MCM-140 Manifold attachments

[Libbs]

Hi guys,

My MCM-140 manifold had a lovely crack in it, and had to be replaced. The new manifold did not come with new end plate & water intake, so I removed them from the old manifold, removed rust, gave'em a nice new coat of paint, and now I'm ready to put them onto the new manifold.

The manual I have for the engine is great for details on attaching the manifold to the engine, but nothing for these end pieces, except a torque spec.



The end with the hose attachment is for raw sea water coming from the heat exchanger, and the other plate plugs the other end, forcing the raw water up into the riser to mix with exhaust gases.

Questions:

1a) Do the end gaskets need to be coated with sealant? (I have Perfect Seal and an "Aviation Gasket" goop)
1b) Same question for the riser elbow gasket to the maniold...sealant or no?

2) Here is a screenshot of the torque specs from the manual:



I'm assuming "end cap", for some reason listed singular, is the torque value for BOTH the end plate and the hose attachment end. Agree?

3) Here's a pic of my riser elbow...



The nice rusty nut at the front (left) is quite easily accessible with a torque wrench. But how do I properly torque the aft one in that little nook? I can only get to it with a regular wrench.

Thanks guys!

EDIT:
4) What about using Loctite...Yes or no?

 

[ENSIGN]

Re: MCM-140 Manifold attachments

I've been using perfect seal on manifolds and engine rebuilds for 20 years and have NEVER had a leak.I would recommend using new mounting hardware on the riser and end caps.Tighten all the bolts evenly and use some Never-Seize on the threads.

 

[achris]

Re: MCM-140 Manifold attachments

Hi guys,

My MCM-140 manifold had a lovely crack in it, and had to be replaced. The new manifold did not come with new end plate & water intake, so I removed them from the old manifold, removed rust, gave'em a nice new coat of paint, and now I'm ready to put them onto the new manifold.

Does your lovely 140 have a serial number?

The manual I have for the engine is great for details on attaching the manifold to the engine, but nothing for these end pieces, except a torque spec.

That's probably because it's just a plate with 4 bolt holes.

The end with the hose attachment is for raw sea water coming from the heat exchanger, and the other plate plugs the other end, forcing the raw water up into the riser to mix with exhaust gases.

Good so far, but does your lovely 140 have fresh water cooling?

Questions:

1a) Do the end gaskets need to be coated with sealant? (I have Perfect Seal and an "Aviation Gasket" goop)
1b) Same question for the riser elbow gasket to the maniold...sealant or no?

You can use a sealant on the end cap gaskets, but the elbow gasket is best put on dry.

2) Here is a screenshot of the torque specs from the manual:

I'm assuming "end cap", for some reason listed singular, is the torque value for BOTH the end plate and the hose attachment end. Agree?

It doesn't say 'Front end cap' and 'Rear end cap', so yes, the torque is the same for both ends...

3) Here's a pic of my riser elbow...

The nice rusty nut at the front (left) is quite easily accessible with a torque wrench. But how do I properly torque the aft one in that little nook? I can only get to it with a regular wrench.

Are you seriously asking this question? Or are you one of the people who use a torque wrench on EVERY bolt on an engine?

EDIT:
4) What about using Loctite...Yes or no?

DEFINITELY NOT!!!

 

[Bondo]

Re: MCM-140 Manifold attachments

Originally Posted by Libbs
3) Here's a pic of my riser elbow...

The nice rusty nut at the front (left) is quite easily accessible with a torque wrench. But how do I properly torque the aft one in that little nook? I can only get to it with a regular wrench.

Are you seriously asking this question? Or are you one of the people who use a torque wrench on EVERY bolt on an engine?

Ayuh,.... That's the perfect spot to employ a Calibrated Elbow for the torque settin'.....

 

[achris]

Re: MCM-140 Manifold attachments

Ayuh,.... That's the perfect spot to employ a Calibrated Elbow for the torque settin'.....

Ah yes, that's the one I use too...

 

[Libbs]

Re: MCM-140 Manifold attachments

Does your lovely 140 have a serial number

Yeah, it does. Would knowing it affect anything? Was there a range of serial numbers where sealant is required and others no? Somehow I doubt it. Looks like you got an answer and a wise-crack in for every question I asked without knowing my serial number. Weird how you could do that...almost like it didn't matter.

But here you go: 1981 MCM-140 ser. 5962629.

That's probably because it's just a plate with 4 bolt holes.

Yep. And that plate is only going to be attached to an exhaust manifold, experiencing large temperature fluctuations while keeping the cooling salt water at bay. You're right...no big deal. Why am I concerned about getting it right. Maybe I'll even omit the gasket.

