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Re: removing carbon in top engine
Posted by: timor19 ()
Date: September 11, 2015 10:56AM

Thanks for sharing these pictures. The water steam washing seems to do a difference. Good to know!

Mike

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Re: removing carbon in top engine
Posted by: spydergear ()
Date: September 11, 2015 10:59PM

I thought I'd mention that the air the engine normally breathes is not free of water. Using my little air compressor, I filled my tires on a rainy day and now get a blast of water vapor when I let out any pressure. When I get around to it, I will have to "change the air" to get rid of some of the water. Just saying that engines normally ingest a lot of H2O, especially when it is raining or during high humidity.

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Re: removing carbon in top engine
Posted by: timor19 ()
Date: September 12, 2015 10:43AM

Yes that's true, but water concentration in air is about 1% in normal air...maybe a little more in high humidity period or rainy days.

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Re: removing carbon in top engine
Posted by: Paulsgt ()
Date: August 11, 2020 08:05PM

So I had my trusted Corvair Mechanic Mike Dawson listen to my car last week. About two months ago I adjusted the valves on #1 cyl that were too tight I now hear a knock. Mike thinks it is carbon. A little back story. I did new cylinders, pistons, rod bearings, had the heads done, etc. about 6-7 years ago. I've put about 4,000 miles on the car since then. I suspect that #1 cylinder has been going along for the ride the entire time (virtually no compression). I poked my cheapy boroscope in there today to try and see how bad it is. I tried to capture the photos I took and post them. (The boroscope app doesn't make it easy to get photos off my phone.) Comments on how to fix this without tearing it down.

Enjoy the Corvair!

Paul Sergeant
CORSA Central Division Director / CORSA Treasurer
Lee's Summit, MO
CORSA since 1975
Member – HACOA, Corvair Minnesota, CORSA, Little Indians, POCI


Attachments:

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Re: removing carbon in top engine
Posted by: ken ()
Date: August 12, 2020 04:25AM

I have never had any luck dumping water down a carburetor to get rid of carbon that a wire brush has a hard time removing . Just my 2c worth .

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Re: removing carbon in top engine
Posted by: jjohnsonjo ()
Date: August 12, 2020 05:07AM

Run a tank full with a bottle of Techron added.

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


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Re: removing carbon in top engine
Posted by: Wagon Master ()
Date: August 12, 2020 05:25AM

I have to ask. with a freshly rebuilt cyl. making low/no compression, how did it make enough heat to form carbon in 4,000 miles? Not likely. No offense to the first guy but have another set of ears listen to this issue. Or give him another shot. Does the sound change when you ground #1 spark plug lead? What is your compression in that cyl. now. Any chance you may have adjusted a rocker too loose?

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Re: removing carbon in top engine
Posted by: Paulsgt ()
Date: August 12, 2020 06:48AM

Didn't try the grounding the spark. The compression was around 80psi. Now at 130.

Enjoy the Corvair!

Paul Sergeant
CORSA Central Division Director / CORSA Treasurer
Lee's Summit, MO
CORSA since 1975
Member – HACOA, Corvair Minnesota, CORSA, Little Indians, POCI


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Re: removing carbon in top engine
Posted by: wittsend ()
Date: August 12, 2020 01:38PM

A high NOX level can be an indicator of carbon in the combustion chamber. I had a daily driver that failed smog and I put a new CAT on it. Even with the new CAT the NOX marginally passed.

Two years later prior to the next test I ran Seafoam through the engine them I did the water injection. I just used a 1/16" piece of KS Tubing that I had pinched to reduce flow and slid it into the rubber intake hose just past the VAM. I did this for about 20-30 minutes and used at least a gallon of water.

The end results were that the NOX was about 20% lower than two years prior when I had installed a brand new CAT. So, to me that is a measurable proof that water works. How long it lasts..., I don't know.

Ideally it would be a long term process (maybe permanent), did not activate on idle or until the engine was up to temperature. In design a temperature switch, a vacuum switch (ideally off the ported vacuum for the vacuum advance) and maybe even a pot off the throttle shaft to control the pump speed keeping it in line with demand.

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Re: removing carbon in top engine
Posted by: corsa1 ()
Date: August 12, 2020 01:58PM

use 93 octane gasoline .the 1964 110 engine is a high compression engine.

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Re: removing carbon in top engine
Posted by: Paulsgt ()
Date: August 12, 2020 02:55PM

I use the highest octane I can buy which I think in Missouri is 91.

Enjoy the Corvair!

Paul Sergeant
CORSA Central Division Director / CORSA Treasurer
Lee's Summit, MO
CORSA since 1975
Member – HACOA, Corvair Minnesota, CORSA, Little Indians, POCI


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Re: removing carbon in top engine
Posted by: gwrench ()
Date: August 12, 2020 03:17PM

I don't have experience with using water in a Corvair, but I've used it on many cars in the tune shop where I worked in the 70's. We had some can's (probably 8 oz) made up with our logo that said "chemical A". We'd fill them out of the sink in the back and dump em down the carb when needed. If the customer asked what it was we'd say it was a trade secret. It takes some practice but even if the engine dies you can get it going with some cranking and pumping the accelerator pump. It should be easier with a setup like a corvair where you're only dosing half the engine at a time.

