640 Head and Piston Tops

pburchett · Mar 11, 2019

Since the rear main was leaking I decided to redo the rings and valves. Thankfully the head came off without breaking any bolts. A little sludge and carbon on the head.

Cleaned the piston tops off looking for size.

The water jacket looks a little cruddy. Any suggestions to clean the rust up?

Janicholson · Mar 11, 2019

Thee three pistons that have clean edges are using oil. You were correct in the need to do a ring job. Be sure to crosshatch the cylinder walls at 45 degrees to allow break in.
Jim

kencombs · Mar 11, 2019

Try filling the block with white vinegar. Let it set overnight and flush out. I just did that to a 56 Dodge block. seemed to work pretty good. A second or even third soak may be needed.

Steve@Advance · Mar 11, 2019

Be sure to check the bearings too.

A leaking rear main seal is often a symptom of loose main bearings.

I don't know if that is a rubber seal or a rope seal. Rope seals are really difficult and exacting to get right. They require proper bearing clearance or the crank play will beat it out quickly. Take your time to get the ends right. Too long they will hold the cap up, too short it will leak. An Exacto knife is the tool you'll need.

1948CaseVAI · Mar 11, 2019

(quoted from post at 13:17:53 03/11/19) Try filling the block with white vinegar. Let it set overnight and flush out. I just did that to a 56 Dodge block. seemed to work pretty good. A second or even third soak may be needed.

FWIW when you want to clean with vinegar you can get strong vinegar at Home Depot in gallon jugs. It is much stronger than grocery store vinegar and it is made for cleaning. Works well.

showcrop · Mar 11, 2019

pburchet, watch out!! this started as a valve job:

But seriously go to you tube video Holden V8 rear main seal install. watch that and you will be ready to do one. Another option is the two piece rubber lip seal which is what I prefer .

john in la · Mar 11, 2019

A 640
That is a sleeved motor isn't it????

If so you would hope the pistons are std in a sleeved motor.
If it worn to oversized you just replace the sleeve.

pburchett · Mar 11, 2019

I know what you are referring to. I started packing the front wheel bearings.

I like the color of you Ford. I hope for mine to look that good someday.

showcrop · Mar 11, 2019

(quoted from post at 16:34:04 03/11/19)
I know what you are referring to. I started packing the front wheel bearings.

I like the color of you Ford. I hope for mine to look that good someday.

The colors on your 640 are different from those on my 901

640 Head and Piston Tops

pburchett

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Janicholson

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kencombs

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Steve@Advance

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1948CaseVAI

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showcrop

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john in la

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pburchett

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showcrop

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