Unit constuction Royal enfields
 

Does anybody have any experience of the the new Royal Enfields with the unit constuction engines, Any comments would be most welcome.:helpsmilie:

Hi
I am also interested in the unit construction Enfield and often find info from these 2 website forums.

AussieEnfields.com

Royal Enfield Motorcycles - The Official Home of Royal Enfield in the USA

The big ends are prone to failure as they are the same assembly used in the old Electra.

Common causes are poor case hardening of the crankpin flaking off
Poor quality steel in the crankpin
timing running too far advanced.
not helped by running the needle bearings directly in the aluminium conrod.
Wrongly machined crankshafts are the main culprit for the incorrect timing, but it can also be the rotor or stator being out of tolerance. There is no easy adjustment without machining.

Where did you get this information from? From the forums I have read these bikes have received nothing but praise.

These engines are made with the latest CNC (japanese) machinery.

So are the AVL electra. Butthat does not stop them failing.

The information, well it comes from several sources.

Re the bad materials of the crankpin, the case hardening flaking off and the wrongly machined crankshaft. My own bike and several others on the enfield forum I am on. also from several manufacturers who are busy manufacturing better crankpins and who machine the conrods to take a steel shell for the needle bearings to roll on. (Priceparts and Alpha bearings) the wrongly machined crankshafts see Hitchcocks. The information that the new unit engine uses the same assembly comes from Watsonian the Importers.

It would seem that the350cc version is by and large trouble free, not so the 500's.
many of the 500's have had crankshaft failures at around 10k miles ( including my own).

you might want to look through here The British Bulleteers' Forum :: Index and search through various threads.

Watsonian seem to acknowledge this to some and have been known to supply replacement cranks, to others they just deny everything. guess it depends whether or not they have stock of the cranks that dont fail.

hope that helps top clear some of the hype.

Unit construction Royal Enfields
 

Thanks for the input on this subject, It seems strange that they appear to have problems with engine as they market it as the new imptoved and even more reliable Enfield. I have noticed that prices of these models can be found quiet cheap perhaps this is the reason. Any more comments that could help me decide would still be most welcome.

I bought into the new improved Enfield hype. with new designs (avl engine and 5 speed gearbox) latest machinery and special European build to disguise the price hike from £1,200 retail in India to more than triple the price in Europe.

Actually the design is fine although there is no way to adjust or compensate the ignition timing. If is is made wrong is stays wrong. I have been months making by hand parts to alleviate mine running too far advanced and as a consequence have only managed 320 miles for the year since my crank failed. The gearbox is excellent, but does work better as a right hand shift. They are ALL ( including European ones) made in the same factory and are just pulled from the home market line in Madras. there were rumours that indicated they had paintwork and European made bearings fitted in the UK but this is not so. All they do is customise ready built bikes to make 'sports or offroad' models. In fact the European importers do not even have a paint shop.

IF they were built to the design dimensions and with the correct grade materials they could be good bikes. When running properly they are a joy to ride. But they are very labour intensive, more so than any of my 1959-1970's Triumphs.

They (Enfield) need to train their staff better, they need to have a more thorough quality control and they also need to have some kind of after sales service that does not just depend on the goodwill of the dealers, some of whom are excellent.

Thanks for your advice, I think based on this I may be on the lookout for a older Sixty Five with the old engine.

Let me correct some erroneous information.

The older Iron Barrel engines had an alloy connecting rod.

The AVL engines have a forged steel connecting rod.
( I am looking at one right now.)

The newer Unit Construction Engines have a forged steel connecting rod also and overly large bearing for the power output levels of this engine.

I have been inside several Iron Barrel engines and a few AVL engines
The AVL is the better of the two.

The UCE engine has earned a reputation in the U.S. as a tough, durable, reliable and better engine with only one engine being replaced there as a precaution but none having failed since its release there in 2009.

You can see for yourself what the Americans have to say about it in their forum.
Royal Enfield U.S. Community Forum - Index

Cheers for reading this.

This actual discussion is in progress on these sites here by more knowledgable Royal Enfield owners/riders!:

http://www.aussieenfields.com/aebb/F...num=1313430006

Your comments appreciated please !!!

You might want to look in hitchcocks 2011 parts catalogue, page 40 part number 90125c.

