Corvair DiagramCorvair Photo
Corvair Center
home forum corvairs calendar links Corvair Podcast
California Corvairs
Clarks Corvair
Clarks Corvair
“CORSA"



Chevy Corvair License Plate
Chevy Corvair Chrome Wheel
Corvair Center Forum :  Corvair Center Phorum The fastest message board... ever.
Corvair Center 
Pages: 12Next
Current Page: 1 of 2
...Only 9 miles a gallon? Help?
Posted by: Johnnya101 ()
Date: May 11, 2019 10:31AM

Finally filled up my 61 to calculate my mpg. I am getting 8.9 mpg. 91 gas.

Seems a little low to me.

Carbs are opened to around 2.25 turns and are balanced by a Corvair pro.

Broken t stats (new ones on the way). Has only been driven around 1000 miles since the 80s. 50000 original miles documented.

No visible gas leaks. New fuel Clark's mechanical fuel pump

I did forget since it is a 61 it's a manual choke. Would a manual choke really make that much of a difference?

Ideas?



Edited 1 time(s). Last edit at 05/11/2019 10:33AM by Johnnya101.

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: MattNall ()
Date: May 11, 2019 10:34AM

Just make sure they move to the fully opened position...
What kind of driving and how many miles between fillups?

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: Johnnya101 ()
Date: May 11, 2019 10:36AM

Stop and go town driving. I usually fill-up at half empty, so around 5-6 gallons. This half fill-up was 50 miles. Took 5.6 gallons...

Powerglide as well. Fresh tune up from experienced Corvair guy.

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: MattNall ()
Date: May 11, 2019 10:42AM

Too few miles....

And to be exact...

1 Fill up until you see gas in the filler neck

2 Record Odometer reading

3 drive at least 100 miles shutting engine off as few times as possible.. and no prolonged idling.

4 Refill tank to here you see gasoline. Record mileage # of gallons to the TENTH.

Determine miles driven... divide by gallons at 2nd fillup..

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: 2ragtops ()
Date: May 11, 2019 10:42AM

I would check for fuel leaks, float settings wrong [dumping gas]

fuel in the oil [check fuel pump] and maybe the jets in the carbs.

Others may help further.

Bob Bauer

Show-Me Corvairs

1966 Monza Convert 140 P/G with A/C, plastic wheel with tele-column am-fm posi-traction
1966 Corsa Convert 180 wood wheel tele-column am-fm sport steering posi-traction
1965 Corsa Coupe Crown V8 temporarily red lined for repair
House Springs, Missouri

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: Johnnya101 ()
Date: May 11, 2019 10:43AM

Yeah I figured it's just too short of trips. I've been reading 10 is normal for short trips around town, highway is when it gets better. I'll report back next fill-up I suppose and see if it changes.

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: MattNall ()
Date: May 11, 2019 11:04AM

Low 20's on a road trip... to Corvair meets!! gg

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: Johnnya101 ()
Date: May 11, 2019 11:10AM

2ragtops Wrote:
-------------------------------------------------------
> I would check for fuel leaks, float settings wrong [dumping gas]
>
> fuel in the oil [check fuel pump] and maybe the jets in the carbs.
>
> Others may help further.


No fuel leaks. Pump is new and I didn't smell gas in the oil. Carbs seem fine otherwise, fresh rebuilds from Clark's and my local Corvair guy (he worked on the assembly line for em) said they look and function great.

Usually I let it warm up idling with the choke half closed for 5-10 minutes and it's a 5 minute drive to where I bring it. So short trips. Probably just that then?

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: Timothy Shortle ()
Date: May 11, 2019 11:35AM

New fuel pump: what is the fuel pressure being pumped to your carbs? I have heard some new pumps have too high of pressure.

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: Johnnya101 ()
Date: May 11, 2019 12:10PM

No idea but no signs of leaking or overflowing, and no gas smell.

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: MattNall ()
Date: May 11, 2019 12:20PM

Still can be too high... we want 3-4 psi max!

Here's a simple tool to make... break the 1/4" fuel line for pass. side at TEE..

