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    • CommentAuthorjay rich
    • CommentTimeApr 28th 2009
     
    hi guys giving the a.r engine a break basicaly letting the gremlins get out of the engine i think its time to try my luck and my poor brain i have casted a new engine design its a inline 8 all ready i hac\ve been cursed the first to casting where long bars of aluminum but lady luck was with me on number 3 some flaws but machinable but the gremlins got me agian as i was cleaning up the block my mill just stoped i think i am going to go nuts so now the pc board has a bad componint some where and any help on this please let me know so back to my trust lathe and made all the cylinder liners and a cylinder liner tool next all of our favorite valves and seats i do have a machineing ? i have some 1018 fo the crankshaft how hard is 1018 to machine on a small lathe most of it will be cut on the mill but i will need finish cut the mains and crank pins on the lathe well wish me luck and if any one can help with the mill problem please let me know thanks guys ....jay
    • CommentAuthordavid
    • CommentTimeApr 29th 2009
     
    Jay, please consider a work in progress page for this 8 cylinder engine so everyone can see what you are doing.
  1.  
    I second the motion!
    •  
      CommentAuthorgphunt
    • CommentTimeApr 30th 2009
     
    I agree!
  2.  
    Jay:
    Careful with the crank, 8 in line, need to allow for torque forces which were responsible for braking one too many cranks or at least producing enough twist in them under heavy loads.

    Some older designs used big diameter connecting rod's and multiple crank bearings to avoid deflection too.

    Keep us all posted.
    Jaime.
    • CommentAuthorjay rich
    • CommentTimeMay 1st 2009
     
    i was think of useing the big bar i have of 1018 i do have a ? how is this stuff to machine i am also baseing the j 8 after the seal engine and the lost inline 8s of time past when i was a kid at englishtown race way park i got to see a inlie8 dragster i think i was 6 or 7 and i fell in love with the noise and look of this engine and then the 454 v8s that also stole my heart well so far ive done a lost foam cast and what a pain its a big block but the third time i think and hope i have it but i have bad news just as i started to clean the block up my mini mill died well the pc board did no smoke just blah dead so ive been makeing cylinders and valve assembleys i have some pics to e mail david most of this engine is just dubbleing the seal but with my touch of me in it ....jay
    • CommentAuthorjay rich
    • CommentTimeMay 1st 2009
     
    its funny you say this jamie i woluld like to ask or all of us take a vote should the crank be on piece or a bulid up and siversolered together and yep its a o ring engine i think i am going to try to use regular spark pluges in the one oh yes i would like to ask uncle dale on his spark plugs the size and thread oh and the ar engine is still at rest i had it going foe a bit on hydrogen i have no clue how fast the rpms were but it broke my crossslide vice and my camra died so its on the bench with the pistions out sometime i scaremyself ....jay
  3.  
    Jay....The plug threads are .250 X 32 ......The plug measures from the shoulder that the plug will seat on , to the tip of the threaded section of the plug is .290 .....UD
    • CommentAuthordavid
    • CommentTimeMay 1st 2009
     
    Here is a link to the work in progress for Jays inline 8. ->link<-
    I hope he will share details about the casting process.
    • CommentAuthorjay rich
    • CommentTimeMay 1st 2009
     
    thanks dale and the casting what a pain well first thing is the foam i used blue dow styrofoam i glued and stacked it to three high next i made my copys on paper and did a cut and paste to foam next to form the foam to the patern leveing room to machince and shirinkage of the alumiumn to pour this cast i used fine sand in a garbage pale a small one to prep the sand i used a mix of water and sand to get it to a mix of think paste level the bottom and place your foam in to the foarm slowly add sand and compact it to the foam till you cover the foam and the spru i used a peice of round iron tube at the top of the foam to guide the pour into ans a over flow chamber next let the cast set up i wait about a hour its fun and i am still learning on how to get my casting skills better oh you guys might like to know the cast of the j 8 is all mountain dew cans ,,,,jay
  4.  
    I have a friend who casts aluminum with foam molds. He dips the foam in that stucco/popcorn ceiling spray stuff. A coat of that and let it set. Then a second coat and roll it around in the sand and imbed sand in the coating. Then lightly pack the mold and pour after everything is very dry.

