leakdown & compression test

[grumpyvette]

first DON,T PAY FOR IT ...DO IT YOURSELF!!!
IT WILL COST LESS EVEN AFTER PAYING FOR THE TOOLS, than paying for it AT MOST GARAGES.
A compression test,ALONE, IS NOT A LEAK DOWN TEST, a LEAK DOWN TEST WILL GIVE YOU THE COMPRESSION TEST INFO, ALONG WITH OTHER INFO

you'll find that you'll gain basic skills, own new tools and PAY LESS MONEY

http://en.wikipedia.org/wiki/Leak-down_tester

http://www.carcraft.com/techarticles/11 ... index.html

BEFORE YOU GET INVOLVED WITH TESTING , YOUR ENGINE,READ THRU THESE THREADS, AND LINKS AS THEY WILL HELP ISOLATE THE PROBLEM, and THEY HAVE A GOOD DEAL OF USEFUL INFO

http://www.chevyhiperformance.com/tech/ ... index.html

read this carefully, for you do it yourself types

http://www.hondatuningmagazine.com/tech ... index.html

http://www.motorcycleproject.com/motorc ... kdown.html

http://www.vmaxoutlaw.com/tech/leakdown_tester.htm

Heres, more, useful info, you'll want to know before testing

http://www.carcraft.com/techarticles/116_0406_cylinder_leakdown_tester/index.html

http://www.xs11.com/tips/misc/misc3.shtml

http://www.goodvibesracing.com/leakdown Tester.htm

http://www.globaltoolsupply.com/cgi-local/SoftCart.exe/online-store/scstore/p-P1-275.html?E+scstore

http://www.tavia.com/cat8.html#3



http://www.motorcycleproject.com/motorcycle/text/leakdown.html

http://www.xs11.com/tips/misc/misc3.shtml

http://goodvibesracing.com/Leakdown Tester.htm
1) For most accurate results, engine should be up to operating temperature.

2) Remove all spark plugs.

3) Rotate crankshaft until piston being tested is at top dead center of compression stroke.

4) Screw the spark plug adapter hose into spark plug hole making the sure the o-ring is seated properly.

5) Connect the spark plug adapter hose to the coupler of the leakdown tester.

6) Connect leak down tester to a good source of compressed air, preferably a filtered and water trapped source.

7) Adjust the regulator on the leak down tester so the the LEFT HAND GAUGE indicates at least 10 pounds less than your source pressure. The leak down percentage conversion table shown below is based on regulated pressures of 100, 90, or 75 psi.

8) Read the RIGHT HAND GAUGE (differential gauge), then look up gauge reading on the conversion table below to get actual leak down percentage. After noting percentage of leakage, turn the regulator knob counter-clockwise to relieve the pressure. This reduces the shock to the gauges. If you ever get an unrealistically low pressure reading on the right hand gauge, there is a finite possibility that something is blocking the small orifice located within the hex tube located between the regulator and the main body of the leak down tester.

9)To remove any obstruction that may be lodged in the metering orifice, unscrew the hose coupling assembly from the aluminum body. Utilizing a 1" wrench, remove the knob assembly from the regulator. Blow compressed air in the opposite direction (from the coupling end) to clear the orfice. Re-assemble the regulator and the coupling.

NOTE: DO NOT ATTEMPT TO REMOVE THE BRASS HEX NIPPLE BETWEEN THE REGULATOR AND THE ALUMINUM BODY. DAMAGE MAY RESULT.

http://www.maximausa.com/technical/leaktest.html

http://www.meyerracingonline.com/leak.html

http://www.compressionking.com/leakdown.htm

http://www.lcengineering.com/TechNotes/TechNote47.htm

common compression test results will fall in the 150PSI-170PSI range on nearly stock engines , and ideally all cylinders will read within 5%-10% of the rest
I don't start getting too concerned until numbers start pushing over 12% -15% for hot rod stuff. Normal car 18-22%. Most test procedures you will see say 25% acceptable , but at that point you need a ring and valve job
ID be More concerned with the cylinder to cylinder variations on individual cylinders, I want to see consistent numbers across the board, maximum variation of 10%. If one is at 12%, I want to see a total range of 11-13%. Keep in mind, gauge, engine temp, piston position in each cylinder, and should be consistently at TDC when testing each cylinder, and yes it will effect the readings.

 

[grumpyvette]

http://www.harborfreight.com/cylinder-l ... 94190.html

Leak Down Testing — How It Works And What It Tells You

Leak-down testing can provide a lot of information beyond the general health of the cylinder. We discuss the whys and hows.

www.enginelabs.com

HARBOR FREIGHT, UNDER $40

http://buy1.snapon.com/products/diagnos ... pv309a.asp

SNAP ON $330

http://www.summitracing.com/parts/SUM-900010/

http://www.summitracing.com/parts/OTC-5609/

SUMMIT $80-$100

theres is a difference in gauge quality but the summit, leak-down tester works every bit as well as the more expensive set, from snap on from what Ive seen, and Ive used both, and several other, even the HF gauge worked ok MOST of the time, but it was a bit less consistent.
be aware that these are a useful tool but not 100%, accurate in all cases
USED IN CONJUNCTION WITH THESE TOOLS BELOW , and A VACUUM GAUGE AND A TIMING LIGHT AND MULTI METER PLUS SOME SKILL ARE READING SPARK PLUGS ,YOU CAN LEARN A GREAT DEAL BEFORE YOU START TEARING INTO AN ENGINE


http://www.toolrage.com/prodView.asp?sku=SLI-PV618 (do a google search on (SLIPV618)

http://www.thetoolwarehouse.net/shop/SLI-PV618.html

ProVision 618 Flexible Fiberscope w/ 18" Non-Obedient Shaft



High resolution lens provides a clear image of objects as close as 3/4 inch and over one foot away while providing a wide 40 degree field of view.
Powerful lamp illuminates dark crevices on-demand with the push of a button conveniently located on the handle.
Ergonomically designed handle is comfortable to hold and allows one-handed focusing and light activation.
Rugged and water resistant, ProVision is made of high impact ABS and flexible cable sheathing. (Note: Shaft is water resistant, not the handle.)
PV-618 and PV-636 models have .23†diameter, flexible, non-obedient cable. Durable carrying case included.
Accessories available to optimize ProVision for specialized applications.
Made in the USA
Specifications:

