A Royal Enfield forum for the people

[gashousegorilla]

Got ya on that ... good . Yeah, probably nothing wrong then. I have always put the wide band right in the same spot as the stock narrow band, and never had a problem. Drill/ grind out the stock smaller narrow band sensor bung , and weld the new one on right in it's place. I know what you probably read about that, and I questioned it to. But no issues.... works fine on the Dyno and with the auto tuner right where the stock one was. And I think being close to the exhaust port like that , gets it hotter quicker and keeps it happy... I believe they need to see a good amount of heat to work effectively, and being farther down the pipe would cool them down . This MAY not be the case with a multi cylinder engine .... there is always hot exhaust hitting that sensor, no matter what the other piston or pistons are doing. So they can get away with farther down the pipe... we have a LONG stoke, slow revving and low reving motor. It take more time and effort to keep the heat up on those sensors I figure...

[swamp2]

Yeah, I'd say your logic makes a lot of sense. In a multi-cylinder application, assuming only 1 O2 sensor, it would seem most logical to locate it where it's seeing the combined "average" response effect from the cylinders Wouldn't make sense to mount it in a single head pipe, I wouldn't think. I can't really come up with a reason it wouldn't make sense to leave it in the stock location on our beloved RE singles...

[gashousegorilla]

Looks can deceive, when looking at that stock head pipe ... Looks big enough ,right ? Again, it's just a very small pipe inside a larger outer pipe. And the motor is trying to breath through that cocktail straw sized inner pipe. That little inner pipe runs inside that outer pipe, from the exhaust port , down to maybe 6 or 8 inches before the outlet side of the head pipe . Here is a picture or two of a section of that inner head pipe that I cut out. It has a 1 1/8 " ID. My thumb is almost as thick ! Hahaha...

IMG_1777[1].JPG (1.27 MiB) Viewed 974 times

IMG_1778[1].JPG (1.14 MiB) Viewed 974 times

One of the reasons why I believe, they CLAIM 27 HP at the crank.... and you wind up with 19 hp at the wheel. Freeing up that exhaust and intake alone will will make a good bit of difference !

[Tim]

That is bananas, I knew it was there but seeing it.....

[gashousegorilla]

Yup... I remember seeing it for the first time and shaking my head. THIS is why ! Hahaha !

Really though, I think it's ALL a design thing with these bikes. Their goal was ... slow ... not a lot of power , with a big emphasis on FUEL ECONOMY and emissions. Right from the air box , the EFI system , to the low compression , to the meek cams and the crazy straw sized head pipe with a wet sponge on the end.. Haha! These bike where intending that way I think. A head pipe alone will make them feel more like a 500 cc should.

[swamp2]

So... Tim, can you propose any cost effective solutions to this quandary? I contacted Hitchcock's about their 1 1/2" ID pipe, and it would set one back over $200 shipped to the US. Seems a bit on the spendy side!

[Tim]

So... Tim, can you propose any cost effective solutions to this quandary? I contacted Hitchcock's about their 1 1/2" ID pipe, and it would set one back over $200 shipped to the US. Seems a bit on the spendy side!

$200 or £200? Head pipes are expensive the stock pipe would cost you at least $150. Did HMC mention the origin of their stock? If I had to guess I would say they ended up with the CMW Barn Burner stock. See this thread post 261 viewtopic.php?f=20&t=52&p=261&hilit=barn#p261. It would have cost you $199 + shipping in 2014 so if you can get one delivered from Europe for that, jump on it. They won't know what Barn Burner is, I would just ask if they got them from CMW.

[swamp2]

The pipe was 85 GBP which is certainly reasonable enough. It was the additional 70 for shipping that struck me as painful.

I didn't ask where they came from, but the ad says UK made.

[Tim]

The pipe was 85 GBP which is certainly reasonable enough. It was the additional 70 for shipping that struck me as painful.

I didn't ask where they came from, but the ad says UK made.

There are 6 pages to this thread, I think it's safe to say you caught the bug. Look away as you hit the "confirm order" button and enjoy the pipe.

[gashousegorilla]

You figure ? .... it cost me about a 100 bucks to have a custom head pipe made at a local muffler shop. Took about an hour or so ? And that is a pretty average per hour shop rate . It was aluminized car type pipe... corrosion resistant. Made to my spec. With the flange and etc. Just left a little longer so we could tune it to length. BUT... it was unfinished. No Chrome or fancy schmancie ceramic coating and such. THAT stuff get's expensive ! Even if you can still find a chromer around here ... I bet it would cost just as much as making the pipe , to get it chromed . OR .. one could go the very much less expensive approach and heat wrap the pipe . Depending on your tastes.