LSx Engine w/ 1" bore

[bigmellon]

Hello all,

This is my first post here, although I have been poking around a bit. I am excited to see a high number of people on here using SolidWorks, FEA, and all kinds of fabrication skills. It really is inspiring to read all of the projects on here.

I started playing around with making an LS-like engine design with my main design criteria being a 1.0" bore. This is roughly 1/4 scale, but I am not leveraging dimensions from an actual motor. I have needed to modify some dimensions as this is scaled down. My intent is not necessarily to get the engine running... Rather I would like a very nice desk display that uses aluminum, stainless, copper, and brass - and rotates slowly so that you can see how it all works. I have been thinking about possibly sectioning a cylinder head or making some parts translucent... We will see where it goes.

For now... I have started a number of models in SolidWorks and am printing my second revision of a cylinder head as I write this. I think I might machine the little bits and install them on the plastic sample to see how it all works.

So, without further ado... Here goes. It is nice to make your acquaintance and I look forward to getting value out of this site and your feedback. Thank you!







More pics to come...

 

[Swifty]

Welcome, if you go to the welcome new members section, it would be interesting if you let us know what machines you have to make things with. You mention that you will puts some parts on the plastic sample, do you have a 3D printer?

Paul.

 

[crueby]

Sounds like a neat project. One cylinder a cutaway, one can dispense M&M's...

I always loved seeing the cutaway models of big engines in museums as a kid - looking forward to seeing how it comes out!

 

[aonemarine]

Looking forward to seeing the printed parts.

 

[bigmellon]

Yes, I have a MakerBot and printed this thing today. It took about 5 hours to print, but looks decent

I will look for the new member area, but honestly I have so much equipment, it is likely easier to list what I don't have (CNC).

 

[bigmellon]

Another picture from he other side. This thing actually has a water jacket inside it! Pretty happy with the print quality and general shape of the part.

 

[aonemarine]

pla or abs?? Great looking print btw....

 

[bigmellon]

This is made from ABS.

I went out to the barn tonight to play around with some scrap material to see the best way to machine the valves. Since I have all manual machines, I tried a number of ways. It looks like the best results for me was to turn the flute of the valve first, then run the stem out as long as I need it. Still sort of funny to see these little valves in a 15" chuck! Ha!

Now to pick up some odd bits and some new materials...

 

[rcfreak177]

I will be watching this one with interest

 

[bigmellon]

A few more screen shots of the model... Added the valve cover and a copper head gasket.

 

[bigmellon]

I am thinking that my goal will be to be able to duplicate the following pictures in miniature for display purposes. I really like the idea of laying out all of the parts, but that is likely to be knocked off onto the floor and lost! I really want to be able to have a mini "crate engine" for display, possibly with cutaway to show it operating.

 

[stevehuckss396]

I am thinking that my goal will be to be able to duplicate the following pictures in miniature for display purposes. I really like the idea of laying out all of the parts, but that is likely to be knocked off onto the floor and lost! I really want to be able to have a mini "crate engine" for display, possibly with cutaway to show it operating.

There have been folks in the past that wire parts onto flat boards and create some real nice displays. No worries about parts dropping.

Look at the way Mr Luhrs displayed his radial and inline 4.
http://www.craftsmanshipmuseum.com/luhrs.htm

 

[bigmellon]

Steve - Thanks for the link! I think I have come across his work in the past. That is definitely a great option! So much detail there... Great reference.

I was thinking about different casting methods over the weekend. Would you guys say that most home model engine guys would investment cast (lost wax) parts if they are not machining from bar stock? I have seen a few "kits" available online that look like unmachined castings with a set of drawings.

I am thinking of trying my hand at casting the cylinder heads with a functional water passage inside the heads. Having small complex cores tends to make me want to play with sand casting rather than investment castings... Any feedback you guys have would be much appreciated. I don't want to reinvent the wheel...

I think my goal would be to cast the net shape and then machine & drill the casting to print. I believe the finished product will look very similar to the stock engine parts in terms of surface finish.

 

[aonemarine]

You could try doing it as a lost pla casting from a printed part. But the internal passages scare me a bit with this process. Its likely for the investment to fail, but you never know it might work out fine.
Lost wax is certainly a better solution. You could make up molds for the cores and shoot them in dissolvable wax and place them in a master mold to be injected with wax to form the head as one piece, or split the head into two haves to be joined. Would be a cool project for sure..

 

[bigmellon]

I was playing around with some casting supplies and molds that I made recently. The molds are printed on the Makerbot... I wanted to try a new technique I have been thinking about.

I have been looking at the 3D sand printers online quite a bit. It is amazing how the hardened sand blocks fit together snugly and they are able to get very good looking castings from their process.

https://youtu.be/Z8MaVaqNr3U

So, I thought maybe I could duplicate this with a "mold for a mold" that I could fill with hardening core sand and then glue the two pieces together to make a mold. Heck, that could even work for low volume production needs



Close, but no ceeegar. The regular white silica sand that was used is too large of a grain to really get the surface finish right on the parts. I think the sides of my mold having lines from the makerbot made it a bit tougher to pop out the hardened sand block (even with 5 degree tapers).

I also packed in some green sand (yes, I know it's brown) and the surface finish was excellent. This was really just to see what it was like... and compare the two options. Obviously, the green sand was not able to be handled, but the hardened core molds were.



I may look for a finer grit of sand and try the core mold process yet again. Any input from he group would be appreciated... I know a lot of you have more experience with casting than I do.

 

[aonemarine]

You could try some of the wax filament from machinablewax.com and see how it works out for you. Bit of a learning curve to print with but pretty cool stuff. Ive also printed abs molds, vapor polished, and shot wax directly into them. You need to put them in the freezer for a bit so the wax releases from the abs more easily.
Im not much into sand casting, but if you can track down the videos on YOUTUBE by Nick Muller? Hes done some pretty trick sand casting of small parts with vaccum assist that would be right up your alley.

 

[bigmellon]

Thanks for the pointers! I am off to Youtube to check into that!!

Also, please explain vapor polishing. How exactly would you do that not he ABS parts? Sanding seems to take forever!

 

[aonemarine]

Just sit your abs part in a crock pot or something with some acetone and warm it up. In a few minutes you will have nice shiney abs without print lines. You just want the abs part to come in contact with the vapors, not the liquid.
Check out lost pla casting on yt while your out there....chances are you find me. Lol

 

[bigmellon]

Is this the video you were talking about?

https://youtu.be/QijGV2G26JI

Great concept for thin walled features. I assume the vacuum assist helps pull the aluminum through the thin cross sections. I guess the assist comes from the fact that it is still being gravity poured, but needs help because of the thin walls.

 

[bigmellon]

With vapor polishing - How does that affect dimensional tolerance? Do parts shrink or warp?