Corvair Engine Questions

[TORQUER]

Guys,
I'm new to corvairs, but not new to Air Cooled engines. Ive owned a few VW's. Now my dad is trying to pick up a 1964 Corvair he found and is going to let me have it to restore. Its a complete car. Pretty well preserved. Ive been browsing around on this forum and have learned alot.
My questions are:

1. How much power and reliability can i achieve from a completely stock setup? I mean concours correct stock engine.
Ive seen some guys adapting EFI to the Vairs, and that interests me because I hate points. Id rather set it and forget it.
2. Does EFi actually improve power or mpg?
3. What are some of the better more respected aftermarket ignition systems for these engines?
4. I fully understand that a stock Corvair cooling system suffices for a stock daily driven setup, but are there any modern improvements I can make to the cooling system?
5. Any other modifications i can do to the engine to reliably increase torque? I'm not going to be building a track day car, but with a 2-speed powerglide i would like the umph to get going on the freeway when needed.
6. Is there anyone out there dropping in a Subaru engine into these cars?

Im not into gimmicks and shinny bits. I like proven reliable parts, and a relatively stock setup.

BTW, I am very well aquainted at this point on how the corvair engine is setup. Its much like a VW engine. Gotta love Air cooled motors. Thanks for any help and suggestions.

[marvgarr]

what engine do you have 95-110-150? petronix has a points eliminator kit for corvairs fits under cap and looks stock with cap on except for extra wire from distributor cooling is sufficant for what ever you can through at it stock wise I live in the mohave desert and the car never gets hot i can go to work 30 mile trip up hill get there shut off the car get out pull the dipstick and the oil is not real hot as long as the fins are clean belt is tight and baffles are off it will stay cool stock carbs are reliable as long as they are rebuilt right if the shafts are worn then they get tempermental power wise I have 102 hp monza with a power glide and when i get on the gas it goes and it is stock even has points i drive the highway all the time efi is a headache keep it simple a carbed engine will still get you home with a little tinckering when efi goes your stuck thats why i ripped out the efi out of my 93 s10 blazer as far as the subaru engine part why do you want to ruin a nice car keep it stock and it will last my .02

[TORQUER]

Marv,
Thanks for the advice. I will look into the Petronix kit. I do not know what engine is in this car yet. My dad is supposed to be picking up the car soon. The guy who owns it got thrown in jail and his wife is selling off some of his cars because the city has ordered her to clean up their yard. Dad said it looks like a stock 64 corvair carbed engine. I think he said it was a 95 horse. I have a friend who has an uncle with a late model vert and turbo car that might be selling me the turbo setup with the engine.
As for EFI, I differ with my opinions. Carbs are simple yes. However EFI can be alot less work in the long run. With a properly setup EFI system I have had better running engines. If you educate yourself on EFI than you will see its benefits, and will not be affraid to work on it.

[marvgarr]

on the turbo set up you need a turbo motor or you will be asking for problems i understand the whole efi system i have modified a lot of efi engines and they are great if it was set up for efi if you add efi to a corvair it becomes a headache as when you balance them as you have two iac motors in the throttle bodys that compensate so unkown how you get them right the only efi i put on an engine that was not efi is the powerjection 3 setup it is all in the throttle body including computer and is self learning and is boost friendly but you did say concours stock set up efi is not concours stock

[TORQUER]

Nah, what I meant was to compare a stock setup versus a modified EFI tuned engine. Anyways, I would think you could set it up without multiple IAC's. Use one throttle body and four intake runners going to it. I wonder if a mid 80's ford speed density setup would adapt easily. You know, one from a 6-cylinder car of course.

[marvgarr]

if you did that with a single tb you would be ok i think easy to tune also now if you changed the heads over to 140 hp heads you can by the holley four barrel intake from clarks get a tbi adapter plate for square bore and run a chevy tbi system but the only thing is these are water cooled you would have to have some way to tell the ecu the engine is at operating temp which is higher temp then water cooled also in the winter the intake tubes would ice up

[TORQUER]

Is the chevy TBI throttle body heated from the engine coolant like some Ford throttle bodies? If so, maybe you could hook up a tank of water that had a hotstart heater in it and circulate the hot water through the TB for winter driving, thus keeping the intake from icing. My 86 f-150 tb is like that.

