International Harvester 304 SVC Rebuild

[rustybucket]

As part of my Resto-Mod build of my 72 Scout II, I need to refresh or rebuild the 304 V8 that came out of it.

Here is a shot of the motor before tear down.

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[rustybucket]

After stripping the top of the engine down (Carb, hoses, etc), it was time to do a leak down test.
Normally you would do a compression test, but the engine was out of the vehicle and that didn't seem feasible, so I opted for the leak down test  Even at that, the engine should be warm for a leak down test, so this was just going to be a ball park shot.
First I had to find top dead center.  The way I did that was to put a rod in the cylinder and turn it until the rod was at it's highest point.  In the picture, you can see I used an aluminum rod.  Don't do this, use a wood dowel.  Less of a chance of scratching anything.  I was very careful not to scratch the cylinder wall. 

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Once we found top dead center, we proceeded to do the leak down test.  We hooked the tester up to the cylinder and then pumped it up with air.  Then we watched to see what percentage of leak down we had on the gauge.  After testing all eight cylinders the engine looked pretty good.  I went ahead and tore the engine down anyway, since at the very least we would have to replace all the gaskets and seals.

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You can watch a long boring video we put together on it below.

[rustybucket]

Now we finish tearing down the engine.  It is all pretty straight forward.  In these two pictures you can see the Intake manifold and the valley pan after the manifold is removed.  There is a lifetime of grime buildup under the manifold.

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In this pic you can see the manifold once it is off.  Looks OK, I will have quite a bit of media blasting to do to get it ready to paint.

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[rustybucket]

Now we get the valve covers off and the valley pan.  All looks good in the top end.  It does look like we will need to do a valve job.  They aren't real bad, but having gone this far, we will do it right.

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Now we get the oil pan off and remove the Oil Pump.  On the Scout's the master rebuild kit doesn't come with the exact oil pump. So you have to use the parts from the new oil pump in the old one.

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[rustybucket]

Next step, ream the ridges and remove the pistons.  Then we remove the freeze plugs and take everything to the machine shop.

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Here is a short video of the process.



Now we wait until the machine shop gets it's work done.

[rustybucket]

Got the engine back from the machine shop today. 
They had to bore it at .030, the crank was turned down .010 and they milled .007 off of the top.  All in all pretty good.

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Now I need to wait a day for the temps to get out of the freezing range and for me to get over a cold and we will start putting it back together.