Allis CA

steve(ill) wrote:

i was wondering about that Les... the cam has "about" 50 teeth so divide that into 360 degrees and each tooth is "about " 7 degrees ?? ........... i would guess thats how it works..

Yup.

360 degrees/46 teeth = 7.826

That 'might' get it close enough. It is the easiest thing to change anyway, and given my inherent laziness I would try it before doing any fancy machining work. Plus, it would get it closer so an offset key wouldn't need to be quite as big.

If it were mine I would focus on finding that Intake Valve Closing Event @ 0.050" lifter rise before (and after) moving it one tooth because that is what controls the trapping of your compression.

Guys,

I escaped to the shop. Rolled the cam gear one tooth each direction.

First rotated the cam gear one tooth clockwise the final degree number of the center-line of the intake lobe = 126

Next rotated the cam gear back past crank TDC mark one tooth counter clockwize. and the Lobe centerline final number was =96.

interesting that the math 126 + 96 = 222 divided by 2 = 111 humm!

So will need to cut a new keyway in the cam at the correct location I believe. More thinking on that location and dimension.

Regards,

Chris and Cheryl

Edited by Sugarmaker - 16 Feb 2025 at 7:19pm

D17 1958 (NFE), WD45 1954 (NFE), WD 1952 (NFE), WD 1950 (WFE), Allis F-40 forklift, Allis CA, Allis D14, Ford Jubilee, Many IH Cub Cadets, 32 Ford Dump, 65 Comet.

Sugarmaker wrote:

...

Les, Are you talking about when the valve just starts to open plus .050 on the indicator, then read the angle?

...

Yes.

On the intake valve closing point you would read the degrees 0.050" before closing.

The reason I keep going back to this 0.050" thing is because that is the typical number that most modern cam grinders use to specify the effective duration (rather than Gross Duration, which is bigger).

If you can check the 0.050" duration, and if it comes anywhere near 197 degrees, then we will know that the cam grinder did actually use that number in the specs.

Then all you would need to do is get the intake to close (0.050") somewhere near 26 degrees ABDC and you will be where the cam is designed to run.

If he didn't use 0.050" then you need to determine what lift he did use (say, 0.006" or maybe 0.020") that corresponds to 197 degrees. Then you can use that number.

Closing the valve later will move the RPM range up, but may harm the low RPM torque. If you intend to run near stock RPM, then you don't want to close that valve very much later than the stock cam. Trouble is, I don't have that number.

Folks,

i will work on finding the duration (197) More trials to do to find this and be repeatable.

I am using the plus and minus .050 inch from the top of the intake cam lobe to capture the degrees and then average them to get the lobe center-line. Seems to give good numbers.

Regards,

Chris and Cheryl

Edited by Sugarmaker - 16 Feb 2025 at 9:37pm

D17 1958 (NFE), WD45 1954 (NFE), WD 1952 (NFE), WD 1950 (WFE), Allis F-40 forklift, Allis CA, Allis D14, Ford Jubilee, Many IH Cub Cadets, 32 Ford Dump, 65 Comet.

Folks,

The crank stayed at TDC and the cam lobe center-line moved CW or CCW one tooth.

At its current keyed location in the cam gear the cams intake lobe is at 111 deg when the cam and crank are lined up on the marks. As you move the cam gear CW or CCW one cam gear tooth each way, the lobe moves advanced or retarded Approx 15 deg each way from the 111 on the degree wheel.

Regards,

Chris and Cheryl

D17 1958 (NFE), WD45 1954 (NFE), WD 1952 (NFE), WD 1950 (WFE), Allis F-40 forklift, Allis CA, Allis D14, Ford Jubilee, Many IH Cub Cadets, 32 Ford Dump, 65 Comet.

Guys,

I have some of this backwards too.

Couple things:

The crank gear turns two rev and the cam gear turns 1 rev.

Did some noodling on the distance that the cam needs to move and the direction.

