Logo

Distributor help for chrysler 440 marine engine reverse rotation

captain_ed

Regular Contributor
I am trying to replace the distributors on both my standard and reverse rotation engines. The springs inside are rusty and I don't trust that they are working correctly. I am currently working on my starboard (reverse rotation) engine and have not touched the port engine yet. I just had the heads rebuilt by a machine shop that does a lot of marine motors. My original heads had cracks around the spark plugs probably caused by heat, bad timing, or possibly bad timing advance. Whatever the cause was, I don't want it to happen again. I am trying to eliminate the possible causes.

I was given a brand new Mallory YLM578 AV marine distributor. Mallory says that this distributor will work for either the standard or the reverse motor. I pulled the reverse 440 distributor and compared it to the Mallory and they don't match up. I called thier tech support and they say that this is the only chrysler 440 marine distributor and it should work for either motor.

View attachment 6434010.jpg014.jpg015.jpg016.jpg

The distance from the base of the distributor (just above to o-ring) to the end of the shaft is different. The original distributor measures 4 3/4" and the new Mallory measures 4 1/8" long.

Even if I left the "thrust bearing" off, it would still not be the correct length.:mad:I don't know why the reverse motor would need a thrust bearing. There is no gear on the end of the shaft that would create thrust. I am confused and frustrated.....

Does anyone have experience with this? Any ideas???:confused:
 
The original distributor has a tag that says CHRYSLER 3675632 and under that DH 7003A 15 5. Another tag says MARINE SAE J354.
 
The purpose of that thrust collar is to hold the oil pump drive gear down on the reverse engine, it is not really need at all on the standard rotation engine. Since the cam turns in the opposite direction, but the oil pump must turn in the same direction the gear is cut opposite on the cam shaft and the oil pump drive gear. This makes it want to rise up, the thrust collar holds it down. Without the thrust collar it would drive itself upward destroying the distributor in a short period of time. The distributor has weights in it that are directional sensitive, you cannot reverse the rotation as you will not have any advance.
Basically you have 2 options for the reverse engine. A factory electronic ignition system, or, if you can find one, an aftermarket reverse direction with a long shaft to make up for the thrust collar, I have never seen one. Also the 383/400 distributor has a shaft with a slightly shorter length than a 440. They are 3 7/8", a 440 is 4 1/8" So mixing them up won't work either.

Shortly I will be posting a completely programmable, distributor less ignition system upgrade for the 383,400,440 engines that can be used in either rotation. It works great and with a laptop, or even a smart phone, you can change the timing curve, specs anyway you want. I am using this in our fuel injection system.

Anyway, do not put a distributor in the reverse engine without the thrust collar. You could always take the distributor to a good auto electric shop that has a distributor machine and have it cleaned and set up. The old Ma Chrysler stuff was well built, but it all need love sometime.

Good luck.
 
Ed, I have openly admitted that I'm not a Chrysler Marine engine expert in any stretch of the imagination.

510Mopar is 100% correct regarding the distributor driven gear helical gear cut, and the lateral force difference between a Std LH engine and REV RH engine regarding the distributor shaft.
Apparently this is what the thrust collar takes care of.

The GM V-8's have a very similar issue between RH and LH rotation.
Like with the Chrysler, the distributor and oil pump rotate standard in either engine, but the opposite gear cut causes a downward force that the standard distributor housing is not equipped to counter.
(I'm thinking that the Chrysler is just opposite of this, in that the REV RH engine causes an up-lift)

Nonetheless, either requires a special distributor for the RH engines, or in your case, the thrust collar unit.


Question:
Although this appears to be a Prestolite, using Hall Effect, can you confirm?




Chrysler was the Pioneer in VR technology (VR = variable reluctor.... I.E., Magnetic Triggering).
The Mallory YLM is also VR.
If your OEM is VR, the new YLM (short of the OEM needing an over-haul) won't really perform any better.
However, if the original is Hall Effect, then most definitely find a way to make the new YLM work.

