<VV> Question on Hot Knocking

[roboman91324 at aol.com]

Frank,
 Yes, carbon removal with the use of water is a good idea in general though it seems Todd's engine probably isn't a good candidate for this treatment. You are correct that pouring water down the carb with a bottle could lead to a spill that will immediately lock the engine and cause damage to rods, pistons and bearings.  To avoid this possibility, I use a squirt bottle.  To be effective, you will need a squirt bottle set to a healthy squirt not just a mist.  This allows you to control the amount of water entering the engine and avoid risking damage.  This method also permits you to give this treatment to a turbo carb. Changing the discussion back to a previous point in this thread....  Todd, even though your octane booster seems to have mostly solved your knocking problem, I would suggest you try retarding your timing a bit.  I understand that you don't want to risk degrading the performance of an engine that seems fine other than the knocking.  keep in mind, if the engine doesn't like the new setting, you can easily return it to the old timing and return to your octane booster fix.  Record the original setting.  If the new setting works, you (or another driver) won't need to buy the booster and suffer the hassle of measuring out liquid in varied amounts when you fill the tank.  To test the new timing, you will need to have a fresh supply of gas without the booster.  Changing the timing and using the booster at the same time will tell you nothing about the proposed retarded timing fix. Doc~~~~~~~~~~~~~~~~~~~~~~~~
In a message dated 10/27/2023 9:00:19 AM Pacific Daylight Time, virtualvairs-request at corvair.org writes: 
Message: 1Date: Thu, 26 Oct 2023 12:40:19 -0400From: Frank DuVal <corvairduval at cox.net>To: virtualvairs at corvair.orgSubject: Re: <VV> Question on Hot Knocking - UpdateMessage-ID: <8f2bfcce-e010-444c-ac80-a56dc5a86175 at cox.net>Content-Type: text/plain; charset=UTF-8; format=flowed Sounds like you have high compression. Higher than GM made it. The compression can be high from carbon build up. Do a compression test and see what numbers you get. The old decarbonizing trick is to fill a "pop" bottle with water. Warm engine up. Take off air cleaner assembly. With engine running, dribble water into a carburetor (Corvair), increasing speed as engine slows down. Do NOT pour enough water in to stall the engine, as it can HYDROLOCK and that is very hard on connecting rods. Use a bottle (or whatever you can dribble from about 12 to 16 ounces) in each carburetor (assuming? two cab Corvair, no need to do secondaries on a 140, and turbos are too hard to do this trick ?). I've had to do this an several cars back in the day, inlne 6s and V8s. GM makes a top engine cleaner if you want to use a more expensive product. That is a solvent, so it will cut more carbon/dirt along the intake path that water does not do. Water just steam cleans the piston tops and combustion chamber. I also do this before taking an engine apart, as it is nicer to work on cleaner parts! Frank DuVal