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Old 21st June 2012, 20:44   #16
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Default Enfield UCE or CI Engine - Confused!

I am at a point in life where I can heavily modify my Royal Enfield Thunderbird Twinspark as it is almost 3 years old now as I don't like it in stock condition anymore, or I can sell it and scout for a Standard 350 with cast Iron Engine and modify that to my liking.

Needless to say, both the engines have their pros and cons. I need help in identifying the correct course of action so I am listing down the pros and cons of each.

Thunderbird Twinspark:

Pros-
  • 3 Years of trouble free ownership, no niggles
  • Excellent acceleration and can compete with the Japs in City as well as Highways
  • Engine does not overheat even after long rides
  • Integrated decompressor & Electric Start are very helpful in City traffic
  • No Oil leakages
  • Excellent riding & seating position for rider as well as pillion
  • Excellent Mileage
Cons-

  • Lacks the legendary Thump
  • I crave for the unique gear pedal on the right and brake on the left configuration
  • Neutral finder is missing
  • Looks could be subjective but I don't thing Thunderbird is a looker
  • can't modify to look like a post war model
Standard 350 with CI Engine:


Pros-

  • No match for the legendary thump
  • Just a simple paint job and can be a breath taking machine to look at
  • Neutral finder
  • Unique gear & brake configuration
  • Can be heavily modified to suit personal tastes
  • FEEL of a Bullet when you ride it
Cons-

  • RE does not manufacture these anymore and has to be procured in the used bike market
  • Notorious for niggles and Oil leakages
  • Service Centers may not have the know how to maintain these anymore
  • Engine Overheating is a known issue
  • Need good DIY knowledge to fix frequent issues
  • Probably dated technology
Please help me make an informed decision. My 3 year old TBTS would probably fetch me 60-70K and I could buy an Old Standard for the same. the cost of mods would be more or less the same on both.
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Old 21st June 2012, 21:17   #17
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

Who said that the UCE engine cannot cruise at 40 kph in 4th gear ? My standard uce runs around at 40 kph in 5th gear without lugging. In the 4th gear the bike reaches 40 kph with the bike in the top of the power band.
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Old 21st June 2012, 21:39   #18
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

a bit OT...Thanks adrian! I just ordered a copy of PROFICIENT MOTORCYCLING : THE ULTIMATE GUIDE TO RIDING WELL
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Old 21st June 2012, 21:45   #19
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

You can't have a discussion on the cruising of Bullet without some sounds. This is the sound of my Bullet (Standard of '86) - start and idling. Listen to it on proper speakers or headphone for the full glory of the thump. This is virtually unedited with minor bass boosting.

BulletJuneEdited192012 by Calcuttan on SoundCloud - Create, record and share your sounds for free
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Old 21st June 2012, 22:31   #20
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

I was worried when my new thread was merged here and now I am sure this will turn into a UCE Vs CI debate. I personally like both. However, both serve a different purpose. There is no such thing as a bad engine.
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Old 21st June 2012, 23:10   #21
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

Quote:
Originally Posted by Sankar View Post
Maybe not. But it does change the way how an engine behave in the real world.
In my Bullet (1970) i have run with the OE heavy crank and a lighter 1980's light crank. Heavy crank stores more energy than light crank.

Heavy crank pulls the bike from slow speed, lighter crank required dropping a gear.
Heavy crank took time to reach higher speeds, lighter crank reached those speeds faster.
Heavy crank sustained the high speeds when let off the throttle, lighter crank dropped speed faster when let off the throttle.
How was the throttle response when you crack open when cruising? Also any difference in FE? Overall which did you prefer?
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Old 22nd June 2012, 08:15   #22
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

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Originally Posted by Mpower View Post
How was the throttle response when you crack open when cruising? Also any difference in FE? Overall which did you prefer?
With the heavy crank the response was not as immediate as with the lighter crank, it took time to spin up, lighter crank was immediate with throttle responses.
I never calculated the real fuel efficiency figures with either cranks, but noticed better FE with lighter crank as it didn't go into reserve as quickly as with the heavy.
I preferred lighter crank for quick acceleration inside the city and on highways for quick overtaking bursts and i wasn't cruising. For cruising heavy was good.

For sudden changes in acceleration lighter is better, for keeping a steady hand and steady speeds heavy is fine. Also you get lesser engine braking with heavy, it doesn't slow down as much as a lighter crank would when throttle is closed, so it takes longer to stop while braking from high speeds.
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Old 22nd June 2012, 13:52   #23
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

Quote:
Originally Posted by josepeter View Post
a bit OT...Thanks adrian! I just ordered a copy of PROFICIENT MOTORCYCLING : THE ULTIMATE GUIDE TO RIDING WELL
You won't regret the decision. It is worth each penny
Quote:
Originally Posted by Pedaltothefloor View Post
Mods - Please allow this as a new topic instead so that I can get a few responses instead of the never ending debate on CI Vs UCE.
You cannot add the good attributes of the CI to the UCE and vice versa by doing any modifications what so ever. What is possible and practical is to sell your T-bird and buy a standard 350 or 500 UCE. This will get you closer to your dreams except for the thump and the right side gear position. Now you can ride a machine with a simple paint job with no oil leaks with good mileage which is not overheating...phew.. man, your list is too long for a bulleteer who should never be a perfectionist !
Regards adrian

Last edited by adrian : 22nd June 2012 at 14:09. Reason: typo
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Old 22nd June 2012, 19:36   #24
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

Pedaltothefloor - my sympathies with you. Now I see and understand that you had asked a totally different question and it probably got merged with a completely unrelated thread and 90 per cent of the people who see this thread will perhaps not even notice your question, let alone answer. But then you have to accept that in life not everything happens the way we want them to.

