Thread: 351C rebuild

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This week, I began the romval and rebuilding of a 351C in my 73 Mercury Cougar. Today, I finally got the power train out of the car. As I am doing this rebuild in school, I will update this thread weekly with more information.

This Week: The Removal

This is the car in question, a 1973 Mercury Cougar with a 351C and an FMX. 2.73:1 gears ride inside a 9" rear axle.

To start preparing the motor for removal, disconnect all electrical components that attach to the engine. On this particular car, there is a harness on the engine that conviently has quick-disconnects at the firewall. Note: The Carb was removed to keep the Bronco rolling, as the Cougar was in storage.

Once you have the wiring out of the way, remove the Alternator, starter, the fan shroud and fan, the radiator, and anything else connected to the engine that could impede its removal. Also pictured is the Proto tool box the school issues.

Now, you'll need to do some undercarraige work. These help.

Next, remove the rear driveshaft.


This particular car has a Slipyoke on one end. Most Bko's have CV joints and U joints.

Anyway, back on topic. You'll need to drain the oil and transmission fluid as well. The easiest way to drain tranny fluid is simply to remove the pan.
Note: This is an FMX, with a clip on filter, C6's have a bolt on style.

While the car/truck is in the air, remove the shift linkages, the speedometer cable (or disconnect VSS) and the mounting bolts. Also, in this application and many others, removal of the transmission crossmember may be required. Also, make sure that the motor mount through bolt is removed, and the exhaust system is free of the headers. And disconnect the AC system. I have moved the PS pump out of the way this time.

I don't have a whole lot of pics, 'cuz I was doing most of the work solo, and in the back lab. Once everything is disconnected, attach the hoist's sling.

You'll want to use strong mounting poins. Intake bolts are not recomended, though they can be used. I had to use on ein the back, and this up front:

Once everything is secure, work the motor off it's mounts (easier said than done) and slowly lift it out of the vehicle, while making sure nothing snags or catches. Also, if removing the transmission too, you'll need to tilt the motor up so the transmission can clear the tranny hump and engine crossmember.
When you're done:


Wheel it into the shsop, and remove the transmission. This will leave just the Engine.

First, mount the engine to a stand:


Take it to your work bench (I just wanted to show this off)

To begin disassembly, take off all the accessories and their brackets.

Then, take off the valve covers.

and remove the intake manifold.


Remove the lifter valley tray:

to reveal the lifter valley:

Remove the distributor (it'll probably need to be pried out with a BFS).

Remove the water pump:

And use the proper puller to remove the vibration dampner (sorry, only have pics of the puller on this one).

This will allow you to remove the front cover (a peice of sheetmetal on the Clevland style motors, and a full cover peice on Windsor blocks) and inspect the timing set. Notice the damage on this set. These are literally Ford OE parts from 1973.

The next step is to remove the cylinder heads. To get to the headbolts, you need to remove the rocker arms and the pushrods. Use a tray to keep trak of the location of each peice of the valve train. Inspect the parts as you remove them. Also, my lab partner is seen here as the Marine in the blue coveralls.

OK, now for a quick difference point out: The clevland and modified style engines have pedastal mounted rocker arms, and the windsors have stud mounted rockers. If you happen to be working with a windsor block, it will be necessary to remove the studs prior to cleaning the heads.

You'll also need to remove the exhaust manifolds to remove the cylinder heads (and it'll make the assemblies a lot lighter. The cast iron heads are heavy enough)


Ok, with that done, grab a buddy, and a 18" to 24" breaker bar and pop off the heads.


Inspect the combustion faces of the heads for evident damage (we'll do a more through inspection later).



First remove the oil pan and oil pump:

to reveal the main and rod caps:

Then carefully rotate the engine in the stand so that it is upside down. This will make the remaining tasks easier:

Now, remove the pistons by unbolting the rod caps and tapping the rods with a plastic faced hammer.


Make sure you keep the pistons in order, so the rods go back in the proper place.

When you have all of them out,

remove the timing set:

In order to remove the camshaft, you will need to remove the retainer on the front of the block and tap the lifters out some. when the cam can clear all the lifters, it will come out easily. (note: my infamous BOSS 302 hat is in the tool box)

Next, tap out the freeze plugs.

and then tap out the lifters completely (incase the engine is as dirty as mine was, they will wait for you to do this.

Next, (if you forgot to take of the blocking plate, or want to make it easier for you) remove the engine from the stand and place it on the floor. Take an impact to the main bearing cap bolts and the flexplate bolts. Also, the tool in use in this picture is for the instalation and removal of Camshaft bearings. Very useful.

With the cam bearings removed, lift the crank straight out and stand it on end. NEVER lay it on it's side w/o a proper stand at each end. The block is now ready to be cleaned.


The crank has close to .030" wear at some points, and the cylinders have between .002" and .005" wear. Go figure.

Ok, I got the block bored and the heads apart.
1) Scrape off ALL gasket material:




2) Chase the threads (Tap to appropriate size)



3) Check Your specs:

4) Check your measurements using micrometers

Make sure to check the cam journals and crank journals:


[IMGhttp://www.supermotors.org/getfile/151086/fullsize/Cylinders.jpg[/IMG]
5) after making sure the deck is flat, mount it into the boring machine:


6) locate the boring shaft in the center of the cylinder (please get info on how your particular machine works so you don't mess it up)

7) setup two cutting bits, one at .005" less than the desired diameter, and one exactly at it. make your first pass with the smaller one:

8) make a second pass with the larger bit, then stup the boring shaft. scoot the machine back a bit to move the cutter away from the cylinder wall before you remove the second bit from the cylinder:

Finished:

Repeat on all 8 cylinders (6 for jeeps)


9) onto the heads: Clean the carbon off the combustion chambers:


10) Remove valve springs by removing the keepers after compressing the spring:


11) remove the valves and valve seals and the heads will be ready to clean:

12) using a wire wheel, clean as much of the carbon off the valves as possible. I had a lot of crap on the exhaust valves and they wound up taking about 5 min each.




Next week is valve grinding and lower end assembly.

~Critter

been busy with the rebuild, so not many pics. I kinda wish the img code worked over here. Anyway, I have the lower end pretty much assembled. all 8 pistons are in and the crank truns fairly easily (no binding) and the cam is in and timed. the front cover is on and the oil pan is on.

pics to follow.

~Critter

Very nice writeup and pics. Good luck with your build and are you doing any performance enhancers? G.

Originally posted by FFR428
Very nice writeup and pics. Good luck with your build and are you doing any performance enhancers? G.

4bbl intake, holley 750 (need 360 jets for it though) and edelbrock valve covers & Aircleaner.