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Discussion Starter · #1 ·
I wanted to ask the opinions of those who see this stuff more often than I do. I've only built a handful of engines but many transmissions.

This is a new Motown Lite Aluminum SBC I just received, "race prepped".
I requested this since I have no confidence in local machine shops after bad experiences in the past. I live in a small town with only a couple of shops.

My question is: What do you think of the cam bearings? They look like someone took 320 grit emery to them, some worse than others, front worst of all (see pics). Is this normal/acceptable? It almost looks like they did their line hone after instead of before. :pain: I test fit with a cam shaft and I can wiggle it slightly after 4 lobes are in but not after the fifth. Thing is, I read a guys post on this forum before ordering and told sales guy of this and asked specifically that I not encounter the same problem. Maybe this is his "payback". :spank:

Thanks,

Jim
 

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I dont know about everything else, but I do know that cam bearings are not the same size. They are larger at the front than the back, so if you have 4 journals in, there is going to be a bit of play. Once, all the way in, the right size journal is in the right size bearing.

That cam bearing does look a bit scratchy, but like I said, I am no expert.
 

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I have never seen any that were that scratchy before.......The machine shop that I use, uses a reamer to size and true the cam bearings with after he installs them.....they always look nice and smooth.
 

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Discussion Starter · #5 ·
thanks Poncho62 and Henry.

I didn't know cam bushings weren't all the same size or that they needed tweaking after they've been installed. I don't have the tool needed to install them. I presume some experience is a big plus on installing these.

Jim
 

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Sure looks like someone tried to get bearing to loosen up by sanding it to me. I would change them. Should be able to spin cam with 1 finger when its right.

Some engines have cam bearings bored in the block after installation at factory when engine was made, then I could see maybe having to do a little carving with bearing knife after installing new bearings.

Not 100% sure but I thought the journals were all same but o.d. of bearing is different size. :confused:
 

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Greg Latvala said:
Not 100% sure but I thought the journals were all same but o.d. of bearing is different size. :confused:
That may be true, I just knew they were not the same, thus I asumed it was the I.D....Maybe, Big Tom can tell us for sure.
 

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Discussion Starter · #8 ·
Greg Latvala said:
Sure looks like someone tried to get bearing to loosen up by sanding it to me. I would change them. Should be able to spin cam with 1 finger when its right.

Some engines have cam bearings bored in the block after installation at factory when engine was made, then I could see maybe having to do a little carving with bearing knife after installing new bearings.

Not 100% sure but I thought the journals were all same but o.d. of bearing is different size. :confused:
yeah, I've carved a few bushings with a feeler gage after knocking them in but only on the leading edge. It just seemed like crude workmanship. The cam does spin okay, I just don't like dropping all that cash and having them ship something like that to me...especially after I specifically asked told them I was going to be looking at that aspect of the purchase.

Jim
 

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I wouldn't run them and yes, sbc cam bearings get bigger as you come foreward. I don't know the specs as Woodys in Sandringham vic does all mine but I remember they go in from the front.
You there Tom?
 

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Our shop is set up to blue print bore cam tunnels for over size cam bearings and roller cam bearings and we have seen more problems with the World blocks and they use stock type cam bearings big in the front and rear and smaller in the middle.

Ands check if the the center ones oil at 6 O'clock as we have had blocks set to us to machine the cam tunnel b/c of spun cam bearings on start up, With the oil holes at 6 O'clock and if your running a roller with high spring pressures it shuts the oil off to the journals.

After we cut the cam tunnel for over size bearings we cut a groove in the OD of the bearing and drill another small oil hole at appox. 4 O'clock and this seems to take care of the problem.

And we alos do this on the BBC as well.

I would say the cam tunnel has issues and they had to do a little work on the bearings to get the cam to fit. Or maybe they marked the bearings putting them in and tried to cover the mess up.

Who knows But keep us posted on your findings
 

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Discussion Starter · #12 ·
CNC BLOCKS N/E said:
Our shop is set up to blue print bore cam tunnels for over size cam bearings and roller cam bearings and we have seen more problems with the World blocks and they use stock type cam bearings big in the front and rear and smaller in the middle.

Ands check if the the center ones oil at 6 O'clock as we have had blocks set to us to machine the cam tunnel b/c of spun cam bearings on start up, With the oil holes at 6 O'clock and if your running a roller with high spring pressures it shuts the oil off to the journals.

After we cut the cam tunnel for over size bearings we cut a groove in the OD of the bearing and drill another small oil hole at appox. 4 O'clock and this seems to take care of the problem.

And we alos do this on the BBC as well.

I would say the cam tunnel has issues and they had to do a little work on the bearings to get the cam to fit. Or maybe they marked the bearings putting them in and tried to cover the mess up.

Who knows But keep us posted on your findings
Thanks for your reply. I checked, all bearing holes are @ 6 o'clock. My AFR Heads say 130#'s on the seat. Crower roller but nothing extreme. I'll follow up when I figure out what to do about this.
 

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Somebody did a very hacky job in trying to make the cam turn in bearings that are too tight or mis-installed. I would remove them and check the cam bores for sizing. If they are okay, have someone with experience install new ones. If the cam bores in the block are too tight, raise hell with the block manufacturer.

tom
 

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jleeheat said:
Thanks to Tom and everyone else for offering an opinion. I'm going to see what World Products will do to make this right.

Jim
We stopped dealing wiht World as the last 2 bolrks we got were filled with epoxy up to the freeze plugs and of my my customers did not want his and world would not take it back so we sold it a cost to another engine builder.

So good luck with Worlld.
 

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Discussion Starter · #16 ·
Thanks CNC BLOCK N/E

I ran web searches for posts on Bill Mitchell/World Products before purchasing and came up with 95% positive info. One neg. post said internals were not what was advertised. Another said he received a block with scratched cam bearings and sent it back and they replaced them. Another said crate engine lost oil pressure and fought to get "most" of his money back. Most posts though said "get a Bill Mitchell". When I placed the order, in as nice a way as possible, I told him I researched his company and saw a post about bad cam bearings and asked him to make sure I didn't have a similar problem because I didn't want to have to send it back. Tried to warn him you might say. Did me no good as you can see.
I emailed sales rep. yesterday with pic and gave them a day to think things over. Today I begin calling. He didn't reply to email.

Jim
 

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If you want let them know you have pics on the NET and if yoou want let them know I have seen cam tunnle issues before with there product. As that work they did was very unacceptable.

Keep us posted on how they take care of this issue and hopefully the salesman does not say if the cam fits in thats all we are concerned about!!!
 

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Discussion Starter · #18 ·
CNC BLOCKS N/E said:
If you want let them know you have pics on the NET and if yoou want let them know I have seen cam tunnle issues before with there product. As that work they did was very unacceptable.

Keep us posted on how they take care of this issue and hopefully the salesman does not say if the cam fits in thats all we are concerned about!!!
Good idea. I'll keep ya posted. Thanks again.

Jim
 
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