Sbc cambearning installation

I have seen housing bore misaligments, improper sized housing bores, bent camshafts and camshaft journals that are made a little bigger than they are supposed to be. If the new cam is tight I will first try my known to fit good used cams. That helps me to learn if the block is the problem or the cam is the problem. If that fits fine then I will measure the journals. It's not uncommon to see the journals up to. I will also check the cam with a dial indicator on the lathe or V-blocks.

If the cam is bent I will send it back. Sometimes the camshaft housing bores become misaligned from years of heating and cooling cycles. You can line bore the cam tunnel for oversized bearings or you can run a "cutter cam" to clearance the cam bearings where needed. The cutter cam is not a perfect solution but it has saved a lot of blocks. I can't remember off the top of my head but the bearings have slightly different o.. Post by rebelrouser » Sun Jul 07, pm Most likely it is the block not the cam, if something is bent.

If you were a mopar man then this would be a common thing, big block mopars are notorious for this problem, and its almost always the block warped. I have used a bearing knife, or a mandrel with some paper to touch cam bearings many times.

I use and old cam, tap it in gently and then tap it out, just look where the cam bearings are shiny, and gently polish them until the cam spins smooth. I have seen guys make a reamer out of an old camshaft, the cut a groove lengthways on the journals, then slowly push in and rotate, the groove will clean off a little bearing material for a perfect fit.

Also for example just did a big block chevy and the cam would not go in, did a little measuring and the front cam bearing was too thick, it was an off brand I had not seen before that came in an engine kit.

Post by af2 » Sun Jul 07, pm Did you chamfer the bearing on the side the collet pressed against? Post by garym » Sun Jul 07, pm Thank you for al of the replies. I think that the roller cam that I ran in this block has to be bent as I remember that on one of my sb chevy drag motors the cam was difficult to remove, but I do not know if it was in this block. As far as touching up small areas on the bearing where there are small nicks is it ok to use red scotch bright pad to touch up the bearing surface?

What brand cam bearings have you all like? I was going to use the engine tech coated cam bearings but in this case I will use King or maybe try the ACL aluminum type cam bearing , but I will check this cam out with a dial indicator and 2 v blocks on my Bridgeport milling table. Post by Dave Koehler » Sun Jul 07, pm To the OP If you try a third set. Install the first bearing and check the fit with the cam. Install the second and check with the cam.

Rinse, repeat with the rest of them. The point here is that you will find which bearing is giving you grief. Do i put 1 bearing hole at 12 oclock aligned with the feed hole and the other at 4 oclock? If so, is the hole at 12 oclock hole alignment made so oil is squeezed out of the bearing to lubricate the timing chain?

Wouldnt that give the mains less oil? The hole in the block at 12 is for lubricating the cam itself and needs to line up with the bigger if there is one hole on the bearing, the second hole in the groove is going down into the block, I positioned mine at 12 and 4 but I was always told its for the fuel pump eccentric not the timing chain. Joined: Dec 6, Posts: 1, Profile Page.

Hello, im still having probs with hole positions, So many different opinions on youtube vids, The three central brgs ive put at 4 oclock. The old back one was at 12 oclock heads upwards is that correct? The front one with 2 holes ive seen at 10 and 2 oclock heads upward , is this good? The old front one was at 12 and 4 oclock heads upwards Im mister confused and i dont even drink! Hope you all have a great christmas,. Joined: Sep 12, Posts: 43, Profile Page. Joined: Oct 22, Posts: 5, Profile Page.

If your sbc has the grove behind the bearing Duro Bond info likes the 2 Oclock position. Joined: Dec 22, Posts: 6, Profile Page. Joined: Sep 20, Posts: Profile Page. H , Dec 29, Thanks Beaner, Thanks everbody, Their in, Made my own turned tools. Happy holidays.

The cam was tight. I used a dremmel and cut off disc to make 2 grooves at an angle on each journal of the old cam. Put this in with a bit of oil and turned to "scrape" the bearings to size, Hardly any marks on the cam bearings. Worked wonders, new cam turns lovely without play, Thanks guys, david. You must log in or sign up to reply here. Show Ignored Content.

Share This Page Tweet. Your name or email address: Do you already have an account? No, create an account now. Yes, my password is: Forgot your password? Atomic Industry www. Our Affiliate Link Policy. Typically, whenever a higher level of loading is encountered, greater precision is required to maintain reliability. Conditions such as cleanliness, alignment, clearances, journal surface finishes and lubrication must all be controlled more closely. Following are some recommendations to help optimize performance when using aluminum alloy camshaft bearings.

Sufficient clearance is necessary in the initial installation. These stronger bearings will not wear in rapidly to make their own clearance like softer materials. Minimum clearance should be. Optimum clearance range for high performance applications is. Because of the stack up of tolerances on the block, shaft and bearing it is impossible to control clearance to this range in the manufacture of the bearing alone.

Clearances must be measured at installation. Honing the ID's of cam bearings to increase clearance is not recommended because hone grit may become embedded in bearing surfaces which will cause shaft wear. Bearing ID's may be reamed, but the most practical means is to adjust camshaft journal diameters by grinding.

Even if not ground to provide additional clearance, camshaft bearing journals should be polished to a surface finish of 10 micro-inches Ra or better with the camshaft rotating in the same direction it will rotate in the engine.

Like clearance, alignment is also extremely important especially for high performance applications. Any block that has needed to have its main bearing bore alignment corrected due to distortion is likely to have experienced cam bearing bore distortion as well. Adequate clearance will help compensate for minor misalignment of less than.