Leakdown Testers - Page 2

mschafer · 11-26-2021, 10:37 AM

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

Dave Bergfeldt · 11-28-2021, 06:12 PM

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

sst5167 · 11-29-2021, 09:13 AM

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.

reknapp52 · 12-12-2021, 04:27 PM

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.

SGSST109E · 12-13-2021, 07:43 AM

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

sst7250 · 12-14-2021, 02:01 PM

Had an OTC for years with no issues

Mike Pearson · 12-18-2021, 02:24 PM

Quote:

Originally Posted by reknapp52

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.

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.

garyc · 01-31-2022, 02:49 PM

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

garyc · 01-31-2022, 04:50 PM

most times leak down was used to find a dead cylinder

FED 387 · 01-31-2022, 06:29 PM

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

11-26-2021, 10:37 AM	#11
mschafer Junior Member Join Date: Oct 2014 Posts: 42 Likes: 0 Liked 9 Times in 8 Posts	Re: Leakdown Testers I have a OTC also ,works well and would recommend it.

11-28-2021, 06:12 PM	#12
Dave Bergfeldt Junior Member Join Date: Jan 2010 Posts: 31 Likes: 32 Liked 8 Times in 6 Posts	Re: Leakdown Testers Do Not .... I repeat Do Not get the Harbor Freight unit ... Difficult to use ... inaccurate numbers!!!! __________________ Dave Bergfeldt 106 SST/SG

11-29-2021, 09:13 AM	#13
sst5167 Junior Member Join Date: Dec 2009 Posts: 52 Likes: 17 Liked 17 Times in 9 Posts	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.

12-12-2021, 04:27 PM	#14
reknapp52 Junior Member Join Date: Nov 2008 Location: Cascade, CO Posts: 48 Likes: 22 Liked 7 Times in 5 Posts	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.

12-13-2021, 07:43 AM	#15
SGSST109E Member Join Date: Jun 2007 Location: NJ Posts: 342 Likes: 54 Liked 124 Times in 58 Posts	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

12-14-2021, 02:01 PM	#16
sst7250 Member Join Date: Jan 2009 Location: Las Vegas, NV Posts: 177 Likes: 9 Liked 38 Times in 28 Posts	Re: Leakdown Testers Had an OTC for years with no issues

01-31-2022, 02:49 PM	#18
garyc Member Join Date: Mar 2021 Posts: 124 Likes: 0 Liked 51 Times in 30 Posts	Re: Leakdown Testers whats normal leak down on a new motor? does it matter what ring package? thanks mike Last edited by garyc; 01-31-2022 at 04:49 PM. Reason: previous post

01-31-2022, 04:50 PM	#19
garyc Member Join Date: Mar 2021 Posts: 124 Likes: 0 Liked 51 Times in 30 Posts	Re: Leakdown Testers most times leak down was used to find a dead cylinder

01-31-2022, 06:29 PM	#20
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,349 Likes: 320 Liked 280 Times in 150 Posts	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

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