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Riser and Elbow Removal

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major_tom

Regular Contributor
I need some help on removing the riser/elbow assembly on my fresh water cooled crusader 454 gen IV engines with log style manifolds.

I drained the coolant from the exhaust manifolds and removed the four nuts on the riser studs. Then I beat the riser/elbow assembly with a 3 lb hammer but no luck. I guess I'm going to need a BFH and some eye and ear protection.

Between the exhaust manifold and the riser is a small spacer block that is also fresh water cooled. I'm worried I'll damage the spacer block and/or the exhaust manifold if I use excessive force....

Any help would be appreciated.

Best wishes,

Tom
 
So, the only thing adhering the riser is the gasket, correct? The 4" exhaust hose is off? It's a little risky, but you can consider using a thin chisel between the riser and the donut, staying on the AFT side of the stainless block off plate. You will replace that anyway.

Does the manifold have an unused pipe plug high and aft? ANd, do you use non-riser type elbows? If so, you might consider removing the donuts as well, and transferring the 1 1/4 hose to the exh manifold. This will remove those long studs and a gasket joint as well. Then, you can use 1" long 12 point bolts that make this job easier next time. I've done this exact job, it does make the exhaust hose an inch too short, but you may have extra on the fittings.
 
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Dave,

You got me going on this one too....I had asked this question a few years back about eliminating those water adapters and seemed as though it was not happening. I only replaced the elbows last week and that entire thought came back to me. Are you saying to just move the hose that comes from the heat exchanger to the exhaust manifold instead and keep the ss block off plate between the elbow and manifold and attach the coolant hose to the manifold ?

Tom, if its any help, I used one of those 5 in 1 painting tools that looks like a scraper with a 1/2 moon cut into it and tapped the space Dave talks about, I used dry gaskets in the original install and they stuck VERY WELL. Took a little effort to clean the surface for the new install
 
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Diver Dave the risers are Osco 7169 and the elbows are Osco 8086. Not sure if the elbows are the non-riser type or not. I presume not. I did not remove the 4" wet exhaust hose from the elbows because it appeared flexible enough that it would not prevent breaking loose the elbow/risers from the adapter. Maybe that was a mistake.

I had also considered using a chisel or wedge but did not want to bugger up the mating surfaces. Staying on the aft side of the SS block off plate is a good suggestion but at some point the SS plate will also have to come off.

My manifolds do have an unused pipe thread plug at the top that could accept the coolant hose from the heat exchanger. As you suggest this would eliminate the spacer/adpater, which might be necessary anyway if it gets damaged during removal. Since I had not seen a replacement adapter in any of the online catologs, I was concerned about damaging this part. It now appears I have the option of removing it and eliminating a gasketed joint in the process.

I don't understand how I could use 1" long 12 point bolts next time. Is the 1" a typo?

I am armed with a larger hammer and eye and ear protection. Since both you and Al suggest the careful application of a wedge-like device, it looks like I'll be trying this method tonight.

Thanks for the suggestions.
 
OK, you have 8" risers. I have none, and go right to the elbow. So, the 1" x 3/8" bolt idea won't work for you. You can still get the donut if you end up needing them. CRUSADER 97295 Crusader Water Spacer Block. Your friction problem is those long studs that rust and cause seizing of the iron parts.
 
By the way Tom, I have 4" hardwall with the wire inside and it is only 12" long before it attached to the muffler....it adds plenty of extra support unless it is already reasonably loose so it may be a good idea to remove the hose first. Once you lose the ability to have the elbow attached on the engine to support the hose removal process, it may take a bit more effort to slide the hose off of the elbow. Like a giant vise to hold it and tons of lube to slide it
 
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Thanks very much Dave and Al. I'll remove the exhaust hose. This will allow inspection of the elbow.

And now I know what is holding the risers on--the long studs are rusted to the cast iron risers. Wasn't 100% sure of this until I read your posts.
 
You may have a little luck if you can get two nuts on and tighten them against each other then try to unscrew them or even just break the bond
 
Well I got one side apart. Took a lot of beating with a sledge hammer. Aslo used a woodworkers chisel as a wedge. Mostly the sledge hammer, though. Hope I didn't damage the exhaust manifold to head gasket, or worse, the head gasket itself. Will take a break to let my inuries heal and then tackle the other side. Replacement parts arrive Friday.

