Cam won't fit into block!!!!???
Thread Starter
Melting Slicks
Joined: Aug 2004
Posts: 2,165
Likes: 950
From: Keizer Oregon
Cam won't fit into block!!!!???
Yeah thats right, After spending $800 on getting my block hot tanked, decked, clearanced for stroker crank, align honed, bored .030 over and cam bearings installed, my cam will not install into the block. It won't make it past the first bearing.
The block is a 350 4-bolt 010 casting, cam bearings are clevite 77 "good ole" standard cam bearings. Cam is a Comp 286HR retro-fit hydraulic roller. I tried a second cam with the same results. The machinist came highly recomended by a local engine builder, but for some reason the guy always acted like I was bothering him and I was some sort of dumb $hit....( I am an engineer
)
Unfortunately I had the machine work done about 1 year ago and was not able to spend the time or money to complete the build. I decided to take the block to a different machinist/shop today. He tried to put the cam in....same result...at least I am not crazy. I thought about dealing with the original machine shop/guy but honestly I would rather not screw with it. So for now the block is in a new shop for new bearings and test fit with my cam.
Has anyone else had this happen? There didn't appear to be any ridges or imperfections in the bearing....it felt smooth. It just wouldn't fit the cam!!!!
The block is a 350 4-bolt 010 casting, cam bearings are clevite 77 "good ole" standard cam bearings. Cam is a Comp 286HR retro-fit hydraulic roller. I tried a second cam with the same results. The machinist came highly recomended by a local engine builder, but for some reason the guy always acted like I was bothering him and I was some sort of dumb $hit....( I am an engineer
) Unfortunately I had the machine work done about 1 year ago and was not able to spend the time or money to complete the build. I decided to take the block to a different machinist/shop today. He tried to put the cam in....same result...at least I am not crazy. I thought about dealing with the original machine shop/guy but honestly I would rather not screw with it. So for now the block is in a new shop for new bearings and test fit with my cam.
Has anyone else had this happen? There didn't appear to be any ridges or imperfections in the bearing....it felt smooth. It just wouldn't fit the cam!!!!
Last edited by oregonsharkman; Mar 27, 2007 at 10:33 PM.
Advanced
Joined: Feb 2007
Posts: 90
Likes: 0
Cam Problems
Occasionally this does happen. Normally it's just a matter of reinstalling a bearing or two. It sounds as though the very front one may have not gone in exactly straight. You will have to start over. Hope you didn't assemble the short block first there. It's not repairable with the crankshaft and rods in.
When doing an assembly you always put the cam in first. An up to par shop will try a cam in the block before it leaves the store.
Harry P. Hunter
When doing an assembly you always put the cam in first. An up to par shop will try a cam in the block before it leaves the store.
Harry P. Hunter
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
I've run into it.
I have the $125 "Professional" cam bearing installation tool you see in all the hot-rod mags... (as opposed to the $69 Chevy only tool). It's a series of collets that adjust to the cam bearing's ID, and then the cam bearing is tapped into the block using a driving rod and a hammer... like the ones in Summit. I've used it for 35 years. Suddenly, the good o'l bearings can't take the abuse of being "tapped" in anymore.... I think they are softer than previous. They mushroom, and the cam cannot be installed.
The solution is to buy the $600 tool that pulls the bearings into place via a threaded rod. Of course, for $600 you get more than a piece of Home Depot threaded rod... but for the average DIY guy, $600 is too much.
In certain engines, the cam bearings ID gets smaller as you go front to back, even though the OD is the same. If you install them out of order, the cam won't go in. (FYI)
http://www.autozone.com/servlet/UiBr...3d8004e4e4.jsp
I have the $125 "Professional" cam bearing installation tool you see in all the hot-rod mags... (as opposed to the $69 Chevy only tool). It's a series of collets that adjust to the cam bearing's ID, and then the cam bearing is tapped into the block using a driving rod and a hammer... like the ones in Summit. I've used it for 35 years. Suddenly, the good o'l bearings can't take the abuse of being "tapped" in anymore.... I think they are softer than previous. They mushroom, and the cam cannot be installed.
The solution is to buy the $600 tool that pulls the bearings into place via a threaded rod. Of course, for $600 you get more than a piece of Home Depot threaded rod... but for the average DIY guy, $600 is too much.
In certain engines, the cam bearings ID gets smaller as you go front to back, even though the OD is the same. If you install them out of order, the cam won't go in. (FYI)
http://www.autozone.com/servlet/UiBr...3d8004e4e4.jsp
Last edited by Tom454; Mar 28, 2007 at 04:12 PM. Reason: Add URL
Drifting
Joined: Aug 2004
Posts: 1,883
Likes: 124
From: Lubbock TX
Check to see if there's a small lip on the edge of the bearing that's keeping the cam out. That can be removed with the edge of a sharp knife and you won't have to R&R the bearings. I've seen it quite a bit on the newer LS stuff. By the way, a good shop should check the bearings for burrs and test fit a cam every time, IMHO.
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Race Director
Joined: Jul 2004
Posts: 12,706
Likes: 329
From: Scottsdale Arizona
I though about this when the post first startted, but the back cam journal needs to fit into the smallest cam bearing, so this shouldn't be an issue.
Advanced
Joined: Nov 2006
Posts: 90
Likes: 1
From: New Paris Indiana
Had this happen a couple of times back in my engine building days. I once used a brake cyl. hone to smooth out a bore in the block before installing the bearing for the 3rd time so it wouldn't crush too much. I dont think it ever happened on a sbc, I think it was a 2.8 v6 and maybe a ford v8 of some kind. Being the front bearing, I wonder if he tried to install it from the front and got it a little crooked??? Maybe he was too lazy that day to take it off the engine stand to put it in from the back for good alignment?
Thread Starter
Melting Slicks
Joined: Aug 2004
Posts: 2,165
Likes: 950
From: Keizer Oregon
All the work was done by a machine shop that came highly recommended by a local engine "guru". In addition to cam bearings, they also clearanced the block for stroker crank, bored .030 over, etc etc. Everything else looks fine, just the bearing are screwed up.
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
