Ontopic History of an Old Car

gee said:
asa, are those 3D printed mockups?

I've heard of people doing lost PLA casting with good success, might be worth a try. Probably a lot easier to cast something and clean it up than to machine one from stock.
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Yeah, sorta half-assed mockups to get me to the point of "what do I need to do now?"
I can see three or four more iterations of them as I go at a minimum

I've done lost PLA casting for some old outboard parts. I posted a thread when I did it, but didn't get many views I think. It works pretty well, need a decent mold media and a decent positive, but out of that you're good.

The few aluminum things I have cast have not reacted well when machining. Not sure if it was a crappy alloy or if it might not have aged yet.
 
Mr. Asa said:
Yeah, sorta half-assed mockups to get me to the point of "what do I need to do now?"
I can see three or four more iterations of them as I go at a minimum

I've done lost PLA casting for some old outboard parts. I posted a thread when I did it, but didn't get many views I think. It works pretty well, need a decent mold media and a decent positive, but out of that you're good.

The few aluminum things I have cast have not reacted well when machining. Not sure if it was a crappy alloy or if it might not have aged yet.
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Could be trapped stress due to uneven cooling in the mold. Anneal it before you machine it - I'm told a self cleaning oven does the job beautifully.
 
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gee said:
Could be trapped stress due to uneven cooling in the mold. Anneal it before you machine it - I'm told a self cleaning oven does the job beautifully.
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One example, when I pressed the brass rod in this chunk pressed out.
Old GM transmission body donated the aluminium, open faced mold so it might've air-cooled on top. This was after machining down roughly .1" to get a clean surface, then light sanding

:iono:

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Transmission case metal is great, it's a proper casting alloy and it's consistent. If you melted down a bunch of old heatsinks and pop cans, that'd be a different story.

Yeah, do your next mold fully enclosed. Open top mold will cool unevenly, plus the top will collect impurities - better to have them collect in a sprue.
 
gee said:
Transmission case metal is great, it's a proper casting alloy and it's consistent. If you melted down a bunch of old heatsinks and pop cans, that'd be a different story.

Yeah, do your next mold fully enclosed. Open top mold will cool unevenly, plus the top will collect impurities - better to have them collect in a sprue.
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Yeah, this was an open faced mold as that was the easiest way, and we were more concerned with what the wood would do when metal was cast onto it. When we finally finish the project it will be sprued and molded properly
 
Updated pics of the twin Weber mockup.
The adapter for the front is printing now (I think it is. I might've fucked up and started printing this one again. It's using the school's printer and filament, though so I don't give a shit.)

Basically trying to ensure that I'm able to move the throttle linkage all the way.











 
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Take everything off and make a mess? The lifters are hydraulic, so I shouldn't need to adjust them more than once or twice and then ignore it. The only time I've ever made an adjustment on the valves was when I replaced the head, and that was once.
 
So I'm trying to get the rivnuts in place in order to be able to bolt down the adapters with no loss of airflow from putting the rivnuts in the right way (also using rivnuts as there is no room for threading.) The rear flange went down decently, but the front is looking like an asspain due to a couple little inconsistencies Vs the rear.

Anyone have an idea on how to better do this? Of course, neither hole lines up with the intake ports so I can't reach an extension through.

@gee @Jehannum @Mustard Dispenser


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The rivnut with the washer around it was a test piece so I could model it in solidworks. It does show how much further this one has to go before it's tight, though.
 
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