Mercruiser 140 rebuild

[carlsoncvx18]

When we set the valves on my motor iif i recall it was done just after assembly with the lifters not pumped up full of oil.

[75starflight]

After sleeping on it over night, I am going to reset the valve lash. I am thinking that my valves may be partly open during the compression stroke. I tend to over do things a little when I am working on stuff.

I am planing on measuring the valve springs as they are now and then measure them when they are fully uncompressed, then I will measure them again after doing the valve lash and compare the first and last measurement to see if I have any change.

On a funny note, I had the machine shop balance the rotating assembly. When I first started cranking on the motor I had to look to see if the flywheel coupler was actually rotating. She is spinning so smooth I thought maybe the starter was not working.

[Jason]

I'd do a quick compression check too. That should tell you too if a valve is not closing and at least give you an idea of where to start double checking your valve lash.

[75starflight]

I'd do a quick compression check too. That should tell you too if a valve is not closing and at least give you an idea of where to start double checking your valve lash.

Yep I did that last night and no readings on the gauge so the valve lash is where I am going to start.

[Plugcheck]

    I doubt they are too tight when they were installed, probably not opening due to a lack of oil, but by now they have had some oil from cranking.   At least I hope so.  You could prime the system, then crank it over several more times, then set the valves.    Also notice the timing marks in relation to the valves on #1 opening and closing.   It should be readily appearant where both valves are closed and piston coming up on compression.   When the timing marks align on the compression stroke, take note of where the dizzy rotor is pointing to.   I would assume the 140 doesnt care which cylinder is plumbed to which distributor position, that the order is correct.  On my beloved VW's, they retarded #3 cylinder 3 degrees to keep it cool.  I got your VM, I will try to call later.   I'm in Chicago for the week.

[OleRed]

if you know the timimng marks on the cam gear a aligned like they are suposed to be, it's real simple to adjust the valves, pumped up with oil or not, I always pump up the lifters before I install them, I also prime the oil system with a dummy distributor before installing the real dist.
if the timing marks are aligned, pull the valve cover and the sparkers,  rotate the motor clockwise with a ratchet and socket on the front of the crank, watch #1 ntake valve, when it opens and begins to close, thats is a compression stroke, I use a skew stick, or 1/4 dowel, to find tdc, set the distributor to #1 spark plug there, then advance it about 1/4 and snug the dist, while I'm rotating the motor, and the stick goes down as far as it will, just before it starts back up,  that verifies the tdc timing mark on the harmonic balancer.  From tdc on the #1 cylinder, you can adjust both intake and exhaust valves, just back off the adjusting nuts till they are free of the valve stem, then rotate the pushrod with your first finger and thumb, turn down the adjusting nut until you feel the spring resistance of the lifter, thats "0" tolerance, then follow your firing order, and the next cylinder is coming to tdc, use the stick, tdc, and adjust those valves also, so on the other two cyl's.
prime the carb, pour gas in it, just know you got gas, that puppy will fire up immediately if you got spark.

[75starflight]

Thank you Red, you actually explained it better than my book did. It is so nice having so many friends with knowledge of engines and rebuilding boats. I will give my valve lash another try tomorrow after work.

I am taking the night off from boat work, Amber is not at work for once so I get to have some one to talk to. :-)

[Jerry]

Valve overlap on the opposite cylinder is much easier. You don't need to stick anything in the cylinder. If you ever ran a dragster ya learn how to have it set right before you fire it up.

[75starflight]

Valve overlap on the opposite cylinder is much easier. You don't need to stick anything in the cylinder. If you ever ran a dragster ya learn how to have it set right before you fire it up.

Jerry, maybe you and Dottie should have stopped by on your way home and helped me with my build.

[Jerry]

Ya learn by doing. Did you put a new cam or lifters in? Are you sure they're hydraulics?

[75starflight]

Ya learn by doing. Did you put a new cam or lifters in? Are you sure they're hydraulics?

Yes you do Jerry. The machine shop got me the stock cam and lifter set for my 140. Funny thing every thing from the pistons, rods, and lifters are all stock 350sbc. Well the pistons are now .30 over.

[OleRed]

Valve overlap on the opposite cylinder is much easier. You don't need to stick anything in the cylinder. If you ever ran a dragster ya learn how to have it set right before you fire it up.

it's not a dragster Jerry, it's an iron duke, and the stick is a simple reference, why complicate it ?
Oh .. by the way, how many of my motors have you seen bust off on an initial start, on video, maybe I'm not doing it right, the last one I had to hit the starter twice.

https://www.youtube.com/watch?v=Nifgi80_hjA

[75starflight]

Valve overlap on the opposite cylinder is much easier. You don't need to stick anything in the cylinder. If you ever ran a dragster ya learn how to have it set right before you fire it up.

it's not a dragster Jerry, it's an iron duke, and the stick is a simple reference, why complicate it ?
Oh .. by the way, how many of my motors have you seen bust off on an initial start, on video, maybe I'm not doing it right, the last one I had to hit the starter twice.

https://www.youtube.com/watch?v=Nifgi80_hjA

Actually that is a common mistake calling the 140 an iron duke. The mercruiser 120 is based off of the iron duke, while the 140s or 181cid as GM lists them was never used in an automotive application. It was designed as an industrial engine only. It was used in everything from forklifts, irrigation power units, to boats and other industrial applications.

On that note, I have done way to much research on the 140. 

[75starflight]

Its alive! Its alive!  Will post video later.


Sent from my XT1080 using Tapatalk

[OleRed]

there was several applications for the 153cid and the 181cid 4 cyls in automotive and racing applications, from the early/mid seventies, to the later model 3.0 most common in boats, the first of the 140's was a 153cid, with a 4 barrel carb, year or two later it was a 181cid @ 140hp, thats is the most common today.
There was even a racing motor in the early 80 they called the iron duke, that had very little resemblance to our boat motors, check them out if you have any douts.

[Diamond Chad]

I was looking at red 500 metric in Oklahoma with that engine, and the dealer said that engine was a popular find for Sprint Car racers.   Very tough and very good torque .  I'm not sure if its the same one but he said it ran a Ford 460 head.

[75starflight]

I was looking at red 500 metric in Oklahoma with that engine, and the dealer said that engine was a popular find for Sprint Car racers.   Very tough and very good torque .  I'm not sure if its the same one but he said it ran a Ford 460 head.

Yes they were very popular for sprint cars. The head on my 140 is from one of those race engines.

[OleRed]

  I'm not sure if its the same one but he said it ran a Ford 460 head.

The head, rods and pistons on the 470 4 cyl was a early 460cid V8 application, and to raise the comprssion on one of the 470s with-out changing pistons, you could install an early 429 head, but cooling was a problem then, because of the closed cooling system

[75starflight]

Well here they are, it is running excellent! After redoing the valve lash she fired right up!

http://youtu.be/UN3I9Wt2lCc

http://youtu.be/7cSsuAbM6Ps

http://youtu.be/JHegWuNEYP8

[Jerry]

Sounds great. Bolt her in!