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Re: Detonation/Pre-Ignition
Posted by: DaSpyder ()
Date: May 17, 2009 07:42PM

MattNall Wrote:
-------------------------------------------------------
> No,, yours are 1961 -3 [ pending proofreaders
> approval! ggg]
>
> You are supposed to Bend them!
>
> Do yourself a favor... Cut rectangles and make
> your plates...
>
> Summer = ON Winter = OFF

Thanks for the info Matt,

I have the plates from the Spyder tin so I'll just cut off the bent tin on the Monza and drill some screw holes and use the plates from the Spyder. - Dan

If you believe in forever, then life is just a one-night stand; Righteous Brothers

64 Monza 110 4 speed (driver), 64 Spyder 4 speed (basket case)

Sparta, TN

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Re: Detonation/Pre-Ignition
Posted by: BillPappy ()
Date: May 18, 2009 04:50AM

Mark

Did you get your Detonation/Pre-Ignition stopped?
I didnt read where you did OR I just missed the post.
Did you have the heads reworked? Step renoved?
What size head gasket did you use? Meaning How thick..

IF you didnt get your Detonation/Pre-Ignition under control
Leads me to think only one thing. Im really surprized
someone didnt ask you about your heads already..



Edited 1 time(s). Last edit at 05/18/2009 04:51AM by BillPappy.

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Re: Detonation/Pre-Ignition
Posted by: munasm ()
Date: May 18, 2009 03:33PM

I haven't gotten the chance to do any real work on them and probably won't until Saturday. Its raining like heck here and has cooled down tremendously so it might not be a good test. I did frabricate a new summer/winter plate and put it in place. Cleaned the PCV pipe, sealed all the seams in the shrouding, pulled and plugged the VA ports on the distributor and carb. I also moved the coil. Rain came and I didn't get to re-set the timing or check the mechanical advance spring. I also want to recheck the carb synch and mixture. FYI - I used standard head gaskets with the rebuild from Clarks. I'm going to try to retard the timing slightly. My notes show I set it to 14 degrees BTDC.

Thanks to everyone for the help. I really can't tell you how much I appreciate it. I am getting pretty frustrated and it seems nothing I knew as a shade tree mechanic was working for Corvair. Its definitely an engineering marvel - much more complex than I thought. I have worked on VW's and they are pretty simple by comparison, but don't seem as efficient. I really like my vair and don't want this to sour me.

Mark

Kissimmee Florida
1966 Monza Convertible - 110

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Re: Detonation/Pre-Ignition
Posted by: BillPappy ()
Date: May 18, 2009 07:41PM

standard head gaskets with the rebuild from Clarks

I didnt know they had a standard head gasket

Im thinking you used .032 head gasket. That would be stock size I beleave.

Did ypu have the step truned down in the head? IF not you have .142 Squish, Quench, That was find in the late 60s But todays gas that dont work to good.

Give this a read.. [www.chevyhiperformance.com]

Alot of the old timer corvair engine builders here knows this. A tight Quench is cruishal on a vair engine to stop Detonation .040 Works good. anything closer then .032 will give you get piston to head slap. Above 4000 RPMs I Been useing 0.037.

IF you have adress this,then I am sorry for taking up your time and mine.



Edited 1 time(s). Last edit at 05/18/2009 07:43PM by BillPappy.

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Re: Detonation/Pre-Ignition
Posted by: munasm ()
Date: May 19, 2009 06:18PM

BillPappy

sorry about the standard reference...i meant stock. I haven't done anything to the heads. I didn't have a problem before, and didn't realize I needed to machine the heads since the seats were good and so was the head seating surface.






i

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Re: Detonation/Pre-Ignition
Posted by: 66vairman ()
Date: May 19, 2009 11:05PM

Mark - I've had a number of rebuilt engines in several old cars and on more than one occasion they ran hot and pinged for the first 5,000 miles. Just a little too tight after rebuilding. Once they were "broken in" the overheating and detonation problems went away. If you retard timing more than 2 degrees and still have detonation then you may have a timing problem. Either cam is off (happens) or the distributor has a problem (not unusual) with vacuum advance or weights and springs, and as previously mentioned the harmonic damper does sometimes slip with age giving a bogus timing indication.

