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Jerry From LA
Jerry From LA Dork
10/7/14 11:16 a.m.

yes it is, but I would think the difference in length would be a bigger problem. A 2.5 liter 6 is a pretty long motor but a 4.2 liter would be quite a bit longer.

Jerry From LA
Jerry From LA Dork
10/7/14 11:19 a.m.

What about a 3.0 liter straight six out of an old Supra?

Storz
Storz Dork
10/7/14 12:14 p.m.

Rover 4.0 V8? Stick with the British theme...

Ian F
Ian F UltimaDork
10/7/14 2:12 p.m.
Jerry From LA wrote: yes it is, but I would think the difference in length would be a bigger problem. A 2.5 liter 6 is a pretty long motor but a 4.2 liter would be quite a bit longer.

The Triumph 6 isn't really a big lump. I have a spare GT6 2L (same basic block as the TR6 with shorter stroke crank) and a Volvo B20 I4 next to each other in the shed and the dimensions don't seem drastically different. If I get home at a reasonable time tonight, I'll take some dimensions.

93EXCivic
93EXCivic MegaDork
10/7/14 3:02 p.m.
Jerry From LA wrote: What about a 3.0 liter straight six out of an old Supra?

Funny you should mention that but I know for a fact that will fit... 7MGTE

JoeTR6
JoeTR6 Reader
10/7/14 7:42 p.m.

My wife had an IS300 with the 2JZ-GE (mk4 Supra) motor. I tried to determine more than once whether it would fit. Normally aspirated, it's good for 217 HP and torque. The main problem is it's probably heavier than the Triumph motor. That's why I was thinking a newer, all-aluminum I6. To fit a large motor (like the BMW 3-liter), you'd need to relocate the battery to the trunk and cut up the firewall a bit to move it back a few inches. It would be some work to make more room in front of the motor.

A V8 is cheaper power, but width is an issue in the TR6 engine bay. The length would be better, though. For me, I just think an I6 fits the chassis (and it's limitations) better, and I like the sound and smoothness.

Storz
Storz Dork
10/8/14 6:34 a.m.

Hard to go wrong with an M54. Good power, aluminum block :)

fanfoy
fanfoy HalfDork
10/8/14 7:02 a.m.

Now for something totally left-field:

The 3.5L 5-cyl. L52 as found in the GM Colorado, H3, etc... or it's improved version the 3.7L LLR.

Both are available with a manual transmission, are cheap as dirt, are all aluminium, produce good power (220hp or 242hp) with lots of torque and since they are GM, they should be easy to swap.

The L52 had head problems apparently, which the LLR has curred.

And if you are really set on an inline 6, you could get the 6 cylinder LL8 as found in Trailblazer, Envoy, etc...

JoeTR6
JoeTR6 Reader
10/8/14 7:19 p.m.

If it wasn't so heavy, a VW VR6 motor would be interesting. It's basically a shorter (in length) I6. There are adapter plates available for an Audi Quattro trans, but a standard RWD gearbox may be harder to adapt.

Whatever happens, I'm reinforcing the differential mounts like crazy just in case...

CrookedRacer
CrookedRacer New Reader
10/8/14 8:13 p.m.

Rotary motor, like GRM's own Ro-Spit?

I want to help. If I can't help, then just let me drive it when you're done. :-)

JacktheRiffer
JacktheRiffer Reader
10/8/14 8:24 p.m.

What about an l series from nissan?

mightymike
mightymike Reader
10/9/14 5:24 p.m.

The specs I've seen say that the GM 4.2 inline six is 30" tall. Ford 302's are 27" tall. 3" in height is a pretty big difference. I don't think the length would be an issue at all.

I really like the idea of a fuel-injected, aluminium I-6 that makes 270 hp and costs less than a grand.

How in the world do you determine if a certain motor will indeed fit?

Dusterbd13
Dusterbd13 SuperDork
10/9/14 5:37 p.m.

Didn't the tr6 have a bulged hood? Could you add height to clear if necessary?

mightymike
mightymike Reader
10/9/14 6:16 p.m.

There is a ton of info on the British V8 website, and several of the TR6's on there have hood scoops, etc. I could entertain the idea of a good that looked like the 60's era cowl induction hoods.

Another plus for the GM inline six is the steering. With a V8, you have to fabricate some links and joints into the steering column.

JoeTR6
JoeTR6 Reader
10/9/14 6:45 p.m.
Dusterbd13 wrote: Didn't the tr6 have a bulged hood? Could you add height to clear if necessary?

It has a certain amount of curvature, but things might get pretty tight towards the front. Now that I have the body on the frame, I can take some measurements of the space available.

mightymike wrote: Another plus for the GM inline six is the steering. With a V8, you have to fabricate some links and joints into the steering column.

The exhaust headers are also tight. We barely have room for a 6-to-1 header next to the stock block. You'd need block-huggers for any V8 swap.

Ditchdigger
Ditchdigger UltraDork
10/9/14 7:07 p.m.

There is a gent in the UK that fit a BMW M52 from an E36 into his Triumph 2000 in place of the same 2.5 that the TR6 has.

Even the shifter location on the BMW transmission came out damn close to where the Triumph was.

I realize the unibody 2000 is a totally different car than the TR6 but the drivetrains are the same.

JoeTR6
JoeTR6 Reader
10/10/14 11:46 a.m.
Ditchdigger wrote: There is a gent in the UK that fit a BMW M52 from an E36 into his Triumph 2000 in place of the same 2.5 that the TR6 has.

lol, that is so full of awesome.