[flat6_musik]

Or oil?

[marvgarr]

no the chevy tbi used the exhaust to heat the throttle body in the intake you could do the same just make a plate and run some steel tubing up to it from the exhaust make a valve so you can shut it off in the summer the 60 corvair had a choke heated by exhaust i think cant remember for sure the water idea you just have to make sure it has antifreeze in it flat 6 has and idea but not for tb icing but for the cts sensor you can put it in the oil pan so the ecu knows the engine is warmed up and thats all use a 4.3 tbi system v6 that way you can make the distributer work some how the or use a 2.8 but these have a weired firing order some times

[TORQUER]

Oh yeah, exhaust or oil through the tb would be a better idea. Less mess. You could route the oil through on its way to the oil cooler. I wonder if a late model 4.3L v6 mass air system could be used.

[PHX65CorsaHT]

Torquer, efi has been done plenty on vairs. Maybe think Fiero system. Do a search on it you will find some good stuff to move you that way if you desire. Or like you said it can be done with the the four runner setup like I have (carburated mind you). I have a 500cfm two barrel dialed in now and it is great. You could for sure get better fuel economy with the efi. Mine is setup to be a an early 911 killer!

[USAF_vair]

There are plenty of different ways to set up the corvair engine with fuel injection. i have a four barrel throttle body set-up on a slightly bored and cam'ed engine that is putting out around 130's hp. there is a lot of different things you have to look at when installing a fuel injection system on the corvair. you have the IAC, air temp, Surface temp, oil temp, cam sensor, crank sensor, Map, and O2. these all need to be custom wired in and in the right location, trust me a few inches here or there makes a 5 hp gain on some sensors. we have worked with using the stock 95 or 110 carbs and put fuel injection into the carbs of the stock corvair. we do this using one IAC and only the needed sensors. it still is a lot of work.

to answer some other question you have, the gain is reliability. no more issue with Vapor locking, torque and fuel economy does increase. my brother has a turbo corviar running well over 200 hp and is still driving his car at 3200 rpms at 70 mph down interestate and still gets 24 mpg. everything with engine is how you control the fuel and spark.

if your looking for a good set-up to inprove your overall engine in the corvair. Buy the Crane Cams XR700 electronic ignition from Clarks Corvair, along with new wires, the magnetic ignitor to replace points, flame thrower coil. the spark plugs bosh have work well in most corvairs but E3 does have a spark plug that is a lot hotter that works with the corvair engine but costs a lot more. the gain to using E3 is really noticed with performance engines.

Cooling system------ Stock----Stock ---- Stock---- many have tryed electric fans and such. some work fine others don't. buy 2 good belts and the fan will be the best.

[TORQUER]

USAF VAIR,
Thanks for all the advice! I will probably end up with a single carb and the Cran Cams ignition. Ok, now this is just me brainstorming a bit, but has anyone attempted front wheel drive in the Vair? I know there is alot involved, but once I get around to working on this Vair I will have a full shop access to do all sorts of fab work. Anyways, I was thinking Subaru flat four engine and transaxle in the front of the car, with the rear driveshaft blocked off. You could take the whole front clip suspension and all from the subbie and graph it in under the stock sheet metal. yeah yeah yeah, I know, its crazy. Just thinking. Or maybe one of these late model 260+hp minivan v6 engines in the rear? Call me crazy, I know.

Stock engine with single carb and aftermarket ignition will probably win out. But it would be awesome to show up to a corvair meet with a minivan engine in one of these things. No one will ever hear the thing running. They would stand next to the car and think "what the F, I can't hear it running, whats it got under the hood?"

[Scott V]

take a look at http://www.american-pi.com/corvair/html ... tion1.html these guys have done lots of efi conversions on vairs. id think that they would be able to answer your questions.

-Scott V.

[Leon Tombong]

Sorry for reviving this thread up. I'm looking for corvair engine help and fortunately I saw this one! Anyway, thank you guys especially for the tips and advice, I've been looking for help a couple of months ago but I'm not that satisfied with the answers that I'm getting to other sites because they have different opinions and insights. Thanks!

