Author Topic: Casting a V8 first ever attempt!  (Read 2042 times)

Offline gadabout

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Casting a V8 first ever attempt!
« on: July 26, 2020, 08:47:47 AM »
First Casting, this is my first ever attempt at pattern making ,furnace building , core making and ramming a pattern then pouring, quite happy , a few flaws but I am going to give myself a pass mark!😁
cheers
Mark

Offline nj111

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Re: Casting a V8 first ever attempt!
« Reply #1 on: July 26, 2020, 09:37:30 AM »
Very good, I recall my own efforts went on for months until I got decent results!
Nick

Offline Vixen

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Re: Casting a V8 first ever attempt!
« Reply #2 on: July 26, 2020, 10:22:33 AM »
Hello Mark,

Wow, that's a fantastic achievement. Well done. :ThumbsUp: :ThumbsUp: :ThumbsUp: :ThumbsUp: :ThumbsUp:

There is nothing in the world like the excitement and joy of knocking the mold box into the sand pit and finding the gleaming metal of your first successful casting sitting in the burnt sand and still too hot to handle.

So, we have the first ever flathead V8 Seal pup!!!!  Does your newborn engine have a name yet? That's sure going to be an interesting engine build to follow.

What metal did you use? Was it an ingot of 'new' metal or did you recycle a mountain of empty Fosters tinnies?

The core material looks untouched by the heat. What did you use for that?

Is that a centre bearing I can see?

Well done: Bravo Bravo

Mike
« Last Edit: July 26, 2020, 10:40:51 AM by Vixen »
It is the journey that matters, not the destination

Offline scc

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Re: Casting a V8 first ever attempt!
« Reply #3 on: July 26, 2020, 10:57:01 AM »
Great job :ThumbsUp: :ThumbsUp: :popcorn: :popcorn:    Well Done         Terry

Offline Zephyrin

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Re: Casting a V8 first ever attempt!
« Reply #4 on: July 26, 2020, 11:23:01 AM »
I would have liked to get that for a first attempt! a flat head V8 with cored passages wow, congrats...a pretty good start !

Offline Jo

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Re: Casting a V8 first ever attempt!
« Reply #5 on: July 26, 2020, 11:59:43 AM »
Well done Mark  :ThumbsUp:

There is no limits to what models engines you can do casting for now.

Jo

P.S. What Ali did you use? I have been told that Alloy car wheels are very good source of metal for home casting  ;)
Enjoyment is more important than achievement.

Offline Mcgyver

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Re: Casting a V8 first ever attempt!
« Reply #6 on: July 26, 2020, 12:48:07 PM »
nice work...that really expands the capabilities and possibilities

Offline gadabout

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Re: Casting a V8 first ever attempt!
« Reply #7 on: July 26, 2020, 08:00:32 PM »
Thanks guys(and gal)!
Mike, was thinking maybe a Walrus! you know an oversize Seal! Yes centre bearing web hopefully. The cores were a baked sand recipe from Myfordboy's pages
Mike/Jo, the ali was some offcuts from years ago that came from  cast aluminium repro lace fence panels that I saved from a welding shop.
Will post some core and pattern pics when I can work out how to from my work computer.
cheers
Mark
« Last Edit: July 26, 2020, 10:28:54 PM by gadabout »

Offline gadabout

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Re: Casting a V8 first ever attempt!
« Reply #8 on: July 26, 2020, 10:13:29 PM »
These are some pics of the patterns and cores, there is one more core not shown. The patterns had 12 loose pieces that had to be withdrawn after moulding. I think I moulded about 15 times before I was happy enough to pour, even then they were really not good enough but I needed to pour before I lost interest in it all!! The cores are two piece, placed into each half of the moulding boxes. The core box is a built up arrangement from ali plate ,baked in an oven for 1.5 hours at 200 degrees in the core box, the core box is then disassembled to extract the core. I really do need better sand than my homemade stuff of silica sand and bentonite, really would like to try petrobond but have not been able to find any here in Tasmania, Australia
regards
Mark
« Last Edit: July 26, 2020, 10:28:28 PM by gadabout »

