RE: [Chrysler300] Fwd: My 300H engine issues

Agree, done all the time on hi po /race; but can induce WOT knocking at 2k rpm or so, and higher, but factory rate is conservative. There is room. Problem with doing this is none of those “stronger springs” come with any calibration. (how much stronger?) Stronger changes rate of rise (slower rise actually) so you make that up with more initial lead. Has the effect you describe. Brutal to iterate it by pulling distributor in and out , in fact impossible due to frustration, if you are honest about it. You are never sure what you really did. Need old sun distributor machine to do right. I even sent Chrysler a letter 15 years ago..their own “upgrade kit” for electronic ignition does not have an advance curve shown to you, and their kit of springs is 3-4 springs with no curve info. My reaction: Garbage. Made a little noise as they hit the trash can. Same “hi po” curve for hemi, B and A block? Garbage.

After a lot of screwing around, you need about 13-15 initial , but MUST change distributor to limit internal to about 15 too, (low 30’s total, obviously no vacuum). Knowing that, still do not know what specific spring is right. Stock light spring is OK if advance limited is what I did, what I did on another engine, blocked slot travel with braze or weld . (tried screw, no room—the slot is hardened steel)

Kind of related and others may have more info, the two springs are not what is often said they are. The heavy wire one really is a dead stop, (with elongated slot on one end. It stops the light one from advancing more, at maybe 3k rpm. Trying to figure this out with no info is brutal)

Reminds me of all the hot rod advice that says: “recurved distributor” ; now I know lees than I did a minute ago. You need the curve!

All this very general info..your mileage may vary..

PS,. Studeaker has a nice big graph of this in every service manual since at least 1950, sorted by distributor app. Even an acceptable error band is shown. Nothing from Chrysler except initial set and a few points. And 50 different distributor numbers. You cannot in general change factory initial very much without doing something with curve, or you end up too advanced at high RPM and holes in pistons at 4 grand.

From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Michael Moore mmoore8425@xxxxxxx [Chrysler300]
Sent: Wednesday, January 14, 2015 7:59 AM
To: William Huff
Cc: chrysler300@xxxxxxxxxxxxxxx
Subject: Re: [Chrysler300] Fwd: My 300H engine issues

Thanks Bill.

Mike

On Jan 13, 2015, at 9:40 PM, William Huff <czbill@xxxxxxxxxx> wrote:

Rather than retarding the engine's initial timing you may consider slightly increasing the strength of the mechanical advance springs. This should raise the RPM the advance begins at but still keep that off the throttle snap.

Bill Huff

At 07:42 PM 1/13/2015, Michael Moore mmoore8425@xxxxxxx [Chrysler300] wrote:

Begin forwarded message:

From: Michael Moore <michaelpmoore@xxxxxx>
Subject: My 300H engine issues
Date: January 13, 2015 at 4:40:28 PM PST
Cc: chrysler300@xxxxxxxxxxxxxxx
To: TFM@xxxxxxxxxxxx, John Grady <jkg@xxxxxxxxxxxxxxxxx>, lindsey@xxxxxxxxxxxxxxx, Charles Clark <flatheadeng@xxxxxxxxxxx >, Russell Vaughan <russ300@xxxxxxxxx>, Tony Rinaldi <awrdoc@xxxxxxxxx>

Dear Tom, John, Lindsey, Charles, Russ, and Tony,
I want you each to know how much I appreciate you taking the time to respond to my post about ideas to improve my poorly running 300H.
It is obvious all the ideas represented thought, and will result in varying degrees of trauma to both the engine and my wallet!
I have read and thought a lot about all the ideas, and I think what I will do initially is to get it back to a known stock condition with the original 300H camshaft I bought from Fern. The carbs are as new, the dissy is as new, the damper is new, compression is good, valves are set correctly .
Pinging is an issue with me as Iive on the top of a 1000 foot hill, so when it gets hot up here it is an issues coming up the hill. My first step then will be the camshaft, if that doesn't make a big improvement, the next step will be to get a thicker head gasket, which I guess I can have made by Cometic (they made one for my 63 Jaguar) .
Thanks again for all the help! This is a terrific resource!
Mike Moore
300H