Mercruiser 140 3.0 Makeover

Goldie627

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I've decided to consolidate my engine journey into one thread. I will attempt to document my makeover as it unfolds, I plan to include photos and videos of the following:
  • Order Gaskets - Done
  • Outdrive Removal - Done
  • Engine Removal - Done
  • Oilpan Removal - Done
  • Timing Gear Cover Removal - Done
  • Timing Gear Cover Removal - Done
  • Engine Painting
  • Intake Removal
  • Intake Testing with Acetone
  • Valve Cover Removal
  • Rear Main Seal Removal
  • Timing Gear Insepction
  • Running the Engine While its out of the Boat
  • Minor Bilge Makeover
  • SPLASH!!!
All of the required gaskets are on the way. I will mark things on the list "Done" as I proceed. I wonder how much extra vacuum I'll have after repairing the intake? Its not a big leak so im guessing I'll move up from 13-14 to 15-16ish maybe... Im so excited to see what the difference will be and to finally close the chapter on this mid throttle lean condition.
Dreams really do come true!!! :bounce:
 
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Scott Danforth

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have the mods merge the threads or you can have links tying them together
 

fishrdan

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[*]Outdrive/Engine Removal and Installation

I haven't followed your other thread(s), but have the bellows been done? Might be a good time to replace them if not done in the last 3-4 years. (5-year service items) Lower shift cable?

When I rebuilt my 140HP, I also replace the starter, alternator and water pump, as I didn't want to have to monkey with them in the future. Been 7 years and all of them haven't been touched. Carb, now that's another subject, have to rebuild it every 2-3 years due to ethanol junk. If replacing the starter, get a gear reduction starter, $60-70, 1/2 the weight of the old Delco and much more torque.

For the timing cover, you're supposed to use a crank alignment tool, to center the cover's seal over the crank snout. Being cheap, I use a roll of electrical tape striped off until it fit inside the seal tightly. Worked prefect...
 

Goldie627

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I haven't followed your other thread(s), but have the bellows been done? Might be a good time to replace them if not done in the last 3-4 years. (5-year service items) Lower shift cable?

When I rebuilt my 140HP, I also replace the starter, alternator and water pump, as I didn't want to have to monkey with them in the future. Been 7 years and all of them haven't been touched. Carb, now that's another subject, have to rebuild it every 2-3 years due to ethanol junk. If replacing the starter, get a gear reduction starter, $60-70, 1/2 the weight of the old Delco and much more torque.

For the timing cover, you're supposed to use a crank alignment tool, to center the cover's seal over the crank snout. Being cheap, I use a roll of electrical tape striped off until it fit inside the seal tightly. Worked prefect...

Thanks for the tips Dan, Bellows and Lower Shift Cable were done last summer, new gear reduction starter coming, also new water pump and new alternator coming too, already did the thermostat
 

Goldie627

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Make over is going well... oil pan is off and the motor is upside down. I want to replace the rear main seal, and purchase a new crankshaft bearing set. I pulled the cap off the main bearing thinking the bottom main bearing would tell me if it was standard or .001 or .010 or .020 for the life of me i cant figure out what size set to buy as the bearing stamped numbers did not return anything meaningful via google.

I don't have a micrometer.

I couldn't find my crankshaft bearing size on the crankshaft counterweight or the block near the front left oil rail...

How do i know what size crankshaft bearing set to buy?

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Goldie627

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I have a new harmonic balancer coming, i don't want to hit it with a hammer. Im fabricating a bridge plate (thanks bondo!) Im using my front motor mount as a template to mark the hole placement for the four bolts. four bolts go through the bridge plate into the block.

My question is should i tap and die a passthrough hole in the bridge plate to have threads for the all thread to go through? or do i drill a hole on the bridge plate then weld a cheap harbor freight presser to the back of the fabricated bridge plate? could also probably just weld a nut for the allthread to pass through...

Bondo, how did you get your all thread to pass through your bridge plate?

Any suggestions are welcome
 

Goldie627

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Do my timing gears look ok?

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Goldie627

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Timing cover exterior has bad surface rust interior looks ok. If i sand blast all the rust off and clean metal prime then enamel black paint it do you think the rust will return? Im debating on buying a new timing gear cover...