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Re: Detonation/Pre-Ignition
Posted by: flat6_musik ()
Date: May 21, 2009 10:28AM

If this were my vair, I would probably look closely at how fast the advance is coming on, and also the synch-ing of the carbs. If you've got one bank of the engine's carb 20% open and the other bank's carb @ 30%.....it stands to reason that the bank @ 30% is trying to do a lot more work and those combustion chambers will be hotter. Also, did you rebuild both carbs?.....hope those float levels are perfect height and you're not leaning out. Good luck!....don't get frustrated.....you'll win eventually!

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Re: Detonation/Pre-Ignition
Posted by: mattlockwood ()
Date: January 19, 2021 12:45PM

Yikes- I just read that I should not be using vacuum advance with my powerglide. So I should disconnect the vacuum hose and plug it at the carburetor?

------------------------------------------
1970 VW Bus- converted to a 110hp w/a PG. Now with electronic ignition!
Kansas City, Mo

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Re: Detonation/Pre-Ignition
Posted by: RobertC ()
Date: January 19, 2021 01:55PM

mattlockwood Wrote:
-------------------------------------------------------
> Yikes- I just read that I should not be using vacuum advance with my powerglide. So I should disconnect the vacuum hose and plug it at the carburetor?

I have not reread the thread, but I think you misread.

I think that is / was done to test the problem.

If your engine does not ping, you are fine.

The current vacuum advance canisters are not exactly the same as stock.

110 / PGs seem to be more sensitive to pinging. You may need to adjust the timing so that it does not ping. Also could be dependent on where you live (altitude) and which brand of gas you use.

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Re: Detonation/Pre-Ignition
Posted by: MattNall ()
Date: January 19, 2021 02:01PM

In our FAQ's are instructions on how to "adjust" the stock cannisters.

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: Detonation/Pre-Ignition
Posted by: joelsplace ()
Date: January 19, 2021 02:51PM

I can't think of any time you shouldn't run a vacuum advance unless you are running computer control of the advance and even then the program would need to adjust timing based on vacuum.
If you only run wide open then there is no need for vacuum advance.

Joel
Northlake, TX
5 Ultravans, 116 Corvairs and counting...

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Re: Detonation/Pre-Ignition
Posted by: vairmech ()
Date: January 19, 2021 03:10PM

The vacuum advance in it's self does not cause spark knock. What the vacuum advance does is increase your cruising fuel mileage.

If you are having issues start your own thread with some details and maybe we can help.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

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Re: Detonation/Pre-Ignition
Posted by: MonzaJPD61 ()
Date: January 19, 2021 03:53PM

What kind of compression do you have? Wondering if on the high side?

Advance plate could be hanging up?

Apologies if you already checked and I overlooked it.

B'ham, AL
1961 Monza coupe 98hp, 4spd
1963 Monza coupe 102hp, pg
Vulcan Corvair Enthusiasts
[corvaircenter.com]

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Re: Detonation/Pre-Ignition
Posted by: JimBrandberg ()
Date: January 20, 2021 04:58AM

Maybe I missed it but do you have the proper 1110319 distributor? The number is stamped on the outside of the distributor body clockwise from the vacuum advance unit. Only the last 3 numbers (319) mean anything.
Corvair distributors are not all the same. If you take one designed for 6 degrees initial timing and install it at 14 it will be too much.

Jim Brandberg
Isanti, MN
CorvairRepair.com



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Re: Detonation/Pre-Ignition
Posted by: Timothy Shortle ()
Date: January 20, 2021 08:04AM

I agree with Ken. Start a new thread since this one is almost 12 years old.
Think of vacuum advance as the "informer" for the ignition system as to how much load the engine is under. Strictly for fuel economy.

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Re: Detonation/Pre-Ignition
Posted by: joelsplace ()
Date: January 20, 2021 08:10AM

It can also make the engine run cooler.

Joel
Northlake, TX
5 Ultravans, 116 Corvairs and counting...

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Re: Detonation/Pre-Ignition
Posted by: JimBrandberg ()
Date: January 22, 2021 04:04AM

Above I was responding to information in the 2009 thread so never mind.

Jim Brandberg
Isanti, MN
CorvairRepair.com



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