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PostPosted: August 15, 2016, 7:43 pm 
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After a brief look around and a few questions on kijiji I have finally decided to buy a 1965 Chevy Corvair donor car. It will arrive tomorrow morning and I will start tearing it to pieces. Here is what the Chevy only flat six could look like when it is clean (not mine..... yet)

http://www.wilsonauto.com/about-us/work/chevy-corvair/
http://www.conceptcarz.com/view/photo/8 ... photo.aspx

Some of you will ask why. The Corvair engine being air-cooled weighs only 212 to 220 lbs depending on the options. Nominal power for the 1965 models I believe 140 HP. My plan is to tear it apart , rebuild it with new moving parts, stronger valve springs and larger valves, as well as performance cam. Six carbs instead of 2. Hopefully, I should be able to pull 180-200 bhp from the monster, which is all I need. The other question is how am I going to fit it into a seven. Goooood question. A flat 6 engine is wide. I may have to position the engine (as I did on my first Seven) , closer to the cockpit- almost a mid-engine- so that the heads will be out of the way of the back of the wheels. I will need a longer/wider chassis. Jacks' catfish nose and scuttle.

All this is still at the thoughts level, not the design level.
And then there is the question of adapting this engine which is a rear engine rear wheel design like the early VW and Porsches to a front engine+ regular tranny and rear wheel drive which is what I want.

What do you think?


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PostPosted: August 15, 2016, 7:54 pm 
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Very cool Phil. But given that engine's history, and your starting with "build from scratch," why not go mid-rear? Those engines are crazy low. So low you could make a locost middy pickup.

Yeah, not sane, but I've been reading JDs post again...

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PostPosted: August 15, 2016, 7:55 pm 
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Good luck with your project! Most of the 2-carb 'Vairs were about 110 HP. The 140 HP motor had the 4-carb setup. IIRC, it also had a slightly more aggressive cam! Again, Good Luck!

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PostPosted: August 16, 2016, 8:02 am 
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ngpmike wrote:
Good luck with your project! Most of the 2-carb 'Vairs were about 110 HP. The 140 HP motor had the 4-carb setup. IIRC, it also had a slightly more aggressive cam! Again, Good Luck!


First car I ever owned was a '65 Corsa 180
It was factory turbocharged and put out 180 hp.


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PostPosted: August 16, 2016, 9:25 am 
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ngpmike wrote:
Good luck with your project! Most of the 2-carb 'Vairs were about 110 HP. The 140 HP motor had the 4-carb setup. IIRC, it also had a slightly more aggressive cam! Again, Good Luck!


Thanks,
Thumper is right. The stock Corvair after 1965 came with power options. 140 bhp and I think a turbo version with 180 bhp. I am not sure yet what I have. Having two carbs, it could be the 110 bhp version with a 2 speed powerglide tranny(the horror show). The fun is to turn this into a monster :lol:

I have seen a lot of upgrades, mostly in the hands of folks who convert these engine to light aircraft. I have even seen fuel injection.

My main challenge will be to figure out how to keep the transaxial transmission (and independent wheel suspension) and still have a front engine.

Any thoughts? :cheers:


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PostPosted: August 16, 2016, 9:49 am 
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Yep,
Attachment:
IMG_1910.GIF

Attachment:
0825091657%20-%20Copy.GIF


I did not use the corvair transaxle but the 924/944 setup. One big advantage of the torque tube is the width in the pedal box area.


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PostPosted: August 16, 2016, 10:20 am 
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Worthless fact: On the early Corvairs, the front suspension was mounted on a removable cradle. But the geometry may be set up to counter the oversteer.


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PostPosted: August 16, 2016, 11:56 am 
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Our local road racing circuit was always littered with bits of corvair fan belts in the 70's and early 80's (the last that I saw a corvair on the track was about 83). Seems the belts self destructed at high RPM. Did anyone ever figure out a solution for that problem?

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PostPosted: August 16, 2016, 1:35 pm 
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Yep, you shim up the pulley. I used to have that problem fairly frequently.

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PostPosted: August 16, 2016, 1:44 pm 
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cwhite wrote:
Yep,
Attachment:
IMG_1910.GIF

Attachment:
0825091657%20-%20Copy.GIF


I did not use the corvair transaxle but the 924/944 setup. One big advantage of the torque tube is the width in the pedal box area.



