Idler Pulley for 2.3L Duratec w/ exhaust side alternator mounting

[ashyers]

I'm looking for options for an idler pulley that mounts above the water pump on a 2.3L Duratec with exhaust side alternator mounting.

 

Currently I have a Ranger timing cover that has a different belt arrangement than the typical FWD version of the engines due to the fan drive pulley. I run a 50amp alternator on the exhaust side. I'm converting to a Brise mount on for the alternator and deleting the fan drive stuff.

 

Here's what Raceline offers:

 

https://www.raceline.co.uk/products/part_details.asp?categoryID=1&SectionID=20&VariantID=130

 

Does anyone have one for sale or any clever ideas that may work with factory stuff? I know they used a bunch of belt arrangements on the Duratec.

 

Thanks,

 

Andy

Edited January 13, 2023 by ashyers
added photo of belt arrangement

[MV8]

If anyone is curious, the pic is of a fwd cover with a dry sump showing aftermarket drive components.

No experience with the duratec but I've made a few belt drive adaptations and brkts for vee and serpentine belts.

I'd remove the fan drive from the cover, check fan drive boss clearance with a ruler or straight edge between the alt and upper right idler. If there isn't a 1/2 inch or so of clearance for dynamic belt flop, I'd mill the boss and/or raise the idler and/or raise the alt.

Should be able to use an oem tensioner to the left of the crank if you can get the belt length right. This would be just long enough to allow installation with the tensioner pulled back yet still have enough tension when released.

For coolant pump wrap, it would be better to fit an idler between the crank and oil pump behind the gilmer belt but you'd need some creativity with the ranger cover, since it has no provisions. If not fitting a dry sump, I'd probably put the fwd alt where the oil pump is and eliminate the need for the idler.

[MV8]

Pic for the words.

[JohnCh]

I've run the Raceline tensioner on my 2.0L Duratecs since '04.  Picture below shows that setup on the most recent engine.  Although the belt gets very close to itself, it has never been an issue.

 

 

For the Caterham with the 2.4L I had planned to do the same but discovered that clearance between the pulley and one of the chassis tubes is really, really tight.  They didn't touch but until the engine was in its final position with the trans on and mounted to the chassis, it didnt inspire a lot of confidence.  I don't have a great picture to show the gap, but these two will give you an idea.  The fix, if needed, is very simple: just a flat metal plate that bolts to the stock block locations and is drilled to mount the tensioner ~3/4" higher.

 

 

 

I considered using the Ford self-tensioner as fitted to stock Caterhams but discovered it won't fit with Jenveys.  It's a large, bulky part and attempts to occupy the same space as the left-side throttle shaft.  The first photo shows it in place on the 420 engine.  If you look closely, you can see it uses the two top mounting bosses, whereas the Raceline only uses the lower bosses. 

 

 

 

 

Couple of other points.  First, the 2.3L block is 13mm taller than the 2.0L.  I suspect that when the tensioner wheel is lowered by that amount relative to the chassis, the clearance reduces further so although it isn't a consideration for you, I/m mentioning it for anyone else reading this who has a 2.0L.  Second, Raceline uses a different bellhousing than Caterham which shifts the engine back in the chassis about 20mm.  This renders the potential interference with their tensioner moot as it would now sit well back of that chassis tube.

 

-John

[ashyers]

MV8 and John,

Thanks for the suggestions and photos. I included a photo of the setup the car came with. It has worked fine since carefully aligning it when we rebuilt the engine, but it's a bit wonkey and I'm going to swap it out when I get the opportunity. I'm really curious to see if the stock Ford self-tensioner would fit with my early SBD/Jenevy throttles and Arch chassis. John, do you know the P/N?

 

Andy

 

[JohnCh]

The part number used on the 420 engine is 3M5Q-6A228-AE.  Here are a few more photos to help you visualize the interference with the current Jenveys which might help answer your question about your SBD TBs.  

 

Front view of tensioner.  Similar to yours but there is no forward-facing bolt.

 

Top view of the tensioner.  Note where the top mounting bolt is in relation to the 420 intake runners

 

This picture shows that same bolt boss in relation to the edge of the Jenveys and the throttle shaft.

 

-John

[ashyers]

John,

Thanks! That's a huge help. Did you notice it's made in Turkey? Wow.

 

I'll take a look tomorrow and see if it looks like it will fit.

 

Andy

[JohnCh]

That caught my eye too and I had the same reaction.  Shoot me a PM if you need any measurements.  

 

-John

[ashyers]

John,

Thank you for all the photos. It looks like the throttle shaft is in approximately the same position on my car, so the Ford tensioner won't fit without some hacking and whacking. Raceline or fabricating a new one looks like the best option at the moment.

 

For future reference the Gates P/N is 38318.

 

Andy

Edited January 16, 2023 by ashyers