1976 140 Exhaust

['72TR6RV]

Hey all.....
Little update and question / opinion on exhaust types.
My rebuild project is coming along fairly well. Almost ready to bring it to life. My question and or opinion is about the exhaust. The headers that I got with the bike are obviously not the ones that were fitted to it. The 1- 3/8" inlet slides into the head way to easy and will not seal. So I purchased a pair of push in spigots that aquire 1-3/4" pipes. So are the balanced headers the way to go, or go with the unbalanced. Which ones perform better in ones opinion.
Thanks

 

[grandpaul]

For typical / casual use, I much prefer the balanced headers.

Depending on how far from original you are, or are willing to be, I like the look of Norton Commando style "peashooter" reverse cone mufflers on the OIF Triumphs...

 

['72TR6RV]

For typical / casual use, I much prefer the balanced headers.

Depending on how far from original you are, or are willing to be, I like the look of Norton Commando style "peashooter" reverse cone mufflers on the OIF Triumphs...

My uncle always said that the motors seem to run better with the balanced headers. My Tiger has the balanced headers and I have the Dunstall style mufflers on it. Got a deep sound and look good.
As for how far from original with the Bonneville build, I'm trying to bring it back to close to original as I can. I was looking at the reverse cone mufflers....they look good but not sure how they sound. Need to bring the tank back to original still, but keeping the chrome K&N pancake air filters and installed a Boyer Electronic Ignition. Will post some pictures soon as I get new headers and mufflers.
The bike came with 18 or 20 inch cocktail shaker mufflers and I believe they going to be too dam loud and barky....dont like being the tail end rider all the time....
Thanks for the input....

 

[Rudie]

My uncle always said that the motors seem to run better with the balanced headers.

One reason given by Triumph for fitting them was then each cylinder's exhaust pressure then had two outlets. Another reason was the noise was then reduced a little without changing the mufflers.

purchased a pair of push in spigots that aquire 1-3/4" pipes.

You will struggle to find a choice of mufflers to fit 1-3/4" pipes, or do you mean the spigots are 1-3/4" o.d.? If so, most pipes to fit over spigots were/are a smaller diameter, just with the spigot clamping part that diameter.

how far from original with the Bonneville build, I'm trying to bring it back to close to original as I can. I was looking at the reverse cone mufflers....they look good but not sure how they sound.

Commando style "peashooters" sound - deep and not too loud; however, you won't notice much difference in sound from the Dunstall style mufflers.

Otoh, if you mean "reverse cone" mufflers like '76 originals, they were heavy and imho ugly and too quiet.

 

['72TR6RV]

One reason given by Triumph for fitting them was then each cylinder's exhaust pressure then had two outlets. Another reason was the noise was then reduced a little without changing the mufflers.


You will struggle to find a choice of mufflers to fit 1-3/4" pipes, or do you mean the spigots are 1-3/4" o.d.? If so, most pipes to fit over spigots were/are a smaller diameter, just with the spigot clamping part that diameter.


Commando style "peashooters" sound - deep and not too loud; however, you won't notice much difference in sound from the Dunstall style mufflers.

Otoh, if you mean "reverse cone" mufflers like '76 originals, they were heavy and imho ugly and too quiet.

The outlet of the press in spigots have a O.D of 1.65"...... so 1-5/8" to 1-11/16".
The headers I've been seeing have a 1-3/4 inlet and now wondering how well they will fit the spigots.

 

[Magno]

Hey all.....
Little update and question / opinion on exhaust types.
My rebuild project is coming along fairly well. Almost ready to bring it to life. My question and or opinion is about the exhaust. The headers that I got with the bike are obviously not the ones that were fitted to it. The 1- 3/8" inlet slides into the head way to easy and will not seal. So I purchased a pair of push in spigots that aquire 1-3/4" pipes. So are the balanced headers the way to go, or go with the unbalanced. Which ones perform better in ones opinion.
Thanks

My current T140 has the original pipes still on it but when they rot I'll be fitting Norton peashooters. I did it on a previous Bonny and they sounded and looked great. I seem to remember I also changed the carb needles one notch although I'm not sure that's strictly necessary. I'd also keep the balanced headers. Good luck with it!

