Idle timing on Chrysler 440?

[Philip Lochner]

Hi all

Does anyone have any experience on a stock low compression Chrysler 440? I have just implemented MS-2 (36-1 crank trigger wheel) on this engine (ignition only so far) and find that it wants to idle at 30*BTDC!! This is far more than any engine I've had before and I would just like to hear if so much advance is normal on this engine? The engine certainly sounds happiest with this much advance.

I've heard it said that the crank damper outer part can move with respect to the inner part (on the rubber joint) and I will try to verify if mine is ok but so far I've not been able to get exact info on where the TDC mark is supposed to be with respect to the key slot in the pulley.

[440roadrunner]

Many engines "like" much more timing than the fender smog sticker said. My 67 318, was 360, with "about the same" as a 340 cam likes around 15-17 initial

What kind of ignition? MSD multispark can play heck with some timing lights.

Easy to find out if your timing marks are accurate, ----and they might not be. Some motorhome engines, etc, were made with different timing tabs, and in the case of SB Mopars, early engines were on the opposite side. Additionally, balancers can slip on the outer ring

Get or buy a piston stop. Remove the no1 plug, make sure the piston is "down a ways," and unhook the battery ground. Install the device. You may have to play with the depth the first time you use it. You are not trying to stop the engine at TDC, but rather with the piston "down some."

Rotate engine until piston stops on the device. Make an accurate, temporary mark under TDC on the timing tab.

Rotate the engine backwards until it again stops, and make a second mark. You will now have two temp marks some distance apart. True TDC will be 1/2 way in between, and if the original is accurate, that is where it will be


I used to do this routinely back in the early '70's. Ford 352/ 390 FE engines seemed to be particularly bad with this back then.

[Philip Lochner]

Thanks 440RR

I've been trying to avoid going this route as it is so difficult to get to that plug hole.

Could you post me a link of a "piston stop" please? Never seen one of these but I have heard of the principle involved. Only way to set the adjustable timing reference on a Jaguar V12 (with heads on).

[Philip Lochner]

Sorry, as to the question of what ignition?

MS2 + 4 ign outputs + 36-1 trigger wheel + forward mounted ignition module with 4 IGBTs controlling 2 EDIS coil packs directly.

[trakkies]

Thanks 440RR

I've been trying to avoid going this route as it is so difficult to get to that plug hole.

Could you post me a link of a "piston stop" please? Never seen one of these but I have heard of the principle involved. Only way to set the adjustable timing reference on a Jaguar V12 (with heads on).

You can use a more accessible piston to do this - on a V-8 usually 7?

The piston stop thingie may also be called a TDC finder. Or you could make one using an old spark plug - break out the insulation and drill to accept a tight fitting rod.

[440roadrunner]

On a 440 you can use either no1 or no 6. Google "piston stop." You can buy or make them

https://www.google.com/search?newwindow ... _xjbW43Yvg

The length is not all that critical, you simply want to stop the piston at some point as it rises. As the piston gets closer and closer to TDC and "over center," it slows down, so accuracy is less, at the top of the stroke. So all you are trying to do is to stop the piston at the same point in both rotational directions of the crank. Some commercial adjustable stops do not appear to have a means of locking the plunger threads. This is a necessity. You do not want the plunger to move after it's set.

[trakkies]

Mine - a commercial one - is spring loaded with a scale on the side. Bit like an old tyre pressure gauge.

[440roadrunner]

That sounds more like a dial indicator. I believe some "odd" engines were timed by bringing the piston up to a pre-determined height. The problem is, for this application, trying to get both CW and CCW (or before and after TDC) readings the same is difficult. That is why a stop is used.

[Firehawkslp]

Hi all

Does anyone have any experience on a stock low compression Chrysler 440? I have just implemented MS-2 (36-1 crank trigger wheel) on this engine (ignition only so far) and find that it wants to idle at 30*BTDC!! This is far more than any engine I've had before and I would just like to hear if so much advance is normal on this engine? The engine certainly sounds happiest with this much advance.

I've heard it said that the crank damper outer part can move with respect to the inner part (on the rubber joint) and I will try to verify if mine is ok but so far I've not been able to get exact info on where the TDC mark is supposed to be with respect to the key slot in the pulley.

NO this is not normal I'm not even sure it's possible at idle. Something is diffently amiss. Does the engine sound labored when cranking hot; if not.Then no matter what the light says your not running anything like that kind of advance most engines have a total advance of around 36 degrees with vacume and mechanical advance all in, and then only in steady state light load situations only.

[Philip Lochner]

Well, I did use the piston stop method to verify the TDC mark which is correct and right now she idles happiest at 25º BTDC....

She cruises at 55º (40kpa) with 36º at full throttle (85kpa) @ 1400m AMSL.

She starts easily (cold and warm with 0º advance) and I get 17L/100km (13.8mpgUS 16.6mpgUK) @ 100km/h (62mph) with a 3.07 diff and undersize tyres (205/65/15). Gearbox is a 3-sp Torqueflite 727.

There is another chap in the UK who also EFI'ed his 440 (also in a Jensen Interceptor) and he reports similar figures.