Checked your timing gear?

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Moparmal

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Id like to hear reports from people on what timing chain wear / stretch they've found after the first tear down or cam change.

I've always been under the impression that 360s and SB strokers are hard on chains, so maybe this thread can be used to gauge whats worked for people and what has been found to be POS stuff.

Some of it comes down to what the car is used for - so be sure to include that.
 
I have found that no matter what chain I used from the cheeeeep replacement to the expensive roller master or what ever, the all stretch. While the pricer ones with the better features stretch less, they still stretch.

Bar none on any size engine, be it daily driver or hot street car. Period.
 
Idling engines and stick shift engines are harder on chains, and a 360 being harder on a chain than a 318, would be impossible, there is no difference on cam gear....... remember, anything but a low idle the chain isn't slapping back and forth, the valvetrain overides the inertia of the camshaft and sprocket, so the chain is always on a tension, four speeds and low idling engines would cause a bit of slap, with the herky jerky from the clutch.

The older engines with the hollow cam cover bolt and deflector seem to have the chains last the longest, as long as they aren't nylon........

high paraffin oils also seem to collect of the chain, cutting iff the oil to the joints, because the chain runs cooler.

I put 110,000 on a cloyes double roller chain, sure, it stretched, but I saved it for re-use, it wasn't that bad, that chian spent he first 10K pulling a solid roller 590/610 lift cam too.
 
and a 360 being harder on a chain than a 318, would be impossible, there is no difference on cam gear.......
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The 360 is likely to be running more torque though the chain though, yes?

Thats not a big deal though - I am interested in the respective experiences in different brands.

As R/Fish says - seems they all stretch and 100K miles will see even the good ones "run out"

Mainly wondering of there's a huge difference between a Cloyes and a Rollmaster etc?
 
Here's the deal. Mopar put the cam much higher in relation to the crank than chuvy did. This is good when you want to build a stroker as there is more room for crank throw but bad in regards to chain stretch.

Comp Cams double rollers stretched noticeably after only 5K miles. Cloyes did after 15K but not as much as the Comp. I use a tensioner now on all my LA builds and my timing is much more stable, but the cam timing (and ignition timing) will still vary with use but the slop is pretty much eliminated. If I were to build a strip only Mopar with very high spring pressures, I would go with a quality gear drive like a Milodon.
 
rumblefish360 said:
I have found that no matter what chain I used from the cheeeeep replacement to the expensive roller master or what ever, the all stretch. While the pricer ones with the better features stretch less, they still stretch.

Bar none on any size engine, be it daily driver or hot street car. Period.
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My findings exactly. Only thing I'll ad is it does it on all small block Mopars. Not just 360's and strokers. The bigger/more aggressive the cam and stouter the valve springs the worse it is. I think the main reason is there is so much chain there since the cam is positioned up high in the block. The more chain the more stretch per link ads up.
 
fishy68 said:
The bigger/more aggressive the cam and stouter the valve springs the worse it is. I think the main reason is there is so much chain there since the cam is positioned up high in the block. The more chain the more stretch per link ads up.
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Yep!
 
Along those same lines what does everyone think about using a chain tensioner on a street driven stroker engine? I plan on building a 408 this time next year and don't know whether this will be overkill or not?!? Can you get away with just using a good quality chain and gear set?
 
yes, use a chain tensioner every time on every build on all small blocks.
 
BrianT said:
Along those same lines what does everyone think about using a chain tensioner on a street driven stroker engine? I plan on building a 408 this time next year and don't know whether this will be overkill or not?!? Can you get away with just using a good quality chain and gear set?
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Thats was going to be my next question - seems there's a few votes in favour......

R/Charger - RE gear drives - any issues with harmonics effecting valve spring life?
 
he my 340 from about 2 yrs ago time would jump all over the place put a new comp cam chain in it same slop same thing with jumping around...took motor apart and re ring,bearing and cam, gasket and add a cnine ten. and no problem with the time now except a little slop in the dist. need to tighten the shift up a little in the drive...soon to come....i plan to use the ten. for all my new builds ....read on moparts that some of the big name (builders ) had a post and they would not run without one...8)
 
They all stretch and they stretch fast. Thats Mopar started using a tensioner on the Magnum motors. Great investment for $35
 
Can I add a chain tensioner on a '67 273 commando engine? If so, how's it done?
 
intergalactica said:
Can I add a chain tensioner on a '67 273 commando engine? If so, how's it done?
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Yes. Basically the same as replacing the chain & gears/sprockets (whatever the correct name for them is) except that while you're in there you remove the camshaft retaining plate & replace it with a chain tensioner.
 
Moparmal said:
Thats was going to be my next question - seems there's a few votes in favour......