The conrod material is often too soft and it needs to be sleeved with harder material. They, Alpha bearings and Priceparts all make a living changing out the original failed assemblies. Sadly the crankpins also have the same problem. sometimes badly machined, sometimes poor materials and sometimes wrongly heat treated. If everything is done correctly it works well, but if any one is not correct you will suffer early failure. On my own bike the crankpin was soft and the case hardening started flaking off, a common fault. It was aggravated by the timing being off ( too advanced) but whether that was the crank wrongly machined ( the woodruff key slot was milled to the wrong depth, but not sure if in right place or not) or a production fault in the stator or rotor I do not know. I found out about the slot being too small when I tried to fit an offset woodruff key. I have to make by hand a smaller one.

I did visit Mr. H's site and entering the part No. brought up the following

"CON ROD WITH FITTED ROLLER BIGEND, **electra only**

PART No.:90125C"

It is regrettable that you and others have had problems with your AVL machine but I suspect those to be the minority of the total of machines produced. Alpha and Priceparts do offer some exceptional kit but I hardly doubt the AVL big end is the main source of their livings.


The original post;
blues2,
In searching a bit more I've found the one UCE engine mentioned earlier as being replaced as a precautionary measure, was due to faulty alternator mounting resulting in swarf in the oil. It was covered under warranty.

I've ridden the UCE machines belonging to my mates and they do ride like the Bullet always has, albeit a fair bit nicer with their better shock absorbers, reliable electric starters, disc brakes and all that.

I will admit to being mildly envious as their machine are oil tight and require very little upkeep especially compared to my older Bullets.

Regards,
D.E.D.

Thanks to DED
 

Thanks for taking the time to find out what the problemm was with the UCE engines. It appears to me now that most of the bad press relates to the AVL engines.
Time for a rethink about the new Enfields.
I have booked a test ride this Saturday to give it a good try out. I will post again after this has taken place.

Sadly your "research" has again been a bit shallow. Had you read the full entry (page 40 of their catalog) you would have seen this.

Photos Of trip to the Flytrap

The fact is All three companies have thought it worthwhile to set up the tooling to manufacture a better part. Given that the original complete crankshaft assembly is priced at £145 and sufficient owners have elected to pay the approx £250 for the improved crankpin, bushed conrod and bearing alone has to say something about those owners perceptions on the reliability of the original part.

When mine failed on the way back from Poland I had to abandon my bike in Antwerp as by then it was really rattling. I went back for it with my car and trailer. Watsonian insisted that it couldn't be the big end as these do not fail as they were the same as those fitted to the UCE. They insisted it had to be a piston, but I know the difference in the sound and any way the bike does not use any oil between oil changes or blow any gas out. Yet they had to my knowledge now given free replacement assemblies to others. At The time (early Oct 2010)
Watsonian were out of stock of crankshaft assemblies. So Was Hitchcocks who also had none of their improved parts available. Alpha bearings were running with an 8 to 10 week queue for their assemblies. So I arranged to take the bike to Priceparts in late January. There he showed me his collection of failed units.

Click on the thumbnail for better picture

Please re check you "facts" all the resources available to me indicate the AVL engine uses a Forged Steel Conrod. My experience and a magnet confirm this fact thus far to date.

Having done as requested:

Hitchcocks Motorcycles - Crankshaft

and then selecting the tab "Fitting Guide" brings up the following, which I have cut and pasted here.

This is the fitting guide for electra bigend and conrod
Model 350cc 500cc
Bullet (export) No No
Bullet (ind market) No No
Bullet Redditch No No
Electric Start - No
Sixty 5 - No
Electra (x) - All
Thunderbird All -
Electra EFI - No
Classic EFI - No

According to Mr. H's table, the EFI lump also known as the Unit Construction Engine uses different conrod than the AVL.


Contradicts with earlier statements.

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I've put 42,000km on my road going bullet powered by the classic lump with cast iron cylinder and aluminium conrod, all with out failures. Of course it was properly run in and though ridden with spirit, not abused.

My green lane machine had developed a loose gudgeon pin which sounded like a big end failing, but such things can and do happen when machines are flogged without mercy or regard. I accepted that as the price paid for my own exuberance.