So my slant still pings a bit on premium(91) and with only 26* of timing all in. With that setting we dyno'd 155rwhp and 200ftlbs, with about as good as you can get a fuel curve (line, lol). My dyno guys said to try some race gas and see if that helped with the ping and allow for some more timing. I put in a ratio of gas today, so that it works to about 96.75 octane.
The ping is gone as far as I can tell on the drive home today, I'm going to try some on ramps tonight or tomorrow, then play with the timing a bit more to see if I can hit the coveted 30*

I know nothing about your engine and set up, but if the combustion chamber is carbonned up, you will get preignition sooner. Try running some Sea Foam through the engine with the next tank of gas and see if that helps. It will clean some of the carbon out.

There are other top end cleaners as well. Amsoil makes an excellent one called Power Foam you spray into the carb as you rev the engine at idle. It will really clean out the old carbon. If it is bad, it may take two cans.

This maybe way off base, as I do not know how clean or recently rebuilt your engine is.

Sam

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Just use water to burn off the carbon...............

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Head was off 10k miles ago, its nice and clean in there, motor only has 12k miles on it.
Ported and polished heads, milled .050 off
Decked the block to zero
Comp cam
aluminium 2bbl intake
3 to1 headers

I think the ping has something to do with head cooling and some hot spot in the combustion chamber to be honest. The motor only pumps 115psi static compression, ad it only pings once the head gets all nice nice an toasty. I think that the fuel distribution for clys 1&6 is absolute junk as well, and I'm thinking of fabbing up a 3 1bbl "bundle of snakes" style intake, just to see. I got the itch to make this into a low-buck hot rod Salt Flat car, so I'm hoping to drive it to Speed week next year, make the runs, and come back. But I've got to get this thing reliable enough that I can wood it for 3 miles, lol.

I don't agree—this is my opinion, here—that Spamsoil makes anything excellent, except profits for those at the top of their sales pyramids.

It is not necessary to spend Scamsoil money to get an excellent top-end cleaner. As has been mentioned, water is one such.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Agreed. I've heard bad things about multiple cleaners including seafoam and I don't recommend it. I also agree with Dan.
I guess window wiper fluid is also a good one because it's just 50/50 water/methanol and Blue #1.

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'73 Scamp (the girlfriend): 225ci super/6 2BBL conversion (Almost done!)
'90 Subaru, wagon (the wife): H4-cyl 2.2L

1977 Mercedes-Benz 300D, 5cyl diesel(For sale!)

I had excellent results years ago with Power Foam on my old Duster. It ran like new afterwards. Of course, I did not know about water. Really. How do you do the water thing?

It did cost me 8 bucks at the time. And maybe some one at the top did make some money off me. But, the car ran better. An honest product? Maybe not. But I got some value out of it. It did show me the value of a clean combustion chamber.

It is my understanding that the guy who started the company developed the first synthetic oil to keep the oil from jelling in high altitude fighter planes during WWII. It was an impressive story anyway. The guy who told me this was not a representative.

Sam

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Someone correct me if i'm wrong here but I believe you spray it through a vacuum line in the intake manifold....?

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'73 Scamp (the girlfriend): 225ci super/6 2BBL conversion (Almost done!)
'90 Subaru, wagon (the wife): H4-cyl 2.2L

1977 Mercedes-Benz 300D, 5cyl diesel(For sale!)

Dan-O, I am really interested in your equal distribution intake. Don;'t hesitate to discuss your thoughts and progress as it happens.

Here are some thoughts:

If you are using three carbs, could you make 3 separate manifolds to avoid the thermal expansion problems of an inline 6? How about side draft cabs?

Could you design one with a bigger, longer plenum to even out the runner lengths and avoid the snake thing? I don't know if this would be effective, or even possible. It is just a thought I have been kicking around.

How about a copy of the long factory setup they made for NASCAR. I cannot remember what they call it. That brain leak thing. Those runners are much more nearly the same length.

