SOT: The truth about Corvair engines, Nothing but the facts and experience, please Options

[Dr Evil]

There has been lots of interest in the corvair power plant over the years as a possible source of cheap HP for many vehicles. There are used in experimental aviation, dune buggies, buses (such as mine), and in place of many other air cooled VW power plants. They are fairly cheap to buy and build, very easy to build and maintain, and plentiful with readily available parts from several suppliers.

The main divide in the corvair engine line took place in 1965 when the displacement of the engine was moved to 2.7L and was offered in a NA 110HP, NA140HP, turbo 150HP and turbo 180HP. The only differences in the long block between these engines are the nitrided crank found in all but the 110HP, and the heads: 110 had one single barrel on each head, the 140 had 2 with one acting as primary and one as secondary. The turbos had a single barrel blow through setup.

The heads are the major limiting factor in the design. They are not built in an intuitive way and rob much hp. The 140 head had bigger valves, but like its 2.0L TIV analog, would drop valve seats due to the limited amount of material between the seats in the head, and the inability of larger seats to shed heat as well as smaller seats. This can, and has been overcome by those who have been rebuilding these heads fro decades by making sure the crush tolerance on the seats are correct, and staking the seats in place.

Currently, you can get a set of rebuilt, 140hp larger valved heads, with new hardware and no core for about $1200 from Corvair Ranch in Gettysburg, PA. I bought a set that was rebuilt and had the plenums taken off for tri porting for $1500 shipped off of ebay from Starr Cooke in El Cajon, CA, another well known Corvair entity.

Modified with plenum removed for individual runners:


The above uses an adapter that allows the placement of Weber triples. My set came with this adapter.

Here is a head with a stock plenum, modified with bungs for FI. This is a 140 head as it has two carb bases on it:


Standard engine:


One of the cool things that many ACVW folks like is that the corvair engine has stock hydraulic lifters on it that use standard lifter, push rod, and rocker parts from Chevy. Easy and cheap to obtain.

Another great feature that I like over ACVW is the box design on the case. The top and bottom come off and allow for any maintenance. Swapping rods, bearings, what ever, is easy.

[Dr Evil]

One thing you hear time and again is the claim of the cooling system tossing belts. This is an old problem that is not very common in the corvairs today as it is understood what was causing this.

First, the original fans has pitched blades like a typical fan. This causes a lot more load on a belt when the engine RPM increases and the belt attempts to speed up the fan. The pitched fan resisted enough to cause the belt to pop off. This was solved vie placement of a zero pitch fan setup. Less resistance and adequate cooling.

The other issue causing tossed belts is actually the tendency on the mechanic/owner to tighten the belts too tight. This is a sure fire proven way to toss a belt. Anyone who has messed with the belts on a 944 understands how picky some systems can be, but how well they run when properly maintained and installed.

In many ways, the corvair cooling system is superior to ACVW systems. Tangerine racing is using these horizontal fans in upgraded cooling setups .

[Dr Evil]

Corvairs being used in aviation:





A great site with tons of info and pics by Mark Langford:
http://www.n56ml.com/corvair/

[VaccaRabite]

I understand that the valve springs are made of chewing gum and the cranks use a special bearing that is created using the blood of children.



Zach

[Dr Evil]

The corvair engine rotates opposite of most engines. This is a problem when one is interested in mating it to a different drive train. The prevalence of these engines in swaps using such drive trains allows for the ease of finding the parts to reverse the rotation of them. All that is needed is a cam and reverse dizzy gears.
Here is a link to Clark's Corvair site and the kit.
Current list price for a reverse cam (comes in several grinds) and dizzy gears:

Cam - $261 (up since when I bought mine)
Gears - $182 (Was $90 when I got mine)

I did not use my reverse parts as I ended up using a corvair powerglide auto tranz. Also, Clark's is only one vendor. There are many and most under cut Clark's significantly.

The part to mate your VW/Porsche tranz to a corvair engine is not usually hard to find either.

[Dr Evil]

I understand that the valve springs are made of chewing gum and the cranks use a special bearing that is created using the blood of children.



Zach

(IMG:style_emoticons/default/stick.gif) Dont be a dick, you tubby bastard! (IMG:style_emoticons/default/poke.gif)

[Dr Evil]

Dont think that these engines can be made to kick some ass? Google the Yenko Stinger and read up (IMG:style_emoticons/default/smile.gif)

Only SOME of the suppliers for these engines/cars:

Clark's http://www.corvair.com/user-cgi/main -- best on line catalog, pricey

Corvair Ranch http://www.corvairranch.com/ -- Jeff, the owner, is a great guy. Good prices. My favorite.