510Mopar's suggestion of having your OEM run on a machine and checked/re-set, is a good one.
The person operating the distributor machine will need the Marine ignition advance curve information.
The problem is....... no one here at MarineEngines.com has been able to find a Chrysler Marine Corp published ignition advance curve graph. We can find BASE advance all day long, and some of the guys have posted the Automotive curves.

Play it safe, and DO NOT use the Automotive curves for Marine engine loads!






.
 
Last edited:
I spoke to Scott at Mallory/prestolite again. He now says that he can special order a YLM 5000AV marine. He said that it has a longer shaft that will work with the thrust bearing. I ordered it today. Supposedly these distributors can turn in either direction. My current distributor turn counter-clockwise in this reverse rotation motor. The new distributor is $329 plus shipping. I was given a price of $275-300 to rebuild the old distributor. I figure that it is better to have 2 new distributors with the same advance curve.
 
I tore down my port engine and found it has the same 4 3/4" shafted distributor? The thrust bearing stays inside the block on this engine. This is a standard rotation (CCW) chrysler 440.

I thought that the standard engine would take the 4 1/4" shafted distributor that Mallory says will fit the chrysler 440. This is strange.....
 
Supposedly these distributors can turn in either direction.
Ed, the 440 should rotate the distributor and oil pump CCW (when looking downward) regardless of engine rotation.
The camshaft "drive" gear and the distributor "driven" gear will correct the distributor rotation for a REV RH Rotation engine.


.
 
I thought that the CCW motor would not have the thrust collar and therefore would not need the rare 4 3/4" shafted distributor. My understanding was that only the CW motor needed this.
 
Ed, perhaps I'm not following you correctly. And let me preface this by saying that I'm not a Chrysler Marine expert by any means, so the Chrysler boys would need to confirm this.


Either rotation engine turns the distributor and oil pump in the same OEM direction. This could be a Chrysler, could be a Ford, could be a GM.
Due to the helical cut of the two gears, and with either gear set turning the oil pump in the OEM direction, one gear cut causes an "up-lift" force, and the other gear cut causes a "down-load" force. This force needs to be "checked" or "controlled".

One exception to this, would be a REV RH engine that uses a twin gear camshaft drive.
In this scenario, the REV RH crankshaft turns CW, but the REV RH camshaft remains in standard rotation (and of course the cam profile is correct for REV RH rotation).

If I understand this, the OEM 440 standard LH rotation "driven" gear's lower thrust surface checks the down-load force..... (not via the distributor housing).
But with the 440 REV RH rotation "driven" gear, the distributor housing (or adapter) checks the up-lift force (not the gear's lower thrust surface, as it does in a Sd LH engine).

(this is actually oposite with the BBC or SBC, whereby the Std LH Rotation gear set causes an up-lift on the dist shaft)

But again, this is due to the difference in the helical cut of the gears, and the change that this creates with regard to the Up or Down forces, while either gear cut rotates the oil pump/distributor in the same direction.
IOW, it's all about the helical cut gear differences.

But like said, the Chrysler boys would need to confirm this.




.
 
Last edited:
Yes, that sounds correct. Both engines turn the distributor CCW. I was surprised to see that the CCW motor has a thrust collar also. Both of my engines need the extra long shafted distributor. In my case, the standard Mallory 440 distributor will not fit either motor. I guess that $300 was wasted on the YLM 578 AV. If the special order longer shafted distributor (YLM 5000 AV) fits my starboard engine, I guess that I will have to order another for my port engine. The YLM 578 AV Mallory distributor won't fit either motor. I don't want to run the port engine without the thrust collar or whatever it is. The engineers must have put it there for some reason. The reverse rotation engine makes sense.....the standard rotation longer shafted distributor is strange. The marine engine (or at least mine) must be different from a regular chrysler 440?
 
Hi Ed
The thrust collar is not needed on a standard rotation engine. Chrysler put it there so all the engines were the same. You can run with it, or without it for the standard automotive rotation. I do not use those collars all all, however we do not build reverse rotations engines anymore, we reverse in the transmissions.
That should answer your question
Dan
 
Dan, that is all fine and dandy, and I'd agree with you if Ed's transmissions are "opposite of engine rotation" capable!
However, if Ed's boat does require a REV RH engine on his Stbd side, he'll also need to accommodate this gear thrust issue..... yes/no?
 
