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Spyder cooling
Posted by: joelsplace ()
Date: December 17, 2017 11:58AM

64 Spyder all temps referred to are on the factory gauge
It would run 70mph at about 375 on a 100 degree day.
I made one change from stock tires to 205/60R13s which bumped the RPM up. Now it won't stay cool even when it's only 70 degrees outside.
At 70mph it keeps creeping up to about 425 and then I back off. At 60mph it runs about 375 like it used to at 70.
Maybe a lean spot at the new cruise RPM?
The tach is at least 700RPM off so I'm not sure what it's actually turning. It claims 4000 at 70mph but it is way lower than that. I believe it has 3.55 gears.
Thoughts?

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Re: Spyder cooling
Posted by: MattNall ()
Date: December 17, 2017 12:02PM

Strange for sure.... got a regulator on it? try adding 1/2 psi..





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Re: Spyder cooling
Posted by: joelsplace ()
Date: December 17, 2017 12:06PM

That's a thought. I forgot that I did mess with the fuel pressure. No regulator but I swapped in a fuel pump spring from a NOS AC pump trying to get it to quit leaking at idle. It seems to run fine with no clatter which doesn't point to fuel. I guess I need a wide band O2 sensor.

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Re: Spyder cooling
Posted by: jjohnsonjo ()
Date: December 17, 2017 12:26PM

What is the REVs per mile of those tires, If they are lower than the stock 13" 4000 at 70 might be correct. 3500 at 70 is normal for stock with 3:55 . The belt is supposed to be loose, but not tooooo loose. Might be slipping at the higher R's.

J.O.

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Re: Spyder cooling
Posted by: 66vairman ()
Date: December 17, 2017 01:20PM

jjohnsonjo Wrote:
-------------------------------------------------------
> What is the REVs per mile of those tires, If they
> are lower than the stock 13" 4000 at 70 might be
> correct. 3500 at 70 is normal for stock with 3:55
> . The belt is supposed to be loose, but not tooooo
> loose. Might be slipping at the higher R's.

A club member ran those tires and at an indicated 70MPH EVERYBODY was passing him. An EM runs the speedometer off the transaxle so in your case an indicated 70MPH is actually about 63MPH and the tachometer should read about 3,300RPM.

Now if you go an actual 70MPH (Phone/GPS) with those tires the engine will be at about 3,900RPM!

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Re: Spyder cooling
Posted by: joelsplace ()
Date: December 17, 2017 01:37PM

I was talking 70mph according to the GPS. If my tach is correct this thing doesn't make a lot of power until about 5000 and I shift at 6500. Not likely.

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Re: Spyder cooling
Posted by: TerribleTed ()
Date: December 17, 2017 03:20PM

Your engine is turning a bit around 9% higher rpms to get to any given speed since the tires you installed are 9% smaller than stock. ( 185/80 13 = 24.7" diameter and your current 205/60 13 are only 22.7" diameter) This higher RPM would likely generate more heat. An accurate tach would be a good idea as you may be getting close to the redline at 70MPH.In any case it does not seem to like it why don't you put some normal diameter tire on it instead of over revving the engine at all speeds. Not to mention filling the wheel openings for a better look (my opinion on this).

---------------------------------------------------------------------------------------------------------

Avid Corvair hobbiest since 1984.
I have personally performed ground up restoration on over 20 Corvairs.
I currently work full time at restoring and repairing Corvairs.
Located in the Atlanta Georgia area.
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Edited 1 time(s). Last edit at 12/17/2017 03:22PM by TerribleTed.

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Re: Spyder cooling
Posted by: TerribleTed ()
Date: December 17, 2017 03:38PM

I would not be shifting any Corvair engine out beyond or even at the 5500RPM redline indicated on the factory tachs unless the engine was purposely performance built to do so. Doing this otherwise is asking for trouble. Max shift point should be more like 5000 to be safe. These engines generally make max HP around 4500RPM and max torque in the 3,000s somewhere. Operation above these RPM's makes no more power and simply increases wear and heat build-up.

---------------------------------------------------------------------------------------------------------

Avid Corvair hobbiest since 1984.
I have personally performed ground up restoration on over 20 Corvairs.
I currently work full time at restoring and repairing Corvairs.
Located in the Atlanta Georgia area.
[www.facebook.com]

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Re: Spyder cooling
Posted by: curt ()
Date: December 17, 2017 03:56PM

At the listed 375 and 425 temperatures, What would the oil temp be at the filter? the same?