One tune I regret was a Ford Bronco 302. It had a cylinder and plug that was fouled horribly. I was sure it could run much better with new plugs etc. but I forgot about how much carbon would have built up. The carbon knock was horrendous but I didn't think to do the water treatment. I sent the customer on their way with condolences. I hope the carbon got knocked out before they did something radical.

I saw in later years how a failed head gasket cleaned up a combustion chamber on a Ford 8N.

Water can work wonders IF that is a problem. I haven't seen it personally in years.

Dale
Loveland, Colorado

1965 Monza 140 barn find

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Re: removing carbon in top engine
Posted by: alphasud ()
Date: August 12, 2020 05:44PM

As a technician working on the east coast I witnessed on several occasions where customers had cars towed in with a crank no-start complaint. What would happen on really damp evenings carbon would break loose in the combustion chambers and when they would try to start the car in the morning the carbon would get hung up in the valve seats and lower the compression enough to keep the engine from starting.
My service manager had a old Grand Wagoner with the 360 that the timing chain failed. He could not get this thing running again. Finally he asked if I could drive to his house to diagnose. After checking all the suck, squeeze, bang, and blow basics I asked him to remove the Supertrapp mufflers because I felt the carbon had broken free and clogged the discs. After removing it started right up! Major bonus points when you can get the boss’s car running.

David North Idaho
1965 Corsa Turbo converted to 140
1971 Super Beetle with 2.5L Subaru engine
1988 Citroen CX 25 GTI Turbo

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Re: removing carbon in top engine
Posted by: RexJohnson ()
Date: August 12, 2020 06:33PM

Isn't water injection suppose to help keep an engine clean inside?

RJ tools
Salem,Oregon

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Re: removing carbon in top engine
Posted by: MattNall ()
Date: August 12, 2020 06:58PM

Yep and, reduce pinging. Mamy times we used the washer reservoir and washer nozzles at the top of each carb in the filter housing.. Just refill when in the engine compartment.

Also, polishing the tops of each piton really helps!

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: removing carbon in top engine
Posted by: Paulsgt ()
Date: August 12, 2020 08:08PM

Yesterday I did run a 1/2 bottle of Seafoam through the RH carb using a spray bottle. I put the other 1/2 bottle in the gas tank. Mike says run 1/2 water & 1/2 brake fluid. I'm guessing I have to run more than the 6 or 8 oz that I did with the Seafoam(?)

Enjoy the Corvair!

Paul Sergeant
CORSA Central Division Director / CORSA Treasurer
Lee's Summit, MO
CORSA since 1975
Member – HACOA, Corvair Minnesota, CORSA, Little Indians, POCI


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Re: removing carbon in top engine
Posted by: joelsplace ()
Date: August 12, 2020 11:36PM

Anyone skeptical about water cleaning a combustion chamber has obviously never replaced a bad head gasket on a water pumper. The leaking cylinder(s) are readily obvious because they are so clean compared to ones that aren't leaking.

Joel
Northlake, TX
5 Ultravans, 141 Corvairs and counting...

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Re: removing carbon in top engine
Posted by: JimBrandberg ()
Date: August 13, 2020 06:38AM

I've always used Seafoam trickled into the carburetors, alternating side to side while keeping it running with one hand and then a good dose at the end of the can while letting it stall. Big billows of smoke while doing it. Wait a half hour then go out and beat the hell out of it. I'm fortunate to live adjacent to a rural highway.

I have great respect for the folks using water, it's something I only heard about in the last year or so and I haven't tried it. There's something about using Seafoam special formula that's attractive to me, maybe it's the smell.
Another follow-up can in the gas tank seems like a good idea.

I've never used Techron, is it similar to Seafoam?

I have no idea what I'm looking at in the photos above, looks a lot like trunk splatter paint. I've never had a borescope, maybe one of these days. I don't know if it would be before or after I get a cell phone that takes pictures and stuff.

I usually associate carbon with an engine that's been running rich. What would you say are some other causes? Maybe cold plugs or weak spark...

Jim Brandberg
Isanti, MN
CorvairRepair.com



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Re: removing carbon in top engine
Posted by: Paulsgt ()
Date: August 13, 2020 07:02AM

I think that because that cylinder was running with 80# of compression for 4,000+ miles that there was lots of incomplete ignition and caused the cylinder to carbon up. In all fairness, I did not look at any other cylinders (I'll do that next time I get a few minutes).

The photos I posted were very poor quality compared to what I could see with the boroscope. The sharp edge you see running through the pictures is carbon on top of the piston. Not sure if I'll try water next or a bottle of techcron.

Thanks for all the thoughts and ideas. I appreciate it. Keep 'em coming.

Enjoy the Corvair.

Paul Sergeant
CORSA Central Division Director / CORSA Treasurer
Lee's Summit, MO
CORSA since 1975
Member – HACOA, Corvair Minnesota, CORSA, Little Indians, POCI


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