My father has a 1972 Dodge Charger with a 318ci engine and 340heads. He also runs 7psi through it from a B&M Mini-blower(small 471 type)
Lately he has been getting some mild detonation at higher RPMs.
My 1st suggestion for him was to run some colder plugs and look into some different plugs wires. From there, I am lost. I am sure theres some sort of MSD or Mallory product out there to retard timing a bit.
I have also suggested bumping octane a bit via a Toluene Mix or running a Mix of 100/104 Octane with 93.
Anyone?

 

Was it always having detonation problems or did they just start? I don't see why you would go changing things before figuring out what the orginal problem is.

Has the car been sitting? Did the carb get dirty? Is the gas old and is it going stale? The only thing I can think off the top of my head is the additives they are putting in gas right now. Did he try changing the high speed jet to richen it up a little more. What carb is he running?

 

Well, I just think he didn't take it that high before. The "Pinging" just started recently. The car sits all winter and is lucky to see 500miles of driving a year. I believe he uses some sort of GAS STABIL to store it. Our garage is warm, but not that warm by an means.
He is running an Edelbrock 750 I believe.
Maybe he should drain the gas and start from scratch to begin??
When we were talking about it last night, we figured starting with the less expensive stuff would be the 1st move. Change the plugs, and if that doesn't do it, move on from there.
As of right now, he has done nothing to remedy this problem other than NOT driving it hard. I was even thinking of hooking up my wideband to it to see whats going on with a/f ratios. Hes running about 8.5:1 Compression and 7psi, so that part makes sense from what I understand of these IRON Beasts.
Thanks!

 

i would def drain the gas and start again with fresh gas.

 

First off : change gas, then Spark plug dont go colder it wasn't detoning before with the actual heat range you got.

get a close look at the Dizzy cap and Spark plug wire, there is often corosion induced by whinter storage, look at the point in the Dizzy cap.

after this, make shure the timming didn't moove a tad, or time it back to the original point.

hope this help
jp

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kranked91dx &raquo;</TD></TR><TR><TD CLASS="quote">after this, make shure the timming didn't moove a tad, or time it back to the original point. </TD></TR></TABLE>
if the timing is OK for a quick fix just retard the base timing a couple of degrees until you figure out the true source of the problem. maybe the ignition vacuum advance is just too much?

(this is all assuming he's running conventional distributor and not electronic, since you didn't specify)

sweet ride by the way!!!

 

Thank you so much guys!
I bet the fuel is his problem!
I am anxious to go for a ride when its solved....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by notoriousB &raquo;</TD></TR><TR><TD CLASS="quote">

sweet ride by the way!!! </TD></TR></TABLE>

this is how it started 14yrs ago. Primer Gray, diarhea brown seats, stock 125k mile 318ci 2 bbl. When he 1st bought it, his ideas were basic:
Paint the car Stock White
Swap on a 4bbl Carb
Die the interior black.....
Well, 14yrs.....A nasty engine build, ridiculous paint job, and full custom interior later he has a SURE THING Show Winner. I believe at last count he had over 100 trophies with about 70-80% Being 1st Place in class or BEST OF SHOW/Judges Pick!

Thanks again guys!

This was my beginning in the Car World....Notice the date!!

My MOM is crazy too! This is before the FLAME Job!!!



Modified by NirVTECn2o at 6:04 PM 6/30/2006

 

I was reading a couple of days ago about pump gas getting even worse. I guess on june 1 they took out mtb's (which im not exactly fimiliar with). It doesnt actually lower the gas octane but, i guess the mtb is a anti knock agent. Its just making it even harder to make power on pump gas

 

Damn....that mixed with some old gas would cause this for sure!
We're going to start with the gas tank drain, and I have a feeling this will do the trick!
Thanks again guys! Hope you enjoyed the pics!

My Mom's 1946 Ford Coupe(350 Chevy powered) has since been repainted and treated to a Nasty FLAME job! Orange/yellow/white with a thin blue outline!

I still have a love for ANY V8 that is Pre-1974. Thats when everything went downhill!