Hopefully not much later.

 

Haven't seen this in any 2.5 swap threads. Why?

 

Dunno. But I'm glad I caught it. Prob wouldnt have noticed if I hadnt popped out all of the oil passage plugs and replaced with tapped in set screws a while back.

 

2.5 stock timing cover: (note where you can see where there's a flat surface on top of the middle bolt hole to cover the oil passage)

2.5 head: (I've already tapped and plugged the hole w/ 7/16 - 20, 1/4" or 3/8" length set screw. The length had to be shallow enough to not block the oil passages inside. It's not just a straight shot, there's an oil passage that also connects into it from the top.)

Aand here's the stock 2.3 timing cover. Note the lack of a flat surface to cover up the hole...

 

Here's another pic that shows the impression after I popped the 2.3 cover off:

 

I'm sure if the oil hole caused a massive loss in oil pressure to the head as you say there would be lots of threads about 2.5 engine failures. I haven't seen that yet. Have you actually installed your 2.5 yet to verify? Not being argumentative just trying to clarify if there will really be a problem. Additionally does the later model 2.3 cover for the fusion/Milan lack the boss as well or is it just the focus 2.3 cover?

 

Looks like the fusion/milan cover indeed covers the hole.

 

Hm, good to know. Guess it's just the focus covers that dont cover the hole. Would certainly be easier just to grab one of those 2.3 fusion/milan ones and be done w it.

All I know, is that hole is definitely part of the oil pressure rail that feeds the cams and VCT. Personally, I didn't feel comfortable leaving it that way. Just sharing info here, do with it what you want.

 

Yeah. Thanks. Can't be good losing oil pressure there. I'll be doing another 2.5 build soon and will investigate this more. I appreciate you responding.

 

I've seen this posted before and actually reciprocated by what I would normally consider decently reputable folks like the folks at Esslinger. Brian's post stating the same was actually where I read this first and it freaked me out as I also did not do anything to this oil passage on my focus build. I did do a hot oil pressure test after my build and it was good, 10psi idle and 35 at 2k rpm. Those sound low but these run really low pressure all around and are in spec. I also thrash mine all the time and have run lots of autocross days at this point and it runs like a top so I'm skeptical about what the passage actually is. I'm suspecting that it might be just a cross-drilled port to get somewhere else and may not be under pressure.

I'll be literally picking up a couple 2.5L's for another project tomorrow morning and when I pull the head off one I'll try to trace that passage and see where it goes. Maybe we can get to the bottom of it.

 

Also,

I'd take some brake parts cleaner and just spray into one of the cam oil passages when everything's apart. I would but I gotta get this dumb thing back together. Been getting my cam buckets in spec, even with leaving the stock 2.5 exhaust cam in, they were all still way out of spec. No wonder these motors make so much noise when idling. 0.012"-0.014" on the intake side, and 0.014"-0.016" on exhaust. Every one of them loose and out of spec on a 60k grandma LKQ engine.

 

Alright, while I was waiting for the yard to call me I remembered I actually have a core 2.5 head sitting on the shelf that I was able to do some looking on.

The port in question is definitely in line with the red circled port on the deck side of the head and is part of the VVT oiling circuit.

This is the port in question on the timing cover side. The circuit runs up to feed the vvt solenoid but also to the rear of the head where it's capped off.

This is the end going into the cap for the VVT solenoid. This is an early VVT style head where the #1 cam caps are separate.

So it does seem to reason that you would be dumping oil pressure if you did not do anything about that port even though I've tested the pressure to be in spec without doing so. You would definitely not be able to use the VVT without doing so if you were attempting to so for some reason. I also see swaps where people leave the 2.5 VVT cam and phaser in, but I would reckon that the phaser would fail to lock in it's full advanced position.

I did double check and this circuit does not feed any of the cam journals except the first intake cam journal. The rest are all fed by the oil passage circled in yellow in the first picture.

One of the engines I will be picking up later is going to be a high compression bottom end for my focus. I guess I'll plug this port on the next head going on. Before I pull the old motor, maybe I'll do another oil pressure test on it and the new one and see if there seems to be any appreciable difference. Even though the real scientific approach would be to do it on the same motor. I'll look at the old motors first intake cam cap too and the cam journal and see if there's any wear.

Interestingly, where the oil passage is plugged on the rear of the head, it looks like it was setup to act as an oil feed possibly for a turbocharger.

It could probably be drilled with a flare and tapped. You'd have to be careful though because it's so close to the other hole and on the focus that threaded hole is used for an alternator stud. Interesting though.

 

That front port in the 2.5 block feeds the VVT and the front intake cam bearing.
My 2.3 block didn't have that port, so I plugged the passages in the front cam cap, and drilled 2 small holes from the front journal down into the cam oil galley to feed that journal.
I also plugged the hole in the deck surface of the head.

IIRC, my mods eliminated oil to the passage at the front cover. I may have plugged it anyway.

Do your own research and trace your oil passages when making mods like this.
Make sure oil gets to where it needs to be, and nowhere else.

 

I used a timing cover from a 2008 Mazda 3. Same motor mount as the focus and blocks the oil passage. It does use the larger harmonic balancer and has the wider spacing for the crank sensor so the factory focus parts don't work on it but since I was running a haltech I was ok with that.

 

The 2.3 Timing cover covers that hole

Tom

 

The 2.3 focus timing cover I have does not cover it

 

Then drill and tap it and put a plug in it

Tom

 

That's a great option if the head is off and you can ensure you don't get aluminum shavings in your oil passage.

 

no concern here. i run the mazda timing cover and the 36-2-2 reluctor wheel since I'm running a haltech and that's in the dropdown menu

I used a timing cover from a 2008 Mazda 3. Same motor mount as the focus and blocks the oil passage. It does use the larger harmonic balancer and has the wider spacing for the crank sensor so the factory focus parts don't work on it but since I was running a haltech I was ok with that.

Right, we know