[bbodie52]

Switching to a single center-mounted carburetor is a possibility, and you might be able to find the needed carburetor and manifold on eBay, this Forum, or somewhere else on the Internet. But those systems have their own issues, including choke and throttle mechanism problems and a tendency to be cold-blooded in cold climates due to a lack of carburetor-warming heat from the engine (with the exception of a few oil-warmed manifolds for 140HP 4-carburetor engines that are rare and complex to install).

Another option that I have seen, and that I am considering for my own Corvair is to replace the fuel and ignition system with computer-controlled GM=based Electronic Fuel Injection and electronic multi-coil ignition that eliminates the distributor. Here is what I wrote about this in another post:

I am very much in favor of abandoning the dated Corvair carburetors and distributor in favor of a modern computer-controlled system. The Corvair engine itself is well-designed and reliable as a street performer, but the fuel and ignition systems are flawed in their age and design. There is a reason that carburetors and distributors have been abandoned by the auto industry. Updating a Corvair engine with modern fuel and ignition control can greatly improve its performance and reliability.

I can only propose some ideas that I am considering for my own Corsa with 140HP engine. My goal is to update some of the intake and ignition systems technologies with some new approaches to bring these systems into the 21st century without changing the overall character of the Corvair. Without knowing your budget for your upcoming performance plans, or your own mechanical "DIY" capabilities, I can only suggest some changes for the engine that could produce a "bulletproof" updated engine that would be more reliable and potentially trouble-free for years to come.

Recently a new GM-based computer-controlled Electronic Fuel Injection (EFI) and (distributor-free) Electronic Ignition system (that utilizes no moving parts) has been successfully adapted for Corvairs.

http://www.corvair-efi.com/

This system, as described and depicted on the above Web site, eliminates the 40+ year-old carburetors and mechanical fuel pump completely, and replaces it with a modern GM-engineered EFI system. The distributor, coil and plug wires are also removed, and replaced with a Corvair Distributorless Ignition System (DIS) that has no moving parts. Both systems share a common computer control and use electronic sensors to monitor the engine's needs and control the EFI and multiple coil DIS. The result is a stable and tightly regulated and controlled fuel and ignition system that far-exceeds the design capabilities of the original 40-50 year old Corvair carburetor and distributor-based technology. The fuel mileage is apparently enhanced, and the ability of the engine to work with modern gasoline blends and octane ratings is also improved. Here is a brief description from the EFI system Web site:

This kit was designed and built with 3 major objectives:

- Increase performance and dependability of the Corvair Engine

- Be completely reversible and cost effective

- Plug and Play

Why TBI? The Throttle body was chosen for the dependability and simplicity. This kit is a bolt-on, simple with ease of troubleshooting with its OBD-1 architecture and uses mostly GM parts available at your local auto parts store. Parts that had to be manufactured are of normal home shop quality and not made on production lines/machine shops to keep the parts affordable.

Background: Fuel injection has always been costly for the Corvair mainly because of the Port injection requires costly welding and the manufacture/use of low production parts. This kit uses mostly GM main-line production parts to keep the price low and uses tried and true components for reliability. The dual throttle body has been used before, but was fragmented and used a costly computer to run. This kit uses a GM computer and manufactured parts are of normal supply. Temp control was always a problem due to the wild temp fluctuations of the Air-Cooled engine. We developed a Water Temp Equivalent (WTE) method for the ECM to control and trim the engine. We hope you find this one of the most well thought out, economical and dependable kits ever produced for the Corvair and should provide years of trouble-free service.

Theory: Carbs and points that control the Corvair and all motors of that era are a compromise. The Carbs give the best fuel mixture at only certain times due the design. Distributors can’t compensate for Temp and use flying weights to control the timing… good, but again a compromise. Fuel Injection w/DIS applies the best fuel mixture and timing for that RPM, Load and Temp. Other sensors also trim the fuel and timing, but those are the basics.

What should I expect?: Ease of starting, good all around performance and better fuel economy. This will not make your worn out engine a good engine. It does not fix burned valves, leaking heads, cracked pistons, etc…. its fuel injection. It maximizes the amount of fuel and spark for the best all around performance and economy based on external factors which a traditional Carb and points can’t do.

