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Re: Custom 140 EFI setup
Posted by: 63turbo ()
Date: November 06, 2020 12:38PM

My base timing advance is a little weird, and hard to describe.

heres the points that I remember. Base timing is at 2" hg. I begin retarding the timing at 1" hg . total is maximum timing from vacuum advance.

at 1000 rpm, base timing = 18, total timing = 28, vaccuum at idle= 17-18"
at 3000 rpm, base timing = 31, total timing = 41.
at 4000 rpm, base timing = 34, total timing = 44

The vacuum advance is adding 10 degrees between 21 and 8 inches hg.

Within the peak vacuum advance timing is where closed loop is engaged, and the afr's will be approximately 14.5:1 between 22 and 12", and then depending on rpms, the afrs will go between 12.5 and 11.5 between 12" and 8" and then back into the 12.8 range as it gets closer to boost.


I think you are running into issues with copying the stock timing, because the timing with the stock set-up was done with carbs that are more or less going for "rich best power" + a safety margin, and were done with leaded gasoline, which doesnt "act" quite the same as non leaded gasoline at the same approximate octane. The octane ratings now cant be compared directly to the one used in the 60's because the standard has changed. 92 now is "approximately" the same as 98 or 100 then but now we use r+m/2 for octane, and I think the old standard was using just R or "research" method.

I think you will find that if your max light load timing is between 44 and 46, you wont have any trouble going a bit leaner and the engine will run cooler that way.

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

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: Custom 140 EFI setup
Posted by: Melb-Mike ()
Date: November 08, 2020 02:41PM

63turbo Wrote:
-------------------------------------------------------
> KenHenry Wrote:
> -------------------------------------------------------
> > Thanks everyone. Wow Mike, that must have been a real thrill running your Lotus on the track! I drove the Corvair a few times on the carbs with the WB02 installed, and was surprised that it was so consistently down around 13 AFR. I would like to test my WB02 gauge against a known good one. Mine is the Spartan 2. I should also peek in my primaries to see what size jets were in there...
> >
> > It appears I have to rethink my revised PCV system with a true PCV valve and the fresh air tube running from the oil filler to the air cleaner. I'm getting excessive oil in the air cleaner assembly. An ideas of how I could baffle it to keep oil spray from blowing up into the air cleaner? The engine is likely worn but doesn't smoke and I never had this issue on the carbs. Perhaps just a metal screen? Alternatively I can revert back to the stock fixed orifice system... Ken
>
> One of the benefits of carbs is the ease of getting a steady air fuel ratio... this has everything to do with the continuous flow of fuel and air. The downside is that ideally, you want the fuel air ratio to vary as the load on the engine changes. Really hard loads should produce a richer mixture than for a lighter load. This is both for safety reasons and getting the getting the most out of the engine... lean best power is around 13.5:1 rich best power is around 12.5:1, lean best torque is around 11.5:1 rich best torque is something like 10.5:1, but it is senseless to go that rich! the distinction is that the timing can be stronger and produce better torque, but if this same rich best torque timing is used with the best power afr's the engine will detonate. Being able to manipulate the timing for the afr's and current load is one of the many benefits of EFI.
> I bet you had the same oiling issue before with the carbs, but you just didnt know it, the carbs were likely washing the oil away with gasoline. A air/oil separator can do wonders for things like that!!

On my Lotus, and also my 2007 Z06 Corvette, getting oil accumulation in the intake was a problem. On my Lotus with the Zetec 2.0 L, I made an aluminum “catch” can that was connected to the crankcase vent. It would accumulate 3 to 4 oz of oil per race day. With the Corvette, I had to keep pulling the intake hose between the air filter and throttle body to clean it every hour of operation to keep the oil from messing up the MAF sensor. On the Corvair, make a catch can with one hose from the crankcase vent and the other near the air cleaner intake. As the engine pulses, oil fumes can accumulate in the catch can. Use a bronze sintered plug on top of the catch can for proper venting. My issue with the Zetec on the Lotus was the redline was 8500 rpm.

Mike

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Re: Custom 140 EFI setup
Posted by: KenHenry ()
Date: November 11, 2020 11:31AM

So putting a mesh screen in the oil filler tube accomplished nothing. I removed the alternator adapter and bent up an aluminum splash shield to go under the filler opening. This seems to have done the trick as I am no longer getting puddled oil in the air filter.

There is quite a bit of blow by produced at idle though - enough that the idle is somewhat unstable and improves when I remove the top of the air cleaner. Compression (measured cold with the throttle open) ranges from 90 on the weakest cylinder to 150 on best, so I likely have some substantial engine wear to address. I couple of years ago I found some sections of broken piston rings when I dropped the oil pan to replace a leaking pan gasket. I thought maybe someone left them in after a repair but that is looking less likely given these compression readings. On the other hand it doesn't consume much oil or smoke out the tailpipe...

Ken

Ken Henry, Rochester, NY USA
1965 Corvair Corsa
140 hp, 4 speed

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Re: Custom 140 EFI setup
Posted by: KenHenry ()
Date: November 19, 2020 07:47AM

I decided to pull the engine and take a look at the internals. So far I have the passenger side torn down. I used plenty of penetrating oil and fortunately I was able to remove the head without the studs turning.