JoeTR6
JoeTR6 Reader
10/20/14 6:31 p.m.

A few (hundred) taps with a mini-sledge moved the front valence back in place. The passenger side moved forward by about 1/8" which is all it needed. Now both front fenders line up and the gaps between bonnet and fenders closed down nicely. The only thing I'm still fighting with at the front is to get the rear bonnet gap even.

After bolting on the rear fenders, I played around with the doors and have the door gaps fairly tight and consistent (for a TR6). The new BMH fenders aren't quite as nice as originals. The rears (which are brand new) don't match the rear valence very well. I'll probably need to cut some welds and do a little work with hammer and dolly. The fronts are better, but they are at least 20 years older. The original tooling must be getting pretty tired. Once the rear fenders are fitted, I can move on to cleaning up the frame.

I need to decide at some point to use 1972 or 1976 doors. The later doors are very clean and have side impact beams, but weigh quite a bit more. The earlier doors are OK, but the bottom seams have traces of rust and need more prep work. Even if the newer doors add 20 lbs. or so, I think they may be worth it for the added safety.

JoeTR6
JoeTR6 Reader
10/26/14 6:23 p.m.

The bonnet and front fenders are done. The passenger side is done. The driver's side rear fender fits OK but needs some minor tweaks at the rear valence seam (light hammer work). The driver's door rear seam is tight at the bottom and a little too open at the top. Once the drivetrain weight is back in the frame, this should close up. So really I just need to put spacers between the lower fender and the B-post to open the gap.

Next weekend, the body gets hung above my workspace and the frame goes back on the ground. Time to fire up the welder for some frame reinforcement.

JoeTR6
JoeTR6 Reader
11/13/14 7:37 p.m.

Did I say the bonnet was done. It didn't match the tub very well along the back edge, and that would take some pounding to fix. I fitted a different hood (and I still have another one just in case) that fit much better overall. The only issue with it is a slight hit along the front edge. Several whacks brought the shape of the front edge back into place. Another advantage of this hood is that it has original paint, so there's no hidden damage.

The rear fenders are done. They'll take a small amount of filler to smooth out the hammering marks, but otherwise acceptable.

I've also been filling unnecessary screw holes with the MIG. This shell originally had A/C, but I'm not putting it back on in spite of having two compressors and all the under-dash parts. It's just too heavy and wouldn't get used much. That means I have a few bigger holes to fill in the passenger-side foot well.

Dusterbd13
Dusterbd13 SuperDork
11/13/14 10:44 p.m.

What's the underdash stuff look like on one of these? I've been researching vintage air conditioning systems...

And my project needs something else British.

Ian F
Ian F MegaDork
11/14/14 7:36 a.m.

In reply to Dusterbd13:

I saw a TR6 with it installed a few years ago. I have pictures somewhere. It's somewhat similar to the Volvo system (which is more common) and probably made by the same company. It hangs under the passenger side of the dash with a duct running behind the radio support to the driver's side. The compressor is a typcial York unit that mounts high on the right side of the engine. A bit of searching turned up this thread on Triumph Experience with a lot of info:

http://www.triumphexp.com/phorum/read.php?2,730756

I have a strong desire to install A/C in my GT6 (the car is essentially unusable during the Summer), so I've done a fair bit of research on the TR6 system since the engines are similar. However, the compressor mount for the TR6 won't work in a GT6, so my plan is to install it where a air-pump would normally go, which I think my car once had since it has a second crank pulley.

JoeTR6
JoeTR6 Reader
11/14/14 7:11 p.m.

The worst part of the factory A/C system for the TR6 was that they cut a 4" hole in the passenger foot well to clear the blower motor. They also cut two 1" holes on the side for coolant lines. It used a York piston-based compressor (of which I have two new ones) that apparently aren't very efficient and do not convert well to R134a. The link Ian posted shows what the underdash stuff I have looks like. To me, it looks very tacked-on.

JoeTR6
JoeTR6 Dork
12/21/14 6:31 p.m.

Why is nothing as easy as you originally think? I finally got a bonnet to fit well enough. The third one I tried wasn't good at first, but after some bending and coaxing it was better. Still not as good as the previous hood with a bump along the front edge. That hood fit well and was straight, but the metal had stretched (oil-canned) a few inches back from the front edge. After reading up on shrinking sheet metal, I decided to try heating, tapping, and cooling with a damp cloth. This worked pretty well. I don't have an oxy-acetylene rig, so used a propane torch to heat the metal in half-dollar sized areas and tapped around the edge. The result was a bit lumpy, but nothing that couldn't be smoothed with off-dolly hammering. Here are the results.

The rear hood gap is a little tight. For reference, this is a fender washer barely fitting.

With that, the panel fitting is done. Now I'm moving on to cleaning up the rusty driver's floorpan and underside. I'm going to strip off the undercoating in the wheel arches after finding a small rust hole hidden under some of it. I hate stripping paint and rust. Maybe I'll just have the entire tub blasted and be done with it.

TeamEvil
TeamEvil HalfDork
12/21/14 10:46 p.m.

Considering the original green color and the condition of the body shell. I'd restore it and cash out with a big profit.

TR6s always hold their value and that's a very desirable color. Bring it back to stock, then take a bit of a left and install a buckskin color interior, tan carpets and a tan cloth top. Beautiful and pricey.

If you wanna play there are a TON of other cars that would yield a better result and have no value as a stocker.

Don't throw excellent money away on a project. Do it right, sell it off, and use a fraction of what you get to slide into another cheep half done project to go crazy with.

Seriously !

Luck—

TC

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