Torque numbers for elbow/risers

I am currently replacing my risers and elbows for a 270 engine and I'm looking to see if there are any torque requirements for either the elbow or riser nuts. I am not interested in snapping the threaded rod but I also don't want to leave them too loose either. Wondering if there is a torque requirement to seat those bolt or not. Interested if anyone knows of a specific requirement as I couldn't find anything.

Thanks!

there are torque specs but i don't have access to my library at the moment.

If its time critical, you can use the appropriate table from any engineering reference, for the size/thread/grade of fasteners....nothing Crusader unique.

going from memory - 20 Lbs * Ft

Thanks Makomark - I'd like to reassemble this weekend so I will go on 20lb *ft for now but if you find that's different please re-post so I am aware. To your point though this should be basic!

Thanks

It is - best part (for you) is you recognize there is a preferred value.

I'll check later tonight. I did come acrosss a Mercruiser service bulletin where they now recommend 33 Lb * ft for the fasteners on their cast iron exhaust parts.That should be the upper end.

depending upon which manual you look in, you can find 20 ft*lb for the manifolds and either 20 or 25 ft * lb for the risers & elbows.

Don't forget to re-torque once it has gone though a thermal cycle.

Makomark and CaboJohn - thanks for the info! I will crank those things out this weekend and double check after her first run of the season!

And always use new bolts. I learned this the hard way when I had two old ones break when I was reinstalling my exhaust. I assume the combination of heat and vibration over time weakens them.

Thanks for all the feedback but have one last question. I bought the Osco elbow and risers from ebasic as well as the gaskets. I'm hearing that some people use Permatex and other seat the gaskets dry. I'm going the dry route, and will check them every few months, but anyone think that's a bad idea and I should use sealant? Also, just confirming my set up - existing spacer > single hole gasket > block-off plate > single hole gasket > riser > 3 hole gasket > elbow.

Thanks!

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junior4597 said:

Thanks for all the feedback but have one last question. I bought the Osco elbow and risers from ebasic as well as the gaskets. I'm hearing that some people use Permatex and other seat the gaskets dry. I'm going the dry route, and will check them every few months, but anyone think that's a bad idea and I should use sealant?
Many of these gaskets today call for NO sealant.
Can you see any info on the package that would suggest installing dry or installing with sealant?

Also, just confirming my set up - existing spacer > single hole gasket > block-off plate > single hole gasket > riser > 3 hole gasket > elbow.
In most cases, the block-off plate would be used for a Full Closed Cooling system whereby the manifolds would be part of the closed system loop.

If the Spacer/Riser is used to direct "spent" seawater up and to the Elbow, then the block-off plate would install between the manifold and Spacer/Riser.
Gaskets would follow suit!

If the Spacer/Riser is used to direct coolant (from the manifold) back to the closed cooling system, then the block-off plate would install between the Spacer/Riser and Elbow.
The Elbow would be ported and would be directly supplied with spent seawater.
Gaskets would follow suit!

Click to expand...

junior4597 said:

Also, just confirming my set up -??which one here?? > existing spacer > single hole gasket > block-off plate > single hole gasket > riser > 3 hole gasket > elbow.

Thanks!

Click to expand...

If the 'spacer' connects a hose back to the HX, you'll want a three hole between it and the manifold.

Between the riser and the elbow, you'll want a one hole, not a three hole.

And the other rule is to make sure the 'tabs' on the gaskets are 'up'.

Mark, Junior makes mention of a block-off plate. I assume that this is a full block-off...... yes/no?



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Update, so I think I did this somewhat incorrectly so looking for some additional thoughts. The way I installed them yesterday is as follows - coming off the manifold is a 3 hole gasket before the spacer (note* I did not remove or replace the spacer, left as is so the 3 hole and spacer is "original") after the spacer (and yes it has an outlet to the HX) I have a 1 hole gasket then the block off-plate then another 1 hole gasket then the riser and then a 3 hole gasket before the elbow. I think I need to change out the 3 hole gasket between the riser and elbow to be a 1 hole gasket, correct? That said, since I have the metal block-off plate sandwiched between two 1 hole gaskets does it matter what type of gasket I use? Can I leave that be? I would think since the block-off plate is prohibiting any raw water into the jackets it doesn't matter what type of gasket you use. So, I think my next steps are to leave the 1 hole gasket before the riser (if that's the consensus here) so I don't have to take the time to disassemble and then only take off the elbow to replace the 3 hole to a 1 hole gasket. Would that be correct?

Also to note for anyone doing this on their own, the replacement elbows are about an inch to and inch and half shorter on the outlet end than the originals. That's an issue when your exhaust hose wont reach so keep that in mind as I now have to get some replacement exhaust hose and cut it a few inches longer to ensure the elbow outlet hits the Y exhaust pipe. It never ends!

Your plan is correct. The critical piece is that the one-hole gasket (with the hole at the top) goes between the riser and the elbow. This forces the riser to fill with cooling water before exiting through the elbow.

A few questions:

I'm sensing that this engine fitted with a Closed Cooling system.... yes/no?
If so, is it a Full Closed Cooling system (manifolds in the closed loop) or is it a Half Closed Cooling system (manifolds/spacers/elbows being seawater cooled)?

