Demon V8 Scale Up

[jamestat2]

I just purchased the plans for the Demon. My friend and I have been building engines for quite some time but this will be our first V8.

The question we have is; Has anyone doubled the scale of this engine and successfully built it? I'd like to get some input on this. I'd like to get started on this soon.

I know some people have probably been thinking about it so let 'er fly fellas!

 

[jamestat2]

Well! Lots of people looking but I guess nobody has any ideas about this. I guess I'll get started by myself then.

 

[chrispare]

I think that it will work, just might have to improvise a little.

Hope to see a build thread here too, as I am in the process of building this one.

Chris

 

[gadabout]

On cnczone a guy was building a pair scaled up 1.5 but the thread never got finished I don't think

link here
http://www.cnczone.com/forums/i-c-engines/132147-steve-hucks-demon-v8-version-1-5-a.html

Mark

 

[jamestat2]

Alright! I got a couple responses! Thanks for the encouragement guys!

I'm just not all that into the really small stuff. My friend and I both have big 'ol mitts! Plus we only use manual machines! LOL! Although I am working on aquiring parts for a 3'X4' 4 axis cnc router that will be strong enough to machine aluminum. We are used to working on dozer parts and other big stuff! We have done some smaller stuff but don't enjoy it as much! We are more into larger model engine stuff.

I don't see that doubling the scale would pose too much of a problem as the bore is only going to end up at 1.250". Models tend to not run good at over 1" bore. Unless it's steam or hit-and-miss engines. I think I may have to do something about the oiling situation at this scale though. Maybe an external pump with a spray bar type setup?

Like I said. This is our first V8. We have built Hit-and-Miss engines, a Henry Ford "Kitchen Sink" engine, Pulse Jet and Turbine Jet engines so we have the know how.

One thing we have a problem with is that we are cheap asses! LMAO! It's $200 plus for the aluminum just to do the block! Dang! SO! We have to build us a quickie furnace so that we can melt down a bunch of scrap 6061 (30 some pounds) to cast a slab big enough for the block! Then we will have to precipitate harden it back to a T6 condition. I have gotten the parts for the burner done and now to build the furnace. So I have to get in touch with my refractory buddy and he is out of town on a job for a couple weeks.

I would appreciate any input on this as we prepare to get started here! Thanks!

 

[jamestat2]

Oh and Gadabout. The thread on cnczone is still active. Posts go from 2012 and there are recent ones from 2016. The guy is thinking about getting back on the build. Too bad I can't see any of the old pictures. Thanks for the link.

 

[gbritnell]

I didn't answer right away to see how this was going to go but the quick answer is yes it can be done. Anything can be scaled up or down, it's just a matter of doing the dimensions. Now comes the particular issues. When I and others like Steve Huck design and build an engine certain features are optimized for that particular engine, wall thicknesses, fastener sizes, gears sizes to meet centerline dimensions etc. If you want to do a project like this then you'd have to take the original drawings and lay some of them out to see where they need to be modified. Let's take wall thickness. If in the original the block wall from outside to water jacket is say .125, now you double it and go to .250. Yes it will work but there's no need for it and by thinning it down would provide more coolant area. A screw that's 2-56 (.086) doubled would be .172 so you could use an 8-32 (.164) but not all fasteners work out that well so you would have to check. I have probably 400 hours in design and drawing time in making my latest project so to just double or half it would involve time on the builders part to solve the aforementioned issues.
gbritnell

 

[jamestat2]

Ah Mr. Britnell! Thanks for your response and words of wisdom. I really enjoyed your display at N.A.M.E.S. this year. My friend and I spoke with you for a while on Saturday. This was our second year going and we have been discussing the possibility of bringing our engines (especially our jets) to the show hopefully next year.

I had already taken the fastener situation into account. The cooling aspect didn't cross my mind (Thanks for that tip!) My main concern in scaling this up was the addition of an oiling system because of the increase in the surface area of moving parts. I will have to put more attention toward the water jackets and sizes thereof.

I know I am going to have many hours in reworking the plans to fit my wants. I am working now on scaling up the plans so that I have a 1:1 paper set to actually get a grasp of what the actual engine will be like.

I will be documenting this whole operation with photos to share with everyone. That includes the building of the furnace and information on how to precipitate harden 6061 cast aluminum.

Thank you for your encouraging words sir!