    I have seen his castings and they are very nice. Might not hurt to try.
    • CommentAuthorjay rich
    • CommentTimeMay 2nd 2009
     
    oh kool kinda like makeing a plaster mold of the foam to aid in protecting it during casting sounds kool i got to try that ....jay
  5.  
    Hey Jay could you tell us alittle about foam casting and how you went about doing it all. Type of sand foam and så on. I got all these ideas. Shouldn't be too hard to make complex shapes in foam and I see no reason why foam parts cannot be glued together to help make the complex shapes.... and no draft angles to worry about.
    This could really be of help to guys with smaller machines that are reluctant to hog out of billet.
    Sounds very interesting. I have been searching the net and seen a few very simple furnaces made from scrap that are very functional.
    I have not found plans for free yet.... anybody?????? the simpler the better.... and ofcoures low cost.

    Jan
    • CommentAuthorsundog
    • CommentTimeMay 6th 2009
     
    Having done a wee bit of lost foam casting myself, here are some tips I've learned.

    Use dry play sand. Greensand (molding sand) is good, but too labor intensive to mull and doesn't really add much value to the process.

    Use the blue or pink insulation foam. Green floral foam doesn't cast well, and avoid any of the "expanding foam" insulation/gap sealing foams like the plague. They're polyurethane based and create toxic (read make you sick as hell and detrimental to your health!) fumes. You want polystyrene foam. The white beaded foam works, but tends to leave a rough surface finish and the characteristic "bead circle" texture on the cast part. It also doesn't respond as well to shaping via tools or hot wire as the EPS insulation foam. Use hot melt glue sparingly to join pieces of foam, or to apply fillets to parts where necessary. "Johnny Ring" toilet wax seals also work well to add fillets. New ones, of course!

    Use a rather large sprue, made of the same foam, attached to the part. I generally use a minimum of 3/4x3/4" sprue, and sometimes up to a 1" square sprue.

    I use a pop can, with the top and bottom cut out, as a funnel. I just set it over the top of the sprue and pour into the can. As always with foam, pour fast, hard, and don't let up until you're sure the mold is filled. Any hesitation will usually cause a short pour, or the sand will shift as the pattern melts away, ruining the part. Be prepared for some fire, smoke, and stink.

    Buy a small tub of drywall mud, and thin it about 50/50 with water in a 5 gallon bucket. Once you've made your pattern and glued on the sprue, dip it into the thinned mixture (mix it well before use) so that the coating is about 1" or so up the sprue and the part is completely covered. Let it hang to drip and dry, then repeat. I typically dunk mine about 3-4 times in the course of a Saturday or Sunday, and cast them the next weekend. The dried drywall mud makes a shell that preserves the shape of the part as you're pouring. Keeps the sand from shifting as the foam melts, but the pouring rule above still applies. Above all, *THE PATTERN AND SAND MUST BE BONE DRY PRIOR TO CASTING!* Water plus 1400F molten aluminum = steam explosion. And that means molten blobs of metal flying all over the place, starting fires, burning stuff that you didn't intend to burn, and worst of all, burning *YOU*. I would hope that anybody wanting to cast metal will be smart enough to read up on the safety equipment necessary and not proceed without said equipment... We're all adults, after all.

    I do my casting in an old popcorn tin, using dry play sand. I pour ~3" into the bottom of the tin, then place the pattern, and pour the rest of the sand in until the highest part of the pattern is at least 2-3" under the surface. My furnace is a dozen insulating fire bricks (the light ones, not the 4 lbs each dense fire bricks), with a naturally aspirated propane burner. Runs off a #20 tank with a high pressure regulator, and will melt about 6 lbs of aluminum from cold in 15-20 minutes, and about 5 minutes per melt after that (furnace and whatnot is already hot). Aluminum is about 10 cubic inches per pound, brass, bronze and cast iron are 3 cubic inches per pound. The blue and pink insulation foams are roundabout 1.8 pounds per cubic *FOOT*, or about .01 ounces per cubic inch. An accurate digital scale can weigh your pattern before you dip it to give you an estimate on how much metal will be needed for it. Be sure to allow 15-30% more for the sprue and possibly a bit more for the riser. Aluminum also shrinks about 3-4% as it solidifies, so give yourself about 5% oversize for a "cast to dimension" part, and more than that if you plan to machine an area.

