kids. I think you can only do it on a convertible, Im sure it was in the magazine. Alec would probably know.

Stuart.

I had a 1977 2+2 coupe which was a very well done factory conversion. The number plate was PLH 999R, I was the third owner in 1980. Fuel tank was round, and in the wheel well in the boot. The spare wheel was a proper sod to squeeze in and out! Midgets only on the rear (bench) seat of course

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My last TR7V8 had a 4 seater conversion. It appeared to be very well executed but I could not see the point.  As mentioned the fuel tank was in the boot and not only did it reduce the luggage capacity but also a spare wheel could no longer be carried. The seats could only accommodate very small children and there were no seat belts for them. I’m surprised that it never warranted an MOT failure, but it didn’t.

Rodders.

7A9B0F6A-D727-4185-A4BB-EF8B05BA8610.jpeg

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...The factory made a splendid thing with 4 seats called a Dolomite Sprint

Peter W

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