IS SOMETHING WRONG WITH 340 LIFTER BORES

[Franko]

Has anybody ever seen anything like these lifter bores? The engine is a 1969 340. I'm wondering if this was a really bad engine casting and if this block is junk.

Thanks for any input.

 

[yellow rose]

If you are pulling the engine apart, just very lightly run a brush hone down the bores.

The rest of that is no big deal. Some of it is where the castings are put together.

It's 100% good to go.

 

[Max1196]

What you're showing in the pictures is quite common and there's nothing wrong with it. The "mold" used to create the sections of the block can get some what sloppy looking, being that they get used over many times. nothing that a grinder can't clean up. Be careful on removing those lifters, try not to gaul up the lifter bores because of the rust and that wiped out lobe on that cam.

 

[C130 Chief]

Those globs on the lifter casting bosses are bits of core sand that fell away as the cores were removed. You can smooth them out with a grinder if you want, the factory didn't bother to deburr much on production castings. As for the bores themselves, since the lifters look a little rusty, there may be some pitting. Not a huge deal generally. I lightly hone (using a piece of emery cloth in a shotgun cleaning "eye" rod spun with a drill). Just knock off any loose corrosion and high spots. Better to leave some light pitting and discoloration in place than oversize the bores.

 

[Dartish]

Lightly deburr it if it makes you nervous, then run it and don't give it a second thought

 

[jeffnmo]

They look better than a lot I've seen.
Jeff

 

[Franko]

Thank you gentlemen for you advice.

 

[diymirage]

im surprised no one has suggested it is junk and offered to trade it for a primo 318 block


but as said, your good to go, just watch out for rust in the bores

 

[yellow rose]

im surprised no one has suggested it is junk and offered to trade it for a primo 318 block


but as said, your good to go, just watch out for rust in the bores

I thought about trying that swap thing on him.

Then Jerry spring came on TV and I started watching that instead. It had strippers on it. Must see TV.

 

[nm9stheham]

As said, run a lite hone down the lifter bores. Then scrub some fine Scotchbrite through them in a circular motion to get any rust out of any pitting in the bores. I only mention this as you don't want rust particles floating up out of any rust pits in the lifter bores and scoring the lifters later.

Then measure the bore diameter carefully and accurately. You don't need lifter bores that are .003-.004" worn or more that will leak out a lot of the pressure from oil galleries due to a loose lifter-to bore clearance, and lower the oil pressure through the rest of the engine.

From the grey coloration of the crud on the cam, and the light rust all over, it looks as if there has been water in the oil in this engine. If the reason is unknown, it may be a good idea to have the block pressure tested before going too far.