V6 Timing chain questions.

[Rhysk94]

Run a dual chain. No tensioner.
Run 2x gaskets or maces new gasket (is thick enough)
& and machine oil pump cover to suit.

Have plenty of clearance.
No oil squirter is needed at all
But if your heart is set on it this would free up all the space and improve reliability

[vlad01]

Reading the docs that come with old and new roll masters, they really stress the point of good lubrication and that the higher the rpm, the more lube they need.

Interestingly, on the current docs, they say the damper can be used if desired. Older ones like have in my garage. say nothing about the damper. They still warn of needing ample and good oil.


Before my spare block went into long term storage on the shelf, I took these pics of roughly where I think a simple squirter could be drilled and knocked into. A small drilling from the oil groove in the block can easily go to the right spot for a squirter.
One could also make the squirter long enough that the space from the tip to the timing cover is smaller than the depth it is pressed into the block, so in the case of many mazda complaints, if it came loose somehow, it will be held captive and not become a an oil loss situation. Not that I expect a well made essentially a moderately hard drilled dowel to just come out. But that is my idea to safe guard that in the extremely unlikely chance it came loose. Having it knocked in will allow it to be smaller in diameter as it won't need a thread, the let holes would not be dependent on where the thread lands once tight (like many of the jap aftermarket squirters) and no thread means no weak points at the base where vibration could fatigue it, especially given the length needed and how narrow it would be not to eat into the block material too much under the bearing shell.

Again, the old holden V8s are a good example of how a well thought out chain squirter looks. Simple, easy, compact and effective! Of course some R&D would need to happen to determine the optimal metering drilling size, jet sizes etc to get ample oil without bleeding so much oil that pressure drops excessively. Te V6 with it high pressure pump and high volume will be a good base for this type of mod. Might be a good way to bleed off some of the excess pressure some engines have and actually put that excess oil to work!


Another thing I also think is worth looking at is getting the top sprocket's teeth hardened. This should reduce stretch in the way of reducing tooth an root wear and they are just left as the raw untreated steel. And yes, I have checked, the top one is much softer and can be easily shaved with a blade. The OEM ones are hardened on both sprockets. I also have an old NLA single chain gold series that is fully nitrided. I accidentally got that when I just ordered a single row set for stock engines, and found it was fully nitrided, I never seen the double row ones like that unless it was the gold series adjustable vernier type. Some weird and rare limited option they had at one point I guess.


There are a few places around that do gear hardening and nitriding, I think the hardening is ample and nitriding has downside of potential cracking from stress points as it is brittle, even though it's wear is less.

For when I build my all out engine, or any hot engine, I def will try to pursue the squirter and hardening of the top sprocket route. There def would be longevity there to gain.

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[Rhysk94]

I run the duals to 7600+rpm with 0 issues, no mods, no oiling and no tensioner.
With high spring pressure and big camshafts.
I think you are overthinking it all personally.

[vlad01]

But for how long? 20-50-100k?

Longevity and low as possible maintenance is always my top priority when I build anything modified, or stock for that matter.

My cam is 262 @050 and 303 adv, so I want to make sure stuff lasts, even on a moderate daily where I want the engine to last at least 300k, I'd damn sure want to make certain I get the most life out of a rollmaster as they are more sensitive to wear and upkeep than the silent style chains which gradually fail rather than a catastrophic event that roller chains are known for when they are not maintained properly.

[immortality]

I've seen some mighty sloppy V6 chains over the years which has to effect cam timing and chatter, the tensioner can only do so much. I've even had one V6 where parts of the tensioner was in the sump.

[vlad01]

Me too, but that is pretty much what I mean with the OEM style chains, they slowly die but keep going without catastrophic failure. I too saw plastic bits on a VY with 350k and had the mace rockers, had failed a valve spring too. But the stock chain never broke. Never seen one break as of yet, but on the rollmaster chains, yes I have seen a few breakage and I think a lot if it has to do with them overstretching from premature wear, the roller chains can jump teeth much more easily than the silent chain design I am finding, and I think this is where the sudden breakage occurs.

One hypothesis I have is for those cars that are hotted up but mostly cruised around and not raced, the chain not only whips more but also runs much drier, as most of the lube they get is from oil mist and windage spray, which is far far less at low rpm, bugger all up top if you have ever run an engine with the rocker covers off, up to around 2k there isn't much going on in terms of oil, hit the higher rpm and all of the sudden its like a winter storm, only with oil. The chains in these engines rely primarily from this oil windage to lube them.

I find it interesting that virtually no reports of double chain failures from engines that are raced but heard of a not so insignificant number of breakages early on in street cars. I think the dry or even intermittent dry running is wearing them prematurely or something like a seized /binding link maybe occurring from intermittent lube Chains nearly always break due to a binding, seizing or a jumping tooth situation, the later usually caused by one of the former, extremely rarely do they break from just load itself. "stretch" is well established as a side effect of wear and lack proper lubrication properties.

And like you said, a tensioner is a band-aid in a sense, a necessary one in most cases as nothing stays wear free forever, but the reliance on a tensioner should go down with adequate lubrication, and like wise, a tensioner will reduce the lubrication requirement somewhat as smooth chain to tooth engagement rather than rough one will protect the oil film and boundary conditions better in order for the lube to do it's job better. But like they say, more lube is better than not enough.


It's my opinion that a constant oiling of the double chains would be of high benefit long term, especially where a tensioner isn't or can't be used. And I can't see it being a massive deal as any proper machine shop and skills would make this rather straight forward mod. What is not straight forward is working out the specs of the squirter and it's metering and exact location relevant to the particular engine, that's the harder R&D part, doing the mod itself is nothing in the physical sense.

[Muncie]

Im running a dual row and ZZP tensioner/damper no dramas installing it i did use the machined pump cover and gasket from MACE and so far seems great it certainly has no noise from front of engine.

Ive left my balance shaft in just undriven and cant feel any difference.

[vlad01]

What was the quality of the pin like on your particular tensioner? The quality of the swaging that is. The one on their site looked pretty crap, but may have been an early one and I hoped they have improved.

Keep the thread updated. If you could do an inspection some time in the future after X amount of Ks noted, it will be a great data point, probably the only public one if you do.

[Muncie]

Didn't note anything off with the damper/tensioner it was better assembled than stock my previous engine ate pieces of a stock one.

Will have a poke around in near future

[immortality]

I had one on a VN where the bloody thing was in pieces in the sump. It still did a great burnout before I parted out the car.