Crank angle adjustment

[mhsprecher]

The hole for the crank on the top of the frame didn't line up properly with the front of the engine, so the crank is difficult to use. I removed the radiator for repair and was able to see what the problem is.

As you can see from the photos, the crank bearing plate that fits on top of the frame is not aligned properly with the front of the engine. The plate is not centered properly. It looks like there is some adjustment laterally that would help some, but maybe not enough to solve the problem. Any ideas or tips on making sure I get this right without causing more problems with the repair?

[BRENT in 10-uh-C]

Very likely the head of the tie-bolt or the crossmember centering hole is worn. Remove the crank bearing and see what you have below it.

[Ray in La Mesa]

On some of the crank bearings the locating lugs on the bottom face that fit in the holes on the crossmember were offset. Try turning the bearing 180 degrees. If that doesn't work you might need to find another bearing with the different lug locations.

[Bob Bidonde]

Misalignment of the hand crank bushing and the crankshaft is a common problem with Model A's. The fix is simple. Loosen the rear motor mounts, and the nut on the front motor mount. Using a jack under the oil pan, lift the engine until it is at a 3 degree angle sloping downward to the rear, then tighten the rear mounts and adjust the front mount spring.

To assure you have a 3-degree angle, put the car on level ground before making the adjustment. Replace the carburetor with a bubble level taped to the intake manifold flange. When the engine is at a 3-degree angle, the intake manifold flange will be level.

You can also use an inclinometer to get the angle right.

Once the 3-degree angle is attained, the hand crank should fit into the crankshaft ratchet. If not, something else is wrong. Possibilities are: Bent frame; Cracked rear motor mounts; Float-O-Motor engine mounts.

The 3-degree angle has a significant affect on the carburetor's float setting, so you may have to adjust the float.

[BRENT in 10-uh-C]

Originally Posted by Bob Bidonde

Misalignment of the hand crank bushing and the crankshaft is a common problem with Model A's. The fix is simple. Loosen the rear motor mounts, and the nut on the front motor mount. Using a jack under the oil pan, lift the engine until it is at a 3 degree angle sloping downward to the rear, then tighten the rear mounts and adjust the front mount spring.

To assure you have a 3-degree angle, put the car on level ground before making the adjustment. Replace the carburetor with a bubble level taped to the intake manifold flange. When the engine is at a 3-degree angle, the intake manifold flange will be level.

You can also use an inclinometer to get the angle right.

Once the 3-degree angle is attained, the hand crank should fit into the crankshaft ratchet. If not, something else is wrong. Possibilities are: Bent frame; Cracked rear motor mounts; Float-O-Motor engine mounts.

The 3-degree angle has a significant affect on the carburetor's float setting, so you may have to adjust the float.

Hey Bob, if you look at his picture, it does not appear he is having issues with the horizontal alignment, but more that the crankshaft pulley is not in parallel alignment. Are you thinking your method will correct this too when the rear mount bolts are loosened?

[Chuck Sea/Tac]

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There's a possibility your frame is bent sideways. Look to see from underneath , if the front mount/ hole is worn sideways. Also measure your crank hole from side to side to see if it's centered.

[ericr]

but the crank bearing seems to me to be sitting correctly parallel to the cross member. Could the hole through the bearing simply have been drilled or formed incorrectly when made, as some aftermarket product of yesteryear?

[darrylkmc]

mhsprecher,

In each of your photos, left side as shown, there appears to be a Much Larger Gap between the crank bearing and the U-Bolt on one side.

Is this unequal distance about the same as the offset to your engine?

I would first try loosening the U-Bolt nuts and see if you can tap the Crank bearing and center it.

My Canadian '30 Phaeton uses the same U-Bolt set-up but the crank bearing does not look as well cast and defined as yours.

It could be as Ray in La Mesa says about rotating the crank bearing 180 degrees, but mine had a elongated pin on one side and a round pin on the other, the front cross member has a slot on one side and a hole on the other, so it would only go in one way. Could be yours are missing or worn out.

Darryl in Fairbanks

[Tom Wesenberg]

I would remove the crank bearing plate and make sure the square hole for the spring bolt is exactly centered. Then make sure the crank bearing hole is also exactly centered when installed. The last frame I worded on had some repairs done to it and had NO holes drilled in the front crossmember, so I had to make the square hole and two bearing plate holes.

[mhsprecher]

Tonight I removed the crank bearing plate and Ray in La Mesa had it right! There are two lugs under the plate that fit into two holes, but it is not centered. I rotated it 180 degrees and it looks like it is going to take care of it. I am painting everything while I have it apart, so I will not know until later in the week when I get it all put back together, but so far it looks good! Thanks for the help!

[Bob Bidonde]

Brent,
Yes, my technique will enable some horizontal adjustment. I think it should solve the problem.