News:

It appears that the upgrade forces a login and many, many of you have forgotten your passwords and didn't set up any reminders. Contact me directly through helpmelogin@dodgecharger.com and I'll help sort it out.

Main Menu

What is the vacuum reading of your engine at idle?

Started by Johnnys440Charger, August 27, 2018, 10:27:56 PM

Previous topic - Next topic

Johnnys440Charger

What is the vacuum reading of your engine at idle?  

My 69 Charger:
Stock 440
Holley 650 Double Pumper
Points Ignition
Engine Temp: 190
Cam ?
Engine idle @ 900 RPM
Power Brake Booster

What is the normal vacuum reading for a 69 Charger 440 Automatic?  18-22 ?

440


jefferson


Kern Dog

You are using a 650 double pumper on a stock 440? A street car, right? A vacuum secondary carburetor is a far better choice.  :2thumbs:
My idle vacuum is measured in gear, usually DRIVE. I've had a wide variety of readings since I have had a few different camshafts in the car over the 14 years I've had this 440/493 in the car. The '509 cam from Mopar Performance gave a reading of about 6 hg at a 700 rpm idle. The Lunati solid lifter cam I had was a beast but only gave about 4-5. The cam I have now is another MP cam, the 528 solid. It gives great vacuum, about 11 hg at a 700 rpm idle and almost 18 in neutral at 1000 rpms.

Johnnys440Charger


Johnnys440Charger

Quote from: Kern Dog on August 27, 2018, 11:32:14 PM
You are using a 650 double pumper on a stock 440? A street car, right? A vacuum secondary carburetor is a far better choice.  :2thumbs:
My idle vacuum is measured in gear, usually DRIVE. I've had a wide variety of readings since I have had a few different camshafts in the car over the 14 years I've had this 440/493 in the car. The '509 cam from Mopar Performance gave a reading of about 6 hg at a 700 rpm idle. The Lunati solid lifter cam I had was a beast but only gave about 4-5. The cam I have now is another MP cam, the 528 solid. It gives great vacuum, about 11 hg at a 700 rpm idle and almost 18 in neutral at 1000 rpms.

Great feedback KD    Yes, agree.  swapping the carb for vac secondaries is on my list.
I'm going to chk for vac leaks by removing and capping my brake booster and headlights hoses from the intake.   Chk / increase my timing, idle mixer screws, and distributor gap to maximize my vac reading

Paul G

Vacuum can be adversely effected by an improperly tuned engine.  Do you work on the car yourself or take it in for repairs?

If it has a 650 carb,  which is small for anyting other than a stock build 440 engine, I would expect vacuum in the mid to upper teens.
1972 Charger Topper Special, 360ci, 46RH OD trans, 8 3/4 sure grip with 3.91 gear, 14.93@92 mph.
1973 Charger Rallye, 4 speed, muscle rat. Whatever engine right now?

Mopars Unlimited of Arizona

http://www.moparsaz.com/#

Johnnys440Charger

Quote from: Paul G on August 28, 2018, 07:57:56 PM
Do you work on the car yourself or take it in for repairs?

Myself.   I'm a youtube/charger forums mechanic. 

Kern Dog

Hey, no offense but there is a W I D E range of talent with youtube videos. Some are sharp as a tack and then there are some real hacks!

Paul G

Quote from: Kern Dog on August 28, 2018, 10:14:32 PM
Hey, no offense but there is a W I D E range of talent with youtube videos. Some are sharp as a tack and then there are some real hacks!

You aint kidding. Even I put some on there.  :P
1972 Charger Topper Special, 360ci, 46RH OD trans, 8 3/4 sure grip with 3.91 gear, 14.93@92 mph.
1973 Charger Rallye, 4 speed, muscle rat. Whatever engine right now?

Mopars Unlimited of Arizona

http://www.moparsaz.com/#

M5Ivan


Just 6T9 CHGR

My 440 with an Engle cam (228 @ .050 with .504 lift) gets 16" at idle ....running Eddy Thunder Series 800cfm
Chris' '69 Charger R/T


Kern Dog

Maybe I missed it...are you asking about in gear/automatic?

Johnnys440Charger

Quote from: Kern Dog on August 29, 2018, 05:24:18 PM
Maybe I missed it...are you asking about in gear/automatic?

I didn't know there was a difference.   But I guess I was more wondering who here on the forums makes the most vacuum with their 440 engine?  Just curious. 

Kern Dog

There is a huge difference, especially when the cam is long on duration. Timing plays a huge role as well.

70sixpkrt

My combo makes 15" of vacuum and it's a 4 speed.

440 bored .030=446
KB 237 pistons .003 deck height
Forged crank .010 under
Eagle 4340 H-beam rods
Comp is 10.25:1
Eddy heads 84cc with stage 1 and bowl blend
Straightline Cam 234/242@.050 540/525 solid with 112 lsa (4* built in) installed straight up
6-pack aluminum manifold with stock carbs. (Using ProMax stuff)
Comp pro-magnum 1.5 rockers with 3/8 Smith Bros. pushrods
TTI 1 7/8 headers with 3" X cross-over exhaust to the tips
MSD 8546 dist.
MP MSD 6AL


440-6pk, 4-speed, Dana 60 with 3:54  
13.01 @107.93 (street tires spinning all the way down)