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Re: A Flat 8 Corvair Engine

Posted: Sun Jul 25, 2021 5:52 am
by gETo
Interesting idea. I am going for the 191 cu. in. Next year. {saving up}. I have gathered some initial parts: Tri-port 140 heads with new valve job;
Tri-port Intake with 2300 base; Holley 2300 Sniper EFI. That is why I am trying to get my car running: 1. to operate it. 2. Keep cost low until I can do retro next year. Saw one set of cylinders and pistons but gone before I could get to them. Just awaiting an answer from Ray Sedman about roller cam, etc. I'm not sure HOW MUCH you're willing to spend OR what the result would be. I am hoping the 164 to 191 will be peppy enough for street driving. GOOD LUCK!

Re: A Flat 8 Corvair Engine

Posted: Sat Oct 05, 2024 7:42 pm
by DeathTrap2
I know this is an older thread but… The Cadillac DOHC V6 & V8 heads have the same cylinder bore spacing as a Corvair Block/Case. Not that it would be easy, I’d think an intermediate plate between piston jugs & heads may work with the larger piston Cadillac variants. Of coarse there’s the whole timing issue & water cooling… I haven’t looked into the GM Quad 4 stuff yet.

Re: A Flat 8 Corvair Engine

Posted: Sun Oct 06, 2024 7:39 am
by Phil Dally
The ultimate in air cooled Flat-12.

Porsche 917...there is no substitute.

Re: A Flat 8 Corvair Engine

Posted: Sun Oct 06, 2024 7:37 pm
by sethracer
If you are into playing dimension to dimension games, look at the bore-to-bore centerline to centerline dimension for the Big-block Chevy V8, and compare it to the Corvair.

Re: A Flat 8 Corvair Engine

Posted: Thu Oct 17, 2024 7:00 pm
by VairsUPnorth
This topic brings to mind the GMC 702 cu in "twin six" manufactured from 1960-66 and offered in 7000-9000 series trucks. It had a one piece cast block and 200 lb crank but used four cylinder heads and many components from the 351 60 deg V-6.

https://www.macsmotorcitygarage.com/ins ... -inch-v12/

Some 20 years ago our local VFD sold off their 1965 GMC pumper truck but it was a 6000 series model with a 478 cu in V-6.

A similar design was the 635 HP Detroit Diesel V-16; essentially two 318 HP 8V-71's built on a common block and crank with four cylinder heads and two Roots blowers. https://en.wikipedia.org/wiki/Detroit_Diesel_Series_71

Re: A Flat 8 Corvair Engine

Posted: Fri Oct 18, 2024 5:46 am
by jimbrandberg
I see Valkry9 is still active on this forum. 60 posts in 12 years is about 5 a year.
I have a friend with I think a '54 Pontiac who made a Straight-8 using 2 Quad-4 engines with turbos. He's 82 and will probably finish it, he's bound and determined and getting fairly close.
I love people who think outside the box.

Re: A Flat 8 Corvair Engine

Posted: Fri Oct 18, 2024 6:34 am
by Phil Dally
I cant tell you all anything but it's name...Z12

Re: A Flat 8 Corvair Engine

Posted: Fri Oct 18, 2024 11:23 pm
by American Mel
Just an interesting side note, in the '64 Spyder vert built for GM general manager thread, Frank Duval posted a link to a thread on the Antique Automobile Club website.
If you read that thread, you'll find this interesting photo of a 1904 Buffum racing flat-eight car.
1904 Buffum.jpg

Re: A Flat 8 Corvair Engine

Posted: Tue May 06, 2025 2:55 pm
by turbodan70
i had an corvair mod motor and parts for a spare engine . chev did the same stupid valve seat like on turbo & 140 's installed at room temp :shhh: , a seat came out one and stuck in the cylinder wall . well send pic's later