1964 turbo change carburetor

[Brian0810]

Does anyone know where i can get a 4 barrel adaptor plate for the turbo corvair engine?

[66vairguy]

Very little data to go on in your question. It would have to be a smaller four barrel.

Without some serious modifications a larger carburetor would simply overboost the engine until it failed.

The Corvair turbo, per all the books, seems to be a good working compromise for it's time. Now if you want serious power AND reliability you need to go with computer controlled - ignition, fuel injection, wastegate control, and an anti-knock sensor. The transaxle also puts limits on how much horsepower and torque you can generate.

[bbodie52]

Click on the link below for more info...

Rochester Quadrajet on a Turbo Corvair

Rochester Quadrajet on a Turbo Corvair

http://autoxer.skiblack.com/turbo.html

[66vairguy]

A good article, but 20 years out of date. As stated upfront in the article ---- you need to prevent over boosting and detonation.

A few folks have improved the turbo engine by moving on to fuel injection (and water ethanol injection) and run modern "dry" turbochargers with wastegates, and coil pack ignitions. All run by computer controls.

Not for a budget minded build, but can result in quicker boost, better fuel mileage, good reliability.

The cooling issue is a mixed bag. Within about 30 seconds WOT you are at redline in 4th gear (and really moving). For only off line fast starts, or passing, the engine won't overheat. HOWEVER - it's a serious issue if you want to race on the track for extended runs. Chevy engineer Benzinger claims the turbo could run about a minutes at WOT without overheating the engine, but there are few facts or test conditions to back it up.

The NASH fan may fix the cooling issue, but I'll believe it when I see a real word turbo engine stay cool after a minute at WOT with the NASH fan.

As for the articles reference to a "HOT" coil for the Spyder and later Turbo engines --- I looked that up years ago. The 62-63 Spyder got the coil and "hot" ballast from the Corvette Hi-Po SBC engine back then. It was a ceramic type (unlike the stock ballast) and mounted on the rear frame rail near the coil. The "hot" coil and ballast was notorious for eating up points in the Corvette and a service bulletin went out to change the ballast (less coil energy) IF customers complained (since it was basically a race engine most buyers just changed the points often). Oddly enough no bulletin was issued about the Corvair Spyder that used the same ballast and coil! The 1964-67 Turbo engines used the same stock ballast (1.8 ohms) as all Corvairs, BUT the coil was more efficient and also installed on ALL 140 HP engines (at least through 66 and then the information is lacking for the 67-69 140 HP engines.) It was a GOOD coil and past testing by a few folks in CORSA showed the coil performed better then ALL the so called HIGH OUTPUT coils from the aftermarket companies. Sadly that DELCO coil is no longer available. Another reason to go with computer-controlled coil packs.

[acarlson]

Here is the coil pack I have installed on my '66 Turbo:

It is attached to an EDIS-6 controller out of a 1970 Mustang. The EDIS module is controlled by a MegaJolt/E MK2 ignition controller from AutoSportLabs. The MK2 is a mapped ignition controller which allows downloaded maps to control ignition timing. The controller has a MAP sensor and uses engine RPM to select an ignition timing value. With the map you can change the ignition timing for any RPM and vacuum/boost pressure.

This is just one solution for fixing the turbo timing issues in the stock turbo. I'd fix that before worrying about the carb...

[Nashfan]

A good article, but 20 years out of date. As stated upfront in the article ---- you need to prevent over boosting and detonation.

A few folks have improved the turbo engine by moving on to fuel injection (and water ethanol injection) and run modern "dry" turbochargers with wastegates, and coil pack ignitions. All run by computer controls.

Not for a budget minded build, but can result in quicker boost, better fuel mileage, good reliability.

The cooling issue is a mixed bag. Within about 30 seconds WOT you are at redline in 4th gear (and really moving). For only off line fast starts, or passing, the engine won't overheat. HOWEVER - it's a serious issue if you want to race on the track for extended runs. Chevy engineer Benzinger claims the turbo could run about a minutes at WOT without overheating the engine, but there are few facts or test conditions to back it up.

The NASH fan may fix the cooling issue, but I'll believe it when I see a real word turbo engine stay cool after a minute at WOT with the NASH fan.

As for the articles reference to a "HOT" coil for the Spyder and later Turbo engines --- I looked that up years ago. The 62-63 Spyder got the coil and "hot" ballast from the Corvette Hi-Po SBC engine back then. It was a ceramic type (unlike the stock ballast) and mounted on the rear frame rail near the coil. The "hot" coil and ballast was notorious for eating up points in the Corvette and a service bulletin went out to change the ballast (less coil energy) IF customers complained (since it was basically a race engine most buyers just changed the points often). Oddly enough no bulletin was issued about the Corvair Spyder that used the same ballast and coil! The 1964-67 Turbo engines used the same stock ballast (1.8 ohms) as all Corvairs, BUT the coil was more efficient and also installed on ALL 140 HP engines (at least through 66 and then the information is lacking for the 67-69 140 HP engines.) It was a GOOD coil and past testing by a few folks in CORSA showed the coil performed better then ALL the so called HIGH OUTPUT coils from the aftermarket companies. Sadly that DELCO coil is no longer available. Another reason to go with computer-controlled coil packs.

