Decarbonizing with Sea Foam

[Jetaway]

I'm about to take the plunge and decarbonize with Sea Foam. I've gone to their website and they suggest pouring 1/3 to 1/2 of a can down the carb throat. Simple enough with a downdraft carb but I'm not sure how to do this with a dual side-draft setup.

Posts here seem pretty straight forward about using it, but I'm not sure enough of my own knowledge to convince myself that I know exactly what to do. I'm going to layout my plan here and would appreciate any comments from those who have done it before to keep me on the right path.

1) Run car 15 - 20 miles as warm up.

2) Remove air cleaner.

3) (see attachment) Front of engine is on the right. I assume this is the balance tube that connects the front and back manifolds. The tap closest to the middle lines up with the left side of the K&N decal on the air filter and is connected to something that modulates throttle closing. The Sea Foam site is quite firm about using an induction path that distributes evenly to all the cylinders and I'm thinking this would be best choice. But ... and here is my ignorance talking. What is the purpose of the balance tube? I assume it evens out differences in engine vacuum between the front and rear manifolds due to ??? Unbalanced carbs? Unavoidable differences created by slight differences in valve settings, carbs, other? If so, wouldn't this mean that the vacuum would always be greater either in the front or rear manifold and thus the Sea Foam would flow in that direction? Or is it closer to a plenum and smooths out vacuum fluctuations caused by the alternating fire of the pistons?

I guess regardless of the above, I was thinking of kicking the revs up to 2000 and using a funnel and hose to put the Sea Foam into the tube, maybe 1/2 oz at a time while blocking one of the carbs with a piece of cardboard, then add another 1/2 oz while blocking the other carb, and repeating the sequence four to six times and then shutting down for 15 minutes.

4) Replace air filter.

5) Start up, scare the children with prodigious smoke, and hit Hwy 99 for a 10 - 15 mile run at 3000 rpm.

6) Get home, change the oil and the filter.

Chris

[conedodger]

Put it in a spray bottle...

[sam280z]

You're over thinking this. Just pull the line off of the modulator and stick it into the seafoam. Engine vacuum will pull in the seafoam and it will get distributed evenly enough. YOu will want to kick up the engine speed.

Sam

[Jetaway]

Put it in a spray bottle...

I was thinking of this too (re: next reply -- Yes, I do tend to over think. Especially the obvious.) but wasn't sure if I'd be able to spray it in fast enough to allow for buildup. And a little concerned about the Sea Foam dissolving the plastic. Could check that easily enough. Hmmm... I do have a fairly large chemical-resistant syringe. Or, at least I did.

Thanks. I think I will go with a spray rather than pour strategy.

Chris

[whamo]

I tried sea foam on my car. I wasn't impressed. It might work on lightly carboned engines but after treating my car and still hearing preignition I pulled the head and it didnt appear that the seafoam had any effect at all. I removed all of the valves and cleaned the deposts from them manually. I also soaked the combustion chambers and piston tops in carb clean and scraped the carbon off. It was a long weekend but rewarding, the engine never ran better.

[acador]

I recently removed the valves on my head to clean them up and port the runners. I was surprised how difficult it was to remove the carbon off the valves using a wire brush wheel on a power drill, even after they soaked for days in sea foam. I remember thinking there was no way squirting that down a running engine would do much. That being said, I’d still squirt some in the carbs in the off chance it would reduce carbon buildup.

[ta240]

although it did really smooth out my 280 back when I had it the thing that gets me with the sea foam is all the people that post the videos of the whitish smoke coming out as a sign that it is cleaning. The white smoke is the sea foam. The burst of black when you gun the throttle are the carbon.

[FastWoman]

I could easily be wrong, but I think having the right fuel/air mix will eventually result in the burning/eroding away of carbon deposits in your cylinders. I suspect there's no compelling reason to clean the valves or intake, beyond clearing varnish from the valve guides and injectors. Flushing the motor oil will clean up the valve guides, albeit a bit slowly, and running a bit of a strong solvent through the gas will slowly clean the injectors. I think that's about the best you can do.

