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Previous Next Up Topic Engines / Corvair Power / Corvair Projects.... (56488 hits)
By John S 2 Date 2008-04-11 19:01
I was just day dreaming about a Corvair powered Imp I owned for a couple of weeks.
Wondered if anyone else had anything Corvair powered they were working on.
John Shepard the DBA
By Paul Moran (DBA Architect) Date 2008-04-12 03:06
I had one of them corvair powered Imps in my driveway!  What a coincidence! Was yours green too?

Can you post some pics for us?

Chicago, IL
EMPI Imp 1002 ('69)/Subaru EJ20 Turbo/LinkPlus ECU
By Mel Adjusted Date 2008-04-12 04:48 Edited 2008-04-12 04:51
LOL... I have one in San Felipe I need to pickup.. I was going to convert it. There's a friend who wants the engine.. It's a turbo'd spyder engine with a blow'n clutch and a dead battery.
At my age.. Everything I buy comes with a lifetime guarantee..
By Jay H (X-20) (ManxVair CC) Date 2008-04-12 12:10
I've got a '65 140 H.P. Vair engine I was going to put into my buggy, but never did.

By John S 2 Date 2008-04-13 18:46
I had one of them corvair powered Imps in my driveway!

I knew you would like that one.... :-)

I keep hoping the guy who bought it will show up on here someday.
I would love to finds out what when on with it.
I hated selling it, buying it just happened at the wrong time.

Thanks again for babysitting it for awhile...
John Shepard the DBA
By Scott C 743 Date 2008-04-14 00:12
I never had a DB with a Vair engine it, but I did have a 1964 Corvair Spyder convertable with the turbo engine and 4 speed. Nice car, I cut the fenders off with an axe, and made it my field car, the mentality of a 16 year old....

You can't put a price on your fun, if you do, it stops being fun...
By ManxRob Date 2008-04-15 15:22 Edited 2008-09-22 01:05
I have a Corvair powered Manx. It currently has a later model 110 hp (with the alternator) engine using a Crown adapter to connect to a early bus transmission with the gear reduction boxes removed to correct for the 'reverse engine rotation of the engine. I have driven it several thousand miles over the last couple of years, and am quite pleased with it. It has lots of low RPM torque, and can take the mountain passes at freeway speeds without a lot of downshifting. I originally toyed with going to Subaru power, but decided on Corvair to stay with a 1960's period build.

I'm currently replacing the engine with a slightly modified 140 Corsa engine, and a Rancho built swing axle 'freeway flyer' gearbox with the ring & pinion flipped for what they call a 'mid-engine' configuration. I hope to have it back on the road by June.

By Steve L 858 Date 2008-04-30 20:13
I have a 1965 140hp Corvair motor in my Manx 2.  Here is one picture I have, I'll try to post a picture of the engine in another post.

By Steve L 858 Date 2008-04-30 20:25
Here is the view of the engine...This has the Transvair kit so it has the entire Corvair drivetrain with 4sp manual trans-axle.

By John S 2 Date 2008-05-01 17:29
Great looking buggy.
How big is that carb Steve ?

John Shepard the DBA
By ManxRob Date 2008-05-01 18:24 Edited 2008-05-01 18:28
Here is a progress shot of my Corvair 140 conversion:

It's a pretty tight workspace...

The 110 Corvair engine was just pulled
The 140 is on the floor next to the welder, with the stack of tin to go out for powder coating next to it. That a Otto oil-pan sitting on top of the welder.

Next step is remove the transmission and fabricate some 'raised transmission' mounts to lower the car.

By Steve L 858 Date 2008-05-01 19:40

It is a Holley 390 cfm 4bbl.

By Jay H (X-20) (ManxVair CC) Date 2008-05-02 02:09
Steve, What is involved with the TransVair kit? It looks like it retains the stock VW torsion bars for the springs while bolting the Vair axles to the stock VW spring plates. I surely don't see the rear Vair coil springs.

By Steve L 858 Date 2008-05-08 13:16
Here is some info. on the TransVair kit...

