Farmall B cam timing

[CattleBoy]

I've been rebuilding a C-113 from a Farmall B 1943 vintage. I've had a few struggles, but the latest one has me scratching my head.
First off, I wrecked the crankshaft trying to get the pulley off of it. It was pretty wore anyway, so I didn't care too much. I just got a .010 reground one. It came with the gear, and it only has 1 mark like you would expect.
When I went to put the cam in, I noticed that there were more timing marks than there should be. The cam is the original, and someone maybe made some extra marks.

I have a couple questions If you experts could help me out. It has been driving me crazy!

1) With the crank at TDC #1, should the timing mark on the crank gear be pointing to the cam perfectly? I had to rotate mine 1 tooth to line up a mark with the cam gear.

2) When the cam gear mark is lined up correctly with the crank timing mark, and the governor timing mark is lined up with the cam gear, should #1 be at TDC and if so, on compression or exhaust stroke? Currently mine is at about 10 deg after TDC on the intake stroke, so something seems amiss.

3) Related to question #1... I'm wondering if there were different revisions of the crank gear for different engines with the mark off by 1 tooth. It would seem that you would want everything all at TDC when the marks line up. Mine is not. When I take my front cover I will count the teeth from the keyway to the timing mark and compare to the original. As I recall the original crank gear's mark is located on the 4th valley counterclockwise of the keyway.
4) Are the double marks for the governor, exactly 180 deg from from the single mark that lines up with the crank gear?
I have it in an engine stand still, and the head isn't on yet. I just have to pull the pulley off and the front cover, so now is the time for me to make doubly sure I get it right.
Seems like I'm off a tooth, and maybe 180 deg out on the cam.
I dropped the pushrods into the block, but it is somewhat difficult to monitor them accurately, but it seems like the intake valve starts opening pretty much at TDC. According to the service manual, it should be more like 15 deg After TDC. Kinda supports the one tooth off theory.
1st pic is of the governor lined up on the double punch.
2nd pic crank is rotated 1 turn to show the mark that I lined up with on the crank gear. Notice the confusing double strike and the other 2 punch marks

 

[CattleBoy]

Sorry The pictures won't post. Says it contains words or sequences that indicate spam

 

[DaveBN]

The timing mark on that engine is on the fly wheel. It's marked TC or
TDC 1/4. The flywheel mark lines up with a flange on the cast iron cover
in front of the flywheel below the oil pan. The one mark on the crank
gear lines up with the one mark on the cam gear. Two marks on the cam
gear line up with the mark on the governor/magneto gear.
Their is more to getting it right so you really should get a manual.
Post back with your progress and more questions.
You can't post pictures if you are new here. You must make several posts
to show you are not a spammer.
Dave

 

[CattleBoy]

Thank you for the reply. I do have a manual. I have both the IT IH-8 and the IH one in electronic format. I know about the marks on the flywheel, and the procedure for verifying the valve timing laid out in paragraph 56 of the IH-8 manual. However, that procedure appears to be suited to checking after the head and flywheel are installed, and the engine is in the tractor.
In my case, there are 2 sets of double marks, and one single mark that doesn't look factory. Plus it looks like the gear in my new crank has it's mark 1 tooth off compared to my original crank.
It just occurred to me that my original post contained too much information to actually hold anyone's attention, so in a nut shell if I had answers to these 2 questions, I believe it would go a long way to getting things squared away, so I can move on with assembly. As previously noted there are multiple marks on my cam gear, so it's not a simple matter of saying that the single punch goes to the crank.

1) When the crankshaft gear mark is presented to the cam gear mark, should the #1 piston be at TDC, and if so, compression or exhaust stroke.
2) Is the double mark on the cam gear that is to be lined up to the governor gear 180 deg from the single mark on the cam gear.

 

[used red MN]

Here is something you can do that will fairly closely tell you the cam is timed correctly. Install the push rods for the rear cylinder which is number four. Assuming you have it the engine rotated to TDC no. 1 cylinder. However, when the cam and crank gear alignment marks are properly oriented the engine may not even be on TDC no. 1, I am not sure if this applies to the B engine or not. Rotate the engine until the rear pushrod or exhaust raises and drops down. Once it is down continuing to turn it will then start the front pushrod or intake to begin its upward stroke. You want to stop the engine as the exhaust has stopped downward travel and the intake is beginning upward travel. You are now at valve overlap for cylinder 4. At this point the running mate of cylinder 4 which is number 1 should be at TDC of its compression stroke. This should verify correct cam timing.