    For furnace ideas, go to www.backyardmetalcasting.com, and click on the Forums link. Lots and lots of good information. Plenty enough information to keep you busy for quite awhile.

    It is well within the reach of the hobbyist to cast up to 10 lbs or so of aluminum. Brass, bronze, and cast iron take more expense and effort to manage, along with a higher level of danger, simply because of the damn intense radiant heat of them. having melted and poured cast iron, I can tell you first hand, it's hotter than the hinges of hades, and about as dangerous as a crooked lawyer with a vendetta.

    With the proper safety gear, proper equipment, and a bit of planning, it's fairly inexpensive to build, equip, and operate an aluminum foundry. The ability to make your own castings from foam patterns (or other patterns, if you use molding sand), can be a godsend. but be prepared to flub a fair number of castings before you get the hang of it. But at least with casting, you can throw the rejects back into the pot and try it again without shelling out more money for materials. ;)

    Hope it helps!

    Shad H.
  6.  
    Sundog,

    Thank you so much for your easy to read, easy to understand information.
    Got any pictures of cast parts, machined or not???

    One question when you say "play sand".... what do you mean? Like play ground sand og beach sand ? ? ?

    Thanks

    Jan
    Norway
    • CommentAuthorjay rich
    • CommentTimeMay 7th 2009
     
    ok kids listen to sun dog ive done the same things but have not tried the dry wall trick i got to try that sounds fun and yes he is rite your going to get rejects how i started to pratice is on those hallween foam skull raming a mold and placeing them in to the sand and getting the rite amound of alumiun or brass to fill the mold ive had alot of haf skulls or no skull at all and a alumiun spill on the ground play smart i have tried the orn flour trick where you add 50/50 sand and flour and its been fun smelling like corn bread well i have found some flaws in this cast alot of little pits in and out cylider 8 was the last out of the pour and was my worrie but it looks like it will hold up i sent david some pics to post
    • CommentAuthorjay rich
    • CommentTimeMay 8th 2009
     
    sundog i do have a ?do you degause you alumiun before you pour ? and i have a genral strenth? on 12l14 from my hand book and notes ive sean on the internet 80,00psi Tensile strength 70,000 Yield point psi so do you think it will hold for the j 8 crank shaft ive used 1215 for the sidwinders cranshaft ....jay
  7.  
    Jay,
    I hope its OK to poke my nose in on this one.
    12L14, leaded steel is nice to machine and should be ok .... what it all gets do to is how it will be supported...number of main bearings and what type of running it will be doing. For a proto-type I would make it out of 12L14 and take it from there as you might have to make a new one anyways.... you know Murrfy's Law... LOL
    • CommentAuthorsundog
    • CommentTimeMay 8th 2009
     
    Jay, All,

    The specks and pinholes you're seeing are hydrogen porosity. Molten aluminum picks up hydrogen gas from the atmosphere and from the combustion byproducts in the furnace. When the aluminum solidifies, the hydrogen comes bubbling out of solution, creating tiny voids in the casting. Aluminum also picks up hydrogen from agitation, so don't stir the melt. Stirring the melt mixes in more hydrogen, and it causes the exposed aluminum to oxidize, creating more dross.