I guess this was a popular bolt in kit in the day, especially for VW Vans.  Basically, allows mounting Corvair engine, bellhousing, differential, and transmission into VW.  My Manx has a 1965 140hp Corvair engine, and the rest (trans, Diff., axles, rear brakes) are early model Corvair (think either 1963-1964).

By FulsGld Date 2008-05-11 14:30
I just finished putting a reversed corvair engine into my wife's buggy. It's a 110hp and seems to run pretty good. Still need to sync the carbs and do a tuneup (trying to figure out how to time a reversed engine on a harmonic balancer that is marked to go the wrong way). Needed something stronger to tow the PWC.

GaryB in Wa.
By Darryl B 967 Date 2008-06-11 03:31
Hi Gentlemen,
I have another Corvair for you to look at:
It is a full Corvair (no VW anywhere)buggy. Entire front and rear suspension and and drive train. The frame is custom made to match the suspension and body. Took My Father and I four tries on the frame before getting it right back in 1968. I was 15 at the time. The entire car was restored and updated by my son and I when he was 15 about 12 years ago now.


My website is at

Also here is a Crown Corvair kit that I looked into back then and rejected.
By Lucas C 993 Date 2008-06-23 19:02
could you send me a how to  on putting a corvair engine into a beetle frame?
By John S 2 Date 2008-06-24 19:47
I have always wanted to run one with the adapter.
Now the adapters require reverse running right?
John Shepard the DBA
By manxcraig Date 2008-06-24 23:43

If running a VW transaxle with a Corvair engine the engine must be set up to run reversed OR the ring gear must be "flipped". Either will work.
By ManxRob Date 2008-06-25 02:06
I'm running a standard rotation Corvair adapted to a type 1 transmission. The transmission was built as a 'mid-engine' freeway flyer, which means a flipped ring gear with super diff and other beefing up. I purchased a used Corvair engine with the adapter already attached. For a 'standard rotation' Corvair the adapter part required are:
1) Adapter Plate with allen head bolts, (replaces the Corvair bellhousing)
2) Flywheel with special hardened bolts, with Corvair crank holes, machined for a VW clutch plate, and Corvair toothed starter ring gear
3) Transmission shaft bushing, supports the transmission shaft in the Corvair crankshaft
4) Starter Adapter, Adapts a Corvair starter to the VW transmission starter location
5) Starter shaft bushing, Supports the Corvair starter shaft in the VW transmission case, (the same location as the VW starter bushing).
6) standard Corvair bellhousing and crank case gaskets

I think only part not available new these days is the Flywheel for this meathod of adapting the 'stock' rotation Corvair to VW. Thankfully there seem to be plenty on the used market at reasonable cost. Just be shure to check the ring gear for wear. I have seen 2 styles of flywheel, 1) an all steel one which feels very similar to a standard type1 flywheel in weight, and 2) a lightweight (6 lb if I remember correctly) version sold by Crown Mfg. I'm installing the 6 lb version on my 140 HP engine. The heavier one is supposed to be better for low-end torque, and the lighter weight was advertised to 'make the Corvair rev like a Ferrari'. I'll let you know...

I have heard of potential problems with the 'flipped ring gear' (standard rotation) Corvair method of adapting due to 'power being applied to the back side of the ring gear', but have not spoken with anybody with first hand knowledge of this, so I don't know if it just urban legend, or solved by modern VW transmission builders. My transaxle builder didn't seem to think it an issue. And the old VW busses that ran gear reduction boxes also used the ring gear in this configuration. I only drive my buggy about 5000 miles/year, so I'll let you know if/when I have problems. Also, original advertisements state that "if you are using an IRS type1 transmission you must run a reversed rotation Corvair engine". This must have been true with some early model IRS transmissions, but apparently the VW transmission builders have figured out how to build a 'flipped ring gear IRS'. I have one.

The new adapter kits available for the reversed Corvair engine use the same basic parts, except use a flywheel with a VW ring gear so a stock VW starter will work without an adapter. This would save a few lbs as the Corvair starter is pretty beefy.

If I could afford it I would use a reversed rotation engine adapted to a late (IRS) bus x-ribbed transmission, but with my limited budget I find stock Corvair engines plentiful and inexpensive, so it's easiest for me to go the flipped ring-gear method using 2nd hand parts.