Good so far, but does your lovely 140 have fresh water cooling?

If you mean the manifold, I specifically said it was raw water cooled. If you mean the engine block and head, not sure how that would change any answers pertaining to end caps and risers on the manifold, but, engine is fresh water cooled. ...weird, you still confidently answered all my questions without knowing this.

You can use a sealant on the end cap gaskets, but the elbow gasket is best put on dry.

Thank you, finally, for an actual answer.

Are you seriously asking this question? Or are you one of the people who use a torque wrench on EVERY bolt on an engine?

Yeah, I'm seriously asking the question. I'm sure you had some funny questions when you first started out. Tinkering with engine parts is new to me. I've got to start somewhere, and if I'm not feeling confident about something, no matter how silly it seems, I'm going to be on here asking questions. And until I do get confident and more experience, you're damn right I'm gonna use a torque wrench on every nut and bolt that has a published torque value if I can get the wrench on it.

So thank you achris, for the answers imbedded in the moquery.

Thanks Bond-o and ENSIGN for your input.

 

[achris]

Re: MCM-140 Manifold attachments

Yeah, it does. Would knowing it affect anything? Was there a range of serial numbers where sealant is required and others no? Somehow I doubt it. Looks like you got an answer and a wise-crack in for every question I asked without knowing my serial number. Weird how you could do that...almost like it didn't matter.

But here you go: 1981 MCM-140 ser. 5962629.

Yes it does matter. The 140 has been around since 1968, and has had a few different manifolds attached to it. With a serial number or year I can look up the exact engine you have and give the most accurate answer I can. Without such information, the answers are more generic. Your choice, do you want accurate information or not....

Yep. And that plate is only going to be attached to an exhaust manifold, experiencing large temperature fluctuations while keeping the cooling salt water at bay. You're right...no big deal. Why am I concerned about getting it right. Maybe I'll even omit the gasket.

Yes, you could do that, but I suspect it would leak.

If you mean the manifold, I specifically said it was raw water cooled. If you mean the engine block and head, not sure how that would change any answers pertaining to end caps and risers on the manifold, but, engine is fresh water cooled. ...weird, you still confidently answered all my questions without knowing this.

You used the words 'Heat exchanger'.

The end with the hose attachment is for raw sea water coming from the heat exchanger,

These are ONLY associated with a fresh water cooled engine. The fact that you said the manifold was raw water cooled means nothing. Many engines out there have a 'half system', meaning that the engine block and head are fresh water cooled and the manifold is raw water cooled. So no, it wasn't a stupid question...

Yeah, I'm seriously asking the question. ... And until I do get confident and more experience, you're damn right I'm gonna use a torque wrench on every nut and bolt that has a published torque value if I can get the wrench on it.

And that's the important part.... You also need to use a little common sense...

 

[wrench 3]

Re: MCM-140 Manifold attachments

I'm going to be on here asking questions. And until I do get confident and more experience, you're damn right I'm gonna use a torque wrench on every nut and bolt that has a published torque value if I can get the wrench on it.

The first thing they teach you as an apprentice mechanic (after they teach you how to sweep the floor) is, if you don't know check the book and if it's not in the book ask someone.
A suggestion I've given to my apprentices is to torque a nut or bolt that they can get at, then put a wrench on it to see how it feels. It might not be exact, but at least you will know what tight feels like.

 

[Libbs]

Re: MCM-140 Manifold attachments

Yes it does matter. The 140 has been around since 1968, and has had a few different manifolds attached to it. With a serial number or year I can look up the exact engine you have and give the most accurate answer I can. Without such information, the answers are more generic. Your choice, do you want accurate information or not....

Yes, accurate is nice. Condescending, ...not so much. I came for help, not to be belittled. Need more info, ask away. Keep the wise-cracks to yourself.

You used the words 'Heat exchanger'.

I specifically said "The end with the hose attachment is for raw sea water coming from the heat exchanger, and the other plate plugs the other end, forcing the raw water up into the riser".

Not sure how there could also be fresh water cooling the manifold...but if there are manifolds out there that have raw water running one end to the other, and still have fresh water circulating in the middle somehow, please accept my appology. Either way, what I was trying to make clear was that the two peices and gaskets in question were raw sea water components.

These are ONLY associated with a fresh water cooled engine. The fact that you said the manifold was raw water cooled means nothing. Many engines out there have a 'half system', meaning that the engine block and head are fresh water cooled and the manifold is raw water cooled. So no, it wasn't a stupid question...

