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Triumph TR6 - rebuild 6 or drop in a 4.6 ford cobra
|Hi guys I bought a 74 TR6 four weeks ago the motor has a turned bearing on the crank and scored the crank beyond repair. The block and cam are still good. I wanted this car to be a daily driver I sell software and travel about 40,000 miles a year. To many miles to put on my suburban. I had a 72 TR6 in the 80's which had 160000 miles on it and the elctrical system and floor pans were the pits. I need this car to be dependable. So should I put in a 4.6 a ford mustang crate engine(280hp) $3500 or rebuild the 6 $1500?|
|Hi Ernie. I would first research whether the gearbox on back will withstand the torque/hp from the 4.6.|
Here's a link to a site I found some time ago with some guys who've tried a variety of conversions to big engines.
|Failing that here is a suggestion, find a use TR6 motor, seen some around; or here is a wild one buy a GT6+ motor although it is less powerful (2L) it is the same block and subsequenly will fit in easily with no mods.|
If you are looking for a daily driver to run 40,000 miles per year the TR is neither reliable nor fuel effecient or safe for that matter. With that many miles annually you are best to go the VW golf or Jetta TDi which gets 50mpg and save your TR for the weekend.
The Ford route could make the car a handful: strange weight balance, brakes that are not capable (because with 280hp on tap you are going to drive it differently). I doubt that the rear end can handle it and you are going to pull the diff mounts out (already a weak spot in all our TR's).
I would say get the engine rebuilt and look for a used TDi
I agree with Steven about the TDi if you're going
to be doing alot of miles, but I have to correct
I put a 5.0 Ford V8 into my TR6 and I've had no problems with the conversion.
The weight of the 4.6 you are considering is
exactly the same weight as the inline six that is
in it now! So the there is no weight balance differance. Actually the centre of gravity is a couple
of inches lower so the car handles better than it did.
The stock rear end was built for 250 hp. I have over
300hp out put and have had no problems sofar
and neither have any of the dozen or so other guys
who have done this conversion. Just don't drop the
clutch and you'll be fine.
Brake experts say that you need at least 200 square inches of brake swept area per ton. The stock TR6
has over 250 square inches! And since the weight of the car is the same, you're laughing.
However, the car is a handful. Three times the power
that it use to have, the acceleration is breath
taking. Good luck.
|My TR6's motor has covered 230,000 miles and is still running on standard journals. Given decent oil and filter changes and considerate use you should be able to get many years' driving out of a rebuilt TR6. Maybe changing the main and big-end bearing shells, and the crank thrust wshers, every 50,000 miles would help- but that needs only a couple of days under the car. A few years ago new crankshafts were almost being given away over here.|
|If you're looking for inspiration, check out this site for weird and wonderful Austin Healey engine swaps, including an incredible yellow Bugeye witha 478ci Hemi and 'Vette suspension.|
This thread was discussed between 09/04/2002 and 12/05/2002
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