 

[Rudie]

The outlet of the press in spigots have a O.D of 1.65"...... so 1-5/8" to 1-11/16".
The headers I've been seeing have a 1-3/4 inlet and now wondering how well they will fit the spigots.

You do not appear to be understanding correctly.

Triumph changed - from pipes than pushed over spigots screwed into cylinder head exhaust ports - to pipes that pushed straight into cylinder head exhaust ports - during the 1972 model year.

Look at standard pre-1972 'push over' pipes - they have an enlarged diameter only where the pipe fits over the spigot - the pipe i.d. is not the the spigot o.d. throughout the length of the pipe - if it was, it would cause tuning problems, because the exhaust gas would exit from a spigot i.d. into a larger pipe i.d., which would slow it down. For this reason, both the spigot and the pipe i.d. should be the same (or very similar). So, when you look at standard pre-1972 'push over' pipes, you'll see they have a larger diameter only where they fit over the spigots.

Standard pre-1972 spigot i.d. and pipe i.d. are very similar; consequently the standard pipe o.d. - that any muffler i.d. fits over - is smaller than 1-3/4". Is why I posted, "You will struggle to find a choice of mufflers to fit 1-3/4" pipes" - standard Triumph pipes for twins were/are smaller.

 

[Magno]

I'm with you now. All my bikes have been around 1975/6 with the push-in pipes. Never had any problems with that and Norton silencers fit.

 

['72TR6RV]

My current T140 has the original pipes still on it but when they rot I'll be fitting Norton peashooters. I did it on a previous Bonny and they sounded and looked great. I seem to remember I also changed the carb needles one notch although I'm not sure that's strictly necessary. I'd also keep the balanced headers. Good luck with it!

You do not appear to be understanding correctly.

Triumph changed - from pipes than pushed over spigots screwed into cylinder head exhaust ports - to pipes that pushed straight into cylinder head exhaust ports - during the 1972 model year.

Look at standard pre-1972 'push over' pipes - they have an enlarged diameter only where the pipe fits over the spigot - the pipe i.d. is not the the spigot o.d. throughout the length of the pipe - if it was, it would cause tuning problems, because the exhaust gas would exit from a spigot i.d. into a larger pipe i.d., which would slow it down. For this reason, both the spigot and the pipe i.d. should be the same (or very similar). So, when you look at standard pre-1972 'push over' pipes, you'll see they have a larger diameter only where they fit over the spigots.

Standard pre-1972 spigot i.d. and pipe i.d. are very similar; consequently the standard pipe o.d. - that any muffler i.d. fits over - is smaller than 1-3/4". Is why I posted, "You will struggle to find a choice of mufflers to fit 1-3/4" pipes" - standard Triumph pipes for twins were/are smaller.

You do not appear to be understanding correctly.

Triumph changed - from pipes than pushed over spigots screwed into cylinder head exhaust ports - to pipes that pushed straight into cylinder head exhaust ports - during the 1972 model year.

Look at standard pre-1972 'push over' pipes - they have an enlarged diameter only where the pipe fits over the spigot - the pipe i.d. is not the the spigot o.d. throughout the length of the pipe - if it was, it would cause tuning problems, because the exhaust gas would exit from a spigot i.d. into a larger pipe i.d., which would slow it down. For this reason, both the spigot and the pipe i.d. should be the same (or very similar). So, when you look at standard pre-1972 'push over' pipes, you'll see they have a larger diameter only where they fit over the spigots.

Standard pre-1972 spigot i.d. and pipe i.d. are very similar; consequently the standard pipe o.d. - that any muffler i.d. fits over - is smaller than 1-3/4". Is why I posted, "You will struggle to find a choice of mufflers to fit 1-3/4" pipes" - standard Triumph pipes for twins were/are smaller.

The headers I have ordered have a larger diameter to go over the spigot, then reduce down to 1-3/8" for the remainder of the pipe. The head that came with the bike has a larger diameter exhaust port than the size of the headers that came with it. I have no threads in the ports to accept a thread in spigot. Therefore I have press in spigots from C.B.S that will fit and seal once I freeze them and heat the head with a hot plate. They should seal up fine.
My 72' Tiger has the push in type headers.