First the 105.4 degree spec minus 111 degree current lobe center line. = 5.6 degrees

divide that in half (2.8 degrees) as the cam gear is twice as big so the 5.6 degrees as the point it comes to the cam gear is 2.8 deg of the circumference of the cam gear.

Taking that 2.8 degrees back down to the size of the cam which is 1.5 inches. 2.8 degrees on the 1.5 inch dia =

I did some thinking and came up with a dimension of .036 actual movement in the cam inside the gear. That was based on the delta 5.6 angle divided by 2 = 2.8 deg on the cam gear at 1.50 dia so 1 degree on 1.5 = .013 inch. so .013 x 2.8 =.036 inches of cam movement. Fingers crossed!:)

Now we want the crank gear to come up to the 105 degree number sooner as it turns clockwise, the cam lobe needs to move to a position sooner as it turns counterclockwise. The lobe should move counter clockwise by the .036 inches.

I think I can get this movement with a custom built offset key.

Also I did take a quick check on the 197 degree number that Les was looking for.

Turned the crank until I got to where the cam just started to move, went .050 inch beyond and read the wheel at -16 degrees. Spec says -9.3

continued to other side of the lobe went to where it stopped and backed up .050. read the wheel at 26 degrees. Right on spec at 26 ABDC

so -16+26+180= 190. orig spec was 197

(-9.3+26+180 = 197) So off by 7 degrees? My inspection may need tuning??

Regards,

Chris and Cheryl

D17 1958 (NFE), WD45 1954 (NFE), WD 1952 (NFE), WD 1950 (WFE), Allis F-40 forklift, Allis CA, Allis D14, Ford Jubilee, Many IH Cub Cadets, 32 Ford Dump, 65 Comet.

Guys,

I am going to get the offset key made in the next day or two. Decide to use a .25 wide key and trim it down to fit the keyways. That should be about .036 inch offset in the key moving the cam CCW from the cam gear.

I will have to check the exhaust angles after I get the cam back in.

Regards,

Chris and Cheryl

Edited by Sugarmaker - 19 Feb 2025 at 9:02pm

D17 1958 (NFE), WD45 1954 (NFE), WD 1952 (NFE), WD 1950 (WFE), Allis F-40 forklift, Allis CA, Allis D14, Ford Jubilee, Many IH Cub Cadets, 32 Ford Dump, 65 Comet.

Nice!

I do believe you are on the right track.

Just looking at the picture the cam lobes do not appear to be as pointy as the cam in my B-125 Power Unit engine.

I made a new thread about that cam in case you missed it.

Les Kerf wrote:

Nice!

I do believe you are on the right track.

Just looking at the picture the cam lobes do not appear to be as pointy as the cam in my B-125 Power Unit engine.

I made a new thread about that cam in case you missed it.

A cam with more duration will appear less pointy, kind of counter-intuitive but less "hump" = longer duration

I'm impressed by your dedication to get this thing running to it's fullest potential Chris. Interesting to note the "offset" on Les' camshaft. I wonder, if firing order is in fact an issue Allis had to work around why did they stick with 1243? And do any companies make a more "standard" 1342 cam for the 125 engine?

Guys,

Friend Matt whittled out the offset key to my specs tonight. Assembly fit back together nicely.

John came over today and helped put the centers in the CA wheels:

Small moves at snail pace. Weather has been cold. May get a slight break to start preparing to make maple syrup next week.

We get some results on the cam movement results soon.

Regards,

Chris and Cheryl

D17 1958 (NFE), WD45 1954 (NFE), WD 1952 (NFE), WD 1950 (WFE), Allis F-40 forklift, Allis CA, Allis D14, Ford Jubilee, Many IH Cub Cadets, 32 Ford Dump, 65 Comet.

Any chance of having you do another camshaft check at 0.010" lifter rise on both intake and exhaust so I can compare it with mine? My curiosity is killing me Smile

would be interesting to see if the lobes on #2 and 3 match the grind on #1 and 4... realizing your cam has been "modified"...

Like them all, but love the "B"s.

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