How much vacuum do you have?

[FlaBoy]

I got my car back on the road, and after so long without driving it, I can't remember what good values are for some of the basic stuff (vacuum, oil press. etc).

I searched and found answers for most of the stuff, but couldn't find any help on what sort of vacuum a hotair car should see. I currently have 13-15" when warmed up at idle in park (slightly less when I drop it into gear). I seem to vaguely remember that being about correct, but I'm not sure. When re-assembling the motor, I did my best to inspect all the vacuum lines for damage (I replaced them all a few years back) and I tie-wrapped them them all to their respective barbs/connections, so hopefully I shouldn't have any significant leaks. I'm just wondering if these numbers are about right, or if they are low and I should do a thorough re-check to make sure I don;t have a leak somewhere.

Thanks!

 

[novaderrik]

mine is right in that range, with about 10" in gear.

 

[fyrlt67]

That is about the range I am in also 15 in park around 10 in gear

 

[Jerryl]

I got my car back on the road, and after so long without driving it, I can't remember what good values are for some of the basic stuff (vacuum, oil press. etc).

I searched and found answers for most of the stuff, but couldn't find any help on what sort of vacuum a hotair car should see. I currently have 13-15" when warmed up at idle in park (slightly less when I drop it into gear). I seem to vaguely remember that being about correct, but I'm not sure. When re-assembling the motor, I did my best to inspect all the vacuum lines for damage (I replaced them all a few years back) and I tie-wrapped them them all to their respective barbs/connections, so hopefully I shouldn't have any significant leaks. I'm just wondering if these numbers are about right, or if they are low and I should do a thorough re-check to make sure I don;t have a leak somewhere.

Thanks!

There are a few things to consider;
A stock engine with a stock cam should be pulling around 16-18 inHg.
If you are not pulling that much, you could have a leak (controlled or un-controlled) or a weak motor.

If you have a leak, it will show in your idle BLM's.
I had a FRESH set of ported heads leak on a valve, so don't take anything for granted. Only way to tell is with a leak down test.

Also, don’t underestimate the affect of the vacuum reading with rpm, IAC setting, and the PCV. I was seeing 14-16 at 825-850 rpm with a 212/212 cam, hot idle on Powerlogger, 3 bar map PCV connected.
Oh, and I KNOW the engine was weak.
............. your gage may be off as well.