Sam


So you think your 1 and 6 are very lean?

Sam

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NASCAR thingy = Hyper Pak.

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66 Lil' Red Piggie Valiant (Mater Crusher) - Thanks Zilla!!!!! 72 Demon (Number 1 Son's)

Water is what we used long before the markets went wild creating all kinds of expensive additives. My first car was a hateful '41 Chevy that needed the water treatment about once a month.

Just remove the air cleaner, set the engine on fast idle and dribble water into the carb. The engine will slow down a bit, and will die if you pour too fast. Don't do it inside your garage, as a lot of liquid soot will blow out the tailpipe.

Yeah the general idea will be to to make 3 1bbl carbs, each carb would handle the 2 cyls, that are 180* away from each other 1&6, 5&2, and 3&4. My intent would be to make the tubing as equal length as possible, and most likly with some degree of inclination, to get rid of the "flat spot" that our carbs dump into. I was talking to my local machine shop today about making the flanges, And I'l want to get my headers thermally coated before I do any of this as well, to get under hood temps under control first.

Intake and exhaust manifold flanges are available on eBay. Item 320634297282 for the intake flanges.

Running two 1bbls or two progressive 2bbls on 1-2-3 and 4-5-6 I think is going to give you better results than trying to run #1 and #6 off the same carb. Of course 2 progressive 2bbls start looking like a 4 bbl on a divided manifold.

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Joshua

Sam Powell wrote: Here is a portion of an old post on the subject....Search under water injection...

Since the stock SL6 is very low compression it would be a great way of keeping it clean internally. That way I could eliminate that uneven popping idle. If you pull the heads on 30+ year old SL6 engines, they do collect some carbon which can build up. I think we all have seen the accumulations during rebuilds.

This time I wanted to hook it up so it only pulls on demand at rpms above 2000 which is 50 mph on my car. So I installed a small square radiator overflow tank and brass valve in front of the existing radiator over flow for the alcohol and water mix. I usually use the winter time Blue windshield washer fluid which has enough alcohol in it to keep it from freezing. From there I ran a see through yellowish tinted silicone vacuum line to to a port/fitting (venturi vacuum port for the EGR amplifier) on the 1920 carb. It is about half way up or mid point on the carb body. It dumps out just above or even with the venturi on my Economaster.

This is a very simple system, no fancy pumps. I have it set so at idle it does not engage. When you reach around 2000 rpm then the vacuum is strong enough to draw it out of the tank. You can watch it through the transparent silicone line. When you drop below 2000 rpm it stops.

It keeps the engine running crisp. Idle is steady as a clock, no pops or putts out the exhaust and the throttle response is very responsive. Shut offs are clean and quick. Running two heat ranges lower plugs NGK (UR6) per SL6 Dan's recommendation look and stay very clean.

Click on the red link below my name for pictures of the install.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

The original question was about how to clean the carbon out of the chambers. The regular method is pretty simple and been explained.
Warm engine up to operating temp, set the engine to fast idle/2000 rpms or so. Take off air cleaner, and take a cup of water and dribble a little at a time into the carb throat...if you have bad build up you'll get a nice cloud of sooty steam out the tailpipe... Two bad things can happen with this so you need to take it easy on the quantity of water poured:
1) If you load a cylinder with a big gulp of water the water won't compress as much as a vapor mixture and the rod may suffer/bend,
so don't "dump" a cup of water in, lightly sprinkle.
2) If you have *really* bad carbon deposits, the steam can break a "chunk" of carbon off and sometimes it can get stuck between the valve and the seat causing another problem.

If in doubt about your metering ability, use a spray bottle to mist the water into the carb.

If worried long term about combating detonation due to high compression or using a cam with a tight overlap event, then Ted has posted an easy way to combat "ping" with little effort and saving someone from buying high octane at every fill up. Water injection is a good way to suppress that and much cheaper than 5 gallons of 110 everyweek to supplement the 91/92 at the pump.

-D.Idiot