Hot Rods Dodge Hemi 270 Help

Nice!

 

How did you determine that there was a weak spark on #1 and #8? Really, I'm curious as to how you tested to arrive at that conclusion. A coil in poor shape [occasionally arcing internally between the primary and secondary windings rather than at the plug] would not be selective as far as which cylinders it would prefer to send a weak spark to. Also a coil will ether produce fire at the plug electrode or it will use the spark in an internal carbon trail. It simply starts acting-up when it gets warm. Sooner or later it does all of its sparking internally between the primary and secondary windings. It will not simply 'weaken' the spark at a plug by 'partially' shorting inside the windings. Something else is at work here. Best bet is to use the stock dual point that many of these engines came with. I am on my 241. That "High Zoot" magazine stuff is a **** shoot. Points, condenser and coil are more reliable than any of the "hot rod parts catalog brands" [perhaps with the exception of MSD]. Back when Indy cars had skinny tires and the earth was still cooling we ran big block Dodges on circle tracks. When electronic ignition for Chryslers was offered we said Whoopie! and switched. Was not long before we found the point set-up did not '****ter sparks' beyond 6500 like the Hall Effect electronic that some say is 'better'.

 

i first noticed it when i had car running after the repair, I pulled the #1 plug and didn't hear any fluctuation of the motor, so i was like whats wrong. so i proceeded to pull 1 plug wire out at a time and noticed this on 1 & 8. checked all the wires and they read good resistance, plugs were all brand new. so thinking the only thing it could be was the internal coil inside of the HEI Hunt Disti. Never did figure it out but will look at this new setup more tomorrow when i finish up the timing. Hopefully that problem is gone.

 

If your plug wires were long enough you could have switched wires to known good cylinders for more comparison to rule out lean fuel mixture, wires, cap, etc. Maybe even switched plugs to cylinders to rule them out also. I have seen many spark plugs that were no good from the start.

 

I did swap out plugs and wires with known good ones still the same. I was thinking lean mixture also to those cylinders. will see what i see this week after messing around with newly installed disti.

 

hey guys on another note, what are you running as far advance? been messing with it this afternoon and seems to like a 32 degree advance at idle. I'm running a 3 deuce setup. at idle I have center running with the outers on progressive.

 

That's ridicules...............................................

 

32º at idle? It should be more like 7-8º.

 

yeah best i could get was 27 at about 500 rpm, the mechanical advance is 19 degrees i think and then I have a vacuum advance but this isn't hooked up as I don't have any vacuum ports on this setup. so not sure if that is doing anything or not. its capped off.

 

I would find top dead center and check to see if harmonic (if running one) is accurate................

 

yes tdc, I'm at hash mark on the harmonic balancer

 

What cylinder are you calling #1?

Something is very wrong. It won't likely idle with that much advance.

 

Don't know what your running but some Baby hemi's didn't come with a real harmonic so s0me install a harmonic off a 318. Just meant you could physically find TDC of #1 piston and check to see how the timing marks line up. Something is terribly wrong if your getting 27-32 deg. at idle. Just brain storming for you! Is all this with the new dizzy or the wanna be mag looking one?

 

Number 1 is Number 1. all is running well starts up and idles good

this is all with what I ***ume stock parts, the harmonic balancer only has 1 mark on it. The car starts right up, after sitting over night with just a turn of the key, idles fine around 500 RPM. this is using the new disti setup mentioned earlier in the thread.

 

Ok went and tweeked out some more of the advance the lowest i can get it to without it dying on me and start to sputter is about 17 degrees. going to take it out tomorrow morning and drive around and see how it does.

 

What cam are you running? What is your manifold vacuum at idle?

 

The 318 dampener can me made to work, but the mark will not be in the correct place.

 

not sure on the cam, unfortunately the guy that i bought the motor from or the estate had p***ed and I was never ever 100% sure. I was told it was all stock by the guy selling the stuff which was a friend of the guy. So who knows. it sounds stock, not a real powerful motor. it is in the car you see in my profile. so didn't really want anything with too much HP. I have no vacuum ports, so right now i just have a plug on the vacuum advance port of the Disti.

 

Any way of identifying the 318 dampener?

 

Maybe this guy used the stock Harmonic Balance/Dampener and marked it himself? I was told this guy was a Hemi engine builder and knew his stuff when it came to Hemi's.

 

Possibly. Any chance you could post a picture? There was not just one 318 dampener.

 

You know what, I lied. I think its a dampener I bought from Hot Head Hemi's. need to go look at my receipt log for this build.

 

yes it is a 340 modified dampener from HHH. so i would ***ume it is marked correct from HHH

 

In the old days we would have taken that new dizzy to a Distributor Machine and had it set up to whatever specs you wanted, than you could rule out dizzy and move on to other related parts to your problem.....................................

 

i just found a very good article.

http://webpages.charter.net/dhomstad/Distributor Frame1Source1.htm

 

I rest my case! smiley face.........................................................................

 

I am still not sure that it is possible to have a decent idle at 32° advance.

Are you using an adjustable timing light?

 

X2
You started the thread talking about doing some work on the inside...give us a concise list of what exactly has been done.
Cam specs?
Distributor specs?
Verify TDC vs damper.

.

 

Seems he is getting an erroneous reading, if he dared to drill and tap that great looking intake he could install a vacuum gauge to get a reading. That would help tuning but not help with the mystery advance.....................

 

32º advance on a particular cylinder is within range of plausibly firing the mixture on the previous cylinder in the firing order.

This is why I was making sure that the induction trigger is on the driver's side front cylinder, and not on the p***enger's side front cylinder. #2 is the previous cylinder in the firing order (360º/8=45º).

Firing Order: 18436572 front to rear: left bank: 1-3-5-7; right bank: 2-4-6-8

If you were accidentally reading the #2 wire, you would actually be running (45º-32º) 13º advance on cylinder #1. That would be plausible. Probably not ideal, but plausible.

Either way, I strongly believe that something is wrong.