Cam Sprocket Attachment and Tab Washer

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Paul Mascuch
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Joined: Mon Jan 07, 2013 11:25 am
Location: Parma, Idaho

Cam Sprocket Attachment and Tab Washer

Post by Paul Mascuch » Mon Jul 04, 2016 11:56 am

I'm working on the rebuild of my 1948 XPAG engine and I'm having some problem with the attachment of the camshaft sprocket. I installed the cam sprocket then the oil slinger with the cupped side toward the camshaft sprocket. I then installed the washer followed by the tab washer and the cam sprocket bolt.

The tab on the tab washer goes through the hole in the sprocket washer and the hole in the oil slinger, but there is no hole in the sprocket to accept the projection of the tab through the slinger. Am I supposed to bend the tab over behind the slinger? I didn't do that and when I tried to tighten the cam sprocket bolt the tab pushed back out of the holes in the washer and slinger and broke off. The other problem I had was the sprocket washer pulled into the sprocket and cupped since the end of the camshaft is slightly recessed 1/8" to 3/16" inside the face of the sprocket. I couldn't develop the 50 foot-pounds of torque required since the washer kept cupping as I tightened the bolt.

I believe once tightened I'm supposed to bend up the edges of the tab washer up to secure the cam sprocket bolt, but since the tab on the washer doesn't lock into the sprocket it seems to me that it can't really secure the bolt.

Am I missing something or am I doing something wrong? Any help is greatly appreciated.

Best regards,

Paul Mascuch

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Steve Simmons
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Re: Cam Sprocket Attachment and Tab Washer

Post by Steve Simmons » Mon Jul 04, 2016 12:08 pm

There is supposed to be a hole in the camshaft sprocket which the tab goes into, to keep the washer from spinning. I haven't seen a sprocket without one. If yours doesn't have the hole, you will need to drill one.
1949 TC8975 / XPAG 9609
1948 TC6011 / XPEG1182 (XPAG6472)
http://www.mgnuts.com

Paul Mascuch
Posts: 15
Joined: Mon Jan 07, 2013 11:25 am
Location: Parma, Idaho

Re: Cam Sprocket Attachment and Tab Washer

Post by Paul Mascuch » Mon Jul 04, 2016 2:24 pm

Steve -

Thanks for the input. I didn't make sense to have a tab washer if it didn't lock to the sprocket. I went and looked at my cam sprocket again.

The sprocket has a center web with a hub with the bore through it projecting from each side. What I believe is the front of the sprocket has one tooth marked with a "T" that is the timing mark and the hub projection does not extend past the outside face of the sprocket. The other side, which I believe needs to go toward the block has a hub projection that goes past the outside face of the sprocket. This face rides against the thrust plate.

My sprocket has a hole drilled on the back side of the sprocket where it doesn't do any good. I can drill this hole all the way through to get a hole in the front, but this doesn"t make any sense to me. I don't think I am installing the sprocket backwards since if I reverse it the outside face of the sprocket hits the engine before the hub projection hits the thrust plate.

Any thoughts?

Paul

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Steve Simmons
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Re: Cam Sprocket Attachment and Tab Washer

Post by Steve Simmons » Mon Jul 04, 2016 3:40 pm

Not sure without seeing yours, but here is a photo of mine before I locked it down.
Attachments
cam-sprocket.jpg
cam-sprocket.jpg (65.46 KiB) Viewed 1984 times
1949 TC8975 / XPAG 9609
1948 TC6011 / XPEG1182 (XPAG6472)
http://www.mgnuts.com

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