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

Attachments:
Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: Johnnya101 ()
Date: May 11, 2019 12:40PM

I'll see what I can do

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: TerribleTed ()
Date: May 11, 2019 01:20PM

Johnnya101 Wrote:
-------------------------------------------------------
> 2ragtops Wrote:
> -------------------------------------------------------
> > I would check for fuel leaks, float settings wrong [dumping gas]
> >
> > fuel in the oil [check fuel pump] and maybe the jets in the carbs.
> >
> > Others may help further.
>
>
> No fuel leaks. Pump is new and I didn't smell gas in the oil. Carbs seem fine otherwise, fresh rebuilds from Clark's and my local Corvair guy (he worked on the assembly line for em) said they look and function great.
>
> Usually I let it warm up idling with the choke half closed for 5-10 minutes and it's a 5 minute drive to where I bring it. So short trips. Probably just that then?

OK so you idle it for 5 mins, drive it 5 mins, later idle it 5 mins, and then drive it mins back. You are getting way over 10MPG. 1/2 the operation times is idling with the chokes partly closed. Mileage is likely near double that. There is no need to idle these cars for anywhere near 5 mins except perhaps in the dead of winter when temps are near or below freezing. A minute or so is generally plenty if the car is tuned and functioning properly.

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

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]

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: Johnnya101 ()
Date: May 11, 2019 01:28PM

Ah, that's what I forgot to account for! So at 100 miles, that would put it at 18 mpg, MUCH more reasonable. Makes much more sense.

I only let it idle so long because the t stat doors are stuck open until I get new thermostats (should be here Monday). Just don't want to stress driving it when cold.

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: irfgt ()
Date: May 11, 2019 04:40PM

Idling at half choke for 5-10 minutes is half your problem. Sitting still is 0 mpg. % mile trip, you could have already been there.Lower doors won't make that much difference especially in warm weather. Start it and drive it.

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: Spyderman64 ()
Date: May 11, 2019 05:48PM

Wow! Now I don't feel so bad about the 11 m.p.g. my AMX gets!

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: Murphy ()
Date: May 11, 2019 05:52PM

I think your neighbor is stealing your gasoline!

65 Monza Coupe
61 500 Coupe-W100181
Earliest '61?

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: Spectre ()
Date: May 11, 2019 06:10PM

No need to 5-10 minute idling warm-ups.

David Clamp


1965 Corsa convertible - 140 4spd/3.55/AM-FM

2013 Mustang GT convertible - 5.0, 6spd auto, Procharger i-1

2003 Miata SE - 6spd manual (wife's toy)

"Victory is mine!" - SG

Norman, OK

<a href="[www.wunderground.com] src="[weathersticker.wunderground.com]; alt="Click for Norman, Oklahoma Forecast" height="90" width="160"></a>

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: jjohnsonjo ()
Date: May 11, 2019 06:15PM

when the clutch was going out in my turbo I really had to baby it. Averaged 24 mpg that summer, best ever, except for some highway trips with limited speed limits.

J.O.

65 Corsa Turbo Vert
79 Honda XL 500S
69 Honda CL 160 D
2010 BMW F 650 GS
2003 Bounder 36D
2013 KIA Optima SX turbo-AKA ZIPPY (wife,s car)
69 Newport Holiday Sailboat
Baja 150 dune buggy cart
Coleman HS 500 UTV
2016 KIA Sorento SXL Turbo

Bethlehem,Pa

[corvaircenter.com]

Options: ReplyQuote
Re: ...Only 9 miles a gallon? Help?
Posted by: joelsplace ()
Date: May 11, 2019 06:42PM

Choke on will really kill mileage.
The best I've ever done is 21.
Usually I get 18-20 with 80, 102, 110 engines. Doesn't seem to matter much if I run them wide open or baby them.
15-16 in my Spyder.

Joel
Northlake, TX
4 Ultravans, Lost count at 100 Corvairs...

Options: ReplyQuote
Pages: 12Next
Current Page: 1 of 2


Sorry, only registered users may post in this forum.
This forum powered by Phorum.