The reason for the low compression and blow by is no longer a mystery. All three compression rings on the passenger side piston were broken, one of them shattered. What would cause this?

The inside of the head looks OK to me. Just some oily residue due to the broken rings I would think... Ken

E2625B0C-6EC7-43DF-864D-3A7161BFC95E by kenhenry_06268, on Flickr

4DE18573-E27A-440A-9524-595BF28231B9 by kenhenry_06268, on Flickr

8BEF92C0-B09E-4395-A1D8-B4D951EE3867 by kenhenry_06268, on Flickr

Ken Henry, Rochester, NY USA
1965 Corvair Corsa
140 hp, 4 speed

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Re: Custom 140 EFI setup
Posted by: 63turbo ()
Date: November 19, 2020 08:16AM

My favorite "theory" is the 55-57 degrees of timing that the stock VA+distributor timing allows. The reason this normally doesnt blow engines up or break rings is only because the timing is SUPPOSED to fall off with load and not go there... it can be dangerous though if the car had been re-geared... then theres too much rpm and vacuum advance, the load from wind resistance that would normally drop the timing is not there anymore and causes the burn to complete well before the piston is past tdc (like it is supposed to!!). A guy I know that has a 3.89:1 differential in a 140 with a powerglide busted a bunch of piston rings recently and the same timing issues that this low gearing causes is what is suspected. The other thing that can cause this same thing is oil going down the intake leading to pinging, and the pinging would then lead to detonation and that broke the rings.
Next theory is sometime in the past is "someone" tried regular gas or simply old gas... octane tends to go away fairly quickly with modern gas formulations, and should NOT be trusted if it has been sitting for six months or longer, Ethanol added or not!

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

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: Custom 140 EFI setup
Posted by: KenHenry ()
Date: November 19, 2020 08:51AM

The rear gear is a 3.55 and my tires are slightly undersized: 185/70r13. At least it's easy for me to adjust the timing table now to reduce advance at cruise. I've always run 90 octane ethanol-free and never had pinging, but the rings have likely been broken the whole time I've been driving it. I think I'll rebuild it as a big bore 3.0L! Best, Ken

Ken Henry, Rochester, NY USA
1965 Corvair Corsa
140 hp, 4 speed

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Re: Custom 140 EFI setup
Posted by: Wagon Master ()
Date: November 19, 2020 09:16AM

Bit of a CSI case indeed. What is your ring to ring groove clearance? It's been my experience that you don't break rings from detonation without hammering the lands. Also you'd have to wonder about the ring end cap being too close. But you usually see some bore scuffing from that.

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Re: Custom 140 EFI setup
Posted by: Spectre ()
Date: November 19, 2020 10:20AM

What about the ridge at the top of the cylinder? Can't that break the top ring if not removed?

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

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Re: Custom 140 EFI setup
Posted by: KenHenry ()
Date: November 19, 2020 11:08AM

Unfortunately I don't know much about the history of this engine. I changed the oil pan gasket a few years ago and found a few sections of compression rings and oil control ring in the pan. Not sure if it was debris left over from a previous repair or came from the other side of the engine that I haven't torn down yet. Stay tuned...

David, I don't think they broke during disassembly if that is what you mean. I pulled the cylinders out over the top of the pistons and there was little resistance. The cylinders definitely have a ridge though. Here's a photo I have of one of the pistons that might speak to the ring lands? I can try measuring but rest assured I don't plan to reuse the pistons. Ken

27B2B3B7-D6E5-4DC2-8979-5AAFE7EFEE06 by kenhenry_06268, on Flickr

Ken Henry, Rochester, NY USA
1965 Corvair Corsa
140 hp, 4 speed

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Re: Custom 140 EFI setup
Posted by: Spectre ()
Date: November 19, 2020 11:51AM

I was referring to the fact that new rings will break if there is a ridge at the top of the cylinder. If someone slapped new rings in and didn't remove the ridge, broken rings can be the result.

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

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Re: Custom 140 EFI setup
Posted by: KenHenry ()
Date: November 20, 2020 09:21AM

I finished taking everything apart. The rings on the right side of the engine (1,3,5) were all intact. The #5 piston and rod are replacements (unmarked) and there are two #3-marked rods in positions 1 and 3. The camshaft is an 891. I can feel a slight groove on the larger lobes. How much wear is acceptable for reuse? Ken

75C37E8A-5279-43AD-8901-D5EFB6A88A28 by kenhenry_06268, on Flickr

D1444265-74EE-43BE-974B-AE852501D5B7 by kenhenry_06268, on Flickr

Ken Henry, Rochester, NY USA
1965 Corvair Corsa
140 hp, 4 speed

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Re: Custom 140 EFI setup
Posted by: joelsplace ()
Date: November 20, 2020 10:28AM

That cam is totally shot. I'll bet the lifters look terrible also.

Joel
Northlake, TX
5 Ultravans, 113 Corvairs and counting...

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Re: Custom 140 EFI setup
Posted by: caroseiii ()
Date: November 21, 2020 11:19AM

The ring lands are peened over from being beaten so much. The clearance appears excessive from the photo. Aside from not reusing because of the wear, the heads would likely crack off of the pistons next if you did reuse these.

C.A. Rose
Metairie, LA
1962 Spyders

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