    Here's how I degas my melts,

    I use a bit of pool shock (sodium hypochlorite) in granular form. I use about a teaspoon full twisted up in some aluminum foil like a bomber joint. (excuse the analogy, please) When the aluminum is all melted, I drop that in, and use my skimming tool to push it to the bottom of the crucible. Then back off and let it work. The sodium hypochlorite melts, and bonds to the hydrogen, causing it to bubble out of solution. I leave the skimming tool in the crucible, holding the degassing packet at the bottom. Do *NOT* use liquid shock. It'll flash to steam/vapor with the same effect as water! Use the granular form only, and don't store it in a tightly sealed container, as it offgasses chlorine and can burst a container from over pressure. I use HDPE containers with a snug, but not overly air-tight lid. You don't need much, so it may behoove you to hit up a pool-having buddy for some.

    STAND UPWIND, HOLD YOUR BREATH WHEN DROPPING IN THE DEGASSING AGENT, AND BACK OFF UPWIND!!!!

    This process generates hydrochloric acid fumes and small amounts of chlorine gas! Nasty, nasty, nasty stuff that'll mess you up badly even if you just get a whiff!!!! The pool shock melts and you'll see orange firey bubbles as it does it's job. Usually takes 15-20 seconds for mine to do it's job and the foulness to drift away on the wind.

    To make it easier to skim the dross off the top, dump in a heaping tablespoon of Morton's Lite salt as soon as you have a heel of metal, and again after degassing. Lite salt is a 50/50 mix of sodium chloride and potassium chloride. Once it melts on top of the melt, it causes the dross to stick together and acts as a flux, separating the molten aluminum from the dross. I find it easier to twist my flux (lite salt) up in aluminum foil, as the fluxes usually degrade the walls of the furnace if they come into contact with it. Easier to handle, also. Only skim before you pour, or if it's necessary to remove lots of excess dross. The scum floating on the top of the aluminum protects the aluminum below it from oxidizing into dross.


    Don't bother melting pop cans (or beer cans) They have too much surface area and oxidize quickly, and the quality of the pour is "iffy" at best, at least for me, even with fluxing and degassing. Plus, there's the risk that there's a bit of drink or syrupy scum left in the can, which can cause a pretty spectacular explosion of molten metal when it flashes to steam. Steer clear of aluminum cans. recycle 'em, and use that money to buy good cast aluminum.

    A note here... Cast magnesium looks an awful lot like cast aluminum. And you don't want to get any mag in your crucible.

    A quick way to tell them apart is to scrape a clean spot and drop some vinegar on it. If it fizzes and bubbles, or produces a black scum, it's magnesium. If it does nothing, it's aluminum, or very likely to have such a low magnesium content that it won't ignite.

    It's worth noting that molten aluminum is a pretty darn strong solvent. It'll dissolve stainless steel in short order, and it slowly but surely dissolves steel. Don't use a stainless steel crucible, or you'll end up with a strainer in short order and possibly it could fail while you're hoisting it out of the furnace or when pouring. Examine steel crucibles for erosion and discard them if they start to get thin. The intense heat and action of the molten aluminum takes a toll on them. Crucibles are "consumable" items, and should be treated as such. If you have *ANY* doubts on the integrity of the crucible, *don't use it!*

    Jay,

    Your pour looked good, though maybe a tad cold at the end. Aluminum melts around 1200F or so, and should be poured at close to 1400F. A foundry type pyrometer is an excellent investment, but after doing some pours too cold, or too hot (there is such a thing), you'll learn the way it should look when ready to pour.

    Finally, freshly-cast aluminum parts are dead soft. Left to their own devices on a shelf for a month or two, they'll "age" to about a T2 temper. I've noticed that parts I cast months ago machine a bit better than ones machined a few days after casting. If you have a suitable oven, you can heat treat aluminum castings, but that's something I've never done, and a bit beyond the scope of this thread.

    Hope it helps, and feel free to ask more questions!

    Thanks!

    Shad H.
  8.  
    Sundog, thanks for your very good information.... just a couple quick question..... what type of sand is play sand??? Just plain old sandbox sand????
    How does your surface texture look when using the plaster dip trick.... does it help? Where can I get Pool Shock? ? ?
    Thanks for taking the time enlightening us all.