I DO have a "half system". My block and head ARE freshwater cooled. That is why I specified that the manifold was RAW water cooled.

The raw water (I've always assumed that "RAW" water meant water drawn in from the impeller in the leg...) first comes into the heat exchanger, where it cools the "Fresh" water coolant. The raw water then leaves the other end of the heat exchanger and into the front of the manifold, cooling it, before being ejected with the exhaust. I thought that by using the words "raw water" I was being clear, but maybe throwing in the words "heat exchanger" was a mistake, causing confusion.

And that's the important part.... You also need to use a little common sense...

Sometimes what seems common sense to an experienced veteran is not to a noob.

As a noob, I'm looking at a nut that has a published torque setting. Common sense told me that there must be a way to apply this torque setting to this nut if it's published. Could there be somekind of flexible adaptor to use? Some other trick? I dunno...How am I supposed to know...I'm new, so I asked you, the veterans.

So thank you again for the answers. If I leave something out next time...just ask. No need to belittle or be condescending.

@ wrench 3
2 of the 4 bolts are accessible, so I should get a good feel the hidden two. Thanks so much!

 

[achris]

Re: MCM-140 Manifold attachments

Libbs, You're been around iBoats since June 2011, 18 months. Enough to see what information we are ALWAYS asking for. Engine serial number, or drive serial number if that's what's being worked on. Have you read the first item in the first 'Sticky' on the forum?

ok.. you did NOT make it clear that you have a half closed cooling system. That is unusual and should have been mentioned in the first post. I often hear the exhaust elbow referred to as a 'heat exchanger', hence I asked the question... As it turns out, I was right to do so!

I suspect you're been working on car engines for a while, the common sense applied on those engines applies on a marine engine too. If it's clear that a torque wrench can't be put on a nut or bolt, then a ring or open end spanner needs to be used and the required torque is then estimated. It's published in the book to keep the legal department happy, and to give you an idea of the torque required.

So, let's finish this and get back onto the topic of your post....

 

[MWG2600]

Re: MCM-140 Manifold attachments

If you cant get close to 35 Ft-lbs with a box end wrench then you need a mechanic. Heck push agenst the wrench with a scale and do the math.

 

[Bondo]

Re: MCM-140 Manifold attachments

So, let's finish this and get back onto the topic of your post....

Ayuh,.... That, is an Excellent Idea, for all parties involved......

 

[Moose truck]

Re: MCM-140 Manifold attachments

For the Aircraft Mechinic types, we need to use a torque wrench for every thing. FCO16A, Wrench, Crowfoot, Open End, 1/2". Then again we can use the calibrated elbow :lol:

 

[Libbs]

Re: MCM-140 Manifold attachments

...You're been around (...) Enough to see what information we are ALWAYS asking for...

You're right. I thought my questions were general enough to omit these, but I should have included them anyway. I understand that they will help if you need more info and require to lookup my engine. Was trying to ridicule my post the right way to tell me though...?

...you did NOT make it clear that you have a half closed cooling system.

No, I did not. My questions were specifically for components of my exhaust manifold, which I still maintain was clearly stated as being "raw sea water" cooled. I had no reason to think this was pertinent information. If the engine's cooling system somehow affects whether or not sealant or locktite is used on the (already stated raw water cooled) manifold, forgive me. To someone new this is not obvious required information. Enlightening me helps. Ridiculing does not and leads to these kind of threads.

I suspect you're been working on car engines for a while,...

My eperience is very limited. I have changed alternators, brake shoes and rotors, etc, but this rebuild is the first time diving deep into an engine for me. I didn't even own a torque wrench until a couiple of weeks ago. Parts that go through large temperature ranges or containing salt water are still pretty intimidating to me, as the consequences for screwing up can be pretty heavy. So some of my questions may seem silly and have obvious answers, but I need to ask them to have confidence in what I'm doing.

Have you read the first item in the first 'Sticky' on the forum?

If you want to play a "sticky" card, let me play one too. Go read the Proper Forum Etiquette post under Forum Rules and Guidlines. The first two words of Step 6 basically sums it up:

Be Respectful.

So, let's finish this and get back onto the topic of your post....

I agree. Sorry for reacting so strongly, I just do not appreciate being ridiculed. I'm going to do my part and go edit my signature to include my boat, engine, and sterdrive info so it is attached to every post.

...imagining a handshake here... No hard feelings. Thank you for the answers and information you did provide. It did help.

Sorry to everyone else for the rants. And thank you for all the input. My manifold is now assembled, and waiting for the engine to be ready for reassembly.

-Cheers.