Cam Chain Robustness

[123Cat]

Ive always thought that chains in motors were a weak point but no
I have never heard of a ford double row ,,,,,is it , ever breaking in history

Its a credit to the design

I was in a Toyota Tiara that broke one

I did hear that Brocky was breaking chains at the end of conrod at one time
didnt quite get the full story , on that

[mik]

Any particular engine we are talking about ? because the vary with each engine.
personally i have always thought the opposite, belts suck , chains rock, like everything some are good some are bad.
my falcon 6 still rocking the same timing chain and tensioner (untouched)for nearly 15 years of age and nearly 240,000 kliks and still going like a train.

[Express]

Originally Posted by 123Cat

I did hear that Brocky was breaking chains at the end of conrod at one time
didnt quite get the full story , on that

Every time he broke a chain his race would be over or at least out of the running, so it would be interesting to know how many times.

I would have also thought double rows would have automatically been used in race applications, I know while doing other upgrades I used to always have them fitted to my old Holden and Chevy engines.

[2011G6E]

The cam chain in the OHC V8 engine in the Triumph Stag was often described as "the size of a bicycle chain and about as robust"...

That's why it used to be common to chuck that engine and fit something cheap and supremely reliable like a little 253 Holden V8 instead which slotted right in.

[123Cat]

Quite so

yes way back when the first bent 8's raced the rule were something like the engine must be stock , ugh with its single row chain ,, hope ,,,,hope it can make race distance , we know it can make power , we all know that they raced them straight off the showroom floor , unlike now

[123Cat]

It was Brocks 1985 Commodore single row chain that gave trouble

[XC50077]

I believe the VH, VK 4.2,5 litre and possibly VL 5 litre had double row sprockets fitted but only a single row chain utilized by Holden to save in production costs, and yes they did break in race applications. I had a VH 4.2 for 20 years and 180,000k without a broken chain.

[buickman]

The HT/HG Holden V8's had the double row chains and oil filled into the timing cover.

[Express]

Originally Posted by 123Cat

It was Brocks 1985 Commodore single row chain that gave trouble

And they changed to a double row in 1986 to add some reliability.


My old man bought an L34 brand new in 1976 and when he went to do a cam swap we were surprised to find a factory fitted double row chain, so anything is possible out there in the car world.

Particularly back in the years when everything wasn't so automated and regimented like today.


As far as double chains are concerned, everything wears over time and a single will usually do the job but if you are going to up the power or boost and it's only has a single, why not upgrade the chain as well just for piece of mind.

That's always been my way of thinking, don't do things by halves as there is every chance it could come back and bite you on the bum, causing you more expense in the long run.

[ebxr8240]

In race form it depends on cam profile and spring tension..
I think these parts where free to modify..
Keep in mind if he threw a rod ?
Breaking a timing chain or pressed steel rocker sounds much less damaging to product..
That's why you often hear them say alternator issues... A rod damaged the alternator..