Hi
I did not apply the response to the reverse engine, lets put the reverse engine out of our minds for the moment. I only answered that the standard engine did not require the thrust collar, he must use it on the reverse engine.
 
To help him so he is not stuck with the short distributor
1 use short dist, no collar, std engine
2 use long dist with collar, rev engine

Or use 2 long shaft dist with collars, both eng as Ma Chrysler did, his option

hope its clear, sorry for confusion
Dan
 
Thank you......that answers my question.:)
Hi Ed
The thrust collar is not needed on a standard rotation engine. Chrysler put it there so all the engines were the same. You can run with it, or without it for the standard automotive rotation. I do not use those collars all all, however we do not build reverse rotations engines anymore, we reverse in the transmissions.
That should answer your question
Dan
 
I already ordered the long shafted distributor for the starboard engine and I have the standard one sitting on my workbench for the port engine.:D


To help him so he is not stuck with the short distributor
1 use short dist, no collar, std engine
2 use long dist with collar, rev engine

Or use 2 long shaft dist with collars, both eng as Ma Chrysler did, his option

hope its clear, sorry for confusion
Dan
 
Thank you soo much for your help! It is a learning experience for me. I was only 11 years old when they stopped making these engines.....
 
I'm in the same boat... and rebuilding a pair of Chrysler RB (big block) based 413 engines... very similar to the 440's.

There are two types of camshaft drives... one with a Chain and gears and one with just two gears.

On the reverse rotation engine, the camshaft turns in the Opposite direction of the crankshaft because of the gears used. (photo below).

On the standard the rotation engine, the camshaft turns in the Same direction of the crankshaft because of the chain/gears used.

In this situation, both of the camshafts, and thus the oil pump shaft and distributor on the CW/CCW engines turn in the Same direction as each other when the engine is running.

My question is this.

1)
If both of these are turning in the same direction, why would there be different thrust directions on the gears?

2) Are there Chrysler RB marine engines (383, 413, 426, 440) that have chain drives on the camshafts on BOTH the CW and CCW rotations ...
3) and the counter rotating versions of the oil pumps???

What am I missing here?

440 with reverse gears.jpg440 with reverse gears.jpg
 
Last edited:
The crankshaft and cam turn the opposite way in a reverse rotating engine. The cam and oil pump gears are then ground backwards to make the distributor/ oil pump turn the same way as a normal engine. That makes the oil pump gear want to RISE (instead of pushing it down). For that reason the thrust collar is needed.

Jeff
 
In this photo (below) of a M440, with factory installed cam and distributor, the Crankshaft turns one direction and the camshaft turns the opposite direction.

There is no thrust collar mounted under the distributor in the photo.

Sincere questions:

Q 1: Is this gear-on-gear driven camshaft in the photo below actually on the Std rotation engine? (the reverse roation engine is the one that runs the chain?)

Q 2: Does the camshaft on a Std rotation engine turn opposite to the crankshaft?

Q 3: Are there some PAIRS of counter rotating engines that run a Chain-on-gear camshaft drive on BOTH LH and RH ?
ie: Are there different configurations of cam drives from the factory on the 440's


440 with reverse gears.jpg
 
Last edited:
The crankshaft and cam turn the opposite way in a reverse rotating engine.

Jeff,

Are you saying that, In a Reverse rotating M440, the crankshaft turns the opposite way from the Camshaft.

OR

That, in a reverse roatating M440 the Crankshaft AND the Camshaft turn the opposite way compared to a standard rotation engine... In this case the Crankshaft and camshaft are turning in the same direction?
 
Last edited:
What I'm doing is talking out of my hat (so to speak).

On a Mopar 318/ 360--that have a timing chain drive--the crank and cam turn the same way.

A Mopar marine 440 (as in the photo) is different: In THIS case the crank rotates opposite to the cam thanks to the gear drive.