Larry's Corvair Parts http://www.larryscorvair.com/ -- Larry is nice. I got a package deal from him for parts.

[Dr Evil]

Many have purported that these engines are too expensive. I bought a set of headers for $200, and just changed my ring and pinion to a different ratio for $30. Doing the same for a 914 is at least $800 for the r/p, usually more. I rebuilt my posi traction for $75, too (IMG:style_emoticons/default/smile.gif)

[underthetire]

(IMG:style_emoticons/default/aktion035.gif) the engine was the only thing other than my mom in 67 to survive when she got hit. Car was almost split in half.

[KaptKaos]

Sherman - set the wayback machine to last month:

http://www.914world.com/bbs2/index.php?sho...=114810&hl=

I'm glad you finally showed up Doc. (IMG:style_emoticons/default/poke.gif)

[Elliot Cannon]

The problem with the corvair wasn't with the engine so much as it was with the handling characteristics of the swing axle suspension. They fixed that in later years but by then it was too late. Other than that, they might have lasted a bit longer. I had a friend who had the 180hp turbo and it was fasssst. (IMG:style_emoticons/default/driving.gif) (IMG:style_emoticons/default/aktion035.gif)

[Dr Evil]

The ultimate engine!

Using 94mm TI VW p/c you can bump the 2.7 to a 3.1 (IMG:style_emoticons/default/smile.gif) It is pretty much the most you can get with the engine reliably.

Here is where I first saw it:
http://www.corvairkid.com/mm01.htm

If you look at Mark Langfords link in the earlier post, he uses this on his aircraft engine. Ray Sedman is a guy who at least used to do this conversion. It is not cheap if you pay for it to be done, but the machine work is not too bad if you know of a reputable and inexpensive machine shop. I have done this conversion 2x and both times it was not too expensive. I did make friends with the shops, though (IMG:style_emoticons/default/smile.gif) The first one was sold when I received a 911 2.7 for my 914 and figured that was easier to do (not so!).

On ebay right now you can get the p/c all machined for $1700. Kinda steep.

What is needed (and this is what is on my bus).

Barrels
- Need to have about 0.3 in removed form the base
- Bottom stud holes drilled for corvair spacing
- cut fins on center barrels (easy to do on your own)

Pistons
- milled material off of the skirt at the pin boss to clear opposing rod end

Rods
- open up small end for VW wrist pin
- oil holes drilled in small end for floating pin (stock is stationary)

Case
- open up registers for VW skirts, head studs need to be left in the case so as to preserve the material and threads that these go into.

Heads
- fly cut open to fit 94mm jugs.

This is not a necessary modification, but hard to resist. A set of 8 (I have one guy that will sell me 6) p/c with rings runs about $350

[Dr Evil]

Sherman - set the wayback machine to last month:

http://www.914world.com/bbs2/index.php?sho...=114810&hl=

I'm glad you finally showed up Doc. (IMG:style_emoticons/default/poke.gif)

Saw it, didnt need it. I have enough cars.....well, I dont have enough space for MORE cars.

[Elliot Cannon]

TURBO!!

[Dr Evil]

The turbo was archaic. But, it did make more HP. I have not seen it done, but I bet that a better turbo and stronger rods would really wake one up. I will likely try this on the bus in the future (IMG:style_emoticons/default/happy11.gif)

[Dr Evil]

Here is a 150, looks the same as a 180. Like a monkey with a fire hose (IMG:style_emoticons/default/smile.gif)
Notice also in this pic that the oil filter is vertical. The adapter to do this is easily available, cheap and a popular conversion.

[racerbvd]

Thanks Dr.
Lots of good info, most I didn't know..
Growing up, a friend down the street, father had a Turbo convt.
This was at a Dark Side DE last year..

[silver74insocal]

(IMG:style_emoticons/default/popcorn[1].gif) whats this thing weigh in at?

[Tom_T]

Damn the Nader torpedoes, full speed ahead! (IMG:style_emoticons/default/biggrin.gif)

Cool shit Doc - keep it coming! (IMG:style_emoticons/default/smilie_pokal.gif)
(IMG:style_emoticons/default/popcorn[1].gif)

[VaccaRabite]

Corvairs are cool as shit cars. After Mike showed me the resources that are nearby for them he made me a convert. I want to build one in a bad way. Either just a motor or the full car. Triple Webers, 3.1L, headers, fucking awesome.

Zach