TR4/4A tr3 body on a tr4 frame

[vrod]

Has anyone ever placed a tr3 body over a tr4 frame. I think this would make a nice car because you have the larger tr4 motor, fully synchronized transmission and rack and pinion steering. Not sure if the wider track would fit within the fenders. I'm pretty sure this would not work with an irs frame because of the spring towers in the rear. Anybody have any thoughts on this.

 

[martx-5]

Yes, it has been done and is a very nice conversion. The procedure is explained Roger Williams book "How To Improve Triumph TR2-4A. On the very early TR4 frames, the body will just bolt right on. On the later ones, the outriggers have to be moved in. It's a very simple cut and re-weld procedure. Wider fenders are available from Revington.

Having said all of that, the improvements you mention can all be done to a TR3 without putting it on another chassis. The TR motor has seperate liners for the bore, so changing capacity is very simple. Any TR4-TR6 tranny will bolt up to the TRactor motor. And rack conversion kits are available for the TR3 chassis.

 

[Banjo]

Triumph produced that very car ,(minus the wide track, they only built a prototype of that).The 62 TR3b was a TR3a body with the TR4 engine and full syncro trans. They were using up the TR3 sheetmetal while gearing up for production the 4 This little overlap was complicated, with only half of the TR3Bs getting all of the upgrades (these ones were also assembled at a different plant) and the others only bieng called a TR3B because of the commission number.
I worked on a TR3 once that had a TR4 rear axle. it fit(just) but it diden't look quite right and it did rub on the fenders just a little. You would definatly need the wider fenders. That would be a cool and subtle mod. that would give an edge to stability.
The irs frame would be more complicated. The TR3 is the same basic frame of the TR4 and the TR4 is very closly the same body as the TR4A IRS (and on up through the 6) so they , with some creative fitting would work. You would want a later TR3A with the flat package tray behind the seats so you would have the space for the upper spring perch in the rear. I've heard of it being done. but I've never seen it. good luck

 

[Alan_Myers]

Hi,

Actually, Standard Motor Co. thought this a pretty good idea, too. You are talking about a TR3A "Beta". There were two such prototypes built about 1960. They were essentially a TR4 frame under a 3A body, although an inch taller main rails were used and the outriggers are were 1" shorter to fit the body. The exterior body differences are subtle, unless the car is sitting next to a standard TR3A for direct comparison. But wider fenders and track make for a very purposeful looking little car! Plus, it can accomodate wider tires than a standard 3.

Triumph built the Beta as a possible replacement for the TR3A. This was before the company had made the final commitment to the TR4 body, while it was still in development (Code named "Zest". I'm sure glad they didn't call it that when it was done!).

The "Beta" should not be confused with the TR3B. The TR3B was a short run of cars built and offered in response to dealer concerns that roadster buyers wouldn't like the TR4, with it's roll up windows, in-dash ventilation and other features that were non-traditional for a sports car in 1961. In fact, the later TR4A solid axle is another example of this sort of thinking and marketing concerns.

There is at least one real TR3A Beta still in existence. I would like some day to build a replica (since I doubt I'll locate the second car, nor ever be able to afford it!), so I've been researching it for a while.

Yes, Revington TR offers both aluminum and fiberglass fenders, doors and rocker panels. They are particularly popular with vintage racers wanting to put heftier tires on their TR3s. Most use the fiberglass, which lack the turn signal eustachion you'd want for a street car, although that would be pretty easy to add. I think the aluminum can be made with or without provision for the turn signal.

But, it's possible to build your own parts out of steel, as was done with the original prototypes, by widening the front fenders 2" at the front, tapering to about 1/4 or 1/2" at the rear. The rear fenders are also about 2" wider. Rocker panels and doors have to be blended into these, of course. The frame rails really don't have to be modified, as the added height really served no purpose, and shortening the outriggers would be a pretty straightforward job.

I think the grill of the Beta differed in some ways, too, but don't yet know the details.

I've got the frame and other parts stashed away. Now I just need the space, time and a TR3A body and engine!

Cheers!

Alan

 

[Geo Hahn]

[ QUOTE ]
I think the grill of the Beta differed in some ways, too, but don't yet know the details.

I've got the frame and other parts stashed away. Now I just need the space, time and a TR3A body and engine!

[/ QUOTE ]

A couple of views of the wiiiide Beta TR3...

Other variations were also tried including the 59 Le Mans cars which were longer (and had 4-wheel discs and the Sabrina engine).

 

[Andrew Mace]

...and if you're wondering where Triumph came up with that grille for the "Beta," wonder no more. (Click on "Attachment")

 

[Alan_Myers]

Hi Andy and Geo,

Interesting info about the Beta!

I'd seen the photos before, but hadn't a clue about the source of the grill. What model is that?

The Beta's front bumper looks like a TR4A, rather than TR4. I wonder what the rear bumper looked like.

Besides the grill, to me the most obvious indication it's not a TR3A or B is the size of the gravel guard on the rear fender. It looks huge!

I'm also unclear on some details about the frame. I know it was made "taller" by welding a section along the main rails. I wonder how this was handled at the front, where they rails are doubled up side-by-side, in the engine compartment and at the front shock towers, or how the minor rails and crucifrom were changed, if at all. Do you know if it had the TR4 style front radiator guard, or the TR3 style rail ends at front?

I find it odd that they fussed with reinforcing the frame to this extent and with some significant loss of ground clearance, then went back to the same height rails, as were used on a standard TR3, when they finally got around to building the TR4. Perhaps the engineers wanted to try a stiffer and/or stronger chassis, then decided it wasn't warranted. Besides, there are much easier ways to arrive at a stiffer and stronger TR3/4 chassis!

I believe the Beta had R&P steering, should also have had 0 degree castor setup front suspension, ala TR3A/early TR4 to roughly CT6000. What engine was used? I wonder if there were any other differences inside or in the drive train. If I ever build a replica, I will use the TR4 axle, I'm sure.

By the way, my TR4 is a '62, but it has some parts that are very, very early. I'm not sure why. I suspect the guy I bought it from in turn got them out of another car a buddy of his had, that was heavily modified with a V8 installed, fender flares, flame paint job, etc. Some "too early for my car" items I've noted are the long-neck radiator (TR3 style, but with 7 psi cap), domed glass on the tach & speedo (but not the smaller instruments) and round-backed seats. I know these aren't TR3 seats, too. Found a tag inside one while pulling it apart, labeled "Zest".

I bet if Standard had decided to build the "Beta" as a production car, they would have had success selling it alongside the TR4.

Thanks for the Beta info!

Alan

 

[Andrew Mace]

Re: tr3 body on a tr4 frame, i.e. TR3 "Beta"

[ QUOTE ]
Hi Andy and Geo,

Interesting info about the Beta!

I'd seen the photos before, but hadn't a clue about the source of the grill. What model is that?

[/ QUOTE ]

The grille is from the Standard Pennant, which was a short-lived restyle/upgrade of the Standard 10 (our Triumph 10 in the States). There were a small number of Triumph-badged Pennants sold in Canada, and the front fender and grill restyle was used on the last of the Standard 10 companions (estate wagon) and commercial vehicles through the early 1960s.

Triumph 10 Estates with that front end were sold as 1960 models in the US and, in fact, were shown in US Triumph price lists as late as spring 1961, alongside the Herald line.