Doing some filing, grinding and sanding to get my ram horns ready for powder coat. Was able to clean up a number of mold seams and such to make them appear smoother and improve final look. Here are some before & after photos: Question: Do these “buttons” one on each “horn” serve any purpose? Is there any harm in grinding them off? Thank you in advance!
Can you see the back side of them or feel inside with a piece of wire? They could be pads the factory put there incase they needed to be drilled for a heat riser choke. If the back side is not dimpled in, I would think they are safe to grind off.
Check the thread on the Warbaby build. Several pieces were textured using a pneumatic scaler. The textured pieces had a very clean look.
Thank you for your help! I fussed around with a wire bent up with a hook on the end and could feel no recess/depression. Then I remembered someone I know has a scope. Didn’t remember if it was my neighbor or someone else. Luckily, it was my neighbor and I went over to perform the “manifoldoscopy”. Thankfully, they both passed. Seems those bumps are on the outside and are not recesses on the inside. Good to go with their removal.
When you say "powder coat" I assume you're referring to Jet Hot, Ceracote or similiar. Normal powder coating will just burn right off.
Needle Scalers give a nice textured look that hides all kinds of grinding. They also work great for removing rust from frames and heavy metal.
My guess is that the bumps are locating points for the bare castings to be held for machining the holes and flat surfaces.
Or the bumps may be the sawed off remains of the pour hole and riser from when the molten iron was poured into the mold.
That's what I like... detailing. Grindy grindy smoothie. I also believe those are set up pads for machining. Feel free to take them off unless you're going to have more machining done.
...and you have the same fixtures as factory! At this point, the machined surface and bolt spacing is the location!
Pete, you are doing good work as usual. Most people will not realize what you have done, but us in the know will appreciate your time and effort.
They are likely nubs used in the processing, to fixture the manifolds. I had newer Dormans with all sorts of doodads on them. I cut most off with the bandsaw, finished with an angle grinder and a belt sander.
Quick update: After many hours of grinding, filing and sanding, I had these manifolds looking really good; especially the areas that would be seen when mounted on the engine. I took them to the powder coaster who agreed they should look very nice when he finished. The next day, he called me to say that when he went to sand blast them, he found a hole. When I went to pick them up, uncoated, he showed me the problem. Seems like a case of “crotch rot” in the valley where the two horns come together. Unfortunately, I can’t seem to get it welded up because as I’m told, the casting there is of poor quality (see below) and he can’t seem to get the weld to work. I have great faith in this person having had him do several challenging pieces of work over the years. He has welded castings for me as well. Bummed over the hours wasted on this and now need to find another 292-312 y block ram horn. I’ll get over it. Any help in locating one (only need one but would buy a pair) or advice welcome.
Dang, that sucks! I've seen a lot of exhaust manifolds that develop scales in hot spots over the years. Most often in the Malaise era when they were running lean and lame timing. Hope Mark can get you fixed up.
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