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Triumph TR6 - Unrestricted breathing

I have been a close watcher for the past few months and appreciate all the tips that you guys share. I have asked this question before but received no response. I understand that you guys are purists and encourage others to follow suit and I try but I am interested in removing any and all emissions gear from my 74 TR. It is registered as an antique and is exempt from any inspections. Any help you guys would provide would be most appreciated.
Thanks
Ashley
Ashley

Ashley,
We are not all purist. I also own a early 74. I have removed ERG value(plugging the head and intake manifold, and capping carb port). I also removed vacuum retard hose from distributor, and capped carb ports. It didn't hurt a thing.
John
John

John
You say it didn't hurt a thing, but did it help at all. Would you recommend removing the equipment?
Armand Allaire

I did the exact same thing as John from Kansas to my 1975. The engine revs free up to near the red line and doesn't seem to 'run out of steam' like it did when the EGR valve was in at around 4000RPM. The hardest thing is to find a thread to plug the head (an odd, non-standard thread)

With the retard out it is easier to set timing for a smoother and consistant idle.

Down side is that the engine has a bigger thirst for gas now...which I don't understand
steven

The DIY guide on restoring the A/H Sprite & MG Midget has a great chapter (written by John Twist I believe) on de-toxing the Midget/Spitfire 1500 motor. I have not seen this book for the TR6 but the principles apply and most of the equipment is the same.

I'm not sure I agree w/ removing the vacuum retard. On my stock 1974 the vacuum retard gets vacuum from the throttle plate area (once it is warm and the thermo switch opens) and only retards to 4 atdc at idle through low throttle settings. As soon as the throttle opens, the vacuum in that area lessens causing the timing to quickly advance. This seems to give the benefits of retard at idle while increasing power at higher throttle settings through advanced timing.

I'm curious as to what benefit you found w/ just the retard deactivated and what your static & idle timing is. Did you change the centrifugal advance to compensate?
Wayne

Ashley,
EGR valve can be a source of problems. It's normal function does not enhance performance of the engine. Therefore it's removal may be beneficial, but definitely will not hurt.
Wayne,
My stock 74 Thermo Switch (Ashley, that's the plastic thing on the upper radiator hose) did not work. Since replacements are not available, removing corresponding piping was next step. My understanding is that vacuum retard is only applied when throttle plates are closed. Therefore this feature was added only for emission control and has no performance value. Only Static timing and centrifical advance effects timing. I set my static timing at 10-12 deg BTDC. Centrifical advance adds 16 deg as rpm increase.
John

The EGR can be plugged with a brass plug . I just did mine on a 73 head. I think the plug is a 5/8, and get one with a wrench style top . Just add some RTV sealant to the threads.
Don K
DON KELLY

Hey Don et al, what happens to the connection between the plate and the vacuum if you quit using it? Do you just leave it hooked up and hope it doesn't move around?
Thanks, Jim
Jim Kinsella

Don't disconnect the rod between the plate and the vacuum retard. It will not move around if there is no vacuum present. I put a rubber nipple on the outside of the vacuum just to make the modification look neater.

If you disconnect it then the plate will move and throw out the timing
steven

Great!! This solves 2 problems! My "points plates" are worn and loose, so all I have to do is tie them together permanently instead of buying used ones for $45-50. Thanks guys. By the way, what kind of thread,size etc are those 2 screws that hold the plates to the distributor body? Hardware store couldn't match them and Roadster Factory didn't have them.
Jim

DON'T TIE THEM TOGETHER!!

You need them to move to get a timing advance when you accelerate.

The plates will be loose because they need to move with the centrifigal force applied to them from the counterweights below .

There is alot of play in them normally, not a precision made part.
steven

Steven, The mechanical advance, on mine, turns the cam, not the points plate. The cam turns on the dist. shaft. The only thing tied to the points plate is the vacuum retard linkage. Anyone else?
Jim

Jim

I stand corrected...just looked at the diagram and you are right. Guess you can tie the 2 plates together because they would only move because of the vacuum retard and if that is disconnected then they would have not use. that way you can firm up the slop in your worn plate.
steven

The screws ,if they are the same as on the tach drive cover are 6X32.
DON KELLY

This thread was discussed between 18/02/2002 and 01/03/2002

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