Compression/leakdown and fills up catch can after 2x passes
06-29-2013, 10:59 PM
#1
Teching In
Thread Starter
Join Date: May 2010
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
Compression/leakdown and fills up catch can after 2x passes Motor Specs - ls1 block 347/ diamond high compression dome pistons bore 3.905 stroke 3.622/ t-Rex cam/ absolute speed stage 2.5 5.3 heads "similar to prc". Runs on 116. 12.96 to 1. Issue is I'm getting around 240 average psi on compression test on all cylinders except on cylinder #2 which I got 190psi. Then I ran it to operating temp for a leak down test and decide to see if my compression test would get better or worse. I got 180psi on the same cylinder. Then I did a leak down test on the cylinder and got 8% on it. Should I be worried about this cylinder? The car is untuned and runs on big stuff 3. I'm about to trailer the car the car 6 hours to be tuned and pay around 1k. Main issue with the car is after 2 passes it fills the catch can and blows the oil cap off. I've added pictures of how the catch can was setup and I really don't want to drill/tap these valve covers as they look clean. I've added pictures for suggestions. Appreciate any help, and sorry if its hard to read as I've posted with my cell phone.
06-29-2013, 11:19 PM
#2
TECH Fanatic
iTrader: (9)
Join Date: Apr 2012
Location: Georgetown, Tx
Posts: 1,053
Likes: 0
Received 0 Likes
on
0 Posts
I think you've answered you own question by going to this length already to figure out what the issue is. That said, with the variance on #2 you seem to have an issue. If it were me, I sure wouldn't take it for a tune that was going to cost me 1k knowing it had a leak down and compression issue.
06-30-2013, 12:29 AM
#4
Teching In
Thread Starter
Join Date: May 2010
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
I think you've answered you own question by going to this length already to figure out what the issue is. That said, with the variance on #2 you seem to have an issue. If it were me, I sure wouldn't take it for a tune that was going to cost me 1k knowing it had a leak down and compression issue.
06-30-2013, 04:14 AM
#5
Yeah, 8% is nothing too bad. I have a cylinder that is 12% (cold though) and use no oil . Im thinking its got to be something with the catch can setup. I cant tell anything from your pictures. Is that the only line on the can? Where is it going? How is fresh air getting into the case?
06-30-2013, 01:33 PM
#7
Teching In
Thread Starter
Join Date: May 2010
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
Trending Topics
06-30-2013, 06:20 PM
#8
Man that is not good. You will blow the most inconvenient seal on any motor like that. At least it always seems that way, LOL.
You need a vent. I think what is happening now is the pressure builds up and pushes the oil into the can. If you vent the filler or preferably both VCs it should help a lot.
You need a vent. I think what is happening now is the pressure builds up and pushes the oil into the can. If you vent the filler or preferably both VCs it should help a lot.
