Some Timing Notes etc...

[amanco]

I thought since I was up to my elbows in it I would share with thhe group.
My first revelation was that when the timing marks are lined up on the crank gear and cam gear, this is the position that the #1 cylinder is at TDC.......THE EXHAUST STROKE!!!! I had no idea and why would they do that?!? #1 TDC at ignition is when the timing marks are opposite each other like in this photo:



Here is a nice photo of the elusive timing marks on the crank pulley.



Check out the differnce in the pistons in my old engine:



And the pistons in the replacement engine, much stronger:



Valve before cleaning:



After cleaning:



Here is the box of .020 undersize rod bearings I got to install.



One of the rod bearings that got replaced. This is typical of what they all looked like. You can see the metal particles that got embeded in the babbitt. Result of a bypass oiling system. I am glad I changed them. The main bearings didn't look nearly as bad.



Here was the culprit of that "gentle knocking sound" in my old engine:



Plastiguage on a rod journal:



New expansion plugs going in. The old ones had some type of sealer on them so I used some pipe sealer.



Two weeks till the Vets Day parade. Plenty of time

[k8icu]

Gee I didn't even recongize that engine block....

I'm glad to see it's all going back together for you so good. Now you just got to get it togther....I'll start a chant for you... Oh and you need that transmission that goes with that... hint hint...

[MSeriesRebuild]

Yes the timing marks have to oppose each other in line to get #1 up on the compression stroke. The picture of the valve before cleaning, this is the typical mess that accumulates on valves & guides when running gas that has been in the tank for a while. Keeping fresh gas in the tank is a must.

[HingsingM37]

Great pics. I am having flashbacks looking at them. One thing I learned having just finished my engine is to do the work bright eyed and bushy tailed and take your time, and if you read my 'Frustrated" post, beware of 'reman" distributors Have fun and keep us posted.

[powool]

Anyone had an issue with a tight camshaft on assembly? I had to tap it in maybe not so gently, and am worried there is either a bent cam or now a damaged bearing. I doubt I hit it hard enough to bend anything, but there were signs of a damaged bearing before I put the cam in.

Glad I saw that pic for cam gear alignment - I surely would have put the marks close together.

[MSeriesRebuild]

Anyone had an issue with a tight camshaft on assembly? I had to tap it in maybe not so gently, and am worried there is either a bent cam or now a damaged bearing. I doubt I hit it hard enough to bend anything, but there were signs of a damaged bearing before I put the cam in.

Glad I saw that pic for cam gear alignment - I surely would have put the marks close together.

Questions, did you line bore the new bushings to fit? Did you have the camshaft checked for straightness? It isn't odd to find a bent one, fairly common in fact.

[Paul in Kempner, TX]

I was really surprised that Charles says, "Yes the timing marks have to oppose each other in line to get #1 up on the compression stroke." I guess that's the Army way for setting up the timing marks on M37s.

My first experience with the military Dodge was when I was assigned a M37B1 w/w while stationed in Korea 1963-1965. I had no opportunity to work on it. It ran flawlessly - even in the winter with chains on all four wheels.

I have a lot more experience working on the civilian versions of the 218/230 c.i.d. motors starting with a 1950 Plymouth in 1958 (actually, I was born a civilian and wasn't called to serve until 1961).

Twenty years ago, my son started collecting Plymouth cars and Dodge trucks and I got reacquainted with the flathead six. His MOPAR fascination eventually got me into collecting military and civilian Power Wagons.

On all the civilian versions of the MOPAR 218/230 c.i.d. motors I have worked on, the timing chain alignment marks go at the closest point in their rotation - the perigee, if you will.

All my civilian service manuals support this. See the image I scanned from a B-1 series factory shop manual. Here’s the link…

http://www.texaspowerwagon.com/timing-chain.jpg

Once again, as I was frequently told during my 20+ years of military service, I have learned the Army way for placing the timing marks.

[amanco]

Paul~ I agree with you 100% Any one who is installing timing gears needs to put the timing marks together. There is no other sensible way to do it!!!
The point I was making and I think got lost in the mix is when you put the timing marks together, as in installation, do not get confused and assume this position is TDC #1 on the compression stroke for it is not. I have always assumed this and I was VERY surprised to find out differently. When the timing gears are installed, you will find the #1 cylinder is at TDC. But it is TDC of the exhaust stroke, not ignition.
The position of the timing marks to put the #1 cylinder at TDC at the point of ignition is exactly like my first photo at the top of this thread. Charles confirmed this.
I could see my self easily thinking this was the #1 point of ignition and installing the oil pump and distributor and then scratching my head for three days not knowing why my engine wasn't starting.
Now for another great question, are all engines like this? If not, then are all Chrysler engines like this?

[Lifer]

Let's see if this makes sense to you: on all engines, the timing marks are set next to each other, which puts #1 at TDC between the exhaust and intake strokes. This is because the first thing the engine has to do in order to run is to suck in some ruel/air mixture. Rotating the crank 180 degrees sucks in the go juice and rotating the crank another 180 degrees compresses it leaving #1 at TDC between the compression and power strokes. At this point, the timing marks are as shown in the first pic. You can't see them when everything is all put together and you're ready to fire it up, so you use the timing marks on the pulley, which shows TDC when #1 is fully charged and ready to fire.

[amanco]

She goes back in today

[k8icu]

Pulling an all nighter then eh? Nothing like cutting it close to your deadline. I hope it all works for you and you get it running in time for the parade. The motor looks good! Nice job on it.

[amanco]

A Little Before & After Action!





Keep in mind this is a different engine that was for the most part torn down and put back together with new rod bearings and gaskets. I still need to do the air cleaner and dip stick tube in gloss black. Also run the fuel tank & master cylinder breather tubes to the intake. Carb needs scrubbed down a bit more too. The fording valves need cable clamp brackets fabed also. I was first able to start it up 10:30 PM saturday night before the vets day parade on Sunday. Runs like a clock. Didn't finish up till 2am so it nearly was an all nighter!

[HingsingM37]

Congratualtions on a fine job. Looks good

[knattrass]

keith - great work and photos! thanks for documenting this one. keith

[amanco]

The Vets Day parade was great. 28+ WW2 Vets attended some wearing their 63+year old uniforms. My special treat was I got to escort 4 active duty Army men who had just returned from a tour in Iraq, for one of them, it was his third tour. They rode in the back on the troop seats. I put wool blankets down because I know how hard thoes seats are! Also the American Legion Post Commander (retired Mater Sargent) of the post I that I am Post Adjutant of (#518 Ashley, Ohio) rode shotgun. Truck ran great. I do need to set the timing 4 Deg BTDC.