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-   -   Running good gas still have cheap gas sound (https://moparforums.com/forums/f7/running-good-gas-still-have-cheap-gas-sound-8825/)

Foedoe 02-24-2011 11:14 PM

Running good gas still have cheap gas sound
 
When you run crappy arco regular and go up a hill or something you get that valve clickey sound
My 67 318 does this even with chevron premo
No sound during normal acceleration
Why?

Silverick 02-24-2011 11:21 PM

Maybe the distributor timing is advanced a bit much.
Back it off a degree or two and it may make the difference.

Foedoe 02-24-2011 11:33 PM

Its set perfect on 10 below
Should i advance because the little timing bracket might not be accurate or?
What would make the correct timing change

Archer 02-25-2011 05:42 AM

Foe -

That "cheap gas sound" is called detonation and due to insufficient octane in the gas to prevent premature or uncontrolled ignition. Most 318s, unless heavily modified don't have enough compression to cause detonation, unless something else is going on.

Are you sure you know what you're hearing? Some times lifter tapping or even an exhaust leak can fool you. You can try retarding the timing (more than expected) to see if the sound goes away.

Archer

samuelcosmo76 02-25-2011 07:42 AM

my slant 6 used to do that when i would put cheap gas in. the timing was waaaaaay off.......fixed it right up.

440roadrunner 02-25-2011 08:41 AM

Several things, here

"Burning oil" (and it doesn't take much) causes detonation. Look, when you rev the engine, and have someone else watch, when you accelerate hard or let off does it smoke?

An engine that is overheating will detonate, as can one that is severely loaded up with carbon.

Timing. Harmonic balancers are two piece with rubber in between and CAN slip and move. It would be wise to check your timing mark, not all that difficult.

Buy or build a piston stop, like this:

http://www.jerrybramlett.net/images/...stallation.jpg

Saw off the crimp on a plug, drive out the guts, and tap for a bolt. Adjust as needed.

Unhook the battery ground for safety, and get a socket on the front bolt. Check with a soft brass/ plastic probe that no1 piston is "down a ways" and then install the stop

Gently rotate the engine until it stops against the piston stop. You may have to play with the length. You do NOT want the piston to stop terribly near the top, but rather down some

With the engine now rotated and stopped against the tool, make a temporary mark on the balancer directly below the TDC mark on the timing pointer/ tab

Now rotate the engine the opposite direction (CCW) until it stops once more. Again, make a mark on the balancer right under TDC

Now, you'll have two temporary marks on the balancer. TRUE TDC will be exactly halfway in between the two, and if your original mark is correct, that is where it will be.

Now you can check your timing with confidence.

Foedoe 02-25-2011 10:08 AM

Alrigt thanks im gonna tweak my timing today to see if thats all it is
I recently put new gaskets on the exhaust but didnt use thee rtv on the bolts could that cause an oil leak where detonation could result

Foedoe 02-25-2011 05:15 PM

I checked my timing it was right on with the vac advance unhooked but not plugged, i plugged it and it advanced a bit so got it set and it seems like that was it.
Im confused though, ive been adjusting my idle mix on my edelbrock, in order to get around the 50 whatever suction units it has to be idling higher than i think is normal
When i set the idle speed shoul it be in gear or neutral?

440roadrunner 02-25-2011 07:03 PM

The "old guys before smog" way of setting idle mixture was in neutral, at normal idle speed AND FULLY WARMED UP, adjust idle screw(s) until highest vacuum reading or highest idle rpm, then just touch the screw TOWARDS lean

Newer "smog" cars have differing procedures, some said same as above, then lean until gas analyzer said "so and so" and there have been certain propane involved procedures.

There used to be specified idle in neutral and in gear, MOST IMPORTANT is "in gear" because you don't want it to die, nor do you want to have to REALLY drag the brake all the time. Hotter cam, built engine, etc, makes this task more difficult.

badsport 03-08-2011 07:47 AM


Originally Posted by Foedoe (Post 64300)
Alright thanks I'm gonna tweak my timing today to see if that's all it is
I recently put new gaskets on the exhaust but didn't use the rtv on the bolts could that cause an oil leak where detonation could result

Did you have the clicking sound before you replaced the gaskets?

You should put sealant on the front and rear bolts as they go into the water passage, all others are blind holes.


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