Timing chain

[promotor]

My wuestion to IWIS this morning:

Will do Jeremy!

Does IWIS make two types of roller chain - one with ‘split’ rollers and another with solid or continuous rollers without a seam?

His reply just now:

Yes, it’s called a Bush chain, but it’s bigger and heavier, I don’t knowingly sell any to Lotus Twin cam people, do you know to any troubles with the standard chain?
J.

Does anyone want to give him an answer?

I can only offer the classic "answer a question with another question" - why have the chains moved away from the design that used endless rollers which were originally supplied to Lotus such as "Morse" and "Renold" products? I have original chains and can confirm both Morse and Reynold used endless rollers.
People aren't too willing to move onto other products when original equipment seems to be better than old equipment time and time again.

Perhaps Jeremy can provide us all with the information to prove that split-end rollers are consistently good for 50,000 miles in road cars and for extended periods in race cars with high valve-train loads? Surely they've done the R&D?

[2cams70]

I think the answer so far is that no one has experienced failures attributed to rollers being split instead of one piece.

[promotor]

I think the answer so far is that no one has experienced failures attributed to rollers being split instead of one piece.

Who knows? Either that, or we don't get to hear about it. Or the chains haven't had enough mileage put on them to test them.

I have just looked through my stock and I've got 1 x brand new Cross & Morse 120 link chain with endless rollers and 1 x brand new Cross & Morse 122 link chain with endless rollers. I can't remember where they came from though unfortunately.

[elans3]

Only that all the IWIS chains I've used on both my Alfa and Lotus Twincams have not had split rollers..
I did buy them from an English (chain / power transmission) company, but I'd have to look through the car's history file to remind me of who it was..

[alanr]

My wuestion to IWIS this morning:

Will do Jeremy!

Does IWIS make two types of roller chain - one with ‘split’ rollers and another with solid or continuous rollers without a seam?
His reply just now:
Yes, it’s called a Bush chain, but it’s bigger and heavier, I don’t knowingly sell any to Lotus Twin cam people, do you know to any troubles with the standard chain?
J.
Does anyone want to give him an answer?

Hal,
As I am sure you are aware IWIS chains are made in Germany. Was this viewpoint that of the manufacturer? ...Or the sole UK agent for IWIS who are now Denis Welch Motorsport (of big Healey fame)?

Alan.

[HCA]

Well spotted Alan!

It is from their UK distributer to whom I was directed! I am maybe not savvy enough on the subject to challenge him..!

[alanr]

Ok Hal,
Thanks for that clarification.
My, probably cynical, thoughts are that I just wonder if the type of timing chain now being supplied has changed since the Denis Welch takeover of the UK IWIS distrubutorship? That just could explain why the issue of split roller chains has suddenly reared it's head perhaps unbeknown to the likes of QED et al who just thought the were selling the same timing chains that they had always sold.
Does anyone on here know when the UK IWIS distributorship changed hands?

I don't know quite how but somehow I think this needs some more investigation.

Alan.

I

[HCA]

I have to admit I had not given the type of chain a second thought until I noticed the price difference out there from $120 down to £15!!

Until Rohan replied with the roller difference backed by others, Endless and split rollers meant nothing.

I guess Jeremy has a point in his question that, actually echoes my question at the start of my post - how many instances are there of chains breaking inside the Twin Cam. I guess that QED sell a lot of £28 chains. How many break?

[andyelan]

Hi there everyone

I would say changing from solid rollers to split rollers is purely a cost saving exercise by the manufactures, but whether this makes them of lower quality I wouldn't know. Manufactures will, I'm sure, say not. What I do know is that if one does let go, then the cost will be far in excess of any savings made by buying a cheaper chain. Remember, as noted at the beginning of this thread, the Twin Cam only has a single row chain so I'd always want it to be the best available.

Regards
Andy

[alanr]

I have to admit I had not given the type of chain a second thought until I noticed the price difference out there from $120 down to £15!!

Until Rohan replied with the roller difference backed by others, Endless and split rollers meant nothing.

I guess Jeremy has a point in his question that, actually echoes my question at the start of my post - how many instances are there of chains breaking inside the Twin Cam. I guess that QED sell a lot of £28 chains. How many break?

But if this is a relatively recent change to the quality of the timing chain being supplied/sold we maybe don't know if it is an issue or not...Yet!

Alan

[HCA]

I think the answer so far is that no one has experienced failures attributed to rollers being split instead of one piece.

Who knows? Either that, or we don't get to hear about it. Or the chains haven't had enough mileage put on them to test them.

I have just looked through my stock and I've got 1 x brand new Cross & Morse 120 link chain with endless rollers and 1 x brand new Cross & Morse 122 link chain with endless rollers. I can't remember where they came from though unfortunately.

mmm - is your 122 link for sale..?

[promotor]

I think the answer so far is that no one has experienced failures attributed to rollers being split instead of one piece.

Who knows? Either that, or we don't get to hear about it. Or the chains haven't had enough mileage put on them to test them.

I have just looked through my stock and I've got 1 x brand new Cross & Morse 120 link chain with endless rollers and 1 x brand new Cross & Morse 122 link chain with endless rollers. I can't remember where they came from though unfortunately.

mmm - is your 122 link for sale..?

I'm sorry to say that it's not. Sorry if that sounded like a tease or an advert, I didn't mean it to be, I was just pointing out that both lengths of chain could be had with solid rollers.

[rgh0]

https://blog.mccchains.com/2020/06/10/s ... ller-chain

Here is some more information on solid versus split bush and roller chains from a manufacturer (in Taiwan)

Will the differences matter in a Twincam application be it normal road use and higher miles or higher stress race use and lower miles, who knows ? I doubt anyone has conducted any proper tests to find out but directionally the split roller chains are inferior ( and cheaper) . I certainly dont want to risk any engine I build with split bush and roller chains.

cheers
Rohan

[2cams70]

Here is some more information on solid versus split bush and roller chains from a manufacturer (in Taiwan)

Will the differences matter in a Twincam application be it normal road use and higher miles or higher stress race use and lower miles, who knows ? I doubt anyone has conducted any proper tests to find out but directionally the split roller chains are inferior ( and cheaper) . I certainly dont want to risk any engine I build with split bush and roller chains.

I don't know if some obscure Taiwanese manufacturer is a credible source of information - especially when they talk about one of the disadvanges of split rollers being that "they leak oil through the rollers". Sounds like though if you've been building engines using IWIS chains that you've probably been building them with split rollers.

A split roller still rolls around a solid pin which carries the tension load. The roller itself is not under any significant tension that would pull it apart. As a engineer I can't see it being an issue. It might even be better depending on the grade of steel used. I see this as being more important than whether the roller happens to be split or not.

By the way if any of you guys wish to get rid of your crappy German made IWIS chains with split rollers please send them my way and I'll gladly swap them for some Taiwanese made ones with solid rollers. The Germans must be still trying to win the war by selling crappy timing chains to suit English engines.

[rgh0]

I have not puirchased new chains for a while. The ones i am currently using are IWIS with solid rollers. If getting those proves difficult in the future i am sure i can find a suitable supplier of simialr solid roller quality chains 9reynold, morse etc)

Probably not from Taiwan , I just posted the article as it provided some concise information around the advantages of solid roller chains. Plenty of other web sites provide similar information

cheers
Rohan