If full, are the spacers/risers part of the closed system?
If full, are the spacers/risers part of the seawater system?

What is the purpose of the block-off plate if not to separate the closed cooling side from the seawater side???

Would you be able to mark up the image below as to show the path of both E/G coolant and seawater?


Example only..... I'm not sure which exhaust system you have!





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Hey Rick to the best of my ability see the below answers

I'm sensing that this engine fitted with a Closed Cooling system.... yes/no? That would be a YES
If so, is it a Full Closed Cooling system (manifolds in the closed loop) or is it a Half Closed Cooling system (manifolds/spacers/elbows being seawater cooled Full closed cooling system

If full, are the spacers/risers part of the closed system? The existing spacer is on the fresh water side, the risers and elbows are on the raw water side
If full, are the spacers/risers part of the seawater system? Riser and elbows are part of raw water cooling

What is the purpose of the block-off plate if not to separate the closed cooling side from the seawater side? The block-off plate is after the manifold (fresh water side) and after the spacer so it does cut off fresh water cooling from the riser and elbow.

Here is a spec of my setup, ironically it points out the gasket locations so in my case I only need to change the 3 hole gasket to 1 hole gasket from the riser to the elbow - leaving the 1 hole gasket at the block-off plate as it doesn't matter what type of gasket you use.

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junior4597 said:

Hey Rick to the best of my ability see the below answers

I'm sensing that this engine fitted with a Closed Cooling system.... yes/no? That would be a YES
If so, is it a Full Closed Cooling system (manifolds in the closed loop) or is it a Half Closed Cooling system (manifolds/spacers/elbows being seawater cooled Full closed cooling system

If full, are the spacers/risers part of the closed system? The existing spacer is on the fresh water side, the risers and elbows are on the raw water side

May I assume by using the term "fresh water side" you are referring to the Closed Cooling System side?
(in my book, fresh water cooling is a misnomer)

If full, are the spacers/risers part of the seawater system? ** Riser and elbows are part of raw water cooling
OK.... then the block-off plate must separate the manifold from the spacer/riser and elbow..... yes/no?

What is the purpose of the block-off plate if not to separate the closed cooling side from the seawater side? The block-off plate is after the manifold (closed cooling side) and after the spacer so it does cut off fresh water cooling from the riser and elbow.
I am not quite understanding you!
"after the spacer" appears to be in conflict with your above statement **.

Here is a spec of my setup, ironically it points out the gasket locations so in my case I only need to change the 3 hole gasket to 1 hole gasket from the riser to the elbow - leaving the 1 hole gasket at the block-off plate as it doesn't matter what type of gasket you use.


View attachment 19879

Click to expand...

Would you be able to mark up this image as to show the paths of the Closed Cooling system and the Raw Water system?
Use green for the Ethylene Glycol side, and blue for the seawater side!

Hi Rick

This is a very crude drawing but it shows the closed loop side vs. the raw water side for the cooling system. I know I have a better diagram that I'll look for but for now this should suffice. From the gasket perspective I think I am all set now (3 hole gasket at the block-off plate and 1 hole gasket at the riser/elbow joint). If anyone references this post to perform your elbow/riser change remember that in my case the new Osco elbow outlet was shorter than what was original - you may need a longer length of wet exhaust hose.

Junior, let me first say that my Crusader experience is very limited. I would not be offended if I am shown to be in error!

That said..... I do have experience with the more conventional style Half and/or Full Closed Cooling exhaust systems.
Basically the coolant and seawater paths are very similar between them.


Let's refer to the 1 or 3 holes in these gaskets and the exhaust components as seawater or coolant "transfer ports".




Meanwhile, I've made some notes on this image.








Again........ my Crusader experience is limited. Hopefully the more experienced members will chime in!



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I have replaced my exhaust hardware once on my two Crusader engines. That's the sum of my experience.

I used Barr products, but I suspect Osco does the same by supplying all the fasteners and gaskets that are needed to complete the installation. I ended up with quite a few extra three-hole gaskets and a couple with one-hole. This is because there are lots of variations in the way exhaust systems are configured. In my boat's case, I don't have spacers or block-off plates - it's a half system. That's why I ended up with extra gaskets.

On a block-off plate, I do not believe it matters which gasket you use. There's plenty of material to make a good seal.

The critical place in the system, as I said in post #15 of this thread, is the connection between the riser and elbow. The one-hole gasket must be used here with the hole at the top so that the riser completely fills with cooling water. If you don't do this, water will of course take the path of least resistance - the lower holes. This would lead to a hot spot on the top of the riser and elbow.

Dan

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DJR said:

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On a block-off plate, I do not believe it matters which gasket you use. There's plenty of material to make a good seal.
Understood!

The critical place in the system, as I said in post #15 of this thread, is the connection between the riser and elbow. The one-hole gasket must be used here with the hole at the top so that the riser completely fills with cooling water. If you don't do this, water will of course take the path of least resistance - the lower holes. This would lead to a hot spot on the top of the riser and elbow.
I understand the potential for a "hot spot" (if the gasket blocked the upper transfer ports) ...... however, I do not understand why we would NOT want all transfer ports to be active between the riser and elbow!

Dan

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