Re: Lifter trouble

[jlandry@domain.elided (John A. Landry)]

The aliens commander decided DSkirtech@domain.elided would make a
perfect specimen for dissection, and he yelled...

>Ive got sort of a "popping hiss" from the Holley Carb.

Dane,

This sounds like possibly an intake valve is not fully closing, or an
intake valve which is not fully sealing (from a burned seat or valve face,
etc.).  There are a number of reasons for this condition which can range
from rust which formed around the intake valve stem (if water got in the
intake... common if an engine sits out in the rain) to a bent valve stem or
even a cracked head.

The first thing I'd try is a compression test.  You should bring the engine
to normal operating temperature, remove the spark plugs, ground the coil,
block the throttle fully open, insert the compression tester into each
spark plug hole and crank the starter until the pressure stops climbing.
This simple basic test should immediately tell you if you have any big
problems.  The compression test shows how much pressure a cylinder is
capable of producing.

If the compression test comes out normal (all the cylinders within about
10% to 15%, then you may wand to try a leak down test.  This test is
usually done by a repair shop because the tester runs a minimum of $65.00
and requires compressed air.  The leakdown test will show how well a
particular cylinder holds the pressure it produces.  If you have a valve
sticking open slightly, this will show up on the leak down test.

Typically if you have a lifter malfunctioning, you'll get some valve train
clatter (ticking sound at half engine speed).  Be forewarned that if you
use a solvent (like kerosene or diesel) in a high mileage / internally
dirty engine, you risk loosening the dirt and having small pieces break off
and possibly lodge inside the lifters.  This can sometimes make the
situation worse by causing more lifters to fail.

I'd try to find the real cause of the problem first and then make a plan on
how to best deal with it.  I don't think the diesel trick is going to work,
and it might actually be bad.

Best regards,

John L.
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jlandry AT halcyon DOT com      | 
Conservative Libertarian        |  "The road to  tyranny, we must never
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WA Arms Collectors              |   of the truth."
Commercial Helicopter - Inst.   |                     William J. Clinton
http://www.halcyon.com/jlandry/ |    10-15-95, speech at the Univ. of CT