Perhaps THAT is how Mopar did their reverse rotating 440? (Don't really know.) Using the gear drive for the reverse rotators, while retaining the chain drive for the normal rotators, means the distributor and oil pumps will still turn the same way. If that is the case, then the thrust collar would NOT be needed for the reverse rotators.


Jeff
 
Jeff...Never took it as talking out of your hat.... you are a great contributor from what I can read so far and I'm grateful as a "newby" here to glean info.

Talked to a Chrysler marine spe******t today... that has been around them since the 60's...

The only RB motors that got the Gear drive were the M-413-E's and a few M-426's...

So all of the others have a Chain-on-gear cam drive... camshaft turning the same direction as the Crankshaft... with the Reverse rotation engines needing the thrust collar to keep the distributors together....As said above... Learning from people on here has been a great help as a "lurker" as these motors become reality... I'll keep you posted.... Intricate buggers!
 
I already ordered the long shafted distributor for the starboard engine and I have the standard one sitting on my workbench for the port engine.:D


As a follow up to this project.....

I put the YLM 5000 Mallory distributor on the reverse engine. When I tried to slide it into place it would not seat all the way against the thrust bearing. It was sticking up about an 1/8". I once again held the new Mallory up against the old distributor that came out of the engine to compare them. It turns out that the shaft on the new custom built distributor was 1/8" longer than the original one. The extra length was in the tab like tip at the end of the shaft.The point (distance) at which, the round shaft started to transition into a flathead screwdriver like tab,was the same. I took a side grinder and ground off 1/8" from the tip. They were now exactly the same length. I bolted it in place and it has been running happily ever since.:D
 
Good deal. I assume Mallory installed some type of thrust bearing inside their unit to absorb the thrust load.

Jeff
 
In this photo (below) of a M440, with factory installed cam and distributor, the Crankshaft turns one direction and the camshaft turns the opposite direction.
Correct!
This keeps the camshaft rotating in a standard LH engine rotation direction.
However, the RH Rotation engine camshaft "profile" is completely different from that of a Std LH Rotation engine camshaft "profile".


There is no thrust collar mounted under the distributor in the photo.
Nor is one required, IMO.
Jeff, am I correct here?

Sincere questions:

Q 1: Is this gear-on-gear driven camshaft in the photo below actually on the Std rotation engine? (the reverse roation engine is the one that runs the chain?)
No.... with chain drive, it can't help but rotate the camshaft in the same direction as the crankshaft.

Q 2: Does the camshaft on a Std rotation engine turn opposite to the crankshaft?
If twin sprocket chain driven, NO!

Q 3: Are there some PAIRS of counter rotating engines that run a Chain-on-gear camshaft drive on BOTH LH and RH ?
ie: Are there different configurations of cam drives from the factory on the 440's
I can't speak for the Chrysler engines, but we will see an array of methods used for driving a camshaft.
Chain/sprocket drive, twin gear drive, four gear drive, etc.

The one pictured below, is a twin gear drive, whereby the crankshaft and camshaft rotate opposite from one another.


View attachment 6950

On a Mopar 318/ 360--that have a timing chain drive--the crank and cam turn the same way.

A Mopar marine 440 (as in the photo) is different: In THIS case the crank rotates opposite to the cam thanks to the gear drive.

Perhaps THAT is how Mopar did their reverse rotating 440? (Don't really know.) Using the gear drive for the reverse rotators, while retaining the chain drive for the normal rotators, means the distributor and oil pumps will still turn the same way. If that is the case, then the thrust collar would NOT be needed for the reverse rotators.
I think that Jeff nails it.
If this was any other engine, the same would apply with a double gear drive as pictured above.

It would not apply when the "drive" and "driven" gears are used with side idler gears...... (I.E., four gears)
In this case, the idler gears would bring the rotation back to the same as the crankshaft.

Jeff, correct me if I'm wrong here..... but it would seem to me (with twin gear camshaft drive) that both of his ignition distributors would be the same p/n.


.
 
Back
Top