 

[gene bender]

the single dot on the cam lines with single dot on crank gear then the two
dots line with the two dots on the mag drive and that would put the piston #1
at TDC

 

[CattleBoy]

(quoted from post at 06:32:24 04/06/21) the single dot on the cam lines with single dot on crank gear then the two
dots line with the two dots on the mag drive and that would put the piston #1
at TDC

There are multiple marks , most of which are obviously wrong. I thought I mentioned that...
Would you happen to know how many teeth from the keyway the crank gear timing mark is located? Mine is on the 5th full groove counterclockwise from the key.
Seems like it is off by a tooth as the timing mark is not pointed squarely to the cam at TDC.

 

[CattleBoy]

(quoted from post at 00:34:28 04/06/21) Here is something you can do that will fairly closely tell you the cam is timed correctly. Install the push rods for the rear cylinder which is number four. Assuming you have it the engine rotated to TDC no. 1 cylinder. However, when the cam and crank gear alignment marks are properly oriented the engine may not even be on TDC no. 1, I am not sure if this applies to the B engine or not. Rotate the engine until the rear pushrod or exhaust raises and drops down. Once it is down continuing to turn it will then start the front pushrod or intake to begin its upward stroke. You want to stop the engine as the exhaust has stopped downward travel and the intake is beginning upward travel. You are now at valve overlap for cylinder 4. At this point the running mate of cylinder 4 which is number 1 should be at TDC of its compression stroke. This should verify correct cam timing.

Are you implying that the intake starts opening at TDC?????
I dont see how thats right

 

[Ken Hansen]

Are you implying that the intake starts opening at TDC?????
I dont see how thats right

When do you think the intake should start to open? The exact point for any one engine might be off by a few degrees when compared to some other engine but the basics are the same for all four-stroke engines.

Some engines have a bit more overlap to allow the inertia of the exhaust flowing out of the cylinder to actually help pull the fresh charge of air/fuel mix into the cylinder.

By the way TDC stands for Top Dead Center. There are two TDC's for each cylinder.

TDC on the exhaust stroke and TDC on the compression stroke. The one on the compression stroke is about where the ignition fires. Where the one where the exhaust is just closing and the intake is just starting to open is at the start of the intake stroke. Got to open the intake to allow the fuel air mixture to be drawn in to the cylinder!

 

[used red MN]

YES, the intake valve starts opening very nearly to TDC of the intake stroke of the cylinder!! Just as Ken has
laid out.

 

[CattleBoy]

(quoted from post at 07:46:54 04/07/21)

Are you implying that the intake starts opening at TDC?????
I dont see how thats right

When do you think the intake should start to open? The exact point for any one engine might be off by a few degrees when compared to some other engine but the basics are the same for all four-stroke engines.

Some engines have a bit more overlap to allow the inertia of the exhaust flowing out of the cylinder to actually help pull the fresh charge of air/fuel mix into the cylinder.

By the way TDC stands for Top Dead Center. There are two TDC's for each cylinder.

TDC on the exhaust stroke and TDC on the compression stroke. The one on the compression stroke is about where the ignition fires. Where the one where the exhaust is just closing and the intake is just starting to open is at the start of the intake stroke. Got to open the intake to allow the fuel air mixture to be drawn in to the cylinder!

I am familiar with the TDC definition and the basic principles of the 4 stroke engine. LOL. The factory farmall manual says intake starts opening at 15 deg after TDC (intake stroke obviously).
Further, the I&T IH-8 manual paragraph 56 says that when intake starts to open (valve clearance is taken up), the DC 1-4 mark on the flywheel will be 4 teeth past the mark on the lower cover . It is a 90 tooth ring gear, so 4 teeth equates to 16 deg.
Seems pretty clear to me.

 

[gene bender]

single dots lined the the double dots line with gov gear will put engine on TDC
and will start and run. I have always lined them up like that and engines have
always started and ran just fine but if you have extra marks on cam gear hard
to say just what you have but single dots together then the double marks should
line up