pea shooter mufflers on a mk3 850

Just becoming a New Norton 850 mk3 owner. Had my first Norton [ a Atlas] back in 1974 so have had quite a break between bikes. What I want to know is firstly did the balance tube exhaust system come out on the mk3, and if I want to change the current Bean can mufflers to the pea shooters will these header pipes [ with balance tube] be ok or will I have to change to the single pipes. I understand I will have to change the muffler mounting plates. Any help would be appreciated. Also on a similar note, what is the consensus on the balance tube headers compared to the singles, i.e, which is better or what difference with either set up.

The crossover pipes were on earlier 850's as well. I have pea shooters on my original balance piped MK 3 with all the original mounting parts. I did have to relocate two holes in each muffler mounting plate about 1" forward. Lot's of different opinions on whether the balance pipe does anything or not. Without a direct comparison on the same machine all I can say is I think it quiets the exhaust a bit and is said to increase low end torque a bit. I know a balance pipes or some sort of pipe connection is the norm on dual exhaust V8 automobiles.

Biscuit said:

The crossover pipes were on earlier 850's as well. ...all I can say is I think it quiets the exhaust a bit and is said to increase low end torque a bit. I know a balance pipes or some sort of pipe connection is the norm on dual exhaust V8 automobiles.

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Dead on, Biscuit. My '74 came stock with the crossover. It was primarily added as a response to the quieter (read, more restrictive) mufflers. Since the parallel twins only exhaust one cylinder at a time, the balance pipe essentially allows each cylinder to "use" both mufflers during the exhaust stroke. While it does screw up any tuning effects at higher engine speeds, it helps add to low- and mid-range torque.

The balance pipe exhaust is frequently considered to be undesirable. The exhaust system often cracks near the cross over. The slip joints at the cross over tend to rust, making it to remove the exhaust system from the head.
Stephen Hill

Nater_Potater said:

Biscuit said:

The crossover pipes were on earlier 850's as well. ...all I can say is I think it quiets the exhaust a bit and is said to increase low end torque a bit. I know a balance pipes or some sort of pipe connection is the norm on dual exhaust V8 automobiles.

Click to expand...

Dead on, Biscuit. My '74 came stock with the crossover. It was primarily added as a response to the quieter (read, more restrictive) mufflers. Since the parallel twins only exhaust one cylinder at a time, the balance pipe essentially allows each cylinder to "use" both mufflers during the exhaust stroke. While it does screw up any tuning effects at higher engine speeds, it helps add to low- and mid-range torque.

Click to expand...

Nice looking bike !

Thanks for the info. I would have thought the balance tube versus single pipe may have invited a bit more debate, but no all quiet out there. guess i will just buy single header pipes cos I really prefer the look of them. The balance tube looks a bit too much like a triumph for my liking. Besides my Norton 850 mk3, [ bought site un seen], arrives tomorrow and after nearly 40 years I will have a Norton in my stable once again, and I am excited like a kid again.

So when you post all the pictures and mail the cigars out, everybody else will be excited as well... good luck...

nnnrh said:

Thanks for the info. I would have thought the balance tube versus single pipe may have invited a bit more debate, but no all quiet out there. guess i will just buy single header pipes cos I really prefer the look of them. The balance tube looks a bit too much like a triumph for my liking. Besides my Norton 850 mk3, [ bought site un seen], arrives tomorrow and after nearly 40 years I will have a Norton in my stable once again, and I am excited like a kid again.

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It's been beaten to death... (Search and read, lots of lively debate) I dislike strongly the balance tube pipes, as it requires the short nuts with less thread engagement. Here's my rant, rotten tomatoes and all... engineering-compromises-leading-exhaust-threads-stripped-t14363.html

YMMV

Youll find theres a variety of headers . The P.R. type giveing better ground clearance , they might even fit if it doesnt have the protruding sidestand lug , if you can find any .