MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

TR parts and Triumph parts, TR bits, Triumph Car Spares and accessories are available for TR2, TR3, TR3A, TR4, TR4A, TR5, TR6, TR7, TR8, Spitfire and Stag and other TR models are available from British car spares and parts company LBCarCo.

Triumph TR6 - OK Ladies & Gents, here's my 1st question

And lease, be kind, I'm new to the TR world...
Since my TR is a 76, can I take off any of the emissions stuff that had to be added for importation?
jac clayton

That depends a lot on your emission testing and what you want to do with the car
DON KELLY

Well Don, I'm open to suggestions...I guess one of the 1st things is convert to unleaded gas....If I've gone that far, would that be the time to replace the cam to get a few extra HP?
jac clayton

See that goes back to my first question
What do you do with this car?
DON KELLY

Hmmmm, OK, I want a quick and responsive car. I want to keep it as stock as possible while also making upgrades that make sense (like being able to run unleaded). If I had a new cam put in, it wouldn't be to turn it into a muscle car or racer, it'd just be to add a few more HP. Actually, if I could get it closer to the 150hp in the UK version I'd be happy. I'd like to get the performance the brits put into it & not the performance left over after the US anti smog regs were applied.

Thanks,

Jim C
jac clayton

Jim

Quick and responsive?? Well you will never get much of that from the stock motor.
If you want to bump the power then be prepared to pull the motor out. A complete valve job to set you up for unleaded gas (note: there are a lot of us running on unleaded gas. This is a very debatable subject. I cannot get the unleaded additive I use to use). Then comes the complete lower end. Then add the super charger and the electronic ignition. I think we are up to around $5,000 so far.
Jim consider getting your car, driving for the summer, then starting your "upgrade" over the winter months.

Yes you can remove some of the pollution crap subject to local emissions laws. I am a '71 so really no crap on my car. There are others here that can chime in on exactly what you can do.
Sounds like you are getting a daily driver.

Rick
Rick Crawford

Jac,

I have a '75 TR6 and drive it without any modif. for unleaded and faced no problems after all these years. For performance a north-america TR6 in original mode is not a real quick responsive car. Just compare with British model with mechanical fuel injection which deliver 150 HP and north-american model @106 HP with a low compression engine. Thats the place to improve things...

Cheers,

Jean G.
J. G. Catford

So, would you suggest a larger cam? And yes, driving it for the summer and then deciding on mods sounds like good advice !
jac clayton

How many miles on the engine Jim?

Almost a mute question at it will most likely require a rebuild.
Jim you will need to check the thrust washers before you drive it. Not difficult but can kill an engine if not changed when they need to be done. Have procedure on CD.

Rick
Rick Crawford

OK, thrust washers. Is there anything else I should check/replace while I'm doing this? I don't plan on removing the engine to have this done....

Thanks,

Jim C
jac clayton

Welcome Jim. If you don't want to remove the engine, I assume you don't want to do a complete rebuild. That limits your options to mostly bolt on stuff. Header elec. fan and not much more unless like Rick said , you want to put on a blower or turbocharger. Big $$$.Can you tell us more about the car, mileage condition of the engine, etc. One thing you should probably do is get the distributer rebuilt. It's only about $1oo and well worth the money as most of these distributers are pretty much beat if they havn't been rebiult. Don't do it untill after all of your other mods have been done though as this will affect what the distributer guy will want to do to it.

Rob
rw loftus

Hi Rob. No, I agree with Rick, that a rebuild is probably in order. At this point I don't have tha car yet. It'll be shipped here sometime around the 1st week in April. I'll want to drive it for a while to see what all it's going to need. Ricks advice says that if the thrust washers are bad it will cause more damage so I want to get them checked/replaced so I don't cause more problems. While I'm getting the thrust washers replaced, is there anything else I should be looking at?
jac clayton

Personally if it drives soundly when you get it just enjoy it for a year or so until you have really thought about it.

If it was me I would leave it stock
My guess if the interior hasn't been done I would concentrate there first as that is the part you see the most
DON KELLY

Jim
The thrust washers can be done with engine in place. Basically you remove the oil pan and check the end play (float) of the washers at the back of the engine. There is not much else you can do down at the lower end without getting real serious. I agree with Don. Enjoy the car for a while...at least the summer then you will get a feel for what you want to do.

