Live help needed! tourqe specs. MCM 140

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rbuljo

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May 30, 2012
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58
After my original 1985 MCM140 block went bad, i`ve aquired a 1977 donor engine with a good block.

86 #A401501
77 #4648980

so i`ve used the cylinder block from the 77, and the head from the 86. but it blew a head gasket just after 5hrs of boating.
I torqued it to 93 ft/lbs, I wonder if this is wrong. and i really need help now as i am in the boat.

I need tourqe specs on the cylinder head bolts. i get confused what tourqe to use cause of the age difference..

all inputs appriciated.

regards..
 
achris

achris

More fish than mountain goat
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May 19, 2004
Messages
27,468
Re: Live help needed! tourqe specs. MCM 140

Head bolt torque...

1977 - 93 Ft.lb.
1986 - 93 Ft.lb.

Yep, I can see the difference there...

You did chase the threads with a tap before putting the bolts in, yes?, and put sealer on the bolt threads....

Check the calibration of your torque wrench....

Chris......
 
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rbuljo

Seaman
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Messages
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Re: Live help needed! tourqe specs. MCM 140

achris said:
Head bolt torque...

1977 - 93 Ft.lb.
1986 - 93 Ft.lb.

Yep, I can see the difference there...

You did chase the threads with a tap before putting the bolts in, yes?, and put sealer on the bolt threads....

Check the calibration of your torque wrench....

Chris......
Click to expand...

93 ft.lb on both yeah, i was not sure if i remembered it correctly. thanks.

I did chase the threads and put on sealer on the threads yes. i suspect it didnt get correctly tourqed last time, but i replaced it now and used a different tourqe wrench. hoping it will hold.

last time it blew when i got 5ppl in the boat and WOT trying to get the boat to plane.
 
Bt Doctur

Bt Doctur

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Re: Live help needed! tourqe specs. MCM 140

Let me see if I have this right:
Maybe 110 Hp if your lucky
5 persons avg wt 160lbs
17-19 ft boat 2500lbs dry
"and i can`t get it to plane off:
 
R

rbuljo

Seaman
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Messages
58
Re: Live help needed! tourqe specs. MCM 140

Bt Doctur said:
Let me see if I have this right:
Maybe 110 Hp if your lucky
5 persons avg wt 160lbs
17-19 ft boat 2500lbs dry
"and i can`t get it to plane off:
Click to expand...

What's the point of being a wise-***? No problem getting it to plane off. Don't know what kind of boating or boats you are familiar with. But the Problem was that I blew a gasket.

Edit: gasket blew after 5secs WOT..weighs about 2000lbs dry.
 
Bt Doctur

Bt Doctur

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Re: Live help needed! tourqe specs. MCM 140

last time it blew when i got 5ppl in the boat and WOT trying to get the boat to plane.
 
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rbuljo

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Re: Live help needed! tourqe specs. MCM 140

Bt Doctur said:
last time it blew when i got 5ppl in the boat and WOT trying to get the boat to plane.
Click to expand...

Ok, kinda hard getting it to plane when a headgasket blows when I gave it wot. So ok, I was trying.. What's your point?
 
Bt Doctur

Bt Doctur

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Re: Live help needed! tourqe specs. MCM 140

the avaiable horsepower for the intended load is the issue. might as well try pulling the queen mary.
the 4`s are very sensitive to timing issues, most are at 0 or 1 deg ATDC . there is a bulletin out to retard the timing after head gasket damage. Plus running E-10 fuel makes it worse.Might try only the driver and 1 person first to check your wide open throttle and maximun timing advance.
http://www.boatfix.com/merc/Bullet/sbcover.pdf
 
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rbuljo

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Messages
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Re: Live help needed! tourqe specs. MCM 140

What's E-10 fuel? I fill 95octane on her.
I tried your link but only got the front Page of the service bulletin. Do you have a link so I could try this? Would hate to blow another gasket. Kinda ruins the day.. Again.

Sorry if I went offensive earlier.

edit: got the link working. now just to find the correct bulletin.
 
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rbuljo

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Re: Live help needed! tourqe specs. MCM 140

i cant find the bulletin you mentioned..?
 
Bondo

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Re: Live help needed! tourqe specs. MCM 140

rbuljo said:
After my original 1985 MCM140 block went bad, i`ve aquired a 1977 donor engine with a good block.

86 #A401501
77 #4648980

so i`ve used the cylinder block from the 77, and the head from the 86. but it blew a head gasket just after 5hrs of boating.
I torqued it to 93 ft/lbs, I wonder if this is wrong. and i really need help now as i am in the boat.

I need tourqe specs on the cylinder head bolts. i get confused what tourqe to use cause of the age difference..

all inputs appriciated.

regards..
Click to expand...

Ayuh,.... Welcome Aboard,....

Was the block's deck checked for flatness,..??
Was the head checked for flatness,..??

My guess is, 1 or the other, or both aren't Flat enough to hold a gasket....
 
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rbuljo

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Messages
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Re: Live help needed! tourqe specs. MCM 140

none were checked for flatness though. hope thats not the case.
 
Don S

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rbuljo

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Messages
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Re: Live help needed! tourqe specs. MCM 140

It mentions that it should be retarded to 1?atdc,that doesn't make sense. But this service bulletin was for 97 98 models, I got like a 85. Would mine even run at 1?atdc?:) I haven't actually used a timing lamp on the engine, just manually turned the rotor till it was running as smooth as possible.
 
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fishrdan

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Re: Live help needed! tourqe specs. MCM 140

rbuljo said:
I haven't actually used a timing lamp on the engine, just manually turned the rotor till it was running as smooth as possible.
Click to expand...

Check deck and head for flatness........................................ then go out and buy a timing light...
 
Don S

Don S

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Re: Live help needed! tourqe specs. MCM 140

rbuljo said:
It mentions that it should be retarded to 1?atdc,that doesn't make sense. But this service bulletin was for 97 98 models, I got like a 85. Would mine even run at 1?atdc?:) I haven't actually used a timing lamp on the engine, just manually turned the rotor till it was running as smooth as possible.
Click to expand...

Did you read my reply just above your post ??? That service bulletin has nothiing to do with your ignition system, unless you have the Delco EST distributor.
 
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