Hey guys, looking for input here - I'm building a 2004 5.4 for an F150 (build write up and pics to follow eventually) and would like input on the iron vs plastic timing chain tensioners.
The 3V motors came stock with the plastic bodied tensioners. The problem was that with the original design, the little silicone tracer seal would blow out under oil pressure and starve the top end for oil, resulting in burned up cam journals and bearing caps. I believe they redesigned them along the way but they still look similar to the originals. My concern that since I'm using the Melling M360HV pump (HV/HP) recommended by youtuber fordtechmakeuloco, I don't really want to have issues down the road from increased pressure pushing the seals out.
I have seen where some guys have used the ratcheting iron tensioners in place of the plastic ones, but a little reading has also found reports of the plastic ones reportedly being superior because they control tension better. Evidently the iron ones tend to lock up as they keep too much tension on the chains and guides (I've seen pics of low mile guides that have chain marks in them - possibly from over tensioning?)
So now I'm a little conflicted. I really don't fancy doing this more than once, so I'd like to make as informed of a decision as possible. The upshot, is that I'm projecting maybe 60-80k miles on this truck, so million mile durability isn't necessary. I think that I'm leaning towards the plastic ones right now.. Not sure that I like the possibility of tensioners locking up and ruining the guides.
The 3V motors came stock with the plastic bodied tensioners. The problem was that with the original design, the little silicone tracer seal would blow out under oil pressure and starve the top end for oil, resulting in burned up cam journals and bearing caps. I believe they redesigned them along the way but they still look similar to the originals. My concern that since I'm using the Melling M360HV pump (HV/HP) recommended by youtuber fordtechmakeuloco, I don't really want to have issues down the road from increased pressure pushing the seals out.
I have seen where some guys have used the ratcheting iron tensioners in place of the plastic ones, but a little reading has also found reports of the plastic ones reportedly being superior because they control tension better. Evidently the iron ones tend to lock up as they keep too much tension on the chains and guides (I've seen pics of low mile guides that have chain marks in them - possibly from over tensioning?)
So now I'm a little conflicted. I really don't fancy doing this more than once, so I'd like to make as informed of a decision as possible. The upshot, is that I'm projecting maybe 60-80k miles on this truck, so million mile durability isn't necessary. I think that I'm leaning towards the plastic ones right now.. Not sure that I like the possibility of tensioners locking up and ruining the guides.