I might have a line on a barn-find TR6
How much HP can I get from a fully built Triumph 2.5 litre motor? No forced induction. High compression is OK as long as it would run on premium pump gas. Is 200-225 hp reasonable?
I've seen the V8 conversions, but if it is in as good of shape as I think it is I hate to butcher it.
Sure. How fast can you afford?
www.goodparts.com
www.prirace.com
I love those Triumph lumps. They sound incredible but for 200bhp it won't be cheap. Add the Triumph fuel injection from a Euro model car and you will reach 150bhp then start doing some engine work. It depends on your plans for the car. A proper sorted Triumph straight six will sound miles better then some old V8 but if you are using it for racing there might be better choices. Do you really need 200hp?
Paeco claims 258hp from a race engine with 13:1 compression. They are not highly regarded for their honesty.
I hate saying this, but it's not worth doing.
Turbos are your friend.
Another thing to consider the frame on that is not known for being very stiff and the drivetrain is not the strongest in the world so unless you want to do a lot of surgery and hack up the car I would say stay with the straight six. Also half the appeal of a TR6 is the sound and look of one and hacking one up for a swap is only going to hurt the value badly. A complete POS I can see a swap on (I am actually helping with one but it had no door sills, floorpans, all the glass was broken, engine seized, etc) but if it is in decent nick then a swap just seems horrible.
I would generally agree... it'll depend some on the condition of the "barn".
A lot of it will depend on what kind of overall shape it is in. The thought of keeping a straight-6 appeals to me for many reasons. But if the frame is shot, a V8 might be the better option.
The old IT car/project and racing kart will take care of track time, so this would just be a hot rod to tool around in.
Just trying to get an idea of the possibilities. I am going to The Mitty, so I'm sure there will be a lot of Triumph goodness to lust after.
Those cars are flexi-flyers in the frame department. If you DO get 200+ hp, you wont really be doing much with them.
Have a good look at the diff mounts. A proper repair is a body-off frame job. The rear valence is double skinned and rust like crazy. Wait, so does everything on this car!
put a three rotor in it.
this is my solution to all my hypothetical swaps.
I'll be saving for a three rotor to put in the s30 after the challenge is done.
I would be tempted by BMW's Straight Sixes.. even an S50/52 as found in the E36 M3 would give you 220 to 240hp..
Dig up some of Kas Kastners books and do what he did. The 2.5 had a bad harmonics problem, but you can fix that, and 200 hp is quite doable. In fact some of the 2 liters are doing that already.
Heres the fountain of Triumph engine knowlege.
http://sideways-technologies.co.uk/forums/index.php/forum/5-engine-and-ancillary-talk/
Can you say 2JZ???
Toyota reliabilty, 215hp 215#/ft is the stock rating for the Lexus IS300 lump.
mad_machine wrote: I would be tempted by BMW's Straight Sixes.. even an S50/52 as found in the E36 M3 would give you 220 to 240hp..
That's been done, although the amount of fabrication involved is staggering. Sort of looks like a M3 powered Locost with a TR6 body. Not necessarily a bad thing, mind you, but the slant nature of a BMW motor makes the swap a bitch.
Cue pic of TR-6 with BMW S52 in 3,2,1...
I've owned several of these in TVR's. 160-170hp is about the limit for a reliable street engine. 200-210 with a race engine using the stock crank and block.
This was a tractor engine originally. It only has 4 main bearings, a 2.94" bore and a relatively huge 3.74" stroke. The head doesn't flow well either.
I have a friend who, just because he likes to do things the hard way, built one that makes 300hp. He used a custom billet crank and main bearing saddles, milled a custom head for it using huge valves, along with custom pistons and rods yielding 3.0 liters and 12.0:1 compression and runs it on CAM2. It flies, but he has close to $20k in the engine alone.
These are cool engines when not overdone. They sound good, but don't really like to rev unless you do some serious head work. You can mill a lot off the head (almost 1/4", IIRC), boosting the compression ratio from less than 8:1 to around 10:1. Add a performance cam and work on the carbs a bit and you can get 170hp with a header and free flowing exhaust. I happen to have a fresh engine of this description for sale if you are interested. 
The TR6 with the BMW engine has been for sale for a while for around $40k. No I don't have a link.
The charm of the 6 is the sound of the engine. 150hp is easily doable. 170hp ain't too hard.
edit: I see the linkie above
mguar wrote: (and GM mid sized SUV's Trailblazer/GMC Envoy) which use a modified Jaguar in line six)
Nope. That's a GM design.
spitfirebill wrote: The charm of the 6 is the sound of the engine. 150hp is easily doable. 170hp ain't too hard.
They were making 150hp from the factory in Europe. Like I said add the European fuel injection and you will hit that mark.
In reply to 93EXCivic:
That's not where the power difference comes from. The European engines had a different cam and head which yielded a higher CR. The Zenith Strombergs on the US engines are variable venturi carbs, and are good for 250hp. In fact, the 300hp engine I describe above uses two of them just like the stock engine, although they are heavily massaged.
I will sell you my l24 and 4 speed after the challenge for a good deal. 150hp stock.
tuna55 wrote:mguar wrote: (and GM mid sized SUV's Trailblazer/GMC Envoy) which use a modified Jaguar in line six)Nope. That's a GM design.
Yup.. if ford had chosen to continue the I6.. they could have used a jag design, but not GM
93EXCivic wrote:spitfirebill wrote: The charm of the 6 is the sound of the engine. 150hp is easily doable. 170hp ain't too hard.They were making 150hp from the factory in Europe. Like I said add the European fuel injection and you will hit that mark.
Borla/TWM has a fuel injection set up... looks quite nice 
http://www.twminduction.com/ThrottleBody/tr6_fi.html
For a street car, you should be looking for torque, not horsepower.
As described above, these are not sophisticated high HP motors.
To get big HP, you have to spin them at high RPM, and spend a ton of money to feed them and keep them alive.
But you can cheaply add an Eaton M-62, or a turbo system optimized for torque to a basically stock motor, and you will be well rewarded.
The biggest problem will be getting the huge grin off your face every time you leave a stoplight.
Here's a supercharged 235 HP TR-6 motor stuffed into a GT6:
http://www.totallytriumph.net/cgi-bin/dcforum/dcboard.cgi?az=read_count&om=46&forum=DCForumID27
Carter
Thanks for the education. If I end up with the car, I will post some pics and plans.
Keep your fingers crossed for me!
We've been autocrossing a TR6 for about 10 years that probably manages 150-160 HP at the wheels. It's streetable, even with triple Webers. Since it ate the cam a few years ago, we've had the opportunity to rework things a bit and add a slightly more radical cam. The sound is really pretty nice, but adding even 20 HP makes me start to worry about breaking the crank, a U-joint, etc. Once it's broken in, it's getting dyno'ed before going back to any autocross.
The real limitation is the crankshaft and bearing design. The crank has bad harmonics above 6200 RPM or so that can break the crank or shake the flywheel loose. A forged crank with extra flywheel bolts and proper balance is the fix, but not for cheap. Then there's the con rods and pistons to worry about. And the inadequate main bearings and thrust washers.
As others have said, it's not the best high-power engine out there, but puts out decent torque and can be made to rev with a lightened flywheel. I'd highly recommend an ignition with a rev limiter to keep the RPMs below 6200 on stock internal s.
BTW, we have the TWM/Borla intake shown above. It's the only one in existence at the moment. Once we get the engine bedded in with the Webers, we're going Megasquirt and fully sequential EFI. After that, I'll probably have a better idea what the upper limit is. 
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