Cable Length: 18" (457.2mm)
Cable Diameter: .23"
Handle Length: 6" (152.4mm)
Handle Width: 1.43" (36.2mm)Overall Length: 24" (609.6mm)
Weight of Scope w/ Carrying Case: 1 lb. 5.7 oz (615 g)
Field of View: 40°
Optimal Viewing Distance: Min. .8" (20mm); Max. is dependent upon ambient lighting conditions.
Lamp Volts: 2.7 volts (Halogen)
Power Source: 2 AA batteries (not included)
Pressure Necessary to Operate Lamp: 2.9 avg. p/psi; 3.2 max. p/psi

viewtopic.php?f=27&t=1514
Ive found its a whole lot faster to use a quality IR temp gun
(Ive used this one for years)
Wide temperature range from -58 to 1832°F (-50 to 1000°C)

many temp guns don,t read high enough or accurately enough
http://www.professionalequipment.com/ex ... ermometer/
that you can use on the engine to check ALL 8 exhaust temps, individually, this quickly locates plugged injectors or vacuum leaks ETC

http://www.professionalequipment.com/xq/ASP/ProductID.3461/id.22/subID.177/qx/default.htm

when selecting an IR gun for automotive use, you really want to be able to read from 0 F deg-about 1400F deg. to cover most conditions you'll test for

http://www.classictruckshop.com/clubs/e ... ac/uum.htm

 

[Grumpy]

GRUMPY,my 454 BBC engines recently rebuilt but smokes badly, I pulled the intake and found this, Does this look normal for 5000 miles?

no! you need to do a leak down test, and other testing to determine the oil source getting into the intake runners and ports,when you see that much oil residue on an engines intake valves in under 20K miles on a newly rebuilt engine, its a great indication your valve seals are either defective or improperly installed,or the wrong valve seals for that application, or have been damaged by the retainer hitting the seals due to insufficient clearance, and probably your valve guides are worn, OR YOUR INTAKE MANIFOLD GASKETS, leak ALLOWING OIL TO BE SUCKED FROM THE LIFTER GALLERY
IF your RINGS were worn or never seated to the bore walls ,the LEAK DOWN TEST SHOULD EASILY SHOW THAT, but it sure looks like a valve guide or seal issue!
light surface ,oily deposits in the intake runners ,are fairly normal due to reversion during the over lap cam timing

but that picture shows HEAVIER oil use than reversion alone would allow in that mileage
one old time test you should do, is the following proceedure
(1) get a buddy in a second car to follow your car and ideally video tape what he sees to show it to you

(2)put the car in first gear on a section of road that you can safely play with the car on without causing issues with other cars

(3) briskly accelerate (but not had enough to spin the tires) through two gears up to about 40 mph, then with it still in gear, pull your foot off the gas and let the engine slow the car.

(4)exhaust smoke during brisk acceleration is probably rings and blow-bye due to high cylinder pressure
exhaust smoke on DE-acceleration while the engines slowing the car, is due to high engine vacuum, and is more than likely defective valve guides or valve seals


http://garage.grumpysperformance.co...-vortec-heads-and-other-heads.401/#post-10405
http://garage.grumpysperformance.com/index.php?threads/removing-valve-seals.4283/#post-11290

Nick Ferrari
http://www.harborfreight.com/catalogsearch/result?q=compression+tester

A compression test reveals the condition of your engine's valves, its valve seats, and piston rings and whether these parts are wearing evenly. Healthy engines should have compression over 100 psi per cylinder, with no more than 10 percent variation between the highest and lowest readings. With a compression tester, a few hand tools, and 20 minutes, you can try this yourself.

STEP 1 Remove the fuel pump and fuel-injection fuses. Disconnect the main wire to the coil and spark plug wires; remove spark plugs.

STEP 2 Start the threaded end of the compression gauge in a spark plug hole by hand.

STEP 3 Turn the ignition on, depress the throttle, and crank the engine four revolutions. This should result in a stable reading; if not, crank up to 10 revolutions, but do the same with all cylinders.

STEP 4 Mark the pressure reading for each cylinder on the valve cover in chalk, then move to the next cylinder.

TIP For a cylinder below 100 psi, pour 1 teaspoon of engine oil into the plug hole and retest. If the reading jumps, the piston rings are worn. If not, think valve problems.

Nick Ferrari

http://garage.grumpysperformance.co...-to-be-a-forgotten-art-form.11838/#post-56133

http://garage.grumpysperformance.com/index.php?threads/vacuum-gauge-help.9453/#post-52071

LEAK DOWN TEST
http://garage.grumpysperformance.com/index.php?threads/leak-down-test.332/#post-14272

http://garage.grumpysperformance.com/index.php?threads/oil-on-plugs.11044/#post-49058

 

[Grumpy]

video with a bit of related info

 

[Grumpy]