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Thread: 1/3 Scale smallblock Chevy

  1. #21
    I would think loads of people would pay a grand for this casting kit just so they could build the engine and see it run.
    That was my original thought, and the reason the master is a double shrink. At one time I thought of flipping the working pattern to cast iron and then still be able to cast a dead nuts 1/3 scale in aluminum. But that was also ten years ago.

    The main stumbling block is the hand work to core the block, manifold and heads. I spent a year of my spare time developing the cores and getting a good head casting. After all that and knowing every thing that is required it takes me 16 hrs to get the cores for two heads mounted on their bases. Then by the time they are shaken out and cleaned up enough to start machining, another 8 hrs. has been spent. So, not counting fuel and supplies, at a barely surviving shop rate of $50/hr that is $1200 for a pair of heads that require a skilled machinist with the proper tools to finish and match them to the block which itself takes about the same time as a head, and then the manifold, also about the time as one head. Then the water pump, oil pump, pistons, vibration damper, all castings and the fan, valve covers and pan sheet steel blows the cost out of the market.

    That is why I did the little single
    http://www.backyardmetalcasting.com/...?p=41464#41464

    I thought I could match plate the crankcase and send it out to a jobshop foundry, and do the same in cast iron for the cylinder. The rest is either purchased or made from bar stock. Bringing kit cost below $300 opens a large market and could work, but I'm doing other things now while I'm still young .

    PS I added a couple links to your thread "So now you can....." last night.
    If you think you can't do it, you're right!

  2. #22
    Sandcrab,

    This is really excellent work, really using your head.

    I work in a fairly industrial setting and every new pattern I see I analyze every new pattern I see - how its made, how the cores set, what does what. Also the coreboxes, ect,. I make a mental note of how everything is made and what little tricks they've used to get things done. Everything pretty much follows a standard so most of my work I tend to stick to these standards as well.

    But this really opens my eyes of purely getting things done, its a tough, time consuming way of doing things but as your finished product shows it works very well. I'll be keeping in mind your methods when I do my future work - especially if I am no longer employed in the pattern shop at my foundry. I've been spoiled by my jointer, planer, bandsaw, disk sander, ect... its so nice but I need to be more reliant on what I have on hand and that isnt much, heh.

    I gotta ask- the first pic there of the wood manifold pattern - how did you carve that?

  3. #23
    Rocketman, I should have included that as a topic on the poll, and since it is too long for an answer here I'll try and do a photo explanation. I have written a couple articles for model engine magazines and I'll see if I can link to them.
    I have always carved. I have had a pocket knife since I was maybe five years old, and carried one since I was eight. Even all through school :shock: . That will date me. Anyway, the patternmaking is my favorite task, casting is next, and I get bored machining, but I had to learn to do it to get the final product.

  4. #24
    Senior Member
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    I'm not THAT old and we (most of the lot) carried a 3"-5" lockblade knife on our belt all the time. Still have mine in a drawer
    Angus MacGyver a.k.a Clifford C. Claven, Jr.

  5. #25
    Quote Originally Posted by sandcrab
    Thanks all.
    Abby I got one to copy, a Holley that is, but I was in a hurry so I just modified one of the alluminum manifold patterns to be a large plennum and fitted two small diaphram carbs from weed wackers as seen in the avatar.

    Motor heads will recognize them as dual Predators . At least that's what I tell the teenagers.
    I think you need to make a Rockchester(sp) FI sys for the '57 boys.
    Heat them up, mold them out.

  6. #26
    The cam grinder was adapted from a design published in Strictly I C magazine in the '90's. I made patterns for the side stands that located in the slots on the old Craftsman table saw top and used the arbor from the saw to carry the grinding wheel. I cast the clamp to carry the router motor and fabricated the guard from steel. It worked for the cam in the V8, but there were so many things wrong with the basic design I would not make another like this.

    Here with the overarm raised and below that with the follower resting on the master cam with the wheel on the lobe to be ground.






    The view below shows the test cam mounted in the index wheel and the master cams, offset 110* mounted on a keyed sliding sleeve. The blank, with the gear for the distributor pre cut, and all the lobes and bearings separated by plunging with a parting tool slightly deeper than the heel, is mounted in the index wheel and indicated in to run true. The holes in the wheel are numbered to coincide with the cylinders so the orientation of the lobe will be correct. Once mounted the relationship of the master to the blank can only be changed by unlocking the wheel and turning it to another cylinder number. Then the overarm is moved over the lobe to be ground, and the master cam is slid on the keyed shaft until it is under the follower. Better seen in the top photo with the thumbwheel that controls the depth of cut. This procedure is repeated for each lobe until the heel is .020 over final size. Then a finer wheel is mounted and the grinding continues to just short of finished size. The small angled stand in the lower center is used to grind the bearings so the rotation of the master cam shaft doesn't introduce eccentricities into them. The other master at the upper left is the fuel pump eccentric. I ground it on my cam, but run with an electric pump.




    This is a cast iron blank with only the rear bearing, gear and number 8 exhaust lobe separated. Once I had the setup on the dividing head to cut the gears, I wanted to have a spare for Murphy, or for a different grind. The bar stock is high grade continuous cast material that is very fine grained and nice to work with.


  7. #27
    Quote Originally Posted by ToddW_00
    I'm not THAT old and we (most of the lot) carried a 3"-5" lockblade knife on our belt all the time. Still have mine in a drawer
    Hell i carry a 4" one everywhere, unless it's somewhere they search you upon entering. Admittedly i never did the public school thing, being homeschooled throughout. So technically i carried one all through school i suppose :P

  8. #28
    The crank.



  9. #29
    Have you only built one of these sandcrab? I was just wondering if all of these pictures were taken along the way.

    I also had the thought that if you had a second engine you should do something just for kicks. Figure out all the costs, including your time at a professional rate (of course you cant really count the mold making time) and add a grand or two to it and put it on eBay. I would almost bet someone with more money than cents would but it regardless of the final tally. This being an extremely short run collectors piece I am going to guess you could attract bids that might gather your interest in terms of the time and cost on your part.

    w3

  10. #30
    I suspect he's right, really.
    I bet someone would plunk down quite a few grand for that, after all there aren't exactly a lot of 'em in existence, ya know?

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