    Jan
    Norway
    • CommentAuthorjay rich
    • CommentTimeMay 8th 2009
     
    ive done the pool tab trick not in this pour and yes it was a bit clod toward the end how i have done the tab trick is make a cage out of stainless steel rod and slow push to the bottom and yes it stinks bad i have a resprator on at this point this pour was ahh a lets see and you can use a chlorie tab to not all of it i have heat treated some steels and 60 61 aluminum for a mold but not a casting and jan here is a good place for fine sand mc master carr the ashtry sand its very fine your choice white or black its works for me i did try after the mold set up putting it in to my ovn at 1100 degress and let it slowly cool down for 2 days this cast machines realy good and i agree the cans have alot of impurties how i cleaned them up is melting themit to ingots and remelt thats how i got this cast ....jay
    • CommentAuthorjay rich
    • CommentTimeMay 8th 2009
     
    jan i do agree i will be having 5 mains and i think i can make the crank last i can try to heat treat the surfice and the fron and last mains will be berrings its just 2 3 and 4 i am worried about to we will see i guess ....jay
    • CommentAuthorsundog
    • CommentTimeMay 8th 2009
     
    Yup, just plain old play sand/sandbox sand is what I use. I get mine in 50 lb bags for about $1.50-$2 per bag, depending on the season, phase of the moon, fuel prices, etc.

    The surface texture using the drywall mud dip is very smooth and uniform. The irregularities in the pattern really show up good. Knocked off corners, jagged cuts, etc, all show on the finished casting, so make sure your pattern looks good.

    Without using the drywall mud dip, the texture varies depending on the coarseness of the sand. Coarse sand makes a very rough surface, whereas very fine sand leaves a smooth (comparatively) surface. The finer the sand, the smoother the finish, but fine sand doesn't vent as well as coarse sand, and is usually "softer", IE, the sharp edges have been broken off the grains, so it doesn't hold it's shape as well. Meaning that fine sand is more likely to collapse and shift while pouring a lost foam pattern that hasn't been dipped in drywall mud.

    The sand around my home (I live in Florida) is incredibly fine, but it has no "bite", and is useless as molding sand. Desert sand is the same way. The grains are smoother and have rounded corners, due to being blown against other sand grains for so long. Beach sand, however, is usually excellent sand! However, most public beaches are "owned" by the city, county, or state park services, and removing beach sand would be considered stealing.

    Hope it helps!

    Shad H.
    • CommentAuthordavid
    • CommentTimeMay 10th 2009
     
    Shad, Would it be Ok if I take the foundry discussion, organize it a little and make a page for the Tips section? If you have some photos of a actual pour and your furnace it would be great.
  9.  
    David great idea, hope Sandog (Shad) is up for it.
    I have always over looked home casting and not been very interrested until I became aware of foam casting. Foam is easy to work with, cheap and there is not alot of specialized tools needed.to do a casting ... and alot of the equipment needed can be made in the shop. I am already collecting stuff to recycle and give new life. I am also on the look out for a freon type vessel to convert into a furnace.
    I'll keep notes as I go along. I will only to doing one off castings when nessesary so I will be going the low budget way.... but safe of'couse.
    As for safty everybody is responsibe for their own safty.

    David, if the responce is good maybe we could have a Casting Gallery.... engine parts type casing of'coures.

    Jan
    Norway
  10.  
    Jay,

    I read some where that a good type of aluminium to use for home casting is cast aluminium salvaged from transmisson housings, engine heads/blocks/pistons and so one. Just clean it up a bit and smash it up with a sledge-hammer. This type of aluminium alloy has something in it that makes it ideal for casting.... might be silicon.... but I cann't recall. I'll check it up.
    Shad any input here.

    Has any of you guys seen the movie "Worlds Fastest Indian"..... he cast his own pistions out of old pistons.... 3 parts Chevy ,2 parts Ford and VUALLA high preformace pistons for his bike. Good movie for people like us, take the time to see it if you haven't.
    Sorry for the side traking.

    Have a good one.

