3V Ford Iron tensioners vs plastic

[The_Eric]

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.

 

[clinebarger]

I run the Melling 3-391SC Timing Set, Have had outstanding luck with them in conjunction with the HV oil pump!! Comes with plastic tensioners.
I purchase the latest Phasers from my local Ford dealer.

If you don't know the shortcut on these (Don't have to remove any rocker arms).....Let me know!

 

[The_Eric]

What kind of time back in service are you looking at for the melling kits (tensioners)?

I'll be running all OE parts in mine - lightly used from the current engine, with exception of tensioners and cam phaser bolts.

On the followers, are you talking about the trick where you pry them in/out with a screwdriver?

 

[clinebarger]

I tore down one that had almost 70,000 miles on the plastic Melling ones, 2007 F250 service truck that broke a valve spring. This truck ran nearly 24 hours a day.
No torn seals!
If you're piecemealing it.....Buy one's from Ford as they are identical to the Melling ones. The Melling kit uses all Ford parts with the part numbers ground off.


Set the crank keyway to 12 O'clock (With both cam marks up) This sets all 8 pistons below TDC, NO need to remove any rocker arms. With the "colored" links.....Having the engine at TDC isn't needed or required.
Use a pair of vicegrips to manipulate the camshafts while installing the chains.

 

[The_Eric]

Oh I misunderstood you... Yep, that's how I do them.

Thanks for the tip on the melling kit - I'll definitely remember that when I do another.

 

[bdcardinal]

Obviously I am supposed to tow the party line and say Ford all the way, but Melling is my go to choice for oil pumps that are in the factory location. As for the other timing set parts, I usually stick with Ford because they are 2 rows behind me at work, but Melling is good stuff.

 

[The_Eric]

Originally Posted by bdcardinal
Obviously I am supposed to tow the party line and say Ford all the way, but Melling is my go to choice for oil pumps that are in the factory location. As for the other timing set parts, I usually stick with Ford because they are 2 rows behind me at work, but Melling is good stuff.

I'm a big proponent of OE stuff in many cases too, but I'm always on the lookout for better value for customers.

Bdcardinal, out of curiosity, do you know if the plastic tensioners have been revised or redesigned?

 

[FlyNavyP3]

Originally Posted by clinebarger
I tore down one that had almost 70,000 miles on the plastic Melling ones, 2007 F250 service truck that broke a valve spring. This truck ran nearly 24 hours a day.
No torn seals!
If you're piecemealing it.....Buy one's from Ford as they are identical to the Melling ones. The Melling kit uses all Ford parts with the part numbers ground off.


Set the crank keyway to 12 O'clock (With both cam marks up) This sets all 8 pistons below TDC, NO need to remove any rocker arms. With the "colored" links.....Having the engine at TDC isn't needed or required.
Use a pair of vicegrips to manipulate the camshafts while installing the chains.


The Ford OE parts are made by Melling. So really the Ford parts are Melling, the parts not sold at the dealer are identical save for the removal of the Ford number.

Melling makes quality stuff, have used it successfully for a few decades.

 

[emmett442]

I'm a fan of the old style iron ones. Melling made both the iron and plastic ones for Ford. They still provide both in the aftermarket.

The most common failure point is not the tensioner mechanism itself. Rather, it's the seal between the engine and tensioner body.

The plastic tensioners require a gasket in that location, creating a potential failure point. On the other hand, the rigid iron ones are machined flat and mate perfectly to the machined pad on the engine, with no gasket. No failure point.

 

[bdcardinal]

Originally Posted by The_Eric
Originally Posted by bdcardinal
Obviously I am supposed to tow the party line and say Ford all the way, but Melling is my go to choice for oil pumps that are in the factory location. As for the other timing set parts, I usually stick with Ford because they are 2 rows behind me at work, but Melling is good stuff.

I'm a big proponent of OE stuff in many cases too, but I'm always on the lookout for better value for customers.

Bdcardinal, out of curiosity, do you know if the plastic tensioners have been revised or redesigned?


I just checked on the shelf as I stock them and the Ford ones are the plastic housings with a gasket and metal internals.

 

[clinebarger]

Originally Posted by emmett442
I'm a fan of the old style iron ones. Melling made both the iron and plastic ones for Ford. They still provide both in the aftermarket.

The most common failure point is not the tensioner mechanism itself. Rather, it's the seal between the engine and tensioner body.

The plastic tensioners require a gasket in that location, creating a potential failure point. On the other hand, the rigid iron ones are machined flat and mate perfectly to the machined pad on the engine, with no gasket. No failure point.


Didn't know that, Learn something new everyday! Make sense as every Melling kit I buy for Fords has the good stuff in it.