Tag Archives: aluminum

Triumph TR6 Bumpers

The other day I received a question about the bumpers on bowtie6 so I thought it might be of interest to explore the alternate solution I took regarding Triumph TR6 bumpers. As you can see from the featured image above, bowtie6‘s bumpers are not exactly “factory”. 😉

First Some History

When I originally purchased bowtie6, the original bumpers were part of the deal (if you want to see what they look like, see this gallery on my original website). However, they were in very poor shape: rusted, pitted and dinged up – not very attractive. I did some research on what it would take to “restore” them and quickly discovered this would not be for me, To have the bumpers chromed would be too expensive, the “chrome” look was not for me, and most important, they were way too heavy.

We thought about giving bowtie6 a “commando” look without bumpers. Something similar to what I did on my old Spitfire (pretty cool, huh?) The problem with that was a TR6 looks plain ugly without some sort of bumpers fore and aft.

Another option would have been to go with the stainless steel bumpers now available on the Interwebs. However, when I worked on restoring bowtie6 the stainless bumpers were not available and they too are too pricey.

The Solution – Bespoke Lightweight Triumph TR6 Bumpers

And so, after many hours of design my cousin Jim came up with this design for the bumpers and this is what the front bumpers look like:

: Front bumper

: Front bumper side closeup

The rear bumper looks like this:

: Rear bumper detail

The bumpers are very simple and extremely lightweight, perhaps fragile. They are a “U-shaped” affair, painstakingly shaped and finished smooth. The finished bumpers were powder coated with a matte silver finish.

So How Were the Bumpers Made?

We worked on the basic shape using the original bumpers as a starting point and made cardboard templates. The templates were then transferred to sheets of aluminum and cut with shears. What we ended up at this point was an “L” shaped form. The top “lip” was then shrunk with a mechanical shrinking machine.

Now, before you start calling bullshit on me here, just keep in mind all this cannot be made in one piece! The bumpers as a whole are one unit, however they consist of several smaller sections TIG welded together. The welds were then hammered and filed smooth. This took patience and effort to pull off. Take a look at the following picture…

Shrink and weld marks are visible in this picture

This is the front bumper seen from below. To orient yourself, note the lower radiator intake on the extreme left. If you open this picture and look closely, you can see the shrinking machine marks, hammer marks and welding seams.

Mounting the bumpers to the body is very simple: they bolt straight up to the body panels with a rubber “washer” between the body and the tabs on the bumpers with stainless bolts. This is all achievable because these bumpers are feather light. All the factory bumper bracing that tie the back of the fender to the frame are not used. They are too heavy!

Here is another view of the front bumper from below (you can see the front spoiler):

Closeup of the mounting tab holding the bumper against the body

This picture shows the close tolerance between the bumper and the front nose. We tried to make this as close as possible so it would give a nice finished look. Pay close attention here because you can also see the custom aluminum finishing strip on the radiator intake as well as the grill surround. These were made using the same technique as the bumpers – they are all aluminum shaped by a shrinking machine.

Very close spacing tolerance between the bumper and body

Front grille surround and finishing strip

And now, here are some pictures of the rear bumper.

Rear bumper corner edge

This bend (shown above) took some time to get because of the angle of the rear fender. The front bumper does not have this longer lip and it was tricky to line up with the rest of the body. Remember, the bumper is one complete piece that must fit perfectly. The rear bumpers are also mounted on tabs against the body with rubber spacer washers. Here are the mounts:

Rear fender mount

Rear roll pan mount

And finally, this is a picture as seen from below. For reference, the “button” in the middle of the picture through the opening is the trunk release.

Rear bumper as seen from below

As you can see in the closeups above the powder coated finish turned out very nice indeed. It is as smooth as the rest of the bodywork and gives a very nice, understated look to the bumpers. I did keep a few “imperfections” – I wanted to show these are hand-made bumpers!

Small imperfections (click on the picture for a closeup)

Excuse the bug marks, stains and overall untidiness… But then again, bowtie6 is not a show car TR6 garage queen – she gets driven very frequently!!

Finally, for a twist on the whole hand made bumper concept, check out the rear bumper on my cousin Jim’s TR4 (click for detail):

If you are interested, you can read more about it in this article I wrote about an Ecotec Powered Triumph TR4 in this blog.

