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91 454 riser /elbo reassembly... Grease studs? Anti seize, gasket seal rtv

S

slauder

Regular Contributor
Risers came off studs with 5 pound hammer. Was going to reuse studs but better safe to get new studs kits.

Assume I should anti seize the threads. What about the length thru the risers.... Should I grease them or more anti seize?

I will use rtv permatex #3 black for gasket sealer. Do I worry about too much of either?

Also I didn't get a new hose nipple for riser. How do you guys get the old one off without tearing it up with vise grips
 
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I'd suggest using locktite on the studs going into the manifold...it will eliminate any post install leaking at those joints...antiseize over the rest of the studs won't hurt.

Permatex #3 is NOT RTV...use any sealer sparingly but uniformly on the gaskets - don't forget to orient them correctly.

remove the old hose barb with a properly fitting wrench, not vice grips...if you don't have one available, a pipe wrench should work...if you have one available, a torch to warm up the cast iron will help...
 
Lock tight on threads into exhaust manifold... Which lock tight? I recall they come come in 3 kinds (color coded). I think you mean semi permanent. At first I was thinking you we're joking since many are having to drill out broken studs, but the lock tight will stop corrosion, yes?

ps. The old studs came out nicely and had black sticky sludge but were manageable and not corroded. That's why I thought grease. Maybe it was just dirty buildup?
 
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Blue should be fine...yes, it will seal the threads and stop any corrosion, at that joint anyhow...the antiseize should help where the studs pass thru the cast iron.
 
I use anti seize along the length of the studs. Most of the time they come off after 5 years ok. I did have one freeze this year - a little too much "Mechanical persuasion" and I broke the studs I was able to Ez out one stud but then broke the EZ out. Hello new manifold :(I have another engine to finish this week. Hopefully that is smoother
 
Uuugh! Broke a few of those off myself. The only way to feild remove them is pound them to death with a succession of punches. Nasty!

Why be careful with RTV on gaskets? Excess sealer can flow downstream and block the holes where the water and exhaust meet. That restricts water flow to that side, causing local over-heating. I now use RTV (despite OSCO's advice) since I've seen tooo may weap leaks of water getting into the motor.

Jeff
 
http://www.marinepartssource.com/crusaderpb/3507dp63.asp I don't understand the gaskets... I have a full block shim #38 with 3 hole gaskets on either side #37. What are the holes in gasket for if they are up against a no hole block off shim! I want to understand why. I actually think I saw my gaskets that came off only had 1 hole.

Can someone confirm either 1 or 3 hole needed for 91 454 4" riser on log style manifolds. Also why the holes if on block off?
 
Crusader has two gaskets, the one hole and the three hole. both also have "tabs" that are visible with the gaskets installed. the tabs are always installed in the "up" position, by convention (12 oclock for a single tab and, for the double tab, with them symmetric about the 12 oclock position).

At the block off plates, you can use either gasket...I think the 3 hole gaskets are slightly cheaper than the single hole gaskets and are recommended for use at that point. Ideally, you would want a "no hole" gasket but they decided not to make one - I'm sure for cost savings.
 
i sent you a diagram via email...the old bar c l a y s address...yes, misspelled to get the 'bots from sniffing it...
 
Where do I get the exact torque settings for studs into manifold, stud nuts on riser, and star bolts holding elbow to riser. My crusader manual doesn't cover these replacements. I snugged the studs to mani with 3/8 drive and thread lock. I remembered DD posted 25 ft lbs for riser nuts. I have to do the elbows tomorrow AM and realized I didn't have the torque in the book. I used a 1/4 drive with socket to take them off since its tight area to get wrench on.

P S. do I thread lock the star bolts too? Planning to.
 
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I would tend not to use thread lock on an assembly that is known to need retorquing after the first hot/cold cycle. If you choose to thread lock, wait until a few hot/cold cycles, keep the assembly torqued, and only then threadlock, one bolt at a time. This will give time for the gaskets to compress to near final values. THese gaskets are fairly thick, especially with the block off plate, where two gaskets are used. I've had to hand craft 12 point box wrenches to fit into these spaces, and can't use a torque wrench on many.
 
Good point Dave, I only thread locked the studs into the mani so far and will take advise on thread locking nuts (will not). I have just enough room for the 1/4 drive socket for the star bolts. So I didn't think to re-torque nuts and since my crusader manual doesn't cover risers and elbows, where do I get the step by step for this job. I'd be totally wrong in many areas if it wasn't for you folks and the forum!
 
Replaced my manifolds & risers 5 years ago. After using penetrating oil and beating on smaller sized metric socket because the heads were so rusted, I replace with 316 stainless bolts. Bolts still tight and look brand new. Been waiting to see corrosion but nothing yet. No leaks either.
 
Just finished the starboard engine. Runs nice and cool but 6 of the 8 nuts on the risers have drips! I noticed the Barr risers I got expose the studs to the water passage area but the crusaders did not.

i used new stud kits with copper washers and torqued to 25 ft lbs. gaskets don't leek. Anything I missed?
 
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How did you treat the stud threads? A straight thread into a pressured water passage needs some help. Blue thread lock or PST.
 
I used thread lock on stud into the manifold. I used anti seize on stud thru the riser. The threaded studs out the riser have only copper washer and locknut. I have heat cycled the risers once now so I'm ready to re-torque. Should I remove nuts and washers one at a time and inject thread lock? I thought you said not to thread lock because we need to re-torque at times.
 
No thread lock on the nuts. If the 12point bolts are used, you might consider the one bolt at a time trick, on a fully compressed assembly. So water is getting past the thread lock?
 
Sound like the leak is where the copper washers sit under the nuts. Like Dave said no thread lock there - just retorque. sometimes, you have to go up to 30 # * ft to get the washer to seal against the cast (rough) surface. if they still drip after a couple thermal cycles, you may need to perfect seal the washers and nuts but I would consider that a "last resort".
 
I think I understand what you mean Dave... Dry fit the riser on the stud, mark off the area of thread that is inside the riser hole and use PST on that part of the thread. So you do that to inhibited the water from traveling the threads to the washers. Is that the idea? If so will that make removal more difficult?

Mark, I think I see less dripping now that I have heat cycled twice. I will re-torque to 30 ft lbs if needed.

Thanks!
 
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