one for all you motor heads..??

[snakeoil24]

The vacuum at idle is 5 Inches? Did you check your intake manifold gasket? I do not mean from above with spraying using a rattle can. Did the intake manifold gasket get replaced with a good layered gasket? The low rpm vacum is some thing more fundemental> Are you using a hyraulic cam or solid lifter cam. If the lifters are collapsed "hydraulic" then you can have low vac. But first eliminate the easy. Is the intake manifold cast Iron or aluminum? Who torqued the intake manifold? Did you follow a pattern in torqing the intake bolts?? Borrow an infafred temp sensor and check each cylinder at idiot for temp variation. If there is a crack in the intake manifold and it is underneath you will only know by inspecting it. Also you said the motor overheated. Was that before or after the vacuum problem showed its ugly head?? Re the heads the correct heads ? Did some one change the heads at the engine shop? They need to be inspected once you take off the intake.

 

[65-440]

5 inHg of vacuum at idle is not abnormal if you have a decent cam. you can pretty much rule vacuum out of any diagnosis procedure ! mine is around 5-7inHg at 1000RPM idle ... anything less than 1000RPM and she's not happy .... what is your idle set too ?? another thing to keep in mind is the carb size, i wont run anything less than a 850cfm on my 440, but then again it all depends how you drive the car ( cruising or drag ) ...

 

[tirefryin-Bob]

Thanks for your reply 65-440, The engine is pretty much stock (read previous post). I've come to the conclusion the previous owner installed blower / turbo pistons in her. the compression is too low.. probable has 8.0:1 / 8.5:1 pistons.. It was already rebuilt so I'm thinking of just swapping over to Closed chambered head (516's), everything I've read says this should raise the compression about a point 9.25:1. visa-virsa when switching to Open Chamber..

 

[65-440]

Thanks for your reply 65-440, The engine is pretty much stock (read previous post). ..

sorry, didnt pay attention !

even with low compression pistons and all cylinders even around 110PSI i would think it should still run smooth. would have a lack of power, but idle smooth. i could be wrong ........

 

[snakeoil24]

Check the Intake for leaks, improper alignment of intake to head from milling heads. Is the open chamber heads matched to a open chamber piston "proper compression ratio for the right head. A good compression should be more like 150 per cyliner with a 10-15 percent max variation. Then next is check your timing chain to see if you skipped a tooth/

 

[scotts74birds]

Bob, I dont know if this applies to you but on my 383 I replaced the torker intake with a Performer RPM. Had problems ever since. I took off a valley pan with the 4 paper gaskets. I used the fel-pro 1214 gasket kit with the 4 paper gaskets and 1 valley pan.....TWICE! Never ran right, but could NOT find a vacuum leak. Tried a fel-pro MS 900? something whatever. It was the valley pan only kit, using Hylomar sealer on both the intake and head side for the pan. Problem solved. Scratched my head and wondered if the heads or deck had been cleaned-up? Just my 2cents. I assume a 440 could have a similar issue. Good luck!

 

[426HemiCharger]

What is your idle speed a curb idle? fast idle?

This is a link I found:
Proper engine operation should result in an even vacuum reading from 15 inches to 20 inches of vacuum with 15 inches of Mercury being more appropriate for high performance type engines.

1. A vacuum reading that cycles up and down slowly could indicate a fuel mixture problem from improper carburetor or fuel injection operation.

1. TracyPerf©98
   [*]Low vacuum readings may indicate intake valve, manifold, or carb gasket leaks including internal or external manifold leaks. Spray carb cleaner around suspected areas to test for leaks.
   [*]Plugged catalytic converters, stuck heat riser valves, plugged intake crossover heat passages, crushed exhaust pipes, plugged mufflers, (check out that mouse nest in the exhaust!), and similar restrictions will usually lead to very low vacuum readings.
   [*]Excessively carbon in engines or those that did not get their oil changed often enough may result in sudden vacuum reading changes when valves stick. It could happen at any engine speed and may temporarily cure itself by quickly changing engine speeds.
   [*]Lower vacuum readings directly related to engine misfiring may be a result of a burned exhaust valve.
   [*]Constantly changing vacuum readings at low engine speeds may indicate a problem with worn valve stems, guides, or seals. Higher engine speeds tend to temporarily cancel out this problem.
   [*]High-speed vacuum readings that change may be a result of broken or tired valve springs, while low engine speed vacuum readings tend to be constant. TracyPerf©98
   [*]High performance or race cams tend to result in lower vacuum readings.
   [*]Make sure that the cam and lifters are matched, (solid/solid, hydraulic/hydraulic, roller hydraulic/roller hydraulic, solid roller/solid roller), etc. Strange things happen when these items are mismatched, although some will actually run that way. Cam indexing/timing will also affect these readings. Also check for sloppy timing chains, and improper or changing ignition timing.

