Rebuilt Small block-zero compression??!!!
Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 845
Likes: 54
From: Bangor, Northern Ireland
Rebuilt Small block-zero compression??!!!
Hi, i've just freshened up my SBC, trying to get her started and i've got zero compression, i've rechecked everything including valve clearances but still nothing on the compression tester (Edelbrock RPM hydraulic cam), the car was running before the rebuild and the only changes are the 0.015 fel pro head gaskets, Help!! ideas guys no matter how obvious/bizarre
thanks.
thanks.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
New rings? Give each cylinder a couple shots of oil. turn it over slowly to spread it around, plugs back in and try it. New cylinder/rings will wash very easy and compression goes to zip.
Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 845
Likes: 54
From: Bangor, Northern Ireland
Tried that, still nothing, i think i'm looking at a ring problem maybe?
There is no sound of air as you spin the engine over without the plugs in and it wont push out a piece of tissue either
Compression gauge doesn't move at all
There is no sound of air as you spin the engine over without the plugs in and it wont push out a piece of tissue either
Compression gauge doesn't move at all
Intermediate
Joined: May 2009
Posts: 34
Likes: 0
When you say that you freshened it up, what all did you replace? Was there compression on that cylinder before you did the work? I am with everyone else on this that it really sounds like a valve train issue as generally speaking there are two compression rings and the oil retention rings so if the rings were shot you should still be getting something. You have to have a pretty large leak to get zero when cranking it over.
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Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 845
Likes: 54
From: Bangor, Northern Ireland
Put some oil in the bores-nothing
3 of us are standing round the car scratching our heads and ready to call it a day when i suggested backing off the valve clearances (again) so that they were very loose, spun the engine over and it sprayed oil all over the engine bay
Compression!!!
i'm surprised how far i've had to back the valves off to get the them to seat
We put the plugs back in and spun her over and she sounded good and caught a couple of times, but the battery didn't have enough life left
I've put the battery on charge and will try again tomorrow
cheers guys
3 of us are standing round the car scratching our heads and ready to call it a day when i suggested backing off the valve clearances (again) so that they were very loose, spun the engine over and it sprayed oil all over the engine bay
Compression!!!i'm surprised how far i've had to back the valves off to get the them to seat
We put the plugs back in and spun her over and she sounded good and caught a couple of times, but the battery didn't have enough life left
I've put the battery on charge and will try again tomorrow
cheers guys
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
Did you soak the lifters and pump them full?
you have to spin the push rod as you tighten the rocker.
Gentle. plus get on comp #1 stroke adjust the correct valves,
make sure you pay attention to IN/Ex valves
spin 1 turn of crank and do the rest
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
the instructions for my new lifters say not to do this.
it says you can soak them in oil if you want but that it is not necessary.
it also says absolutly not to pump them up before install
it says you can soak them in oil if you want but that it is not necessary.
it also says absolutly not to pump them up before install
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Redo the valve adjustment before you fire it up. You obviously missed something in the setup and subsequent tries. Back them off and then setup one cyl at a time. If it does manage to fire up and you have a valve hanging open you can burn a seat. Once more thru is cheap insurance
Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 845
Likes: 54
From: Bangor, Northern Ireland
I set them up to zero lash +1/2 a turn cold, this was obviously too much, i've been very careful and taken my time with the engine and yes i soaked the lifters in oil.
i'm going out to try her again in an hour or so, i'll report back
Very excited!
Thanks for your help guys
i'm going out to try her again in an hour or so, i'll report back
Very excited!
Thanks for your help guys
Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 845
Likes: 54
From: Bangor, Northern Ireland
When the car was cold i adjusted them to zero lash +1/2 turn, car wouldn't start
i then took 1/4 off, still wouldn't start
i then took another 1/4 off, then i could feel and hear the compression, so i was back to zero lash, car started
1 then once hot put a 1/4 back on, car wouldn't start
i then took 1/4 back off, car started
basically i've left it at zero lash and i've got a bad back
i soaked the lifters in oil but forgot to pump them up
i then took 1/4 off, still wouldn't start
i then took another 1/4 off, then i could feel and hear the compression, so i was back to zero lash, car started
1 then once hot put a 1/4 back on, car wouldn't start
i then took 1/4 back off, car started
basically i've left it at zero lash and i've got a bad back
i soaked the lifters in oil but forgot to pump them up
Race Director
Joined: Sep 1999
Posts: 11,358
Likes: 379
From: Plano TX
I take it these are hydraulic lifters?
You're still bottomed out, DON'T LEAVE THEM LIKE THIS!
If you can't get the adjustment right with the engine off, you'll have to adjust them with it running. Get a set of rocker oil clips so you don't spray oil all over the place. Take the valve cover off and with the engine idling loosen the rocker until you hear clacking. Slowly tighten until it is quiet and then (slowly) give it another 1/2 turn.
You're still bottomed out, DON'T LEAVE THEM LIKE THIS!
If you can't get the adjustment right with the engine off, you'll have to adjust them with it running. Get a set of rocker oil clips so you don't spray oil all over the place. Take the valve cover off and with the engine idling loosen the rocker until you hear clacking. Slowly tighten until it is quiet and then (slowly) give it another 1/2 turn.