That said, the old-school way of cleaning carbon out of a flathead engine was to open up the head and dump rice into the intake. Apparently the rice would bounce around inside the cylinders, and the pulverized carbon would come shooting out the exhaust -- not that I'm recommending that to anyone, but I just find it fascinating!

[robftw]

On rotary engines we use ATF to clean the carbon off apex seals in extreme situations

edit: gonna explain why

Sometimes a piece of carbon will chip off the rotor face and gets lodged between the apex seal and rotor housing effectively seizing the engine.

You remove the leading spark plug and put about a teaspoon of ATF inside each hole, remove the FI fuse and attempt to turn the engine over, if it wont budge wait 20 mins - 60 mins - 3 hours etc etc until it rotates.

Once you get it spinning put the plugs back in, put the fuse back in and turn the engine over, your neighbors will hate you if their windows are open.. however the white smoke screen it leaves behind is AWESOME

Edited May 16, 2011 by robftw

[whamo]

I recently removed the valves on my head to clean them up and port the runners. I was surprised how difficult it was to remove the carbon off the valves using a wire brush wheel on a power drill, even after they soaked for days in sea foam. I remember thinking there was no way squirting that down a running engine would do much.

X2 thats the same thought I had, that stuff is very difficult to remove, even with a wire wheel and a scraper.

Edited May 16, 2011 by Arne
quote tag fix

[Jetaway]

Finally got around to doing it.

Given the reports of enormous smoking during the treatment and not wanting to alarm the neighbors, I wanted to perform the treatment away from home, ideally about 10 miles and also located close to a highway.

As a prep, I dumped 1/2 of the can into the gas tank and put around 150 miles on it prior to the treatment. Drove the car around doing a little shopping, then stopped at the K-Mart on Mariposa road, conveniently located, I kid you not, less than 1/10th of a mile from the on-ramp to 99 South. I pulled the air cleaner cover, plugged a hose into the balance tube, turned the idle up to 2000 rpm or thereabouts, then covered one air horn with a piece of cardboard while "sipping" 2 and 1/2 ounces of Sea Foam into the engine. Shut it down, repeated the sipping with the cardboard over the other air horn. Shut it down, put everything back together and waited another ten minutes.

I gotta say, I was a bit disappointed with the volume of smoke. Maybe I was expecting a a scene out of Apocalypse

Now and it wasn't anything like that. It did seem to discourage other drivers from coming near me at the stoplight, however. Viewed from the driver's seat accelerating up to and cruising at 65 -- 75 mph the smoke lasted less than a mile. May have continued at reduced volume after that as a thin wisp of smoke could be seen coming from the tailpipe after arriving home (10 miles or so) and shutting down.

Haven't noticed any differences, but I wouldn't expect anything dramatic, and I haven't taken it out for a ping stress test yet.

Chris

[Jetaway]

Finally got around to doing it.

Given the reports of enormous smoking during the treatment and not wanting to alarm the neighbors, I wanted to perform the treatment away from home, ideally about 10 miles and also located close to a highway.

As a prep, I dumped 1/2 of the can into the gas tank and put around 150 miles on it prior to the treatment. Drove the car around doing a little shopping, then stopped at the K-Mart on Mariposa road, conveniently located, I kid you not, less than 1/10th of a mile from the on-ramp to 99 South. I pulled the air cleaner cover, plugged a hose into the balance tube, turned the idle up to 2000 rpm or thereabouts, then covered one air horn with a piece of cardboard while "sipping" 2 and 1/2 ounces of Sea Foam into the engine. Shut it down, repeated the sipping with the cardboard over the other air horn. Shut it down, put everything back together and waited another ten minutes.

I gotta say, I was a bit disappointed with the volume of smoke. Maybe I was expecting a a scene out of Apocalypse Now and it wasn't anything like that. It did seem to discourage other drivers from coming near me at the stoplight, however. Viewed from the driver's seat accelerating up to and cruising at 65 -- 75 mph the smoke lasted less than a mile. May have continued at reduced volume after that as a thin wisp of smoke could be seen coming from the tailpipe after arriving home (10 miles or so) and shutting down.

Haven't noticed any differences, but I wouldn't expect anything dramatic, and I haven't taken it out for a ping stress test yet.

Chris