[Chiefharlock]

I know this is kind of out of the model scope, but I am interested in pursuing a retro-fit. 
I'm interested in finding out if the header pipe on the Classic Exhaust System is actually rounded like the image portrays: http://nfieldgear.com/enfield-store/aftermarket-parts-accessories/exhaust/classic-exhaust-system-1675.html
I know I would have to weld on a bung for the O2 sensor and that isn't an issue  I just want to know if it really is as round as indicated in the photo.  I really like the look of that style pipe and I'm interested in possibly puting it on my bike.

Any info y'all might have would be helpful and appreciated!

Jason

[mattsz]

Bump...

Anybody have any input on this?  Not that I'm looking for yet another thing to do on my bike, but it's fun to think about!

Classic header?  Sexy...


(pic borrowed from hoohoohoblin.com)



Stock EFI header?  Meh...


(pic borrowed from our hosts!)

[FiRE Comms]

classic header is missing the O2 sensor for the EFI...

[mattsz]

Like the OP suggested... I already have the O2 sensor - all that's missing from the classic header is the hole to plug it into.  How hard can it be to poke a hole - the right hole - in the pipe?

[Royalista]

The NField Gear page states that the airflow is more free which requires rejetting the carb. If the ECU takes into account the specs of the exhaust, fitting another type might cause a new problem. It might be more trickier than poking a hole for the oxygen sensor. Just saying. 

Otherwise, putting both pictures side by side should be forbidden: it hurts, badly... 

[mattsz]

D+D figured it out:

http://www.enfieldmotorcycles.com/forum/index.php/topic,15069.0/all.html

But they went and used the same profile as the stock pipe... 

[gremlin]

...........Classic header?  Sexy...

struth !

[t120rbullet]

Why not just put that muffler on the stock header?

[mattsz]

I have that muffler back-ordered with NFG.  It's the header we're lusting after - some of us like a few extra curves!

[barenekd]

Welding the bung on the pipe isn't going to change anything! Those pipes aren't that critical, especially if the engines are left stock. The length and diameter changes could affect it, but drilling a plugged hole in it isn't going to hurt!
Bare

[gremlin]

the O2 sensor must point down approx 15 degrees (outside higher than inside the pipe), also, it will need to be approximately the same distance from the exhaust valve to stay within its operating temperature range.

[Chiefharlock]

Exactly, it's all about the curves.

Apprently Hitchcock's has one that harkens back to an older era in appearance but has the O2 sensor bung already welded in place.  I may contact them and see if they can provide a photo of the part.

[Royalista]

Exactly, it's all about the curves.

Apprently Hitchcock's has one that harkens back to an older era in appearance but has the O2 sensor bung already welded in place.  I may contact them and see if they can provide a photo of the part.

That would be nice. Please do and keep us in.
Anything to improve the Bullet.

[Arizoni]

I may be thinking about another Hitchcock pipe but I seem to recall someone here on the forum who got one of these pipes.

Rather than being the thick walled pipe that comes on the UCE's, it is a thin wall pipe with a larger inside diameter.

While common sense would say that larger diameter should increase performance, the opposite was true.
Low and mid-range power decreased and the engine still seemed to run out of power at the higher revs.

As I say, I'm going by memory so maybe whoever it was can jump in and tell me I am wrong?

Changing the pipe does change the bend and it does decrease the bikes total weight so there are justifiable reasons for changing it.

[Jack Leis]

I believe your talking about a comment I made regarding the Hitchcocks pipe awhile back. As soon as I fired up the bike with the new pipe it sounded about 50% louder. My thought at the time was WOW, when I take it up to Wrightwood tomorrow, this baby is going to haul ass ! I took it up a long grade and was really disappointed. It had no guts ! Later I tried it with the baffle in the Goldstar and it still sucked. I went back to the original pipe and the bike pulled really well up the same grade. now, all though the bike was louder meaning more exhaust , there has to be an equal amount of mixed air and fuel. We cant get it with the stock EFI set up. If you read the Hitchcocks catalog description of the pipe it states something to the effect of upgrading the standard ECU with a POWER COMMANDER they have developed. Thats why the pipe didnt work worth a s&^t. Im hanging on to the pipe in case some day I go 535 cc. and get the head done. Then I'll spring for a Power Commander .

[Arizoni]

As I understand it, open exhaust pipes often reduce the engines torque at lower RPM even if the air/fuel mixture is spot on.  They do allow more power to be made at high RPMs if the rest of the engine is capable of running there and its cam timing was designed for the higher engine speeds.

[Jack Leis]

 That is why Im patiently waiting for Ace to start selling all the Performance goodies !

[barenekd]

If don't think the one Jack got is the same ones your talking about. The one your talking about, I think is called the "Classic Bike Indian Made" in the Hitchcock catalog. It's not listed in their new print catalog, but it looks the same as the one in the NFG catalog. It's really made for an earlier model. I'd call NFG to make sure it will work! They are pretty good about such things! The price would work out about the same between the two different sources. Ask for Tim if you can't get a straight answer from someone else.
Bare

[ace.cafe]

That is why Im patiently waiting for Ace to start selling all the Performance goodies !

We are getting close, and the latest info that I have is that the exhaust port outlet in our head mod is centered, and wants a 1.625" I.D. pipe. Now, I want to wait until I have that thing in my hand, and measure it before anyone goes out and buys a pipe for it. But it looks like the pipe with the 1.625" I.D., which I think is the D&D pipe, should be the one that will match up to our port the best.

I asked for a memory-refresher on these pipe I.D. sizes on my Ace UCE Project thread, because I can't remember exactly which pipe has which I.D. size.

[b.sheets]

We are getting close, and the latest info that I have is that the exhaust port outlet in our head mod is centered, and wants a 1.625" I.D. pipe. Now, I want to wait until I have that thing in my hand, and measure it before anyone goes out and buys a pipe for it. But it looks like the pipe with the 1.625" I.D., which I think is the D&D pipe, should be the one that will match up to our port the best.

I asked for a memory-refresher on these pipe I.D. sizes on my Ace UCE Project thread, because I can't remember exactly which pipe has which I.D. size.

good to know, waiting for your confirmation though!
thanks for all the work you put into this stuff.
brandon

[ace.cafe]

good to know, waiting for your confirmation though!
thanks for all the work you put into this stuff.
brandon

For those with the Hitchcock's pipe, I believe it would be possible to bore out that reducer to 1.625", and make that one fit too.

[Jack Leis]

For those with the Hitchcock's pipe, I believe it would be possible to bore out that reducer to 1.625", and make that one fit too.

Now your talking ! You scared me there for a minute. Thanks for the information and especially for all you do on the Enfields.