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Since I am a newbee here, let me first introduce myself. My name is Mike and I live in Willits California which is 150 miles north of San Francisco. My main squeeze in automotive pursuits in recent years have been Triumph Spitfires and lately the Spitfire variant, the GT6. I currently own two Triumph drivers, a 64 Spitfire MK1 and a 73 GT6 MK3. I have a garage full of chassis engine and suspension bits from these cars.

Yesterday I drug home a rusted out 69 GT6 Plus with rotoflex suspension in the rear. Triumph briefly introduced rotoflex into the GT6 to replace the earlier swing axle suspension. Unlike the swing axle, rotoflex is fully independent suspension. It utilizes a lower wishbone link and a cross spring upper link with a single trailing link on each side to keep the axle lined up fore and aft. A rubber doughnut outer flex link on the half shaft provides articulation at the outside corners while a u joint on the inner side of the half shaft. provides articulation there.

I am thinking of building a 7 like car utilizing the Triumph Rotoflex chassis as a donor. Spitfires and GT6's already have a coil over system up front. I'm not sure of drive train yet. I have Triumph straight 6 and trans , Spitfire 1300 small bearing motor with trans and Third Gen Camaro 2.8 V6 with T5 trans already in my pile of "bits to work with on this project. My thoughts currently are to set the car um initially with the early Triumph 1300 at least until I get her through California DMV inspections and perhaps later switch to the GM 2.8/ T5 combo. Anyone have any ideas or points on this?

Mike A
Willits California
64 Triumph Spitfire MK1
73 Triumph GT6 MK3
01 Miata MX5

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Nor Cal Mike
Willits, CA

The rubber doughnut also provides lengthwise flex( or plunge?). You'd want to replace those they should be available, still used in older Formula Fords for instance. You don't want those to break and let that halfshaft start spinning around.

I'm not sure it makes sense to go from a 1300 motor to a 2.8, so far as the diff, halfshafts etc. go. Maybe a bunch of the rest of the suspension would be usable. THe GT6 were nice cars.

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The GT6 motor put out HP in the low 90's range. I would guess that is probably the outer safe range with the GT6/ Spitfire pumpkin without babying it a little. I'm guessing the Camaro MPI 2.8 to be in the 125 HP range but I will have to check. I'm thinking that 125 HP isn't too unreasonable for this car if I don't run it too hard.

The rotoflex donuts are readily available through several Brit car dealers here in the states. I have read of folks machining TR6 axles to fit in place of the GT6 axles. That would eliminate the donut but would likely put more pressure on the diff since the cushion of the donut would no longer be there.

I too have seen the Formula Fords running the rotoflex donuts at the SCCA Vintage Classic races at Laguna Secca.

This GT6 sheet metal is rusted beyond repair in my estimate. It has been sitting in the salty air about a 1/2 mile from the ocean for a bunch of years. That is why I am considering using the chassis for this project. The triumph uses a pretty light weight back bone type chassis that runs just under the drive line similar to the tunnel truss on 7 type car. The sills of the body supply the remaining stricture on the outside of the body. I am actually thinking of simply adding the 1inch tube cage structure and 7 body work around the outside of the existing Triumph chassis to replace the stock sheet metal.

The stock wheelbase is 82". Isn't that a little short for a Locost? I'm thinking that about 88 inches to be about right.

Thanks Much:D

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Nor Cal Mike
Willits, CA

If your seriously thinking of the GM v6 swap, I would definately convert to cv joints. The outer cv joint is locked to the hub and axle, but the inner end attaches to the tripod only. The cup attaches to the diff output. The key to adapting cvs is to ensure the tripod doesn't bottom out in the cup with the suspension compressed and/or come out of the cup with the suspension hanging down, weight off of the wheels.

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I happen to have a virtually rust-free GT6+ shell with the roof cut off.
I'm also thinking of a Spit/GT6 single donor build.
Just bought another GT6 ('68 swing axle car) that is nearly complete but has sat a long time.
I too would use the + rear, just need to figure out how to upgrade the original spring to arms and coil-overs.
The guibo's/metallastic joints don't scare me as they will be very visible for inspection and I've put a lot of miles on them in the past.
In a much lighter car they will last a very long time. Rumor has it that there are Mercedes parts that fit and are MUCH stronger than the originals.
One other thing that must be done is to relocate the chassis end trailing arm mounts.

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