Post 5: Lac and Vacuum

If you haven’t started at the beginning, then you are missing some things in your education. Please go to Post 1 and start there NOW to be sure you get a thorough understanding.

In order for you to be able to find the more difficult leaks, you’re in for a surprise. There are only two locations where all the elbow grease in the world won’t help you. I know, you’re diligent and thorough and a true ‘Gadgetman’ and you found all there is to find and STILL The Groove hasn’t produced.

Always remember this: “If a vehicle fails to respond, there is ALWAYS a very good reason for it!” All you have to do is find that reason and you will (in almost every case) solve this frustrating condition. You just have to look somewhere else!

Do you remember Post One? If you haven’t been there, go back and read it again, all the way to here if you need the refresher. It details the function of an engine. From the intake air through to it exiting the engine. I want you to pay very close attention to the operation of the valves, for here (especially in older, more tired engines) is where you will find a true killer of the vacuum.

As an engine ages, depending on a LOT of variables, things just don’t work like they used to. Also depending on what the problem is, you will most certainly find that “cleanliness is next to Godliness” when it comes to your engine.

Inside all HC based motor oils is a compound known as ‘Lac’ (considered a ‘carbon deposit) and is the source for the brown staining (plaque) that appears on all surfaces inside an engine, beginning (when so equipped) at the top of the carburetor. It is the foundation of what we call ‘Lacquer’. Think about that for a minute, for you know what lacquer is and what it’s used for.

Layer upon layer, it coats everything it touches from the gas tank (YES, it’s in your fuel-it comes from oil, right?) through to the combustion chamber. I’ll just detail the moving parts here for your reference. From the gasoline side, they are: Fuel Pump, Pressure Regulator, Injectors (everything inside a carburetor) and valves. From the oil side, well, everything the oil touches. This includes all seals, bearings, and (here it comes!) the valve stems and springs.

mgb_sticky_2in_valveNotice the brown coating on ALL the surfaces the oil contacts.

Over time, this lac coats everything. Mechanical parts lose their tolerances and begin to move more slowly. Seals become stiff and inflexible. Injectors move more slowly and the pressure regulators fail to regulate. In fact EVERYTHING in the engine begins to fight with itself and whatever it’s coming into contact with.

In the case of the valves and valve springs, as they gather up this blanket of goo, they move more slowly. The springs aren’t so springy and the valves begin to stick in the valve guides. Almost invisible except when you know where to look, these engines rolling into your shop can also provide the most dramatic examples of what The Groove (and you!) can do, once you know how to fix it.

But how do you KNOW they’re going bad???

First, THIMK. While you can’t readily test your intake valves, you don’t really need to. You CAN, however, test the exhaust valves.

Here’s a short video that shows an extreme case in a 29 Model A:

What direction does the exhaust go? Rather elementary, I know, but we tend to forget the basics. Start the engine and walk back to the tailpipe. Take a piece of heavy paper and simply lay it against the exhaust and watch it. In a properly maintained (CLEAN) engine, the paper will be blown outward in a steady stream. When the exhaust valves are not sealing properly, it will draw in from the tailpipe, and pull the paper toward the engine.

I used to use a $20 bill for this until I did it one day and it was yanked out of my hand into the tail pipe! Revving the engine returned my deposit, but it was quite filthy when it came home to papa.

That dramatic example should prove to you that when this engine is on the intake stroke, it is pulling in exhaust gases rather than fresh air (as it is supposed to do!) and causes your vacuum to suffer, and suffer BADLY.

If the exhaust valves are dirty, you can bet your bottom dollar the intake valves are suffering as well. This MUST be corrected.

While there are a variety of motor flushes on the market, I simply don’t like them. I feel they tend to thin out your motor oil too dramatically, they’re messy as well as bad for the environment and require an immediate oil change. What I have been using for the last 25+ years is Castrol brand automatic transmission fluid.

All you need do is add one quart of any type of Castrol ATF into the crankcase with your regular oil and drive the vehicle. Within a couple of dozen hours of run time, check the valves again. You are sure to find them operating much more efficiently.

Add a quart into your gas tank every now and again and you will find the same thing happening with everything from the fuel pump to the injectors working better as well. If the valves are REALLY bad, then you may consider using a quality motor flush first, and then use one quart as instructed with your oil change to complete the process.

So, if your vehicle didn’t show gains, this is one area that should not be overlooked.

Next up: Hidden Weaknesses.

If you would like to learn this amazing fuel efficiency technology, we want to hear about it! Use this form to contact me, Ron Hatton, the developer of The Gadgetman Groove and we’ll see what we can do about that.