R/Charger - RE gear drives - any issues with harmonics effecting valve spring life?
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Not so much spring life as cam life as any torsional movement is transmitted directly to the cam without the benefit of a chain or belt damping vibrations. The opposite is also true with a cam at super high revs transmitting harmonics to the crank. A really, really good harmonic damper is mandatory and balancing needs to be spot on as well. My machinist showed me an infrared video he took of a valve train on a spintron fixture at 8k and 9k when he had the Busch series contract. It's amazing what goes on. Everything seems to turn to rubber.

I've looked for a belt drive for the LA's and have been unsuccessful so far. I imagine it would also require an electric water pump.
 
My 65 273 chain was sloppy and worn when I took it apart. It only had a few hundred miles on it since a rebuild. The chain was dry! I drilled a tiny hole in the cam plate where it blocks the oil galley for the lifters. I swear some came that way from the factory, but mine had no provision for oiling the chain. No hollow bolt or slot on the cam retainer plate either. I thought that was weird. When I went through the engine last winter I put in a roller chain that now stays oiled.
 
No, from the crank gear up, the 360/318/340/273 is/could be identical. THINK abou it...........
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Try this for a THOUGHT........:thebirdm: Hahahaha!!! ;)

But seriously - work with me on this and tell me where Im wrong......

As a GENERALISATION (lets assume factory builds to keep this simple) ,

.......a 360 will generate greater rotational force though the crank than a 318, simply because as a general rule, the explosions in the cylinders are greater, and thus make more rotational torque.

I think Im safe in assuming that anyway.

Now - This rotational torque is tranferred through the timing chain to the cam gear and valve train.

I hope thats a correct assumption?

IF........the rotational force through the chain is greater as the engine climbs through the rpm, wouldn't that mean the chain is subject to greater stresses?

Anyhow - Thats the basis of why i was told 360s were harder on chains than 318s "as a general rule of thumb"

Make sense? - or is there a flaw in the logic?
 
There is a flaw in the logic. The flaw is:

It only takes so much to turn the cam and valvtrain on type A (318) engine, if you take the valvetrain and put it in type B (360), even though the engine makes more power at the crank, the cam and valvetrain use the same power, because the cam gear is so light, and the cam is so skinny, there really is no rotational force, so the chain is always slack to one side. No matter what engine it is on.

UNLESS..........

The idle is low.
The idle is lopey, and too low.
Herky Jerky four speed driver.

If anything, the heavier crank of the 360 would make things smoother on the inside, therefore, making the chain last longer.

And it has been from my experience, that the 318 winds faster, and decelerates faster, in stock form. That would be rougher on the chain, than the slower reacting 360.

I think the chain not lasting as long in a 360 is a wives tale....... or, "motoheads" tale...... Whichever you prefer.

Now quit flipping me off. :thebirdm:
 
Moparmal said:
Try this for a THOUGHT........:thebirdm: Hahahaha!!! ;)

But seriously - work with me on this and tell me where Im wrong......

As a GENERALISATION (lets assume factory builds to keep this simple) ,

.......a 360 will generate greater rotational force though the crank than a 318, simply because as a general rule, the explosions in the cylinders are greater, and thus make more rotational torque.

I think Im safe in assuming that anyway.

Now - This rotational torque is tranferred through the timing chain to the cam gear and valve train.

I hope thats a correct assumption?

IF........the rotational force through the chain is greater as the engine climbs through the rpm, wouldn't that mean the chain is subject to greater stresses?

Anyhow - Thats the basis of why i was told 360s were harder on chains than 318s "as a general rule of thumb"

Make sense? - or is there a flaw in the logic?
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more cubes has nothing to do with it. dodgetkboy78 is correct. i would add to his list a bigger "bang" IE: more volitile fuels will stretch the chain too, backfires, timing, starter kickback, etc. if your worried use a chain tensioner.
 
dodgetkboy78 said:
There is a flaw in the logic. The flaw is:

It only takes so much to turn the cam and valvtrain on type A (318) engine, if you take the valvetrain and put it in type B (360), even though the engine makes more power at the crank, the cam and valvetrain use the same power, because the cam gear is so light, and the cam is so skinny, there really is no rotational force, so the chain is always slack to one side. No matter what engine it is on.

UNLESS..........

The idle is low.
The idle is lopey, and too low.
Herky Jerky four speed driver.
Click to expand...


Good thought - you DO know something !! ;)
 
'64 Cuda said:
Yes. Basically the same as replacing the chain & gears/sprockets (whatever the correct name for them is) except that while you're in there you remove the camshaft retaining plate & replace it with a chain tensioner.
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Can this chain tensioner be bought at the dealer?What engine do they come in?Magnums?Thanks for any help.
 
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