Fwd: {Chrysler 300} Ram tuning

Begin forwarded message:

From: Frederick Grossi <e55grossi@xxxxxxxxx>
Subject: Re: {Chrysler 300} Ram tuning
Date: September 17, 2026 at 10:59:38 AM CDT
To: John Grady <jkg@xxxxxxxxxxxxxxxxx>

I have what I think is a similar experience as talked about on this subject. After a few years of rebuilding the engine, transmission, brakes and suspension in my F, I finally received it back last December. The car had a pertronix ignition system before I brought it in to the rebuilder. He suggested we refit the car with its original dual point distributor and no pertronix. I agreed.
In other words, I had him rebuild the engine to as an original specifications as could be. I believe I had a cam craft cam put in which is supposedly as original a cam spec as could be. Also, I was told that since I had the exhaust manifolds repaired/rebuilt, that there were no heat risers available. Mine were no good.
When I received the car back, it started right up and idled beautifully. However, as soon as I stepped on the accelerator, there was a major hesitation. Not necessarily a hesitation when first taking off but as the car got going the car would have a major hesitation as soon as the accelerator was applied. As I drove the car home from the truck stop, the hesitation improved as it warmed up. However, there was still some hesitation when the accelerator was somewhat rapidly applied at almost any driving speed.
The timing was set at 10 degrees advance at idle fully warmed up with the vacuum advance attached. My rebuilder told me to adjust the timing up a little at a time and then drive the car. So, I adjust the timing at first to 12 degrees advance with vacuum advance attached and drove the car. The hesitation was less prominent. Then I adjusted the time to 15 degrees and drove the car and the hesitation virtually disappeared. However, at 15 degrees, I was getting a little pinging upon acceleration. So, I adjusted the timing back to 12 degrees and left it there. I still get a little hesitation, not on initial acceleration but when I step on the accelerator somewhat rapidly at any driving speed. I am in no way anywhere close to being mechanically inclined. I did check the accelerator pumps in the carburetors and they are operating perfectly. The carburetors along with the accelerator pumps were rebuilt to specs along with the engine.
When I start the car in the morning, the chokes are not working but it starts fine and idles at a normal speed until fully warmed up. The hesitation is extremely bad when the car is cold and can be stalled easily if I am not careful about touching the accelerator. I have never experienced the hesitation when the car is shifting gears however. The car can be in any gear and the hesitation will occur, much more pronounced when cold but then improving as the car warms up but never going away completely. I wish there was a way to advance the timing so that the car will not ping. It seems the timing may be the issue for the hesitation.
I intend to bring the car to a mechanic here in Tennessee to look at it but I am still waiting for an appointment.

Thanks to all for your comments.
Sincerely,
Fred Grossi, 300F

On Sep 17, 2026, at 10:37 AM, John Grady <jkg@xxxxxxxxxxxxxxxxx> wrote:

it is NOT a hot cam , you know. I mean max torque is / has to be down low . That 327 you mention w 1 4 bbl has a hotter cam I bet . Hot cam goes directly opposite from long ram idea . you lose -- big

I think it had terrible hp rating while developing ,as an almost RV cam matches long ram -- not good for advertising if F less than E so they leaned toward more duration . End up w worst of both worlds . Whether we like it or not long rams are down 40 hp over a single quad --- saw that in person on a built 440' on dyno . A / b comparison on this exact question . But like most of us customer wanted look of rams , and you do get torque boost around 3000 .
And 62 no rams same / better hp .
62 win nhra into 12's
But , think about this:
Short ram J has less cam (268 )(!!) than long ram ( ~280 ?)
think about it ? That tells you all you need to know And J goes like hell compared to F
J:K really the finished product, 268 matches 4 k rpm
or so and can wind higher without hp crashing ( with less cam!) best of all B blocks, Hp /cu/in
F half baked, why 400 hp one to do anything at daytona . A J in disguise ?
given all this , we still love em to your point .

Going more conventional intake, the B set records almost same as F/
G with only 354 ".

354 punches way above weight , 392 had trouble keeping up ... ss records show

On Sep 17, 2026, at 11:07 AM, dplotkin@xxxxxxxxxxxxxxxxxxxxxxxxx wrote:

As you know the owner's manual supplement, the one that admonishes the driver to respect and control its power with care explains that the specified high curb idle of 750-780 RPM is necessary because of the big camshaft.

Every smart engine guy I know (non 300 type) looks at my idle as way high.

When I got the car someone had the idle down to where it might be on an Impala 327. The engine would struggle to carry the RV2. Mr. Verity raised it and its great, except for the whack to reverse.

I think the engineers did the best they were willing to do, they likely concluded we only sell a couple thousand of these a year, the owners will put up with the idiosyncratic behavior, it is, after all high-performance motor. Let 'em trade it for a New Yorker if its civility they want.

I think Tom Hoover came up with Max Wedge precisely to do away with these giant pipes, hard to tune, make the car hard to work on, expensive castings, iffy drivability, dissatisfied non hi-po seeking customers.

I love them for all that!

Daniel D. Plotkin
Daniel Plotkin & Associates LLC
54 Capri Drive
East Longmeadow, Massachusetts 01028
413 237 9629
dplotkin@xxxxxxxxxxxxxxxxxxxxxxxxx

-----Original Message-----
From: "John Grady" <jkg@xxxxxxxxxxxxxxxxx>
Sent: Thursday, September 17, 2026 8:37am
To: "chrysler 300 club" <chrysler-300-club-international@xxxxxxxxxxxxxxxx>
Subject: {Chrysler 300} Ram tuning

This is an old subject but years have gone by and those interested in this , some pretty smart guys have gotten in pretty deep ..... I have " tuned " a lot of rams over the years and surprised by variability in final outcome . Despite a lot of effort, some cars kind of fight, you a few settle in.
This is not about obvious stuff we all know , it is about things rams do at times. Maybe all times , more or less . And some on site have really gained significant knowledge over past 20-30 years
I have one fighting me now , the constant fight between stable rpm at idle and slamming into gear and then stalling. As if idle has no torque if " loaded up" They even mention this " rough engaging" in user guide on F .
Part of it is due to unported vacuum to ignition , always full advance at idle . If vacuum drops ,at trans engage, ( it does) ignition retards = stall . I mean this is real and anti stall thing grew out of it, but opening throttle more just off idle drops vacuum more . Thin line there . And I think design is flat out wrong we have to tune around it .. I was thinking ??? add a small vacuum can and orifice to slow down advance action , or buy carbs with ported vacuum like every single other car the world has . Carl did that his car runs great . AVS calls to me ..
The second thing is the tendency to stall off a stop sign depending how much you feather pedal .
It feels like it goes lean momentarily ( remember this is some cars not all)
So seems like carb squirt is either late to the party with small thrittle motion startup off idle , not enough gas , or idle mixture wants to be richer than optimal ( as set by vacuum gauge) to cover this transition It us really bad puling into traffic and car suddenly stalls, adds stress to driving . This is tangled around issue 1
I am ignoring warm up issues , another whole thing , but gets into this in first 15 minutes

Lets call it ole ram guys , philosophy etc .

Can be made to be acceptable , yes, but really optimal -- no, not easy to get to . And how about ignition timing ? they say "no spec for that idle timing with vacuum on , just set with off" .but it IS on st idle . And high , ? leading to above sensitivity to stalling slamming all that
Deep thinkers on this , insights gained welcome ..
J

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