Offline gadabout

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Re: Casting a V8 first ever attempt!
« Reply #9 on: July 28, 2020, 10:10:59 PM »
I have done some machining on the casting and there are Zero signs of porosity! A few spots show signs of the ali starting to freeze near the end of the pour and for the next one I will change the sprue size I think as I reckon it was pouring a bit slow. Also I think I might have poured to cold not having any way to measure the temp just poured when it was molten.
cheers
Mark

Offline crueby

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Re: Casting a V8 first ever attempt!
« Reply #10 on: July 28, 2020, 11:50:30 PM »
Looking great - how big are the castings?

Offline gadabout

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Re: Casting a V8 first ever attempt!
« Reply #11 on: July 29, 2020, 12:18:15 AM »
Chris,
 they are 4.75" (120.5mm) long

Mark

Offline nj111

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Re: Casting a V8 first ever attempt!
« Reply #12 on: July 29, 2020, 01:58:55 PM »
Most of my casting problems were due to me overheating the aluminium or keeping it molten for too long, leading to absorption of hydrogen and producing a casting containing thousands of tiny bubbles which become visible once machining has commenced.  Hydrogen absorption increases rapidly above 740'C so I keep it within 760'C max.
I found a probe in the melt (that plugs into most multimeter thermocouple sockets) gave me a reliable indication of temperature and as a precaution I got hold of some degassing tablets (Ecogas 16)  from a foundry supplies firm and I plunge one of those deep into the melt shortly before pouring.  I'm sure if casting more regularly one would get to know exactly when to pour without needing a temperature probe, but I for sure need that information!
Nick

Offline Alyn Foundry

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Re: Casting a V8 first ever attempt!
« Reply #13 on: July 29, 2020, 04:37:50 PM »
Hi Mark.

That's one heck of a casting for a first attempt, very well done.

My first was over 40 years ago and a failure too, it cold shut before fully filling the void.

I'd like to suggest that your " ingate " was a little small onto the casting so you could try making it a little bigger the next time. Aluminium doesn't have the same " weight " behind it so the quicker you can get it in the better.
Your " sprue " diameter looks fine but an additional " header " on top of the box can help increase the pressure in the moulds cavity.

A good " covering " flux will help with both gas problems along with more yield from the metal melted. Believe it or not we used " mothballs " as a degasser before turning to proprietary brands later. The speed at which you can " drop " the metal is also important, this reduces gas absorption to a minimum.

The largest casting in Aluminium that I did weighed 120Kg, took nearly 3 days to cool and ended up as a prototype press tool for MDF flooring. Fun times....

Cheers Graham.

Addendum.

Mark, I don't know where you're placed in the world but when I was in business we used the services of Foseco, Tamworth Staffordshire.  The flux in question was called    Coverall, Salmon pink in colour and amazing at keeping the gas levels low and the " dross " was just dust. We tried to avoid degassing due to the toxic nature of the fume. For Aluminium patterns a few pinholes wasn't much of an issue but we used their tablets for important castings.

Lol.... Tasmania..... Try reading the script properly G.

Oh.... Petrobond has a nasty habit of staining the surface of Aluminium you'd be better off trying to find some decent, fine grained moulding sand and either go the " Green sand " route or try Sodium Silicate mixed with your Silica sand and use CO2 to set it.
« Last Edit: July 29, 2020, 06:45:39 PM by Alyn Foundry »

Online Twizseven

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Re: Casting a V8 first ever attempt!
« Reply #14 on: July 29, 2020, 10:09:01 PM »
Graham,

Good to hear you used Foseco at Tamworth.  My next door neighbour a fair few years ago used to be their Patents Director (he has since passed away).  He got me a summer job working in the research labs when I was 18.  It was great fun mixing up Exothermics to put on top of castings.  Used to make up mixtures, put them in a polybag and then dump them rapidly onto a furnace type of hotplate and then monitor the temperatures and see how they hardened and crusted up.

Colin.

PS hope to come and see you in near future to collect some castings.  Will give you a ring.