Frequently Asked Questions
Lonnie Gilbertson - Milwaukie, Oregonhat drives people toward "Water Pumper" conversions
Lightweight cars + lots of horsepower = plenty of acceleration and speed
Weight distributions close to 50% front / 50% rear + 4 wheel independent suspension = tremendous handling
Acceleration + speed + handling = a great sports car
Where can I find the parts to do a conversion?
There are not many places to purchase parts. Clarks Corvair Parts has a few of the original parts but most will have to be sourced from individuals or buy a completed V8. Check out our VENDORS page on this site or dig around on our V8 Registry Forum.
What is the difference between the Crown Conversion and the Kelmark Conversion?
The Crown Conversion retains the transaxle in the stock location, opens up the forward end of the transmission, and adapts the V8 bellhousing and clutch to it. This works because the stock Corvair engine rotates in the opposite direction of a Chevy V8. The Kelmark Conversion turns the transaxle around 180 degrees and uses a special bellhousing and input shaft to bolt the V8 where the stock engine would normally be connected. This makes the rotation of the differential backwards.
What is the main advantage of the Crown Conversion?
The Crown Conversion has a near perfect engine placement in terms of weight distribution. The Crown setup has a 40/60 to a 50/50 distribution ratio which is ideal.
What is the main disadvantage of the Crown Conversion?
The cockpit space is limited. The driver sits somewhat close to the steering wheel and for those who are tall it can be somewhat uncomfortable.
What is the main advantage of the Kelmark Conversion?
The engine is mounted 11 inches further back in the car allowing for more room for the driver and the use of the stock seats.
What is the main disadvantage of the Kelmark Conversion?
The Kelmark requires the turning of the trans-axle 180 degrees flat to the rear end and connecting it to the engine with a bell housing adapter. A stronger shaft is needed to withstand the torque of a V8. Also, since the ring gear turns backwards it requires a correction for the oiling function or a reverse cut ring and pinion gear set.
What is a Crown four spider diff?
In the early days Crown created a modified Volkswagen differential carrier by adding two extra pinion gears to the existing two gears which in effect lessened the load and made the differentials last longer. It was called a Beef-a-diff. When the Crown Corv-8 was created the differential again being a weak spot was modified by adding two more pinion gears. This created a cross legged look whence the "spider" nickname was derived. Clarks Corvair Parts sells the parts to do this modification.
What is a CIDCO diff?
CIDCO, which stands for Corvair Improvement Distributing Company is owned by Bob Anderson. At one time he developed Corvair transaxles with many improvements, not only for Corvairs but the kit car industry as well. Bob improved the longevity of the differentials thru many modifications, re-manufacture and re-engineering, along with careful assembly. This included having reverse cut ring and pinion gears made for the Kelmark transaxle setup which ran in reverse. His setup was in great demand from the mid engine Corv-8 people. One of the trademarks of the CIDCO diff is the shoulder bolted steel plate cover on top of the
differential in place of the tin cover. At this time CIDCO modified differentials are not available.
What do I look for in an abused differential in a V-8 Conversion?
The Corvair differential was not designed to handle more than 250 horsepower. When you put the power and torque of even a mild V8 to the stock differential, it tries to split the case from the pinion gear being forced against the ring gear.
Is the interior Hot?
The car is not hot with insulation and a proper engine cover in place.
Is the interior noisy
With insulation and the engine cover in place the interior is not any louder than any high performance car depending on the insulation and design.
Is there a forum where I can ask specific questions?
The Corvair Society sponsors a V8 Vair Email List. It can be found at http://www.vv.corvair.org/mailman/listinfo/v8vairs You can also review previous postings or post your won questions on the V8 Registry Forum (www.v8registryforum.com)
Any new or more modern innovations showing up in V8 conversions?
The newest innovation appears to be integrating a Corvette C5 differential rather than using the original Corvair differential. There are several sources showing up with adapters for both manual Saginaw 4 speed transmissions and Powerglide automatic transmissions. This setup provides several advantages - Strength and Legroom. The strength aspect comes from the fact that the C5 differential was engineered for plenty of horsepower and the legroom aspect comes from the use of constant velocity u-joints (cv joints) that allow the entire drivetrain to be positioned further to the rear of the vehicle than the Crown design. Several V8 Registry members are already running this type of setup. Here is a partial list of members who have incorporated the use of a Corvette C5 or C6 differential -
Mark Allen - Decatur, IL
Paul Beck - Pearl, IL
John & Cory Black - Moon Township, Pa
Robert Depalo - Hot Springs, Arkansas
Lonnie Gilbertson - Milwaukie, Oregon
Mike Levine's V8 Coupe - Cumming, Georgia
Rod Tetrault - El Cajon, Ca
Phillip West - Alma, Michigan
Lightweight cars + lots of horsepower = plenty of acceleration and speed
Weight distributions close to 50% front / 50% rear + 4 wheel independent suspension = tremendous handling
Acceleration + speed + handling = a great sports car
Where can I find the parts to do a conversion?
