63 Spyder question...

[scooper]

I picked up a 63 Spyder, needs some work, both body,(floors), and an engine rebuild. I'm primarily planning to autocross the car, with some limited street cruising. My question is, do any of you guys run your engines with out the bottom tins? I won't be driving in cool weather, so cold running won't be a problem. I'd like to not run the ugly boxes with the flapper doors if I don't have to.

[AZScott]

I have both a 63, (with a 4 carb 140 hp motor), and a 64 Spyder, that I run in Arizona. My 63 still has all shrouds attached. However when I last built the Spyder, I left the bottom boxes off. When I installed the metal pieces, I omitted the shrouds that have the thermostats that control the louvers and kept the outer structure for the rear doors intact, but left the flapper doors off. That way I could keep heat from coming up the rear of the engine. I did keep the tin baffles attached to the bottom of the barrels to help direct air to the head. (They are needed.) I read that by running this setup the engine should run 7 degrees cooler, I forget where I read that so take that with a grain of salt.

Like I said I am running this in Arizona, and don’t need to be worried about cold starts below 70 degrees. If the weather does get colder, I am typically not running the Spyder. My fear was mostly running in 100 plus weather and getting caught at three lights in a row. I have installed a very accurate digital temp gauge and I am watching it very closely, I have noted that at a traffic light the head temp actually goes down. So traffic lights are not a problem. My Spyder was a recent build and I don’t have a lot of run time on it, but so far everything is working well.
Hope this helps.

[scooper]

Yes, that helps, thank you for the reply. I fiquired the lower tins weren't really necessary for cooling, just cool weather running. I'm coming right off the turbo and routing the exhaust out the rear of the car next to the pass side reverse light, putting a Super Trapp on the pipe. I'll wrap the pipe with exhaust wrap to keep the heat under the deck lid down.

[bbodie52]

Tue Aug 14, 2018 2:21 pm

I picked up a 63 Spyder, needs some work, both body,(floors), and an engine rebuild. I'm primarily planning to autocross the car...

I know next to nothing about prepping a Corvair for autocross, but you may find some good guidelines using the following link. The 1963 and earlier Corvairs have less torque than the later models, because the engine displacement was only 145 CI and jumped to 164 CI in 1964 with a longer stroke crankshaft. The slow steering ratio is always less than desired for autocross, but there are several approaches to fix this issue. The Spyder has a front anti-sway bar in the suspension design, but lacks the rear transverse leaf spring that was added in 1964 to improve handling. The major improvement in Corvair suspension and brake design occurred in 1965, with a rear suspension that abandoned the swing axle suspension for a design that copied its new rear suspension design from the Corvette. The drum brakes were also improved with a larger drum brake system borrowed from the GM intermediate platform (Chevelle, Tempest, etc.) Adaptation of front disc brakes for use in a Corvair is a possibility. Larger wheels and tires can be fitted, but the 1965 and later Corvair offers more possibilities with more wheel well clearance and five lug wheels instead of the four lug hubs used in 1964 and earlier. The Carter YH sidedraft carburetor on your turbo may be a problem in autocross due to fuel control and flooding problems. There will be many issues to consider beyond restoration and rebuild to prep your Corvair Spyder for autocross, and the following article (and associated articles) is probably a good place to start...

Welcome to the Corvair Autocross Page
by Bryan Blackwell
http://autoxer.skiblack.com/

==========================================

This book contains a great deal of performance information about the Corvair. As a teenager I read the earlier version of this book in 1970 and found it to be very valuable and informative. It is a personal favorite, and here is a recent update...
https://www.amazon.com/Performance-Corv ... +to+hotrod

Many Corvair enthusiasts will remember the original version of this book. I have had a copy since about 1970...


How to Hotrod Corvair Engines by Bill Fisher (1971)

Good luck!!

[66vairguy]

The lower "tin" discussion is an old one. Taking off the lower shroud that holds the thermostat has been reported to lower head temperatures under high load demands. So if you are just racing that may work fine, BUT for regular driving the engine won't warm up completely. Engine tolerances were designed to be optimal at specific temperature range. It's why one should not run an engine at maximum power until it is at design operating temperature.

The other problem with no thermostat shrouds is that if you drive over dirt you get a huge cloud of dirt blowing up around the back of the car. Also the heater won't work very well.

Keep in mind that it's documented that the Corvair cooling system can't keep up with the heat generated by a turbo engine (HP = HEAT) for more than about a minute. But as Corvair engineer Benzinger said when questioned at a convention (long ago) "The turbo Corvair will easily reach top speed in under a minute and sustaining maximum speed would be illegal". Basically the turbo is capable of short bursts of maximum power without overwhelming the cooling system so it was not considered an issue by GM. Now racing is a different matter. Some have used water or water/alcohol injection above the fan.