By manxcraig Date 2008-06-25 02:36
Actually, its the  later VW IRS with only one side cover cant be flipped.
By Darryl B 967 Date 2008-07-04 19:00
Besides the glass body buggy I have (see above which is all corvair and no VW) I do have a Sand Rail that also uses a Corvair to VW transmission.

The engine is mounted mid engine. At first I just ran the engine standard and didn't reverse the ring gear. That made the rail run in the "correct" direction because it was mid engine mounted. However with the turbo Corvair engine's HP, it tore up the gears and they lowered and beefed up. The gears are running backwards the same as in a rear engine mounted with a flipped ring gear.

I ended up reversing the engine and beefing everything up and flipping the ring gear and I can really get on it hard and it holds perfect.

I think if you are on the street and take care in the way you drive, running the engine standard and just flipping the ring gear is OK, but don't try anything to "out of the ordinary" I think.

By Bob E #19 Date 2008-07-21 17:20
Shep, been building a mid-engine GS for about 4 or 5 years now and ended up using the Corviar, a lot to learn but seems all worht it now.  Finally got it registered a week or so ago. 

It's quite a bit different than all of the other buggies I've had, the engines in the middle and close to your ear,  the torque and sound of the Vair are guite a change also.  I'll get a few photos posted soon, I hope or you can dig through my sites listed below.

Boston Bob E.

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Boston Bob E - -
By John S 2 Date 2008-07-21 21:29
I can't wait to see more!!

Got any video of it????
John Shepard the DBA
By Jay H (X-20) (ManxVair CC) Date 2008-07-22 13:37
Ahhh, I LOVE the sound of the corvair motor... The fan is what does it. As long as the exhaust isn't overpowering, you can hear it well.


By Bob E #19 Date 2008-07-22 15:40
I did a couple of cheasy vid's earlier this spring, , google "bimelliott gs" and you should be able to find them.  Also the site has a link to a photo album on this car.  It needs updating I know, but heck it's summertime. 

I plan on driving it to our local VolksVair Fair show in a couple of weeks, (Aug 2nd), hopefully with Lou Mash's red series 1 GS and Mike Rags and his red GS/GT.  Both are close to complete, once again.

Bob E.
Boston Bob E - -
By Bob E #19 Date 2008-07-22 15:50
Here's a few more photos

Boston Bob E - -
By Jay H (X-20) (ManxVair CC) Date 2008-07-22 20:58
Bob, Nice 140 you've got shoved into that thing. I love the 4bubble carb with the 4 runners! That looks mean. I'm glad to hear you're in new england. Hopefully I will be able to make it to the show and introduce myself.

By Bill K 96 Date 2008-07-27 03:09
Bob, Love your S-1 GS!  Very clean, however, I happened to notice that you have what appears to be an early style crank pulley instead of a harmonic balancer. Chevrolet added the balancer when they increased the size of the engine from from 145 to 164. The 95hp came with a cast iron pulley but the 110,140, and turbo's had the balancer.  In the picture it appears to be an early stamped pulley. Any problems? Hope this averts some problems down the road.  Take care, Bill
By Bob E #19 Date 2008-07-28 13:15
Bill, good eyes.  It's a little deceiving and although it has the 140 heads it's actually based on a short (145) crank and lower end.

Thanks for the advice, this is my 1st Corvair after a lifetime of VW's.

Boston Bob E.
Boston Bob E - -
By Bill K 96 Date 2008-07-28 19:53
Bob, I checked out your photos and that has really come together nicely! I remember seeing it on the Doghouse when you first got it and was thinking that is going to be alot of work....congratulations!

My commuter car is a '68 Corvair 500, 110hp and powerglide.
My Series-1 had the Corvair Turbo, reverse rotation, but I wiped the cam and haven't gotten around to fixing it yet!
The Imp is a Corvair powered project after the S-1 is fixed and the Manx will stay VW powered.

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By Bob E #19 Date 2008-08-14 17:12
Nice car Bill, hope you get around to fixing it sometime soon.

