Need L46 acceptable compression values
Thread Starter
3rd Gear
Joined: Aug 2008
Posts: 3
Likes: 0
From: Fair Oaks CA
Need L46 acceptable compression values
I have a 69 with the L46 motor.
Ran dry compression test and got 205 to 225.
Is that OK?
I'm blowing oil through and assume that if I am within range, all I need to do is valve guides.
I was told that if I do a full valve job on it, I might blow the rings out.
This oil burning is the only flaw in the car and it runs strong. I want to sell it, so I don't want to do more than necessary (full motor rebuild).
Also. I can't figure out how to adjust the heat/cool temp. I assume that the center console dials adjust air distribution and fan, but they don't seem to adjust the temp. of the air??????
I also need to find a site where I can punch in the VIN and find out what numbers (block, heads, tranny, etc.) were tied to the original car. Know of a good site?
Please advise.
Thanks.
Last edited by Mark Stoffel; Aug 6, 2008 at 08:43 PM.
Le Mans Master
Joined: Apr 2005
Posts: 6,355
Likes: 425
From: Seattle Area WA
Sounds like you need to get some good answers.
A compression test does not do much except tell you if all cylinders are within the same range within reason. Now if you add some oil to the cylinders when doing it, and the compression numbers go up, you could have some loose rings.
I prefer a leak down test for engine health.
What does "blowing oil through" mean?? Is your car burning oil, smoking upon start up or all the time?? If you are burning lots of oil you could need a full rebuild. A new valve job does nothing to "blow out your rings".
I'm not aware of any website or database that you punch in your VIN and get magic numbers.
What does the engine stamp pad say?
A compression test does not do much except tell you if all cylinders are within the same range within reason. Now if you add some oil to the cylinders when doing it, and the compression numbers go up, you could have some loose rings.
I prefer a leak down test for engine health.
What does "blowing oil through" mean?? Is your car burning oil, smoking upon start up or all the time?? If you are burning lots of oil you could need a full rebuild. A new valve job does nothing to "blow out your rings".
I'm not aware of any website or database that you punch in your VIN and get magic numbers.
What does the engine stamp pad say?
Last edited by Scott Marzahl; Aug 6, 2008 at 09:51 PM.
Thread Starter
3rd Gear
Joined: Aug 2008
Posts: 3
Likes: 0
From: Fair Oaks CA
Thanks for the reply Scott.
I don't know if it burns oil or not. I only have 30 miles on it since I traded it for my 34 Ford.
It gives of blue smoke at start-up almost all out of the left side. Doesn't seem to do it every time.
I'll oil down the cylinders and test again.
Where/what is the "stamp pad"? Block casting is 3956618. Can't find head #s.
I don't know if it burns oil or not. I only have 30 miles on it since I traded it for my 34 Ford.
It gives of blue smoke at start-up almost all out of the left side. Doesn't seem to do it every time.
I'll oil down the cylinders and test again.
Where/what is the "stamp pad"? Block casting is 3956618. Can't find head #s.
Le Mans Master
Joined: Apr 2005
Posts: 6,355
Likes: 425
From: Seattle Area WA
The head castings are under the valve cover. Your block casting is correct, just need to find the date cast into it now. Put some miles on it but it sounds like possible valve guides or valve stem seals.
Race Director
Joined: Apr 2003
Posts: 19,351
Likes: 654
From: Tampa, Florida
A '69's VIN number will tell you nothing about the car as far what it came with from GM. Start with your block, its numbers should correspond with the VIN number. Engine were stamped to match VIN's versus VIN's stating the enigne. VIN's didnt say what engine was in a car until '71.
If the engines number doesnt match the VIN you can look for things like:
1. U-joint caps
2. 1 or 2 fuel lines
3. 4sp. or auto
4. radiator and expansion tank style
5. and a bunch of other thingd
If the engines number doesnt match the VIN you can look for things like:
1. U-joint caps
2. 1 or 2 fuel lines
3. 4sp. or auto
4. radiator and expansion tank style
5. and a bunch of other thingd