There are not many places to purchase parts. Clarks Corvair Parts has a few of the original parts but most will have to be sourced from individuals or buy a completed V8. Check out our VENDORS page on this site or dig around on our V8 Registry Forum.
What is the difference between the Crown Conversion and the Kelmark Conversion?
The Crown Conversion retains the transaxle in the stock location, opens up the forward end of the transmission, and adapts the V8 bellhousing and clutch to it. This works because the stock Corvair engine rotates in the opposite direction of a Chevy V8. The Kelmark Conversion turns the transaxle around 180 degrees and uses a special bellhousing and input shaft to bolt the V8 where the stock engine would normally be connected. This makes the rotation of the differential backwards.
What is the main advantage of the Crown Conversion?
The Crown Conversion has a near perfect engine placement in terms of weight distribution. The Crown setup has a 40/60 to a 50/50 distribution ratio which is ideal.
What is the main disadvantage of the Crown Conversion?
The cockpit space is limited. The driver sits somewhat close to the steering wheel and for those who are tall it can be somewhat uncomfortable.
What is the main advantage of the Kelmark Conversion?
The engine is mounted 11 inches further back in the car allowing for more room for the driver and the use of the stock seats.
What is the main disadvantage of the Kelmark Conversion?
The Kelmark requires the turning of the trans-axle 180 degrees flat to the rear end and connecting it to the engine with a bell housing adapter. A stronger shaft is needed to withstand the torque of a V8. Also, since the ring gear turns backwards it requires a correction for the oiling function or a reverse cut ring and pinion gear set.
What is a Crown four spider diff?
In the early days Crown created a modified Volkswagen differential carrier by adding two extra pinion gears to the existing two gears which in effect lessened the load and made the differentials last longer. It was called a Beef-a-diff. When the Crown Corv-8 was created the differential again being a weak spot was modified by adding two more pinion gears. This created a cross legged look whence the "spider" nickname was derived. Clarks Corvair Parts sells the parts to do this modification.
What is a CIDCO diff?
CIDCO, which stands for Corvair Improvement Distributing Company is owned by Bob Anderson. At one time he developed Corvair transaxles with many improvements, not only for Corvairs but the kit car industry as well. Bob improved the longevity of the differentials thru many modifications, re-manufacture and re-engineering, along with careful assembly. This included having reverse cut ring and pinion gears made for the Kelmark transaxle setup which ran in reverse. His setup was in great demand from the mid engine Corv-8 people. One of the trademarks of the CIDCO diff is the shoulder bolted steel plate cover on top of the
differential in place of the tin cover. At this time CIDCO modified differentials are not available.
What do I look for in an abused differential in a V-8 Conversion?
The Corvair differential was not designed to handle more than 250 horsepower. When you put the power and torque of even a mild V8 to the stock differential, it tries to split the case from the pinion gear being forced against the ring gear.
Is the interior Hot?
The car is not hot with insulation and a proper engine cover in place.
Is the interior noisy
With insulation and the engine cover in place the interior is not any louder than any high performance car depending on the insulation and design.
Is there a forum where I can ask specific questions?
The Corvair Society sponsors a V8 Vair Email List. It can be found at http://www.vv.corvair.org/mailman/listinfo/v8vairs You can also review previous postings or post your won questions on the V8 Registry Forum (www.v8registryforum.com)
Any new or more modern innovations showing up in V8 conversions?
The newest innovation appears to be integrating a Corvette C5 differential rather than using the original Corvair differential. There are several sources showing up with adapters for both manual Saginaw 4 speed transmissions and Powerglide automatic transmissions. This setup provides several advantages - Strength and Legroom. The strength aspect comes from the fact that the C5 differential was engineered for plenty of horsepower and the legroom aspect comes from the use of constant velocity u-joints (cv joints) that allow the entire drivetrain to be positioned further to the rear of the vehicle than the Crown design. Several V8 Registry members are already running this type of setup. Here is a partial list of members who have incorporated the use of a Corvette C5 or C6 differential -
Mark Allen - Decatur, IL
Paul Beck - Pearl, IL
John & Cory Black - Moon Township, Pa
Robert Depalo - Hot Springs, Arkansas
Lonnie Gilbertson - Milwaukie, Oregon
Mike Levine's V8 Coupe - Cumming, Georgia
Rod Tetrault - El Cajon, Ca
Phillip West - Alma, Michigan