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Scott Danforth

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your bearings are fine. what ever you do, do not swap bearing caps around.

if you want to play with bearings, you must own at a minimum a dial caliper, better yet a set of internal and external mics

your this far, a set of timing gears is $32

I would either blast your timing cover or soak it in oxalic acid for a weekend. the soak is my preference because the chemicals do the work and I am lazy

then again, you could wire brush it too.

the reason it looks so bad, is that everything behind the harmonic damper is not painted from the factory
 

Bondo

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Bondo, how did you get your all thread to pass through your bridge plate?

Ayuh,.... Through a hole I drilled,....
Then used a nuts, 'n washers,(pushin' on the hub) on the inside to push the balancer on,....

As Scott said, that main bearin' is in fine shape,....
No reason to replace 'em,...
Just don't mix anything up,...

For timin' gear wear, ya gotta look at the face of the teeth, of the fiber gear for wear,....
'n timin' covers are pretty cheap, do whatever ya want there,....
 

Goldie627

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I only pulled one cap so no mixing worries, thanks for the heads up though.

Initially i was gonna replace all the bearings (required lifting crank shaft) so installing rear main seal would have been a piece of cake. but now that im leaving all the bearings alone im worried about the main seal replacement.

any tips to remove and install the rear main seal?

im paranoid that ill slip while tapping the top seal out and my brass punch could nick the bearing, also, when installing the top rear main seal if you spin the crank to roll the top seal on, wont that destroy the sticky strip on the seal?
 

Rick Stephens

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Those seals are usually pretty easy to tap on with a longish drift, once you start them curving around you can grab em with pliers and wriggle em out.

Get things clean (I like carb cleaner and a lot of air) and reinstall with the thinnest film of silicon sealant around the outer edge and a little bit of assembly lube on the lip. The silly-cone acts as both a sealant and a lubricant during install.
 

Goldie627

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Ok... so after going back and forth with my brother Scott, i decided to pull all the bearings. The plan was that if they looked good i would put them all back, if any looked not so good I would replace them all.

At this point im going to replace them all.







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Goldie627

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more bearings...

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Goldie627

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now that most of the bearings are off the crankshaft i can take some pics so you can see it, i only have one pic but will add the rest later..

so here is where im stumped... There are four possible bearings, STD (standard) .001 .010 .020

my question is, how do i know what size crankshaft bearings i need?

Should i take the crankshaft to a machine shop to have it mic'd and maybe polished?

According to my service manual, the crankshaft main journal diameter should be 2.2983 - 2.2993 (5.838 - 5.840) is that the definition of STD (standard)?

If i can figure out my crank diameter, then i think i can select the proper bearings...

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Goldie627

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The GM numbers on the bearings are almost useless... i cant find a way to cross reference anything

Crankshaft main bearing engraved numbers: 308D(maybe G) & GM4 57591

Crankshaft rod bearing engraved numbers: 17C631 & GM4 5453695

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fishrdan

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Bearings are available undersized, to compensate for the crank being turned/machined. You'll have to pull the crank and measure the journals to to be sure you're ordering the correct bearings, who knows if/when the engine was repaired in the past....

IF replacing the bearings without pulling the head, be VERY careful not to nick the crank with the rod bolts. Use rod bolt sleeves to cover the rod bolts, after the rod caps are removed.

You'll need to remove the crank and inspect all journals, to see if it needs polishing or machining, but from what I can see it looks OK.... so far
 

Goldie627

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Bearings are available undersized, to compensate for the crank being turned/machined. You'll have to pull the crank and measure the journals to to be sure you're ordering the correct bearings, who knows if/when the engine was repaired in the past....

IF replacing the bearings without pulling the head, be VERY careful not to nick the crank with the rod bolts. Use rod bolt sleeves to cover the rod bolts, after the rod caps are removed.

You'll need to remove the crank and inspect all journals, to see if it needs polishing or machining, but from what I can see it looks OK.... so far

Thanks Dan! I understand now. Ive been doing alot of reading about crankshafts and your post was extremely helpful. I went this morning to have my crankshaft mic'd and all journals are in fact standard, i don't see any grooving, nicks or layers removed so i should be good to go.

For crankshaft protection from rod bolts during reassembly i'm going to use some cut hoses. I'm Going to order the bearings today. Here are some more pics of the bare crank.

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