TR6 Adding Some Power

[Martin Secrest]

I've been getting reacquainted with my '72 TR6, 89k miles, the car (except the engine) is well restored. The bottom end was renewed at about 80k miles, oil pressure is good, no smoke, everything works.

I'm wondering about adding another 20-25 horsepower if I can, without doing a crazy amount of work. Maybe this: port/polish the head and upgrade the Strombergs to dual or triple Webbers. No new camshaft or header, but the car does have the 6-3-2 iron exhaust manifold into a 2-1 (Tourist Trophy) exhaust. Electronic ignition, Lucas sport coil.

How much power would the head work and carb upgrade really add? The rest of the car, suspension, etc. can handle any extra power. What say we?

 

[LarryK]

British Leyland had some tuning books for Tirumphs. They were written with the ideas put in place for Lemans and etc. They will be hard to find, but did see them at Roadster Factory and Moss years ago.

 

[Martin Secrest]

And that's quite a car collection you have there Larry, wow. I had a '73 GT6, was a daily driver for years. An 'interesting' vehicle, LOL.

 

[LarryK]

My wife drove the GT6 ( her mini Jag ) for 10 yrs daily to work. Had to pry her out. In 10 yrs only replaced donuts twice, u-joints a little more frequent (caught her squealing tires), rebuilt head at 90K, after a vacation (because of a bad valve) rebuilt tranny once, because I, at 125K , blew third gear. Got some rust and a suspension bolt broke and it left.

 

[UltimateQuestion]

Definitely seek copies of Kas Kastner's Triumph preparation books. The old original competition preparation handbooks (I think TRF sells them) and his newer books as well. http://www.kaskastner.com/kasbooks.html

 

[glemon]

Best bang for the buck is to shave the head to get about 9.5/1 compression, more power across the board. I know you said no cam, but the shave and a mild cam will get you where you want to be.

Story of my build here: http://www.mossmotoring.com/the-all-arounder the Kastner book is a very good resource as is the Williams book on how to modify TR6.

 

[Martin Secrest]

Six Pack did an interesting write up about the kind of thing I'm thinking (though they changed out the cam): https://classicmotorsports.com/articles/six-pack-easy-triumph-tr6-performance-upgrades/

I could take on a head port and rebuild but I do wonder about the wisdom of any of this absent a complete engine rebuild. With nearly 90k on my original motor, it's certainly nearing that time. I have freshened the bottom end, but that's not exactly transformational.

 

[glemon]

I think my engine had 96,000 on it, I got by with a hone, new bearings and rings. But I did put in a new oil pump and had things checked out and cleaned up including boiling out the block. It wasn't very expensive--but good to know it is ok, and I think getting the years of accumulated scale out of the block helps the car run cooler. So get it checked to know it is ok and freshen things up, or, if not ok, you want to know that too, even if it may make things more expensive. Greg

 

[malbaby]

I agree with "glemon".....unless you upgrade the camshaft specs together with the cyl head work, component balancing etc, it is not worth doing.
Also, "freshened" can have a different meaning to "renewed" if you are contemplating increasing the horsepower.