SOHC timing chain longevity

[2000StreetRod]

Soon I will be taking apart my 2000 SOHC V6 to determine the magnitude of my timing chain problems. I've been thinking about how to extend the life of the chains, guides and tensioners once my repairs are completed. I am convinced that the main cause of the timing chain problems is a Ford lubrication design deficiency. From what I have read on this and other forums the rear cassettes do not deteriorate nearly as rapidly as the front cassettes and have never been upgraded. However, the rear cassettes were manufactured from the same materials as the original front cassettes. Obviously, the rear cassette experiences the same number of revolutions as the front cassette. However, the front cassette does not receive lubrication as quickly as the rear cassette after the engine is started.

When I recently changed my engine oil from standard hydraulic to full synthetic I feared that my chain rattle would increase since the thinner synthetic would drain from the cassettes sooner causing a drier startup. Instead, my chain rattle seemed to decrease with the synthetic oil. I suspect that the reduced time it takes for the synthetic oil to flow to the upper front of the engine after startup is more important than retention of the oil after shutdown. I believe that is why adding the oil restrictor included with the 00M12 kit made little, if any, difference in reducing my chain rattle.

I believe that the secret to timing chain longevity is to keep the oil and the engine internal oil passages clean to avoid possible oil flow blockages and to use full synthetic oil to allow the oil to get to where it is needed sooner. I believe that is why people like aldive who use synthetics, a bypass oil filter, and rigorously monitor their engine oil condition have more than 200,000 miles on their vehicle but have not experienced timing chain rattle.

I have followed their example by switching to full synthetic oil and adding remote (for ease of replacement) full-flow and bypass filters and I encourage others to do likewise. After I correct my timing chain issues I intend to add a pre-oiler to maximize my engine longevity.

 

[petetheengineer]

what you have said is interesting and i agree that there is a lubrication problem.
I belive that the tensioners are flawed in other ways as well.
I have re built a few of these engines and have come to the conclusion that the plastic material used on the tensioner is not durable enough and very suseptable to wear. I belive that the oil pump is also very fragile and it preformance is affected severly by poor maintainance. I have seen evidence of this as i have rebuilt engines that have done 250,000 miles and been well looked after having oil changes every 12 thousand miles and in comparison i have in my workshop an engine that has done 64,000 miles and only had minimal services and the oil that came out was in a really bad state.
In my opinion if the engine is maintained to a high standard then it will last past 200 thou no problem. If the guided were made out of something a bit better wearing like umphe or other self lubricating material this would aid when the oil starvation occurs.

I am speaking from my background of mechanical engineering so i am not highly experienced in automotive engines but i am experienced in industrial machine design.