sbc cam bearings installation????

[BillK]

Gary,

Like the others have said I have problems with probably one out of ten blocks. Mopars seem the worse but all of them have bad ones.

All I want to add is that I always put the bearings in one at a time, starting with the rear one and I put the cam in after each bearing is installed. That way if you do have a tight or out of line bearing you will know which one it is.

I have used Durabond bearings almost exclusively for years and don't have any issues with them.

If you have someone that grinds cranks they should have a good set of Vee blocks to check the cam on for straightness. I put them up on my crank balancer and check them with a dial indicator.

[garym]

I received the v blocks today and put the billet roller cam on the v blocks, put my dial indicator on the center cam journal. The runout was over .009 on the center cam journal, I checked the #2 cam journal and it was over .012 .So I guess that is the problem.I would say that this cam is worthless and I really do not have many runs on the engine.I do not think that this cam could straightend. Any ways thank you for all the replies. garym

[bill jones]

---this is my story about straightening camshafts
------------------------------------------------------------
-Straightening cast iron or billet steel cams is easy with a air hammer and a concave curve that's been rounded off----on about a 1" wide x 3/16" thick nose air chisel.

-I made up a set of V-blocks ---could use'm on a mill table or adapt'm to like a piece of aluminum with one slot for an adjustment length to allow various cam lengths.

-I found to use a air pressure regulator----start with the air pressure to the air hammer at about 40psi.

-roll the cam on the v-blocks and find the lowest journal--mark it on the low side of each of the center journals how much it's off.

-roll the high side down---start right next to the lowest journal and rattle it straight down about 6 to 10 shots---and recheck it.

-If you have the dial indicator set up on the cam while you are air hammering the cam---it's a good idea to hold onto the dial indicator stem so the air hammer doesn't ruin the indicator.

-after you get an idea of what the first short burst did--then you can proceed and work both side of the lowest cam journal----and work further away like in between the lobes.

-the low spot on the cam will come up towards the air hammered area.
----------------------------------------------------------
-I can say that I've purposely air hammered .060" of bend into cast and billet cams that I was using for testing----and they will come right back and you can get'm to read less than half a thou.

-BUT---when you have a lobe that has been hit with a connecting rod during an engine blowup----it's a real challenge to move one or two lobes & base circles back into alignment.
-----------------------------------------------------------
--this is one set of V-blocks I made for my mill---but I don't like the idea of air hammering on my mill.

V-blocks set up for checking cams.jpg

---I have also built another pair of V-blocks that slide in slots in about a 40" long piece of 6x2 channel iron
---this allows me to do short Subaru's to long inline 6 cylinders on my work bench.
----------------------------------------------------------

--this is a thread about straightening cams on speedtalk from back in about 2010.

viewtopic.php?t=19803

-

[allencr267]

Push it.
No reason you can't try to make it straight or at least straighter!
Lean on the high spot and see if the runout's down.
//
//
Thank you Bill, more into science instead of us using a broomstick or C-clamp.

[bill jones]

---this is my V-block fixture I use for straightening camshafts--and the air hammers I use and the curved air chisel.
------------------------------------------------------------
---I built a slider bar along the side for the dial indicator---the slider is made of Teflon and slotted so I can remove & replace the dial indicator off that slider bar quick & easy while I use the air hammer.
----------------------------------------------------------
---this particular cam is a brand new General Kinetics----about 30 years old---and it shows .004" warp just from sitting in the box all those years.
----------------------------------------------------------
---personally I would NOT consider trying to press any cast cam for any reason---I'd suspect they'd break with not much of a pressing tweak.
------------------------------------------------------------
---I have seen a steel billet roller cam where one lobe was bent from a part getting wedged in there from a engine disaster---that was pressed on pretty hard to get that one lobe back into position---then normal straightening applied to get the cam journals and the basecircles all back in line.