If you want to put a Quadrajet on a turbo, theres nothing outdated about that site for that... with a Quadrajet, its real easy to get 20psi of boost in first gear. The engine wont blow up from boost if the timing curve is changed. This is really all there is to that! When I put a Weber on my car 20 years ago, the only things done to the timing were to put a 95 manual tranny distributor on and a safegard... real easy to do, and still works fine for street driving. I could get 10psi in first, 15 psi in second, and between 18 and 20+ in third, depending on the choke sizes. On plain jane 92 octane, and no water injection. Yes EFI makes a world of difference, much easier to get good gas mileage, awesome throttle response and as much power and boost that can be had out of the turbo and heads, but sheesh... the "you have too's" get annoying because you dont, as I proved. On cast pistons also!!, and no waste gate.
If there is a "you have to" with hotted up turbo Corvair's its to fix the rotten timing curve! its real easy these days to do that without getting rid of the distributor. The simple button is a CB performance BlackBox. It gives you everything you want, vacuum advance during light loads, rpm advance like every NA car in the world has, including all modern Turbo cars, and of course boost retard. All that really does wonders for getting our cars running a lot cooler in most situations.
Another newer carb option these days is to use a Mikuni Slide carb... I went EFI and programmable distributorless ignition a long time ago and would never go back to a carb but would also never tell someone "they have to" do it that way to keep the engine safe. To keep the engine safe is a matter of fixing the timing!
Now, about the Nashfan... Yes, IT HAS been tested under race conditions on a Turbo car. Here's what happened. !5psi of boost, close to 1.5 minutes and near continuous speeds over 100 mph, and ambient air temps around 100 degrees, with lower shrouds off, the stock fan caused the heads to go over 500 degrees, and took a LONG time to settle down to 300 after the load was removed. Same race, same ambient air temps, speeds and boost with the Nashfan, guidevane bell mouth intake, airflow pulley and lower shrouds removed, now his head temps could only hit 430F and settled down to 300 after the load came off, "like a Porsche" His words!!

[Nashfan]

A good article, but 20 years out of date. As stated upfront in the article ---- you need to prevent over boosting and detonation.

A few folks have improved the turbo engine by moving on to fuel injection (and water ethanol injection) and run modern "dry" turbochargers with wastegates, and coil pack ignitions. All run by computer controls.

Not for a budget minded build, but can result in quicker boost, better fuel mileage, good reliability.

The cooling issue is a mixed bag. Within about 30 seconds WOT you are at redline in 4th gear (and really moving). For only off line fast starts, or passing, the engine won't overheat. HOWEVER - it's a serious issue if you want to race on the track for extended runs. Chevy engineer Benzinger claims the turbo could run about a minutes at WOT without overheating the engine, but there are few facts or test conditions to back it up.

The NASH fan may fix the cooling issue, but I'll believe it when I see a real word turbo engine stay cool after a minute at WOT with the NASH fan.




Now, about the Nashfan... Yes, IT HAS been tested under race conditions on a Turbo car. Here's what happened. !5psi of boost, close to 1.5 minutes and near continuous speeds over 100 mph, and ambient air temps around 100 degrees, with lower shrouds off, the stock fan caused the heads to go over 500 degrees, and took a LONG time to settle down to 300 after the load was removed. Same race, same ambient air temps, speeds and boost with the Nashfan, guidevane bell mouth intake, airflow pulley and lower shrouds removed, now his head temps could only hit 430F and settled down to 300 after the load came off, "like a Porsche" His words!!

I thought it would be really cool to update this post a little. Another Turbo racer in Europe that is also equipped with the Nashfan/Bellmouth and airflow pulley ran his first race with it a few weeks ago, and represents a much tougher test than the earlier test reported above. Its a 1.8 mile track, and "fast" laptimes on this course are 1:40 and under. Peak speeds are in excess of 100 mi/hr. His peak boost is 18 psi and has been dynoed at 250 hp at that boost at the rear wheels. He came in third out of a 20 car field, and half the class runs hotted up Ford V8's- the winner was a Shelby 350. There was only .24 secs difference between the fastest times for first, second, and third place, and the lap times were in the range of 1:37's. The race was eight laps, and his head temperatures stabilized at 425. No water methanol injection , no EFI no fancy computer controlled timing and he's still running a F/F turbo, which is way out of its best efficiency at 18psi so is heating the hell out of the intake air. With a couple more mods, this time next year he might be down to 350-375 head temps at the same boost level!! He is also running one of the "infamous" fan belt guide rollers that I've developed. He has had ZERO problems with chucking belts ever since he installed that. Including test laps on that same course hes put in 35-40 race laps and countless hrs and pulls on the dyno... last year it seemed like all his dyno time was being wasted messing with the belt, and had tossed it a few times on the course, always on the 3-2 downshift like normally happens with the NA cars. He believes that guide roller set-up to be a genuine CURE for tossing belts.