Details About an ECOTEC Powered TR4

2 Replies

After the success we had with bowtie6, my cousin Jim and I had many conversations on improving the concept. I remember countless hours of discussions next to the space heater in Jim’s well equipped shop several winters ago. We quickly zeroed-in on the engine: the Ecotec as fitted to the Pontiac Solstice mated to the Aisin 5 speed gearbox would supply a powerful and reliable drive-train. It would also offer a PCM that we could tweak with a laptop. We also decided a Triumph or MG would be a good platform for the Ecotec. Finally, we would subscribe to the ideas that Anthony Colin Bruce Chapman based his designs upon: keep wight at a minimum.

Eventually, we got word there was a local fellow with several cars in his basement that had to be sold Needless to say, Jim and I quickly grabbed our gloves and jumped in the shop-truck and headed out to this fellow’s basement. Sure enough. We found a 1964 TR4 as well as a Datsun 2000 roadster. The Datsun was our first choice since it is the more “exotic” of the pair however it was missing entirely too many parts. Jim decided the TR4 would be the best choice. A few days later we arrived with a trailer and brought the TR4 home.

I could write about all this for hours but I think you want to see pictures and not a bunch of words, so let me fast forward to the present and show you what Jim’s TR4 looks like today. Unfortunately I cannot cover the entire car in one article; I’ll break this up into several. Today, I’ll start with the outside. After all, beauty can’t be only skin deep, right?

As you can see in the picture above, the nose of this TR4 incorporates many subtle changes. For starters, the turn signals are gone. They are now hidden behind that hand-made aluminum grill. The front bumper is also gone and the oval air inlets below the grill have stainless mesh behind them. Finally there is a hand formed “air dam” with two “nerf” bars on the roll pan. Jim likes his “nerf” bars – Steve if you are reading this, I am sure you will agree with me. 🙂

The picture above shows the new bonnet. When I mean “new”, I mean this piece was formed entirely from aluminum. If you look closely, you will see the “bulge” is missing – I guess it is a matter of choice but this is the way Jim decided to build the bonnet. The trick to making this bonnet was piecing together several sections. They were all carefully formed on the English wheel and TIG welded together. The following gallery shows what the back of the bonnet looks like.

But… Before you start clicking on all these pictures take a look at the first one of the set. There is a small recess, wide enough for two fingers to be used to lift the bonnet once the latch is released. Pretty cool, huh?

Next you can see the backbone of the bonnet. This backbone is also made from aluminum and is not welded, instead it has been bonded to the backside of the bonnet with automotive epoxy glue. Finally, take a look at the third picture. If you look close enough, you can see some of the hammer marks left from when Jim formed the headlight bulges. Yes, all this was carefully welded and shaped just like it in the glory days of hand formed bodies.

The next gallery shown above, displays the hard top Jim made for the TR4. This top is entirely made of aluminum and just like the bonnet, is extremely lightweight. Again, many pieces formed by hand and on the English wheel, TIG welded and carefully finished. If you look at the surface of the top (see second picture) you will see ridges formed by Jim’s Pullmax machine. These ridges are there to add strength and to prevent the top from oil-canning. Finally, to keep weight down Jim used thin Plexiglass in the windows instead of glass. Oh and the side windows open; Jim made special hinges to allow the side windows to pivot. The following collection of pictures shows what the top looks like from the back and from the sides.

The back third of the top has a small taper. It is also formed in such a way to give the rear glass a curved look. At first, one would think this would hinder visibility but the seats are very low in this car, and outward visibility is excellent. I think it looks very cool!

Finally is this picture from the back of the car. The bonnet is also different from stock. Yep, you guessed it. It is also formed from aluminum. Jim made a similar backbone frame for it and it is extremely lightweight. As if that were not enough, take a look at the rear bumper. This one is not as wide as the ones Jim made for bowtie6, but is just as lightweight. This bumper also is different from mine in that it’s finish is made by simply wiping it with ScotchBrite. This gives the aluminum a muted, matte finish.

I hope you have found this interesting. I’ll have more about Jim’s TR4 in future articles, so stay tuned! 😉