# What happened to the Ultravair?

### Help Support HomeBuiltAirplanes.com:

#### Daleandee

##### Well-Known Member
The heads are better than the VW
How much machine work would it take (if it's even possible ... I haven't looked) to cut the Corvair heads down and make them fit a VW? I'm sure there's no way to do that or someone would have by now.

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
Head stud patern on the Corvair is 80mm x 84mm. The VW is 75 x 81.

#### Daleandee

##### Well-Known Member
Head stud patern on the Corvair is 80mm x 84mm. The VW is 75 x 81.
Thanks for that. I know that the 3.0 Corvair conversions use VW cylinders but they have to have mods done to the holes to make the alignment work. I never bothered to look at the heads to see what the difference was.

#### wanttobuild

##### Well-Known Member
How many HP would a four banger make and what would it weigh?

#### Vigilant1

##### Well-Known Member
Lifetime Supporter
Are the 6 cyl Corvair cases, heads, camshafts, and cranks so common and so cheap that it makes sense to cut them up to make a 2 or 4 cyl engine?

#### Marc W

##### Well-Known Member
The big Corvair is 3300 cc. 4 cylinders is 2/3 or 2200 cc. So it would make the same hp as a 2180 cc VW.

#### Vigilant1

##### Well-Known Member
Lifetime Supporter
The big Corvair is 3300 cc. 4 cylinders is 2/3 or 2200 cc. So it would make the same hp as a 2180 cc VW.
Right. And they are still making brand new parts for the VW Type 1, no need to cut anything if you want 75 HP. Still, apparently the idea of cutting up Corvair cases and heads has fans for various reasons. I'm just wondering if getting old parts to modify is easy and cheap.

#### Daleandee

##### Well-Known Member
Corvair cores are plentiful enough. I found a core engine (1964 long stroke) on Craig's list. The guy had the engine and tranny for $300 but I didn't need the trans and just bought the engine at a reduced cost. I honestly forget what I gave him for it but it was somewhere around the$150 mark.

GM made 1.8 million Corvairs: US Production

They do make a fine airplane engine ... but I am biased.

#### wanttobuild

##### Well-Known Member
MarkW
How are your projects doing?
I havent been on hba in a while.

Is the four banger corvair a worthwhile project?

I recently noticed the briggs v twin making up to 48hp. efi, electronic throttle control. Offering a 1 5/16in splinded output shaft . no mods necessary other than air filter. well it needs a redrive. I am speaking of the marine offering, advertised as 40hp.