Boston Bob E.
Boston Bob E - -
By ManxRob Date 2008-09-09 05:59
I finally got the 140 4-carb engine installed in my buggy:
(an attempt to re-create the photo in the old Crown add)

Here is the new rear-shot:

It sure is fun to drive now!

A several problems though, maybe someone here can help with:
1) I have #54 jets in all 4 carbs, and it is running rich. Do most folks run the same jets in all 4 carbs with progressive linkage? What size for sea-level in the NW?
2) My VDO electronic tach doesn't like the signal it's getting above about 3000 rpm and starts going off scale,... and I've fried a condensor already. The Crown documentation shows a resistor on the coil? Does this make sense? Did Corvairs use a resistor?
3) I get quite a bit of 'back-fireing' (through the exhaust) on de-acceleration.

Any ideas on where to start/what to fix?

By Bill K 96 Date 2008-09-10 16:15
First thing: Is everything set to factory specs?  Is the stock stuff performing as it was intended?  Did this engine run okay before being put in the buggy?  What was changed? Do you have good compression? We need a baseline to go by.  After baseline is established we can look at other systems.
Check timing, check advance curve, are the carbs synchronized? Are the floats set?  Are the carbs dripping fuel at idle? I had to lower my float settings from factory recommendation. Is the polarity correct on the coil? Negative goes to points. Did you convert to electronic ignition? How do the spark plugs look?
The stock jets ran from 48-53, my 140 has 51's and my 110 has 50's.  Bill Fisher in his book, "How to Hotrod your Corvair", recommends 54's for 140's at sea level and smaller jets at the higher elevations.
Is it actually backfiring through the exhaust or is that from lack of baffles/backpressure?
Hope this helps, Bill King.
By ManxRob Date 2008-09-11 21:08 Edited 2008-09-12 00:51
Bill, Thanks for the response!

I bought the engine from a Corvair collector that was thinning his collection. It had been stored in his storage shop since the late 70's. It was 'clean' inside, (I removed the valve covers to look for sludge), and dusty out. He said it suffered from 'excessive blow-by'. I pulled the heads and found 3 scored cylinders (2,4 and 6) and a broken compression ring on #6. I found a modified sump cover with baffles when I disassembled the engine, but otherwise no signs it had ever been apart. I had 9 cylinders honed, picked the best 6 that were still in spec, re-ringed the pistons with rings from Clarks, and put the thing back together. I did not 'mic' the pistons.

I rebuilt the carbs, replacing 1 primary and 1 secondary due to bowl/float corrosion on 1. The jets that were in at that time were #50 main, and #51(?) secondary. Per Bill Fishers book I re-jetted all the carbs with #54. I set the floats per Clarks specs, which I believe match the manual.

I put in new points and condenser in the stock 140 distributor. The headers have slip-in motorcycle baffles.

I set the initial timing at 12 deg using the static light method. It fired right up once I went back and re-adjusted the valves on #1 TDC.

I adjusted the carbs and linkage per 'How to keep your Corvair alive' before the initial engine start.

On starting it initially my impressions were:
1) Gads! This thing is LOUD! (And kind of knarly sounding I might add)
2) On initial drive, it was WOW! All the power I will ever need!, and it seemed to wind past my 5000 RPM redline with ease and power. (I know, not great for breaking in new rings, but I honestly forgot!). The exhaust note was just 'blurbaly'.
3) I adjusted the carbs (Idle speed and mixture). I was not able to get all 4 carbs balanced at that point. 3 sounded right, and the secondary on the drivers side has a little more draw.

My troubles started when I went to adjust the valves while running. The headers are so loud it is tough to hear the tappet noise when the valves are loose. I went to blip the gas to get it off the fast idle cam, and it stopped running. And wouldn't re-start. After cool-down I re-adjusted all the valves (again) for initial startup, and still no start. I found there was no spark. When I put test lamp on to check the timing statically I found the light wold not turn off regardless of points opening or distributor setting.

