427/435 intake manifold casting mold crack

[Kerry A.]

Re: 427/435 intake manifold casting mold crack

I was a patternmaker starting in 1963 & I owned a pattern shop that made mostly automotive foundry patterns. It looks like the drag 1/2 of the sand mold was pushed out & cracked when the runner core was set. This would cause that piece of sand to push out past the rest of the casting mold causing that portion to stick up. If the core print was damaged it would cause the core to crush that portion of the mold outward. This is definitely NOT a repair but a brake in the green sand mold. That's why there is no crack on the inside because the core makes that shape.

Thank you. I knew someone out there would have an answer or at least surmise what caused the imperfection. As Steve Blanchard mentioned, a pattern maker should be able to shed some light on the matter. There is not a problem with my manifold but when I read there was a mold problem, I wanted to get it out on the forum so at the very least members would be aware of the issue. Thanks to everyone for your help.

[Kenneth B.]

Re: 427/435 intake manifold casting mold crack

Thank you. I knew someone out there would have an answer or at least surmise what caused the imperfection. As Steve Blanchard mentioned, a pattern maker should be able to shed some light on the matter. There is not a problem with my manifold but when I read there was a mold problem, I wanted to get it out on the forum so at the very least members would be aware of the issue. Thanks to everyone for your help.

Glad I could help. I wouldn't try to do anything to the casting as there is nothing wrong IE crack just a casting flaw.

[Kerry A.]

Re: 427/435 intake manifold casting mold crack

Glad I could help. I wouldn't try to do anything to the casting as there is nothing wrong IE crack just a casting flaw.

Ken, Thank you again. Nope not going to touch the blemish.

For all who helped out, I've attached photos of my intake manifold. Except for the heat shield on mine which blocks out part of the blemish, it is the same as the photos of the intake on eBay. Note the pic where my finger points out the offset which matches the one on eBay. There's always something new to learn.




IMG_20150408_122523862.jpgIMG_20150408_122534418.jpgIMG_20150408_122655648.jpgIMG_20150408_122747703.jpg

[Graeme B.]

Re: 427/435 intake manifold casting mold crack

Foundry workers probably did some Bubba work with plasticine before the Patternmakers could repair the Pattern properly.
I saw lots of temporary repairs as a Patternmaker.

[Kerry A.]

Re: 427/435 intake manifold casting mold crack

Foundry workers probably did some Bubba work with plasticine before the Patternmakers could repair the Pattern properly.
I saw lots of temporary repairs as a Patternmaker.

I'm sure there were quite a few bale wire and duct tape fixes. Thanks for the input

[Steven B.]

Re: 427/435 intake manifold casting mold crack

I was a patternmaker starting in 1963 & I owned a pattern shop that made mostly automotive foundry patterns. It looks like the drag 1/2 of the sand mold was pushed out & cracked when the runner core was set. This would cause that piece of sand to push out past the rest of the casting mold causing that portion to stick up. If the core print was damaged it would cause the core to crush that portion of the mold outward. This is definitely NOT a repair but a brake in the green sand mold. That's why there is no crack on the inside because the core makes that shape.

Just out of curiosity, if you were using green sand for your cope and drag, what were you using for the cores at the time?

Steve

[Kenneth B.]

Re: 427/435 intake manifold casting mold crack

Just out of curiosity, if you were using green sand for your cope and drag, what were you using for the cores at the time?

Steve

I only made the patterns & core boxes as most foundries purchased the tooling from pattern shops. The foundries made the sand castings from the tooling I made. The green sand which is actually black had binders to make it hard when squeezed in a molding machine. The cores which made the internal shapes were made in 2 piece metal boxes & a different kind of sand with chemical binders were added & the box was heated up but later core sand had a self curing chemical blown in. Baked cores to cure the sand were yellow to a baked brown that were hollow & later Isocure cores were hard solid & a white color. The patterns looked like the outside of the casting but with core prints added to make depressions outside the casting itself to set the cores into & the cores boxes looked like the inside od the casting.