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Timing help
Posted by: Mojan_n ()
Date: March 12, 2019 05:40PM

I’m reading the manual to set my timing, it says 10deg BTDC ( my dist is 1110319 I need 14deg).
What should be rpm when I’m checking the timing? At idle ?
Also manual says idle is 500rpm IN DRIVE.

Dose it mean I should set the timing In drive at 500rpm and 14deg BTDC.



Edited 1 time(s). Last edit at 03/12/2019 05:47PM by Mojan_n.

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Re: Timing help
Posted by: playerpage ()
Date: March 12, 2019 05:50PM

Can't help you, but that Tune-up chart sure helps me! Thanks.

Eric C. Player
Porterville, CA
- National Member, CORSA
- Member: Central Coast CORSA & South Coast CORSA
Former Member: Vintage CORSA Orange County. Member, ISA (Int. Screenwriter's Assn.), SAG Eligible, and Producer's Guild Aspirant


* Then: 1966 Corsa 180 Turbo, Red/1965 Monza 110 Purple/
1967 Monza 140 Red/1966 500 110 Black/1965 Monza 110 Yellow
* Now: 1966 Corsa 180 Turbo Project. Blue, Blue/Beige interior.



"Chevrolet's Corvair was a maverick machine, a rear-engined renegade born out of spite and genius." -- Sports Car Graphic, August 1969

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Re: Timing help
Posted by: vairmech ()
Date: March 12, 2019 06:16PM

It's really hard to get 500 rpm in D, I always use 550 rpm. But yes you need the lower rpm because anything much faster than 650 rpm and the mechanical advance will start to come in. Be sure and unplug the line to the vacuum advance unit.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

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Re: Timing help
Posted by: MattNall ()
Date: March 12, 2019 06:16PM

Mojan, NO You set the timing in neutral... then put in drive and set idle speed / adjust idle mixtures for smooth idle..

Let the engine warm up until chokes are fully open[ flat metal arm is almost touching body of carb.

Snap throttle open and let off.... idle should settle down to 600 rpm

Pull VA's hose and plug with screw.... did idle slow down more? If it DOES... let us know before dealing with any problems.

A --- If NOT at 600 rpm or less, shut engine off... adjust idle SPEED screw on BOTH carbs 1/2 turn CCW

Restart.....and if still not slow enough repeat "A"

Adjust timing to 14 deg. BEFORE [ to RIGHT of ZERO! ]. If engine stalls...let us know!





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




Edited 1 time(s). Last edit at 03/12/2019 06:20PM by MattNall.

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Re: Timing help
Posted by: Mojan_n ()
Date: March 12, 2019 07:35PM

Question is when you set your timing 14BTDC what is the rpm?

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Re: Timing help
Posted by: MattNall ()
Date: March 12, 2019 08:17PM

600 or lower in Neutral





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

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Re: Timing help
Posted by: Frank DuVal ()
Date: March 12, 2019 08:41PM

OK, where on that chart does it ever say 14° BTDC?

Also, the red circles are for the 95 horsepower engine. 1964 Shop Manual tune up page.

As long as the timing is set at an RPM below mechanical advance starts, you are OK. Note, vacuum hose disconnected and plugged as note 2 says.

Dwell first, then timing, then idle speed/mixture.

Frank DuVal

Fredericksburg, VA

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Re: Timing help
Posted by: MattNall ()
Date: March 12, 2019 09:00PM

Franks!! 1st post... he has a 319 distributor....





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

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Re: Timing help
Posted by: Frank DuVal ()
Date: March 12, 2019 09:00PM

Quote
mojan
my dist is 1110319

Then why are you looking in the 95 horsepower column of the chart with a 110 HP distributor?

Are you running premium gasoline? Is is a 110 HP engine?

If you have good ears, set it for 12° BTDC, then drive it and see if it pings, especially at the low to drive transition. No ping? Up it to 14, etc.

If 95 HP heads are on it, run regular gasoline and perform the same test.

No Ping! is the goal. Just be on the hairy edge, like modern cars with knock sensors.

Frank DuVal

Fredericksburg, VA

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Re: Timing help
Posted by: Mojan_n ()
Date: March 12, 2019 09:37PM

Yes, it is a 110hp, sorry I circled wrong column.
When I bought it about two weeks ago the PO said the car has new hardened valve seat and he used regular gas on it.
Should I pump premium gas?

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Re: Timing help
Posted by: MattNall ()
Date: March 12, 2019 09:48PM

I would! At least 89 in cool weather... New seats.... $$$$





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

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Re: Timing help
Posted by: vairmech ()
Date: March 13, 2019 04:57AM

Mojan_n Wrote:
-------------------------------------------------------
> Yes, it is a 110hp, sorry I circled wrong column.
> When I bought it about two weeks ago the PO said
> the car has new hardened valve seat and he used
> regular gas on it.
> Should I pump premium gas?
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

The PO used a "Buzz" word of Hardened valve seats! All Corvairs have hardened valve seats. Unless there is documentation don't believe that.

A 110 needs premium!

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

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Re: Timing help
Posted by: Frank DuVal ()
Date: March 13, 2019 08:35AM

Quote
Ken
A 110 needs premium!

Absolutely unless there has been some inside modification to the engine. As built by GM, it was a premium fuel engine of the mid 1960s octane rating system. Around here at sea level that means 92 plus (R+M/2 system).

110 PG very pingy, just do a full throttle launch and hold it to the floor through upshift. Ping is most noticable (and does the most damage) when the air flow into the heads is high (top end of low gear with WOT) and then suddenly the rpm drops during up shift.

If you back off the timing enough to run 87 octane, you get no horsepower and engine heating from timing being too retarded!

Frank DuVal

Fredericksburg, VA

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Re: Timing help
Posted by: Mojan_n ()
Date: March 13, 2019 10:31AM

Ok so before I attempt to tune the carbs and timing I should change to premium gas first.

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Re: Timing help
Posted by: MattNall ()
Date: March 13, 2019 10:41AM

NO!!! Octane has nothing to do with mechanical adjustments!





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

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Re: Timing help
Posted by: Mojan_n ()
Date: March 13, 2019 11:08AM

By the way I have pertronix ignition, dwell is not adjustable right?

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Re: Timing help
Posted by: MattNall ()
Date: March 13, 2019 11:14AM

Correct...





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

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Re: Timing help
Posted by: Frank DuVal ()
Date: March 13, 2019 03:46PM

Octane has something to do with mechanical adjustments, as correct timing for 110 HP will ping with regular gasoline in an unmodified Corvair engine. So timing will be set retarded to eliminate ping until fresh premium is added, or risk putting a hole in a piston if driven aggressively while listening to ping.

Right, no dwell adjustment with Pertronix.

Set it for 8 and listen for ping for now.

Frank DuVal

Fredericksburg, VA

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Re: Timing help
Posted by: Mojan_n ()
Date: March 13, 2019 08:32PM

Okay, found my answer.
Below is the table for setting the timing based on dist.
On top of the chart it says rpm should be 500 and in Drive.

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Re: Timing help
Posted by: MattNall ()
Date: March 13, 2019 09:09PM

Have Fun!

note: that list was not written by GM...



We are waiting for you to ask a question about the Next thing..... we know what it is!! 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

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