Since then I have:
1) Replaced the points and coil with an 'Igniter II' from the old 110 engine. It ran, but seemed to not like to rev, lost power over 3000 rpm.
2) Replaced the points & condenser with 'Nappa' brand. It was this parts man that suggested I check the need for a resistor.
3) Installed the resistor, per the 'Crown - Corvair to VW Installation Instructions', though I'm not sure I have a direct replacement for the Ford resistor called for. When the  points fire the test bulb goes from full glow to dim glow.
4) Disconnected the electronic tachometer at the coil.

It seems to run great, but doesn't have the scary amount of power I remember on my initial drive. Maybe that was just scary loud. Yes I believe it is a 'burble, burble, burble, (back-fire)BANG!, burble' on de-acceleration.

Any insights would be welcome.

Thanks again,
By Bill K 96 Date 2008-09-15 16:10
Rob,  You definitely need a resistor when running points.  The system is designed to start on 12v then gets reduced to 4.5-6.5v to avoid frying the points.  Visit the Ignitor site:  Are you running Ignitor I or II?  They have multiple listings for coils and depending on application you can eliminate the resistor.  I am running the II and have bypassed the factory resistor wire on my 110 'Vair.  I am also running the 0.6 ohm resistance coil.
Are you actually running the 140 distributor?  What is the number on it?  Early 140's like 18 degrees intial with 18 centrifugal in below 3000 RPM.  Total of 36 degrees.  You will need to run 93 octane to keep it alive.
I am not clear on the baffles on the sump cover.  Are you referring to the windage plate located under the top cover?  The only time this would need to be modified is when going reverse rotation.
I prefer adjusting the valves on the 'Vair when cold.  Even with the stock exhaust I have trouble hearing the valves.  I adjust mine one cylinder at a time starting with 1 and rotate to next cylinder in firing order(145236) and adjust that cylinder.  You can also hook up a compression gauge and check the cylinder to ensure one or more aren't misadjusted and hanging open.
Once valves are adjusted and ignition/timing set then we'll deal with carb issues unless corrected with above.
I did notice in both your pictures you are missing the block off plate, located near the oil cooler.  This is removed for winter operation to allow warm air into the engine compartment to prevent icing of the carbs.  With this missing the engine won't get to operating temperature quickly or evenly.  Are the thermostats in place and adjusted?  This won't fix the current issues but will ensure longevity.
Good luck, Bill.
By ManxRob Date 2008-09-19 03:56

Thanks for your suggestions! I put a resister in on the power to the coil, and replaced the points and condenser.  I also was able to set the valves while running by installing some corrugated drainage pipe as muffler extensions to quite the engine enough to hear the valves.  It runs much better.

I took it out for a end of summer cruise on Sunday, from Seattle through Stevens Pass to Leavenworth, through Washington states apple country and back to Seattle through Snoqualmie Pass. It was a total of 250 miles from sea level up to 4200 feet. There is more than enough power to 'rather briskly' accelerate up the steep grades of the pass in 4th gear at well over the legal limit. I get a smile on my face just thinking about it.  It is running rich, I got 17 MPG for the trip, so I think I will reduce the jet sizes from the current 54's to 51's.

Then I got your post info on setting the timing to 18 deg. static. That woke it up! I was unable to verify the distributor is the original 140 since I have to remove it to see the numbers. I'll play with it some more and let you know the results.

Thanks again!

By John S 2 Date 2008-09-19 16:18
This is EXACTLY why we put the work into this website.

For a guy in Virginia to be able to reach across the country to Washington state and say
try xyz that should help.

And it does.

I love these internets. :-)
John Shepard the DBA
By Bill K 96 Date 2008-09-19 17:57 Edited 2008-09-19 18:15
Rob,  I'm glad everything worked out for you.  Do you know what ratio you are running in the transaxle? 3.55 was standard in the 'Vair with a 140 and manual trans.  That 'Vair engine should be getting mid-20's once the jetting is worked out......that is if you can keep your foot out of it! 

I spoke with Alex Dearborn (D.A.C., Autodynamics, Deserter) years ago about Corvair powerplants.  He said that on the dyno the 140 was only making around 90hp.  With the addition of the triple throat Webers off a Porsche they were making the advertised 140!


John-Thanks for founding this site!  The result of sharing information is priceless.
Previous Next Up Topic Engines / Corvair Power / Corvair Projects.... (56488 hits)

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