OzVMX Forum
Clubroom => Tech Talk => Topic started by: FAT-TOY on March 24, 2017, 08:25:29 pm
-
Going to make a leak down tester and looking for a design that works and is cheap to make. Anyone made one and willing to draw a mud map. Biggest problem seems to be finding a low pressure guage at a reasonable price, something that would be easy to see any loss of pressure.
Zane
-
I bought a blood pressure thing that you wrap around your arm for $20 ( new) and used the gauge pump and hoses. Worked great .
-
check out café husky, lots of stuff on leak down testing there...big thing with huskys apparently ::)
-
I bought a blood pressure thing that you wrap around your arm for $20 ( new) and used the gauge pump and hoses. Worked great .
very clever !
-
Going to make a leak down tester and looking for a design that works and is cheap to make. Anyone made one and willing to draw a mud map. Biggest problem seems to be finding a low pressure guage at a reasonable price, something that would be easy to see any loss of pressure.
Zane
Are you looking for a 4 stroke leak down tester or something to check a 2 stroke crankcase?
-
I want it for 2 stroke motors. I can buy a Go Kart pop off gauge which includes a pump for about $60 which can be converted into a leak down tester easily but I think I would rather make my own.
-
You could buy something like this.
http://www.ebay.com.au/itm/New-Fuel-Pump-Vacuum-Tester-Gauge-Leak-Carburetor-Pressure-Diagnostics-with-Case-/401206459158?hash=item5d69c4bb16:g:LUsAAOSwLF1X~1Xf
Just got to make some adapters and add a tyre valve and your in business.
-
I used airline fittings on mine. Blood pressure jobbie for the pump, whack in a gauge, hand vacuum pump with gauge and an airline fitting, made up a spark plug adapter with a sealing o ring.
Couple of rubber crutch tips for the manifold and exhaust, bit of vaseline and all good.
-
Lots of good choices to experiment with!
maybe try standing on your hands whilst taking a pee, that should go with the rubber crotch and vaseline thingo I think...
-
Picked up a Rubber pump bulb for $2 (similar to blood pressure tester) also a 15 psi low pressure gauge for $4. My local bike shop has a air delivery hose screw on type for $4. So with a bit of hose and a small brass tee that I already have I can make it for around $10.
Zane
(http://i907.photobucket.com/albums/ac276/zane255/leakdown_zpstumhuaxt.jpg) (http://s907.photobucket.com/user/zane255/media/leakdown_zpstumhuaxt.jpg.html)
-
I bought one, like this, for a really, really, good price. (gotta love an on-line Auction)
http://www.ebay.com.au/itm/Leak-Down-Engine-Cylinder-Head-Leakage-Detector-Tester-Tool-Kit-Car-Truck-Auto-/131647121913?hash=item1ea6c7a9f9:g:OOsAAOSwzgBY0cAK (http://www.ebay.com.au/itm/Leak-Down-Engine-Cylinder-Head-Leakage-Detector-Tester-Tool-Kit-Car-Truck-Auto-/131647121913?hash=item1ea6c7a9f9:g:OOsAAOSwzgBY0cAK)
Idea is to block the outlet (create 'zero leak') then set the testing pressure with the regulator, (therefore a constant test pressure).
Connected to a cylinder, (2 or 4T) you read the leak rate on the second gauge as a percentage pressure loss.
2T's Loss from rings or head or plug seal with piston rings above exhaust or wherever with inlet & exhaust blocked.
4T's you can listen at the exhaust and inlet ports, for leakage from valves.
Best as a comparison test, against a known good (new parts & bedded in) assembly, than an absolute reading.
Use to monitor wearing in & then wearing out.
One TRAP for Young(ish) players with the Chinese kits. The hose must be the same one they use for the Compression Tester Kit.
It has a Schroeder valve at the bottom.......No leaks are detectable with this valve in place.
I also replaced the air fittings with Nittos (personal preference).
Cheers, Daryl.
-
I put some pictures of the one I made on CafeHusky.
(http://i470.photobucket.com/albums/rr61/grouty60/Husqvarna%20390%20Auto%20Build/DSC00393_zpsfhlbkcry.jpg) (http://s470.photobucket.com/user/grouty60/media/Husqvarna%20390%20Auto%20Build/DSC00393_zpsfhlbkcry.jpg.html)
The low pressure pump I already had. Not that expensive from Ebay. I bought this to put air in the old KLX forks.
The rubber cap came from a fish tank shop, I use this to seal the exhaust manifold. I turned up a piece of scrap alloy bar to mimic the end of a Mikuni carb. It has a small hole through the middle. The outer end is drilled 1/8 NPT to accept a low pressure gauge (cheap on ebay). Another hole is drilled at 90 degrees and again tapped 1/8 NPT for a Scrader valve (similar to one in Ohlins shocks) from ebay. The whole thing (less the hand pump) cost less than $40 (AUS).
I mainly built this to check the seals on the main beraings and the reed housing.
-
finished it today but didn't use the rubber bulb as planned. A mate dropped in an old foot type pump, so I changed the gauge on it from a 100 psi to a 15 psi so it's now a lot easier to see if I have a leak (5 psi takes up a third of the gauge). I have a fitting on the valve end of the hose which actually screws onto the valve and uses a screw on the back to hold the valve open., So even though I didn't use all of the bits I purchased it still came in at under $10.
Zane
(http://i907.photobucket.com/albums/ac276/zane255/Leakdown%20Tester%202_zpsebg3bqcv.jpg) (http://s907.photobucket.com/user/zane255/media/Leakdown%20Tester%202_zpsebg3bqcv.jpg.html)
(http://i907.photobucket.com/albums/ac276/zane255/Leakdown%20Tester%201_zpsw7vxzsdi.jpg) (http://s907.photobucket.com/user/zane255/media/Leakdown%20Tester%201_zpsw7vxzsdi.jpg.html)
-
cool work