# 8 cylinder VW?

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#### BBerson

##### Light Plane Philosopher
HBA Supporter
A twin engine experimental airplane can be flown SOLO without a multi-engine rating.
BB

#### dirk_D

##### Well-Known Member
If you are casting a block why not use a chevy crankshaft and camshaft?
96 to 104mm barrels and a redesigned head for gas flow, you would need 3 patterns, 2 for the case and a universal head.
Fill in the blanks with a mix off VW and chevy derivative parts.

Imagine a set of Edelbrock covers stuck to both sides?
(or weld two cranks and make a 16)

#### Dan Thomas

##### Well-Known Member
If you are casting a block why not use a chevy crankshaft and camshaft?
96 to 104mm barrels and a redesigned head for gas flow, you would need 3 patterns, 2 for the case and a universal head.
Fill in the blanks with a mix off VW and chevy derivative parts.

Imagine a set of Edelbrock covers stuck to both sides?
(or weld two cranks and make a 16)
You would have an engine with an odd firing pattern. The Chevy is a 90° engine. Using that crank in an opposed engine changes the piston phasing by 90° overall. The camshaft would not work and you'd need to make one to fit the weird firing sequence, and the ignition would be really difficult to set up. You wouldn't have the normal four firings per rev, spaced 90° apart.

Dan

#### cdrmuetzel@juno.com

##### Member
...The 1 engine,1 prop rule covers our Recreational Aviation class, ie, RA.Aus, not GA. Coupling 2 props via belts, chains or shafts is still 2 props. ...I have thought of the contra props and a case could be made to CASA, our Civil Aviation Safety Authority that it was a single 'propulsion system' with better characteristics than a single prop.
so, i guess this aircraft would have been an outlaw?

http://en.wikipedia.org/wiki/Wright_Flyer

#### dirk_D

##### Well-Known Member
You would have an engine with an odd firing pattern. The Chevy is a 90° engine. Using that crank in an opposed engine changes the piston phasing by 90° overall. The camshaft would not work and you'd need to make one to fit the weird firing sequence, and the ignition would be really difficult to set up. You wouldn't have the normal four firings per rev, spaced 90° apart.

Dan
You're right Dan, but i was thinking along the along the lines of a Ferrari 512tr, they call these motors 'boxers' when in fact they are a shared journal crankipin. These motors do not have balance shafts, was hoping that the 180 degree line of forces would only leave a mild 2nd or 3rd order vibration. Like a gentle axial rocking motion.

The 16 cyl with the 2 cranks phased 180 degrees would cancel this, this is all dreaming though - i have seen many example of airworthy beechcraft singles in Australia for $40k to$50 and to ignore that and forge ahead with an exhaustive, self funded engine development would mean i would probably never see the skies..

It would be a darn cool engine though!

#### deskpilot

##### Well-Known Member
Hmmmm. Not sure about that one. 2 VW's for sure but like one person questions, what happens if one fails. At least with my set-up, if one fails, you have a total failure and act accordingly. Totally survivable unless you're over tiger country or water. Personally, I don't go over either.

#### dirk_D

##### Well-Known Member
I would be sitting in a pile of warm brown stuff testing that chopper!

This motor is very do able!

111.8 mm bore spacing small block chevy,
112 mm bore spacing vw beetle 1600.

The 0.2 pitch error could be ironed out with balancing the error to cylinder pairs.
All the parts come of the shelf, 3 casting patterns.

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#### dino

##### Well-Known Member
HBA Supporter
Hmmmm. Not sure about that one. 2 VW's for sure but like one person questions, what happens if one fails. At least with my set-up, if one fails, you have a total failure and act accordingly. Totally survivable unless you're over tiger country or water. Personally, I don't go over either.
The VW on a helo can be run at points higher on the power curve than a direct drive prop. This could be enough to give limited single engine capability at the lowest power required point of the chopper.

Dino

#### deskpilot

##### Well-Known Member
Re the chopper, it would make sense that there's some sort of interconnection between the 2 engines and rotors so the if 1 engine died, the other could carry on at least to provide a controlled decent and landing using both rotors. Anyone?

#### delta

##### Well-Known Member
My best guess is that the transmission has one input from the coupled engines, and that the transmission disengages and freewheels when the drive is not powered.