Re: Leakdown Testers
 

I have a OTC also ,works well and would recommend it.

Re: Leakdown Testers
 

Do Not .... I repeat Do Not get the Harbor Freight unit ... Difficult to use ... inaccurate numbers!!!!

Re: Leakdown Testers
 

I bought mine off a Cornwell truck quite a few years ago. I use mine after every race on both car as part of my routine maintenance, and it's been perfect. I would buy another one if I needed too.

Re: Leakdown Testers
 

Turns out my brother has a Matco tester that I will be using. Do I need to warm the motor before running the test? It's been parked in my garage for about 3 weeks without being started. Also, what numbers are acceptable? My motor is 447 C.I. with 14.3 compression.

Re: Leakdown Testers
 

You can leak a motor cold or hot. Just do the same thing each time. A warm motor should leak alittle better the cold. If doing cold just spin the motor over a few revolution to make sure you have some oil on the walls. Certainly under 10% mine usually leak 3 to 5% when fresh cold

Re: Leakdown Testers
 

Had an OTC for years with no issues

Re: Leakdown Testers
 

Depends a lot on the ring type and end gap. Also piston to wall clearance will effect the readings. 10 or better is what you are looking for. You don’t want any blow by on the intake valve. That is a killer. Also equal across all cylinders is another good sign. Leak down is a tool not a tell all.

Re: Leakdown Testers
 

whats normal leak down on a new motor? does it matter what ring package?
thanks mike

Re: Leakdown Testers
 

most times leak down was used to find a dead cylinder

Re: Leakdown Testers
 

definitely less than 10% and if you have gapless end rings less than 5%---if its a tight motor AND NEW never started you are going to see about 3-4 to maybe 5 - 6 %---watch for variations between the cylinder readings especially those cylinders that are next to each other-- not small ones like a few percent but big differences like 10-30%--FED 387