Regarding your question I would suggest, if you know a good mechanic, get an old Bullet and repair it thoroughly. Ride it for the sound and the "effortless cruising" on weekends. But on long trips when you need more reliability take out your Thunderbird. After a while you will realise which one is for keeps and get rid of the other.

The old Bullet is not the most suitable bike for daily commuting, particularly if you are young and in a hurry. It is also not suitable if you live in a congested city with stop and go traffic. It was designed in a country at a time when the total vehicular population of that small island nation was perhaps less than the number of vehicles we have in any Indian city now.

Some of the two wheelers that Eicher manufactures these days with the Royal Enfield badge look remarkably similar to the legendary Bullet. But once you ride the real thing, you know who the pretenders are and who the real royals are.

The original Bullet is a period bike. It is about nostalgia. It reminds you of a period when life was lived in a different way. If you fantasize about that life and era then get one. It is not reliable by any means. It has its own quirks and oddities. But that's what makes it special. That's what gives it a character. That's why it is the only bike in India whose price is appreciating every year.

If you want reliability I think the Bajaj Pulsar 180 or Honda Unicorn are way better than what Eicher makes these days.
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Old 26th June 2012, 21:02   #25
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

Quote:
Originally Posted by Sankar View Post
Heavy crank stores more energy than light crank. Heavy crank pulls the bike from slow speed, .

+ when I was searched in a used machismo with avl engine in 2010, one mechanic shown me an std 350 prepared him (excellently prepared). When I asked him that why at the time of rebuild he prepared a CB point instead of CDI so that bike can be start without battery? He replied that placing CDI will ruin the Low End Torque, at lower speed bike will start jerking.
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Old 1st July 2012, 16:06   #26
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

A while ago, I was trying to locate data on making my Classic 350 cruise faster than its current 'comfortable' cruise speed of 80KmpH. Playing with sprocket teeth or changing gear teeth- is not what I am looking at. There was an article by a Bullet owner talking about basic engine modifications to enable top speeds of 135-140- but also gave cruising ability of upto 100-110.
Can anyone help with positive workable solutions?
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Old 1st July 2012, 16:55   #27
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

What I don't see being mentioned here is the longer stroke of the older RE Bullet which combined wit the (necessarily) heavier crankshaft et al give good pulling power at lower speeds.

Diesel engines too tend to have longer stroke vs bore and petrol engines have squarer bore vs stroke which contribute to the different torque/power characteristics.
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Old 1st July 2012, 18:23   #28
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

Hi Pedaltothefloor,
I have a 1996 cast iron 500cc. Nothing gives me more pleasure than cruising on the highway with the familiar thump in my ears! I have ridden some of the UCE engine bikes belonging to some friends. Both the bikes are miles apart in what they have to offer.
I find that it is pretty difficult to ride my castiron in today's traffic conditions. The UCE bikes seemed reasonably better in handling today's traffic conditions. So, IMHO you must decide where most of your usage is going to be and that would let you decide whether the cast iron or the UCE is the bike for you. After that let your heart decide and buy the cast iron!
Regards,
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Old 2nd July 2012, 13:56   #29
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

Quote:
Originally Posted by vivriti View Post
What I don't see being mentioned here is the longer stroke of the older RE Bullet which combined wit the (necessarily) heavier crankshaft et al give good pulling power at lower speeds.

Diesel engines too tend to have longer stroke vs bore and petrol engines have squarer bore vs stroke which contribute to the different torque/power characteristics.
This certainly is new info as far as I am concerned. Could you please elaborate on the relation of torque to stroke length please ?
regards adrian
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Old 2nd July 2012, 18:06   #30
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Default Re: What makes the Cast Iron (CI) engined Bullets cruise effortlessly at low rpms?

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Originally Posted by adrian View Post
This certainly is new info as far as I am concerned. Could you please elaborate on the relation of torque to stroke length please ?
regards adrian
It's not exactly long stroke = high torque. Long stroke or 'undersquare' engines tend to have higher torque at lower RPM.

Long stroke engines will have longer throw which gives a lever effect. Oversquare engines with short throw and higher RPM rate are more buzzy and will be running at a higher speed for the same displacement as an undersquare engine. This results in the oversquare engine giving the same torque at higher speeds.
Another contributing factor is that heavier crankshaft etc give a flywheel effect which results in longer pulses of power and more pulling at lower rpm.

There are many other factors like valve dimensions, head design etc which all contribute to torque curves.

I'm no automobile engineer but this is what I've learnt.
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