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Re: Spyder cooling
Posted by: TerribleTed ()
Date: December 17, 2017 04:36PM

curt Wrote:
-------------------------------------------------------
> At the listed 375 and 425 temperatures, What would
> the oil temp be at the filter? the same?


These temps are NOT oil temps but cylinder head temps. Oil temps would be a lot lower.

---------------------------------------------------------------------------------------------------------

Avid Corvair hobbiest since 1984.
I have personally performed ground up restoration on over 20 Corvairs.
I currently work full time at restoring and repairing Corvairs.
Located in the Atlanta Georgia area.
[www.facebook.com]

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Re: Spyder cooling
Posted by: 63turbo ()
Date: December 17, 2017 05:54PM

joelsplace Wrote:
-------------------------------------------------------
> 64 Spyder all temps referred to are on the factory
> gauge
> It would run 70mph at about 375 on a 100 degree
> day.
> I made one change from stock tires to 205/60R13s
> which bumped the RPM up. Now it won't stay cool
> even when it's only 70 degrees outside.
> At 70mph it keeps creeping up to about 425 and
> then I back off. At 60mph it runs about 375 like
> it used to at 70.
> Maybe a lean spot at the new cruise RPM?
> The tach is at least 700RPM off so I'm not sure
> what it's actually turning. It claims 4000 at
> 70mph but it is way lower than that. I believe it
> has 3.55 gears.
> Thoughts?

I hate to say it, but those are the kind of temps that I was
getting before I got rid of the distributor and went programmable, and
was able to put a bunch of vaccum advance in. You want to get your timing
to be up around 40-44 degrees at those rpms and load. My car then was geared exactly like yours is now. The other thing is of course to check your afrs
when it is doing that. 13.5:1 isn't rich enough! My car would get to over
400 degree's at 100mph when it was 80+ and the afr's were 13.5.
That was the last time my Weber was being used as a carb, and it was a tuning
experiment gone wrong! I took it off and put the yh back on so I could convert
it to a throttle body for efi.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Spyder cooling
Posted by: joelsplace ()
Date: December 17, 2017 06:58PM

TerribleTed,
I'm not spinning it that fast that is just what the tach shows. I know where the power is on a stock turbo - that's why I know the tach is off. A stock turbo won't pull up past 6k right? I do have the Clark's advance/retard unit so it isn't totally stock.
I really do need

I have a set of 17" wheels that I'm trying to decide what tires to use with. I will get as close to the stock diameter as I can. Maybe 225/45s.

The 205/60s really handle a lot better than the stock size. The original size is awfully sloppy.

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Re: Spyder cooling
Posted by: TerribleTed ()
Date: December 17, 2017 08:26PM

The turbo engine will certainly rev beyond 6k RPM but yes you are well above the powerband at 6k. I would be rigging a tach that reads correctly (at least temporarily) to see what RPMs it is actually at. I had a 3.55 powerglide car that was just about at the 5500 redline at 75 MPH with stock diameter tires on it (I had a proper accurate tach in the car). Keep in mind that the 4th gear ratio of your standard trans is the same as high gear in the PG at 1:1 so engine rpms would be the same. (70 GPS with your little tires would be at the same engine RPM as 76MPH with stock diameter tires). (I switched the PG car to a 3.27 rear gear and liked it a lot better on the highway at a very small loss of get up and go down low...not sure how well the 3.27 would work with the turbo however)

The better handling is likely because of the width and shorter sidewall. You do not need original size tires but staying at or very close to the original overall diameter is a good plan as it does not mess with your overall effective gear ratio, rpm, speedo error, etc. The real issue is 13" tire sizes are very limited at a 24 or so inch diameter. 14 or 15" wheels would make this much easier wheels would make this much easier as there are at least a couple or more sizes that would work well. Here are a couple link to what I find to be a handy place to go look at such comparisons and tire availability. These links are different even though they display the same here. One is the calculator that you plug number in to see differences between sizes the second is a list of available tire by size including overall diameter. Very handy.
[tiresize.com]
[tiresize.com]

---------------------------------------------------------------------------------------------------------

Avid Corvair hobbiest since 1984.
I have personally performed ground up restoration on over 20 Corvairs.
I currently work full time at restoring and repairing Corvairs.
Located in the Atlanta Georgia area.
[www.facebook.com]



Edited 1 time(s). Last edit at 12/17/2017 08:30PM by TerribleTed.

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