 

[tirefryin-Bob]

Thanks for the replies and Info Guys.. I can say for sure, It doesn't have a vacuum leak!!! I've changed the intake gasket(s) and checked (sprayed) on and around the carb, intake & heads.. I've come to the conclusion from previous post this motor (in stock form) has way too low compression..

 

[tirefryin-Bob]

Up-Date.. I know it's been awhile so here goes. I've decided to replace the motor completely. There is something wrong with this current 440 motor and since it's been rebuilt before I purchased the car I don't know what went in to it, I just don't trust it. I do know now it was bored .060 over and may have had improper rings / pistons installed.
Now for what's going in, Since my 65' satellite isn't a original BB car I found a 65' Chrysler 300 in a junk yard that just so happened to had a complete 413HP motor in it. Long story short - the motor was in great shape and only needed .030 to clean-up, Crank mains & rod journals needed only .010 / .010. Found a company that made some forged pistons for it. Got all the machine work done. So starting to tomorrow I get going on re-assembly. Now if I can just remember what to do first since it's been a decade or so LOL..

 

[charger360]

i will bet you it is your timming. your balancer may have slipped. try the vac gauge method see if it helps if so you need to do the piston stop method and see if your mark on your balancer is really in the right spot! if you are driving around with retarded timing it will run hot have low vac. and idle rough. sound familiar?

 

[tirefryin-Bob]

charger360, That does sound VERY familiar.. I'm sure I did check the balancer but since it's been a year or so ago I'm going to re-check it again this Saturday. All the plugs are out of it so I'll verify number#1 piston is @TDC and see where the timing mark is. You just may have something here!!!

 

[tpodwdog]

idle mix issue. my 440 hypo did the same thing. back out the adjustment screws a little at a time and obtain the highest idle you can get then reduce idle with curb idle screw. i just been thru this a month ago. !

ya dont need to have meters all over the car. use your ear and feel. i got 3 classics and i have YET to put a meter or even a timing light on any of them and you can get in them at any given time and drive off and feel confident that it will bring you back home. no 2 cars are the same and no 2 cars will act the same. i see alot of too much diagnosis and some guys will make your head spin off with too much information. do the simple things first. it will save you time, money, and most importantly,,,,aggrivation.

 

[Hemi Rebel]

Thanks for your reply 65-440, The engine is pretty much stock (read previous post). I've come to the conclusion the previous owner installed blower / turbo pistons in her. the compression is too low.. probable has 8.0:1 / 8.5:1 pistons.. It was already rebuilt so I'm thinking of just swapping over to Closed chambered head (516's), everything I've read says this should raise the compression about a point 9.25:1. visa-virsa when switching to Open Chamber..

If this is the case, the only reasonable solution is to put a blower on it!:hello2:

 

[fatecaptured]

idle mix issue. my 440 hypo did the same thing. back out the adjustment screws a little at a time and obtain the highest idle you can get then reduce idle with curb idle screw. i just been thru this a month ago. !

ya dont need to have meters all over the car. use your ear and feel. i got 3 classics and i have YET to put a meter or even a timing light on any of them and you can get in them at any given time and drive off and feel confident that it will bring you back home. no 2 cars are the same and no 2 cars will act the same. i see alot of too much diagnosis and some guys will make your head spin off with too much information. do the simple things first. it will save you time, money, and most importantly,,,,aggrivation.

That's funny you say that. My head hasn't stopped spinning since I started working on my engine. But it's nice to learn all these diagnostics and try them out on my old charger. I plan on a rebuild, but i've been tinkering with it and trying out all these tricks. I just recently discovered that a compression test and a leak down test are 2 different things. Hell I thought they were the same... DER!