So this guy (in his 50's) came by today to look at my 73 454 for sale, after a long visual inspection he asked me to start the car and he proceeded to hold a dollar bill by the exhaust tips, I asked what he was doing, and he said that if the dollar bill went into the pipe, that means the car has a "burnt valve", he claims this is a "old gear head" test.
I never heard of such a thing ???? Anyone here ?

 

Yeah, I've heard of it. Nonsense. I have seen the dollar bill get sucked toward the pipe on a perfectly fine engine. If he really wants the car, there are real tests he can do.

 

I never heard of this test. But a google search gave a few hits.

Here's one listed on Corvette Forum for C4s:
https://www.corvetteforum.com/forums...bill-test.html

 

If the engine has dual exhausts, that 'test' can detect uneven firing and exhaust pulsing. (ignition problems and/or valve problems)

 

Yeah- but I just hold my hand over the tips on dual pipes to see if there's any "skip" on either pipe. Works ok unless you're running any type of cam.
If he buys a corvette he won't have a dollar to cover his A$$, let alone a tailpipe!
Stump

 

to me it falls in with "tire kicking" most "gear heads" as he called them can tell a burnt valve on a stock engine with out heating up any toad pelts......

 

The 5 dollar bill test is 5 times more accurate.

 

yeah and 5 times more expensive.

 

He probably read about that test on the internet, so it must be true. I'm an old guy and I knew about putting your hand at the end of the pipes, but never heard about the dollar. Maybe he just wanted to see how fast the c3 will suck up his money!

 

***** Different test*****

This is a 'dollar bill' test I do...and usually has very good results BUT....it DOES NOT always CONFIRM a bad engine.

If an engine has and sues a PCV. I remove the FRESH AIR tube on the other valve cover and place the dollar bill over the grommet. When the engine is running...IF the dollar bill gets sucked to the grommet....this lets me know that the PCV is good and the engine has good rings. Test completed.

BECAUSE...it the dollar bill blows away from the grommet...then EITHER:

1.) The rings are allowing excessive compression blow-by into the crankcase and the PCV can not handle this excessive pressure and keep up. Thus...this engine can be suspect for rebuild

2.) Valve cover gaskets, 'China wall' sealant is missing or any gasket that would normally seal the crank case is missing or leaking badly....including the gasket for the oil fill cap. Because if these gaskets are allowing the PCV to draw air in from where it is NOT designed to draw from ( path of least resistance)...then the crankcase pressure will 'possibly' be more noticeable.

The same goes for if the dollar bill does not get sucked to the grommet and get blown away from it.

But you can pretty much count on the FACT that the engine needs to be rebuilt if you pull out the PCV and the fresh air tube and when the engine is running....there are BLUEISH -WHITE smoke rings coming out of the valve covers. That is pretty much a dead give-away that the engine is done ( in my opinion)....AND...when the engine is shut OFF...I can turn the engine EASILY just by grabbing the alternator belt and spin the engine ...thus NO RING drag!

DUB