Thanks Chris,
This is very useful to me. I am aiming at a wide Seven; I may not have a pedal clearance issue??? :)
I have read about torque tubes on Porsches and Alfas. Is there anything wrong with the Corvair transaxle?
More pics!!!
Thanks again. :cheers:
Phil


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PostPosted: August 16, 2016, 1:55 pm 
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And they run backwards so you need a reverse grind cam to use them with transaxles and transmissions that were designed for the normal clockwise rotation. (when looking at non-transaxle side of engine, towards the transaxle). Some Hondas rotated counter-clockwise. You must absolutely be in love with Corvairs to go down that route. There are million other engines that are more plentiful, more powerfull, more dependable, more everything than the Corvair. But if you're dead set on it, go for it.

Tom

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PostPosted: August 16, 2016, 8:54 pm 
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Off Road SHO wrote:
And they run backwards so you need a reverse grind cam to use them with transaxles and transmissions that were designed for the normal clockwise rotation. (when looking at non-transaxle side of engine, towards the transaxle). Some Hondas rotated counter-clockwise. You must absolutely be in love with Corvairs to go down that route. There are million other engines that are more plentiful, more powerfull, more dependable, more everything than the Corvair. But if you're dead set on it, go for it.

Tom

Thanks for your points. I am glad to see that you have an opinion.
I guess we all have our own way to look a locost projects: from light BECs to supercharged V8s, there is no right or wrong way to go about this thing. Merit is all in our heads.

What attracted me to the Chevy flat 6 is first the weight. Not so many among the million engines you are referring to weigh less than 217 lbs and can potentially crank out 180 bhp. I also like its simplicity. It is not a bad engine. However, GM just could not build a decent car for it.

My plan is to run the Chevy flat 6 as a front engine-rear wheel traction, which means that I could either bolt it to a conventional Chevy transmission and run a rigid rear axle. Or build a power shaft from the engine bell housing to the reversed Corvair transaxle . In either case the stock Chevy runs like most engines: clockwise when you look at the crank pulley.


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PostPosted: August 16, 2016, 9:05 pm 
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BHRmotorsport wrote:
Our local road racing circuit was always littered with bits of corvair fan belts in the 70's and early 80's (the last that I saw a corvair on the track was about 83). Seems the belts self destructed at high RPM. Did anyone ever figure out a solution for that problem?



Yes, I am not sure what to think of the very long serpentine that runs the big cooling fan horizontally. But I am not aware of this being discussed as a problem on Corvair forums. Maybe it is and they don't want to talk about it. This however will be one of the things I will experiment with when I will rebuild my engine. Thanks for your point.


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PostPosted: August 16, 2016, 9:34 pm 
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I've had a lot of fun in hot-rod Corvairs.
Use Viton seals and a few other tricks.
The Corvair is much more reliable than the VW ever was. :shock:
Try to find a way to eliminate the original fan for a system that does not torture the belt so much.
Might even be able to run modern electric fan or fans?
If you have to keep the original fan system get the lightest fan you can and balance it.
Do not remove the lower tin unless you know exactly what mods you are doing and their effect on cooling.

Corvair to Weber 3V set-up's are fairly cheap and easy to find, but the Webers are crazy expensive.
There are 3V Weber type F.I. bodies available, not cheap, but NEW, and F.I.!

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PostPosted: August 16, 2016, 9:57 pm 
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BHRmotorsport wrote:
Our local road racing circuit was always littered with bits of corvair fan belts in the 70's and early 80's (the last that I saw a corvair on the track was about 83). Seems the belts self destructed at high RPM. Did anyone ever figure out a solution for that problem?



Wikipedia offers a partial answer to your question:
The large cooling fan located on top of the engine required the fan belt to bend from the vertical plane of the crankshaft to the horizontal plane of the fan, causing additional stress. Chevrolet engineers designed a unique fan belt, which many owners and dealers replaced with an inappropriate design. The correct fan belt, properly installed to proper tension, worked well, while other belts even of proper size installed loose or tight would break frequently, giving the engine fan and belt design an undeserved bad reputation. Since failure of the cooling fan on an air-cooled engine leads to immediate overheating much more quickly than in a water-cooled engine (within 15 seconds at the high RPMs when the belts were likely to fail), mechanically inclined owners would routinely carry a spare belt and the 9/16 inch box wrench needed to change the belt, in addition to adding a large and eye catching warning light in parallel with the normally sized factory generator/alternator warning light. Aftermarket manufacturers made available differently sized pulleys which reduced the fan speed to 1.3 or 1.2 times engine speed, rather than the stock 1.5; this reduced the tendency to throw or break a fan belt for engines which spent most of their time at higher RPMs.


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