VaporGrace

[LuPi]

Hello,

I'm working on designing an aviation motor for low emission hydrogen fuel.

It's a Dry-deck Magnesium Block 75* V4 24-OHV 8 spark plug engine with dual redundant systems.

Couldn't find a forum on building engines for aviation use so I rejoined here, knowing how helpful you all are.

 

[aircraftmech]

What kind of scale is this going to be?

 

[LuPi]

The bore is 5cm and the stroke 3.75cm, 295cc displacement.

The whole engine minus radiators is about the size of a 20cm sided cube.

It's the Goldilocks engine, too big for here, too small for hot rodders.

LuPi

 

[rythmnbls]

It's the Goldilocks engine, too big for here, too small for hot rodders.

No such thing as too big , looking forward to your build.

Regards

Steve.

 

[Herbiev]

Sounds very interesting

 

[aircraftmech]

I'm with rythnmbls... No such thing as to big! 😉 Is there a reason why your going with "V" style?

 

[LuPi]

The V style is for lowest weight and compact size (lengthwise) as compared to I4. It also allows Bi-turbo architecture which appeals to the packaging.

These engines are intended to be hung in nacelles on planes. Or alternatively in light motorsport vehicles. The frontal area is slightly more than I4 would be, but with the under-square stroke it is compact enough for most uses. Balance is pretty good, but firing order may not be appealing. (0,90-435,525)

I've been moving, will post images on here when I get the computer setup to run the new CAD program.

LuPi

 

[aircraftmech]

Sounds good! Look forward to watching you build it.

 

[LuPi]

Major change of plans,

I switched over to a four throw four cylinder; which is similar to a flat subaru turned 90 degrees, which is another major change to 90 degrees from 75.

Also, it's a 500cc (mission creep anyone?)

Other than that, I deleted the straight through passages instead adding 2mm to the space between and reducing the space between major cavities for hopefully sufficient general use cooling. Only the major cavities are visible.

Also, if anyone knows an affordable Crank, gear and Cam manufacturer I'm looking to subcontract these parts rather than mess with making them myself.

LuPi