One of the riser raw water cooling passages was clogged with rust and sheeted cast iron. Also evidence of rust at the raw water connection port on the riser. No evidence of rusting through to the central exhaust chamber....
 
Tom:

If you can get an air compressor to the boat, you may find an air hammer may help to loosen things. I'd use the largest flat anvil available and just run it up and down the casting where the studs are, along with some PB blaster (or similar).

normally, I'd get a torch out and heat things up but I don't think your install will let you do that safely.
 
I think I will try the compressor and air hammer on the other side. Maybe some heat too. Doesn't appear that dangerous so I long as I don't get careless. The studs are at a down angle of about 5 degrees and also 10" long so the pbblaster isn't having much of an effect.
 
Rosebud with the O-A tank set....serious heat. I don't think a MAPP cylinder will get the riser hot enough to destroy the paint (while still bolted together).
 
Those risers can be dangerous! actually the bfh can be dangerous.After I hit myself in the knee with the aforementioned BFF, I decided to remove the whole manifold, riser assembly and everything else in one piece.
Once I had the pieces out and on the ground (two engines, four assemblies), I was able to swing hammer, use chisels and other implements of destruction to break them apart with minimal damage to the manifolds or me.
Putting them back in one piece at a time was also relatively painless.:)
HAVE FUN and remember "what doesn't kill you only makes you stronger"
 
knuckle47 said:
...just move the hose that comes from the heat exchanger to the exhaust manifold instead and keep the ss block off plate between the elbow and manifold and attach the coolant hose to the manifold...
Click to expand...

I put the FWC on my new engines. I bought the parts based on the Crusader parts book, including the donuts. They saw me coming! The OSCO manifolds will accept the FWC and the 8" risers are fed through the bottom drain plug rather than the elbow.The block off plate between goes between the manifold and the riser.

Anyone need some donuts and extra long mounting studs?
 
I'd heat the "female" parts, Al. The resulting expansion/contraction cycle usually helps get things free. We used to use it to take apart the lower units, especially on the ancient beasts that lived most of their lives in salt water.
 
When I looked down the clearence holes in the old riser where the riser studs go, there was light coming from the raw water passages. Hard to believe it was desgined like that--must have rusted through from the raw water passages to the stud clearence holes. This explains why they were hard to remove. Probably not long before it rusted through to the center exhaust passage....

On reassembly I want to get the benefit of Diver Dave's experience by coloring the gaskets with a thin layer of Ultra Black RTV. Is this the recommended sealant, or would another one be a better choice?
 
Ultra black or ultra copper will be fine. They are excellent high heat, water proof sealants. Use your fingers, as thin as possible.
 
Tom:

Several posts recently reiterate the use of copper sealing washers, under the nuts, on the studs. With that being the OEM setup, I'd suspect the design is to have the studs "wet". Being as I got rid of the "logs" decades ago, can't offer much more.
 
Yes, the studs are "wet" in the olde log style setup. The copper washers do provide a seal as do the nuts. I was told not to reuse the washers or nuts. The plastic inserts in the nuts actually seal an water from traveling out via the threads in the studs. Seems like a pretty stupid design to me.

Erich
 
I agree the nylocks and copper washers do not seem like the greatest design.

With the help of my 15 year old son I got the other side apart and then everything back together.

Went against the Osco instructions (install gaskets dry). Took Diver Dave's advice instead and used a thin coat of ultra black RTV on the gaskets and no leaks!

Still have a temp rise from 160F to 180F with the new risers/elbows at a 3200 RPM cruise. Previously would climb to about 185 under the same conditions, so about a 5 degree improvement. With 160 degree thermostats installed, this is still not what I was looking for. The other motor rises about 5 degrees.

Installed a new impellor and new coolant the week before. The heat exchanger was prof. cleaned last year. Looks like its time to remove and service/replace the u cooler. Will aslo check the raw water instake for leaks at the strainer and obstructions.

Thanks for the help.
 
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