| Author |
Message |
zac_atac44
Samba Member
Joined: September 18, 2011
Posts: 269
Location: Tennessee
|
 Posted: Sat Aug 02, 2014 5:25 pm Post subject: Compression question (Rookie) |
 |
|
I have a question for you. I got the right side jugs and head on today. After I got everything torqued down I rotated the crank with the flywheel. Just for fun i put my finger over the spark plug hole. I felt "good" compression behind my finger, but when I stopped turning the crank I heard air blowing by the piston. It sounded like it was blowing back into the case. I dont want you to think that it sounded like a crazy amount of air blowing by, but it was quiet in my garage at the time and it was just something that I noticed. I dont expect the rings to have perfect sealing but what is excepable blow by? Is this normal?
Additional information:
-All ring gaps have checked out.
-This is a new build and I only have one side of the jugs on.
-First build and I am just making sure that i havent screwed something up.  |
|
| Back to top |
|
 |
Glenn 
Mr. 010
Joined: December 25, 2001
Posts: 79507
Location: Sneaking up behind you
|
| Posted: Sat Aug 02, 2014 5:28 pm Post subject: |
|
|
If the rings are staggered then they are not seated... new rings do leak.
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
Member #1009
#BlueSquare
עַם יִשְׂרָאֵל חַי |
|
| Back to top |
|
|
zac_atac44
Samba Member
Joined: September 18, 2011
Posts: 269
Location: Tennessee
|
| Posted: Sat Aug 02, 2014 5:30 pm Post subject: |
|
|
| They are staggard and new. So I need to wait untill a good break in before I worry about leak by? |
|
| Back to top |
|
|
Glenn
Mr. 010
Joined: December 25, 2001
Posts: 79507
Location: Sneaking up behind you
|
| Posted: Sat Aug 02, 2014 5:33 pm Post subject: |
|
|
Are the valves adjusted?
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
Member #1009
#BlueSquare
עַם יִשְׂרָאֵל חַי |
|
| Back to top |
|
|
zac_atac44
Samba Member
Joined: September 18, 2011
Posts: 269
Location: Tennessee
|
| Posted: Sat Aug 02, 2014 5:36 pm Post subject: |
|
|
| Havent done any work on the valves yet. Just getting long block set up. Dont even have the rockers or push rods in yet |
|
| Back to top |
|
|
modok
Samba Member
Joined: October 30, 2009
Posts: 27667
Location: Colorado Springs
|
| Posted: Sat Aug 02, 2014 5:45 pm Post subject: |
|
|
That's normal, don't worry about it. The compression will leak out in 2 or 3 seconds.
Rings don't seal 100%, and after all what matters is how they seal when it is heated up and running. |
|
| Back to top |
|
|
zac_atac44
Samba Member
Joined: September 18, 2011
Posts: 269
Location: Tennessee
|
| Posted: Sat Aug 02, 2014 5:48 pm Post subject: |
|
|
| Thanks modok thats what I needed to hear. |
|
| Back to top |
|
|
Brian71
Samba Member
Joined: January 22, 2005
Posts: 183
Location: Prineville, OR
|
| Posted: Sat Aug 02, 2014 8:01 pm Post subject: |
|
|
| Its not the spring in the piston rings that seals them, its the air pressure between the split |
|
| Back to top |
|
|
mark tucker
Samba Member
Joined: April 08, 2009
Posts: 23950
Location: SHALIMAR ,FLORIDA
|
| Posted: Sun Aug 03, 2014 9:59 am Post subject: |
|
|
| Brian71 wrote: |
| Its not the spring in the piston rings that seals them, its the air pressure between the split |
not!! |
|
| Back to top |
|
|
|