My understanding is that the above system is well-developed for a dual-carburetor Corvair engine. The design for a 4-carb version is still under development. however, the dual fuel injector system can be easily installed on a 140 HP engine by blocking off the extra two intake ports for the secondary carburetors. If you feel that you would be interested in an EFI system for your Corvair at all, I would suggest having a discussion with the designer after reviewing his Web site. That is what I intend to do. In truth, the standard four carburetor 140HP Corvair design is often found to have the two secondary carburetors not functioning. Either the progressive linkage is not adjusted properly, or the secondary carburetors are stuck shut. They are seldom opened in normal driving. I believe that the advantages of the electronic fuel injection system coupled with the associated distributorless ignition are so significant that they far outweigh the older four carburetor increased breathing advantage. A good EFI system on a 140HP engine (with its large intake valve heads), possibly coupled with a good set of headers, will likely perform far-better than the stock setup, and perhaps far-better than the 180HP turbocharged engine too in real-world street driving. I place emphasis on those last words, because my focus would be on a reliable street engine with good, reliable and efficient performance, and not a race-tuned, high-rev, high speed engine that has realistically little application in normal street driving. Modern fuel and ignition control are areas that have seen the greatest improvement in the last 20 years or so. Computer controlled EFI and electronic ignition that continuously monitors the operating environment and critical engine parameters permits ignition and fuel control that is tightly controlled and optimized to continuously meet the engine's needs. Decades-old carburetor and distributor designs were always a compromise design, limited by available technologies at the time, and could only approximate a match to try to meet the needs of the engine based on choke settings, throttle position and airflow, and the centrifugal and vacuum advance curves pre-programmed into the electro-mechanical distributor. Electronic engine sensors and computer control coupled with a multi-coil ignition system that has no moving parts and EFI throttle bodies permits fuel and ignition control that could not have been imagined or technologically feasible 40+ years ago. The mechanical design of the basic Corvair engine has been proven to be solid and reliable. Enhancing the fuel efficiency and street performance of the Corvair engine with modern sensor-based computer-controlled EFI and ignition systems can produce a hybrid combination of the old and the new that performs better than the original design could be expected to. EFI and a Distributorless Ignition System (DIS) is not an inexpensive upgrade, but if you are inclined to consider it I would recommend thoroughly researching the possibility befor spending money on older designs using center=mount carburetors, breakerless distributor modifications, or rebuilt stock carburetors. Investigate the cost and performance of all options and then make the choice that you feel most-comfortable with.

Stock Corvair cooling has evolved over the years into a good, reliable system. The implementation of better fan belt designs, a lightweight magnesium blower, and belt guides helped to improve reliability. (The lightweight magnesium blower greatly reduced the "flywheel effect" over the earlier design heavy steel fans. The heavier steel blower fan "fights" changes in engine speed, causing additional strain on the fan belt).

Several stock oil coolers were included with different Corvair engines over the years, and switching to the design that utilizes the 12 plate oil cooler is likely the best bet to improve oil cooling over some earlier designs with less heat transfer capability. The earliest design looks like a finned radiator. This design was also good as it promoted better heat transfer to the passing cooling air. However, the tight folded fin design is somewhat difficult to keep clean and unblocked by dirt, leaves, etc., and an oil cooler that is blocked by dirt cannot transfer heat, since air cannot pass through the blocked cooling fins.

Installing a black, multiple cooling fin aluminum oil pan and valve covers (such as the Otto Parts items offered by Clark's Corvair Parts) can also enhance engine cooling by transferring heat away from the engine oil. If you look at the design of the Otto Parts oil pan below, you will see numerous cooling fins externally and a number of internal posts (24) that add to the total conductive surface between the pan and the outside air, and between the pan and the crankcase oil. The black anodized finish also helps with the transfer of heat to the external air. Polished external surfaces on an oil pan or on valve covers actually inhibits heat transfer to the air. A good synthetic oil also handles engine heat better than conventional motor oils.

Here is a link to a good technical article that discusses Corvair oil coolers:

http://autoxer.skiblack.com/oil-cooler.html

Clark's Corvair Parts - Otto Parts Oil Pan and Valve Covers

http://www.corvair.com/user-cgi/catalog ... age=OTTO-1

http://www.corvair.com/user-cgi/catalog ... age=OTTO-3