    Jan
    Norway
    • CommentAuthordavid
    • CommentTimeMay 10th 2009
     
    If people are interested we can make a page or section just for casting work that could include how to instructions and a gallery of castings.
    Possibly those who know, and do, home casting can provide links to good furnace plans and suppliers of materials.
    I think we also need some safety advice.
    Very few engines here are made from castings other than kits, but as I read old articles casting was often done.
    •  
      CommentAuthorgphunt
    • CommentTimeMay 11th 2009
     
    David
    Sounds good to Me!
    George
  11.  
    David,

    Alot of castings are no longer available, like the 1/4 and 1/6 scale Cirrus by Zimmerman and several Diesels of the early days.
    And other castings are very expensive. Casting is also an alternative to "Hogging" out of stock like some plans call for.
    Its also a nice challenge and a learning experiance.
    I am working on the Barr and Stroud as a side track projecvt and the crank and oil sump would be nice to cast... at least gi til a go :).
    I hope to have a furnace and other casting tools ready for next winter.

    Jan
    Norway
    • CommentAuthorsundog
    • CommentTimeMay 11th 2009 edited
     
    I'd be happy to offer up information for the Tips section. To me, it just seems that building things from scratch and pouring your own castings go hand-in-hand. Bar stock is great for just sitting down and building, and it does have some advantages. Uniform size, known quality and consistency of the material, and inexpensive to obtain.

    Castings, on the other hand, can vary widely in quality. I've made dead-nuts-accurate castings for stuff, and some that were fit only to throw back into the crucible and re-melt.

    David,

    How would you like me to present the information? Should I start another thread and break it into separate posts for each subject, or bash up a text file and email it? I should be doing some patterns and castings in the next few weeks, so I'll be sure to juice up the digital camera and grab some pics.

    I'll start another thread on casting to keep from derailing this poor thread any more than it already has.
    • CommentAuthorjay rich
    • CommentTimeMay 11th 2009
     
    neat and yes when i was 17 i did that same trick burt moroe did i went to the beach the jersy shore and casted a pistion in the sand for my mini bike it came out ok but failed after i used methonol as a fuel its was a wild ride i find old brigss block and weed wacker engines cases and use them also i wanted to use my cans as a goof i real did not think it was going to come out good it was a lazy pour but worked ....jay
  12.  
    Sundog,

    When you do your next casting take WAY too many pictures so complete beginners will have an idea of the total prossess. Like the old saying A pictures says more than a thousand words. Pictures and short captions will save you alot of writing and easy for us dummies to understand.
    Looking forward to seeing pictures of your work..... I am really excited about getting started.

    Jan
    Norway
    • CommentAuthorjay rich
    • CommentTimeMay 13th 2009 edited
     
    great new i just got a email from kirk at hemmingway to use the seal engines full prints in aid of the design of my j8 now is the fun part of crankshtaft machining and its joys i have a ? i can not find any octogon bar stock any where does anyone know where you can get this stuff i am looking for 1/2 stock ???? jay
    • CommentAuthorjay rich
    • CommentTimeMay 14th 2009
     
    opp my dro lied to me well scrap the first crank the space between throws was off as in the mains i cut them to long pusshing the crank to a larger size but good news i can do some testing on how to harden 12l14 and see how it goes ....jay
  13.  
    Hey Jay,

    Don't you hate it when the DRO lies to you....LOL
    I have case harden low carbon leaded steel before using a product called Casinite, I might be misselling that.
    I got it from Brownells. You could give that a go.

    Jan
    • CommentAuthorjay rich
    • CommentTimeMay 15th 2009
     
    i tink i am going to try that i have used it in the past from what i was tol it will harden to 0.060 on 12l14 and that will work i got to say i was getting a great crank till i noticed the last cut in the second main between cylinder 2 and 3 oh well you live and learn ....jay
  14.  
    Jay

    I did misspell it

    here is a link..... pretty cheap and work very well. Easy to use too.

    ->link<-
    • CommentAuthorjay rich
    • CommentTimeMay 15th 2009
     
    thanks jan i will order some and do a test ive used the stuff before and it works well ....jay