The difference is that the early ones were molded plastic and would leak at some point. Ford eventually changed the design and made them out of cast steel/iron.

There is no difference as far as functionality between the two designs other than robustness. You want the metal ones, not the plastic ones.


ks

 

That’s exactly opposite from what I read and see when I tried to buy only sell the cast iron up to 2000. From 2000 on they sell both styles? From what I’ve read now, the early iron ones had a ratchet that can cause too much pressure on the tensioners in some cases, so they switched to the plastic (and likely cheaper solution). Most people seem to agree with you that if you don’t have a high pressure oil pump or race the engine at high rpm’s, the cast irons work fine and aren’t prone to leaking like the newer ones. If you use the plastic it is recommended to use the FelPro gaskets to solve the leaking issue.

 

Use the steel ones in ALL applications. For anyone that is worried about the ratcheting issue (yes, this has been an issue at times) there are two different mods to choose from and both are listed locally on this website.

Here is THE ALL of everything it takes to build one of these motors. Keep this link in your back pocket:

https://www.modularfords.com/threads/03-04-svt-cobra-terminator-table-of-contents-ttoc.74284/?post_id=787796#post-787796

The tensioner mods depending on your ability:

Starting on POST #258:

Aluminator Gibtec Build

Thread update: Table of Contents Since this thread has gotten long and I've received many PM's on Facebook and e-mail with questions about the build, I figured a ToC would help anyone searching. It is based on 15 posts per page, and is also broken down in groups and now with hyperlinked post...

www.modularfords.com

This is the most simple method that you should be able to do with a simple grinding of a few of the ratcheting teeth to relax the tension when the motor is shut off:

https://www.modularfords.com/threads/ratcheting-style-chain-tensioner-mod.214602/?post_id=1995938#post-1995938

ks

 

I see some sold with backing plate and many without. Is there supposed to be a backing plate used with them?

 

Interesting question.. Mine never came with the plates and I've never seen them referenced anywhere in the builds..


ks

 

Mine did not either. I think the backing plate might be for heads that have had the mating surface damaged slightly. If the plate is fiber and not metal the intent is to seal up leaks created by the damage to the sealing surface. If it is metal, I have no explanation.

Like Kevin, when I assembled mine, I used no gaskets or backing plates. I bolted the tensioner directly to the head.

 

I ordered a set, so I’ll let you know what the plate are made of in a few days.

Does anyone have a picture of how to trim the theThe off the rackets?

 

Search function is your friend. The different motor builds on this forum (the ones in your back pocket) are HIGHLY detailed and will answer just about every question you will have. The thread linked below is THE most detailed for every single component that you will ever see on the web. Here's the tensioner mod:

https://www.modularfords.com/threads/aluminator-gibtec-build.236857/page-11

ks