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How many bearings does the camshaft have?

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wantcoffee99 View Drop Down
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    Posted: 17 Oct. 2020 at 2:40pm
Forgive me if I am asking a question that has been asked and answered before; I cannot find exact information on this subject.  I am thinking that my camshaft might have play in it and am considering replacing either the camshaft and/or the bearing(s).  To my surprise, what I have found suggests that there is only one camshaft bearing, which is more of a bushing than a bearing as it has no moving parts.  That bearing is stated to be for the front of the engine.  Assuming that an engine has not been modified ( I do not yet know if mine has or not), how many bearings does the camshaft have?  If it indeed does have only one bearing, on what does the other end of the shaft ride?  I am far from an expert on engines, but this is a strange concept to me.  Thank you in advance for your help.

As far as why I think their may be play in the camshaft:  I have a popping exhaust symptom that I tried to remedy with things I did to the ignition system (rebuilt distributor, replaced most components) and by rebuilding the carburetor, then tried adjusting the valves (to 0.014).  I then readjusted the valves to about 0.013 when my first attempt did not improve things.  My thinking was that the valves are not closing.  I'm starting to think that the camshaft is not rotating evenly.  If you have any insight on what I have done here, I would appreciate it too.
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Mark W. View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Mark W. Quote  Post ReplyReply Direct Link To This Post Posted: 17 Oct. 2020 at 3:04pm
if your asking about a 134L or F it has 1 bearing just behind the sprocket or Cam gear the other 3 journals just ride on honed surfaces in the Block. As the Cam turns at 1/2 the speed of the crank and there is very little pressure on the rear bearing surfaces they opted to not put insert bearings in those locations. There is a Hack where guys have had these journals reamed out and used I believe a Ford V8 Cam bearing set (each one as they go backwards is slightly smaller in diameter.) But that is only required if there is damage or your planning some sort of high performance.
 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Michaeltru Quote  Post ReplyReply Direct Link To This Post Posted: 17 Oct. 2020 at 3:26pm
What are your compression readings?  
Mike in AZ
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jeepsterjim Quote  Post ReplyReply Direct Link To This Post Posted: 17 Oct. 2020 at 3:27pm
As Mark mentioned some guys use cam bearing from a Ford 302 V-8.  There are write ups on it on-line.

Jim
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Post Options Post Options   Thanks (0) Thanks(0)   Quote wantcoffee99 Quote  Post ReplyReply Direct Link To This Post Posted: 17 Oct. 2020 at 8:22pm
Originally posted by Mark W. Mark W. wrote:

if your asking about a 134L or F it has 1 bearing just behind the sprocket or Cam gear the other 3 journals just ride on honed surfaces in the Block. As the Cam turns at 1/2 the speed of the crank and there is very little pressure on the rear bearing surfaces they opted to not put insert bearings in those locations. There is a Hack where guys have had these journals reamed out and used I believe a Ford V8 Cam bearing set (each one as they go backwards is slightly smaller in diameter.) But that is only required if there is damage or your planning some sort of high performance.
 

Thank you for the info.   
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Post Options Post Options   Thanks (0) Thanks(0)   Quote wantcoffee99 Quote  Post ReplyReply Direct Link To This Post Posted: 17 Oct. 2020 at 8:23pm
Originally posted by Michaeltru Michaeltru wrote:

What are your compression readings?  

115-120.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Michaeltru Quote  Post ReplyReply Direct Link To This Post Posted: 17 Oct. 2020 at 10:45pm
Thanks. Good compression
Mike in AZ
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Post Options Post Options   Thanks (0) Thanks(0)   Quote wantcoffee99 Quote  Post ReplyReply Direct Link To This Post Posted: 18 Oct. 2020 at 12:54am
Originally posted by Michaeltru Michaeltru wrote:

Thanks. Good compression

The pistons have been over bored .030.  I think that's the reason why it's so high.  I think stock is 120, new.  
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Post Options Post Options   Thanks (0) Thanks(0)   Quote WeeWilly Quote  Post ReplyReply Direct Link To This Post Posted: 19 Oct. 2020 at 11:07am

  The popping sound might be coming from valve guides being a little tight on the valve stems. The valve springs are not real strong on these motors and doesn't take to much resistance hang the valve up a little.  It will probably wear in after putting some miles on it.

   Jim
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Oldpappy Quote  Post ReplyReply Direct Link To This Post Posted: 19 Oct. 2020 at 11:53am
"tried adjusting the valves (to 0.014).  I then readjusted the valves to about 0.013 when my first attempt did not improve things.  My thinking was that the valves are not closing."

If your thinking was that the valves are not closing adjusting to 0.014 and then to 0.013 is going in the wrong direction, and could possibly end up with burnt valves.

I usually set valve lash to 0.015 or 0.016. A little loose is better than too tight.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Bruce W Quote  Post ReplyReply Direct Link To This Post Posted: 19 Oct. 2020 at 3:35pm
In the “Service Manual for Jeep Universal Vehicles”, on page 38, paragraph D-48, the camshaft is explained, including having 4 bearings, only one of which is replaceable. In the cutaway view of the engine, Figure 31 on page 29, you can see that there is a bearing or bushing in the front of the block but none in the other three locations. 
  You DO have a service manual, don’t you?

Also, on page 23 of the parts book, in figure 10, it shows only one bushing, and on the next page, in groups 10-11 and 10-11A, it lists one “bushing, camshaft front”, and no others. 

  As far as the Ford 302 cam bearing idea goes, it’s kinda like the “$50 Jeep in a Crate” story. Many have heard of it but nobody seems to have ever actually seen it. I have bought and measured a cam bearing set for a 302, and only two of the four bearings can be used, leaving the rearmost cam journal needing to find something else to use. This modification will require machining of the block, which no one wants to do, and grinding of the journals on the camshaft, which again, no one wants to do. 

BW 
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