Everything literally boils down to how deep is your pocket. Post a pic if you got one Jim.

Rick
Rick Crawford

You don't even have to remove the oil pan to do a quick check the end play. Just lever the crankshaft toward the rear of the car (using the the inner part, not the outer ring, of the lower pulley or the hex bolt on the crank). Set up a dial indicator and have someone push in the clutch to fully disengage. Repaet a few times and compare readings. The spec is end float of .006" to .008", if it's much more than that, make thrust washers your first order of business. You can kill both a crank and a block if you let bad thrust washers go too long.

As for the "quick and responsive" bit, you have to accept that this is an undersquare engine so it just doesn't spool up that quick. There's lots of stuff that you can do to increase power, enhance braking and improve handling. It's all governed by how much you want to spend, what equipment you available to you and your skill level (either current or improved as you fiddle with the car).
SteveP1

Jim

I don't think you got a very specific answer about the emissions stuff - my car is a '75, so pretty much the same as yours, I think.

What you have is an air pump (above the alternator) which feeds through a valve (operated by manifold vacuum as I recall?) through a check valve into a small bore header feeding air into injection tubes into the exhaust ports of the head. The purpose, as I understand it, is to dilute the exhaust gas to pass a requirement to have emission of various gases below x ppm. I don't see the point, personally, but it I may be wrong about the function of the system. I took my air injection system off the car when I rebuilt the engine, and found that most of the components were either not working or on the brink of failure. My manifold was rusted through underneath, the valves didn't work as required, and the manifold itself was completely blocked with soot. I would up buying an alternator bracket from an earlier car to put the alternator in a more accessible place and get rid of the large original bracket that served to mount the air pump as well as the alternator. Much tidier after removing the system. I blocked the holes in the exhaust manifold with set screws of the appropriate size (1/2" fine thread, about 3/4 inch long, from memory)

There are other emissions items in the engine bay - there is a vacuum operated retard on the distributor. I capped this at both ends and never looked back. There is also a right-angled pipe joining the EGR valve to the inlet manifold - recirculating exhaust gas to the inlet, again a crude attempt to reduce emissions. I believe that more modern EGR systems work well, but mine was completely blocked with soot - from the EGR valve all the way into the inlet manifold.

On the other hand, there are some emissions items where removal makes no sense (to me at least). There is a carbon canister near the grille on the passenger side - this serves to reduce emission of gas through vaporisation. No possible performance disadvantage, as far as I can see. Whether the charcoal is still doing anything is debatable, but you can replace the charcoal if you like. I haven't done that but intend to at some point. I find that all the fuel in the carb float chambers evaporates while the car isn't used (not used very often) and it takes a lot of cranking (or pumping of the lever on the pump) to get the fuel through to the carbs. This cranking allows oil pressure to build before the engine fires, which I see as a good thing, but I am sure that my neighbours think my car is hard to start!

In short, I removed most of the emissions equipment from my car because it didn't work, and I have seen no issues with my car. I do not attribute any performance gain to the removal, other than perhaps the removal of 20 or 30 pounds of metal - which is about 1% of the car's weight!

Best to check with your state's emissions requirements before you take anything off...

Hope that helps
Alistair
A Hewitt

Thanks Alistair, the info is a big help!

Jim C
jac clayton

Being NH 's motto is live free or DIE
I spec that there is no emission testing ?
DON KELLY

Oh no, we do have emissions testing but I think it only goes back a certain amount of years....I think that a 76 will be exempt...
jac clayton

Don
Been to NH on business a few times in the past and noticed that one right off on very licence plate. Pretty heavy statement.
Thanks for the assist Steve. Knew you would chime in when needed.
I knew someone Alistair would have the answer.

Rick
Rick Crawford

Jac- That's what I expected
DON KELLY

Jim

If you are looking for improved performance then you have lots of options. I can tell you what my experience has been though.

