Cleaning Exhaust Elbow Riser

[Horigan]

It's getting more difficult to acquire exhaust elbow risers for my OMC/Volvo Ford 5.0 EFI engine. I'm replacing one that's been on for eight years and it's not too bad, used mainly in fresh water, or in salt with immediate rinse in a fresh water lake.

I recall years ago on this forum a discussion about cleaning the internal corrosion in the elbow with a cable attached to a drill. Is that something anyone has done with good results? Given the reduced availability, I'm thinking of restoring and keeping the one I've removed as a later spare. Hopefully the used units I'm finding on eBay will be cleaner...

Just putting off the inevitable transition to a carb motor once one of my NLA Ford EFI components fails and can't be replaced.

 

[Scott Danforth]

I have cleaned out rare engine cooling jackets with a section of aviation cable chucked up in the drill after using oxalic acid.

not sure I would do that for an exhaust elbow since the rust flakes used to be cast iron.

you could have some fabricated from stainless. some 3" tube elbows, some 4" tube elbows, some laser cut flanges. would be similar to the elbows done by stainless marine. Its also how I did the cross-over on my motor.

 

[Scott Danforth]

there is also the ford manifolds from Hi-Tek https://www.american-hi-tek.com/hi-tek-replacement-exhaust-manifolds/

 

[Horigan]

KaChing!! Those sure look pretty.

I tried a bit of cleaning on the old elbow riser and the corrosion is tougher than I assumed. Found a couple of used risers on eBay for $80 that I'll pick up. They look better than mine. Only found one new one, at over $500!

 

[Lou C]

Is this because the EFI parts are mounted to the exhaust elbow, but the ones for carbed engines don't have that provision?
If that's the case can they be moved, or is the wiring harness not long enough to allow that so you can use the standard elbow?
Looks like most of the fuel system components and ignition components are NLA, too bad because it's nice to have port fuel injection, but even on Mercruisers of that age some parts are hard to find.

 

[Horigan]

They're different because the intake manifold is wider, so the elbow risers have a different shape to accommodate. On the starboard side the ECU mounts to the riser.

 

[Lou C]

Ah I see so as long as you keep the EFI system you have to use them. A carb conversion does make things easier

 

[Lou C]

Cast Iron Ford 4bbl intake
Holley 4160 or Edelbrock 1409
but if the efi is working well, might as well wait till it needs to be done

 

[Horigan]

So far I've been able to limp along. Other than an electronic failure, I'll be driven to carb when I can't get exhaust risers, or the fuel reservoir for the high pressure fuel system. Their hose inlets corrode. Last time I checked I couldn't find any.

If that happens I'll dive into an engine rebuild or long block to a 351 with a carb conversion. My compression is marginal, though the hole shot is fine. Lowest cylinder is 125 psi, with others 150-140 psi.

Once I go there I'll be following this thread as well as pinging you guys for input,
351 Conversion

 

[Scott Danforth]

you can always relocate the ECM and use the other manifolds and elbows

you can re-create the high pressure fuel tank setup (its actually simple).

you can rebuild the motor

what you cant do is replace the ECM or ignition parts without going full stand-alone.