# Grind off lump inside intake manifold runner?



## Red74Goat (Jul 31, 2015)

I have taken the original cast iron intake manifold off my 1974 350 and noticed a small steel "ball" inside the #5 runner, near the exit to the head. I assume that it is a remnant of the original casting process. I had no plans to do any polishing or grinding of the intake manifold runners, but it seems that I should grind this lump out with a dremel. Any thoughts on leaving it alone or removing it?

I have a couple of pics attached.

Thanks.


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## Hallett Dave (Apr 29, 2016)

Red74Goat said:


> I have taken the original cast iron intake manifold off my 1974 350 and noticed a small steel "ball" inside the #5 runner, near the exit to the head. I assume that it is a remnant of the original casting process. I had no plans to do any polishing or grinding of the intake manifold runners, but it seems that I should grind this lump out with a dremel. Any thoughts on leaving it alone or removing it?
> 
> I have a couple of pics attached.
> 
> Thanks.


I would remove it. You will never know how much the slag affects the flow into the heads without putting it on a flow bench.
Probably not much.
My concern would be if that slag would some how break off and end up in that cylinder and possibly bounce around and ending up in more than just that cylinder. I had a carburetor base plate bolt back out and bounce back and forth from cylinder to cylinder years ago.
YMMV
Dave


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## ALKYGTO (Mar 29, 2010)

Agreed, I would remove that before reinstalling.


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## Rukee (Feb 8, 2007)

I would remove it as well. Maybe just hit it with a screwdriver and a hammer and chip it off.


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## Red74Goat (Jul 31, 2015)

Thanks for the inputs.

I took a very small cold chisel and popped it off with a couple of light taps with a hammer. Came off very clean, no follow-up needed.


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