The later cars like ours suffered much lower compression - I think it was down to 7.25:1 by '75/'76. This was achieved by leaving more material on the bottom of the head during machining, so it is easily corrected by going to a machine shop and asking them to remove some material - I went to about 9.5:1, which involved removing a lot of material - 0.1 inches or so. It was enough that the machine shop called me several times to check what they had written down! I expect that this alone (along with a tune up to make sure everything works with the new compression ratio) would be the biggest gain in power without adding something like a supercharger.

Before the engine rebuild, I added K&N filters and a "sports exhaust", which made it sound faster without any actual provable benefit. I added fancy spark plug wires, which are red, and noticed no difference. After the engine rebuild, I even added a crude "cold air feed" with a couple of 2 inch tubes passing air from in front of the radiator to right by the air filters. Result? Nothing, so far as I could tell.

During the engine rebuild I added a light flywheel (aluminium alloy - I think they still show up on ebay), and removed the engine-driven fan (replaced with electric), and those two things dropped the rotating mass quite considerably - this is one of the few things I really did notice when driving. The reduced rotating mass resulted in a much faster response to the throttle, which is good, I suppose. The light flywheel means that I stall more than I care to admit, as well.

I spent lots of money on the engine rebuild - GoodParts GP2 camshaft, flywheel, alloy pieces to reduce weight, (all kinds of things that I hope my wife never finds out about!), and I am pretty confident that my car is quicker than a stock TR6 sold in America in the '70s. Not as fast as the injected cars, probably, which is how I justified not doing a lot to improve braking. At the end of the day though, I am prepared to admit that I am likely to lose in a traffic light race with a minivan. I suspect that my pick-up truck could out accelerate the TR6, even if it had a full bed and was towing another TR6!

Speaking of towing, where are you picking up the TR6 and GT6?

Cheers
Alistair
A Hewitt

Thanks Alistair, more good info & what I was looking for.....They're being hauled up here from Northern NJ around the 1st of April. I'm terrified....
jac clayton

Jac,

To gain an extra few bits of HP, Gasket Innovation sells: Triumph TR6 GT6 TR250 Cooling Fan Eliminator Kit, which get rid of fan overweight around 6 lbs. It is listed on e-bay for around $25. or Patton machine sells it:

http://www.pattonmachine.com/tr6/eliminator.htm

For a better cam, I bought from British parts-NW a 270 cam which is fine. They advertise a gain of 12-15 HP... They offer a wide selection of camshafts.

Cheers,

Jean


J. G. Catford

Awesome JG, thank you
jac clayton

A quick bit of digging about in the archives on camshafts, I found this, which in turn references other camshaft threads in the archives:

"Here are a few archive locations of prior camshaft discussions:

From 11 October 2006 "Road Cam" (includes discussion of the BPNW supplied Piper camshaft mentioned above)

From 21 February 2006 "TR6 High Performance Street Cam"

From 9 June 2005 "Engine Rebuild Questions"

From 5 May 2005 "Supercharged TR6 Cam"

From 26 August 2004 "How Much HP and Torque"

As far as the stock TR6 cams go, the lamest of the bunch is the early carb car camshaft, the hottest is the early PI car camshaft. The late carb cars and the late PI cars used the same camshaft. That camshaft was in between the fairly agressive early PI cam and that cast iron rod stock with a smattering of small bumps that was used in the early carb cars. The late stock camshaft is not a bad camshaft and if I were to decide on using a factory "stock spec" camshaft, it is the one I would use.

Regarding camshaft bearings, for the most part it is a judgement call. As long as you are not running the high ratio (1.65:1 type) rocker arms or really high spring seat pressures ( which would eat up the cam anyway) or an extremely agressive cam ( which would be teriible on the street any way), cam bearings would not be necessary unless the block was worn badly.

On the cam follower front, bite the bullet and use new ones. Tossing used followers on a new camshaft is a quick way to write it off. Also use a good assembly and run in lube. For assembly I like the Lubriplate white lithium grease and for run in I like that smelly but effective Crane Super Lube."

I do like the grind of the that BPNW 270 cam and you can get it as new one not limited to regrinds like so many others.

SteveP1

Jac,

I forgot to mention a Fidanza lightweight flywheel for an improve acceleration.

Jean G.
J. G. Catford

This thread was discussed between 04/03/2013 and 10/03/2013

Triumph TR6 index

This thread is from the archive. The Live Triumph TR6 BBS is active now.