Inliners International Forums General Discussion Hi Performance Honing Cam Bearings

I'm rebuilding my 292 and I had the machine shop install new cam bearings.

I went to put the cam in and the first bearing is too tight and I'm assuming the other cam bearings will be as well. Is there a way to hone these yourself?

I don't want to load this thing up and take it back to the machine shop if I don't have to.

never heard of it... the first layer of coating on the bearings isn't that thick, I would not want to "hone it" at all.

I just had cam bearings put in my 230 block and the new cam went in nice.

What if they put a wrong bearing in?

Maybe there is a burr on the ID from the installation tool. Try gently scraping the edges of the bearing for a high spot. It may also help to wobble the cam around in the journal to burnish the high spots. You may have to do that for each one.

I'll take a look for burrs or anything obvious but it's really tight.
I see there's some honing tools available for cam bearings but haven't had any experience with them.

Yep it appears it's tight due to burrs left from the installation tool.
I assume I need to remove these but I'm concerned about degrading the bearings but yet don't want the cam going in tight do I?

I've had to hone them many times, its usually a tight cam bore in the block. You can't remove and re-install the same cam bearings, once they are removed they loose their crush, you will have to put more new ones back in.

Do cam bearings only come in one size?

Sorry for the stupid question

These engines use 1 size to fit the cam. If a bearing has spun in the bore , a oversized bearing can be bought. These are used in a block that has been honed oversize, typically .010, .020 ect.

For these 6 cylinder engines, there is 2 different cam bearing sets depending on the year of the block. So no, there is not a one size fits all scenario. The cam bearings are marked as to their location in the block, but still, it should have been up to the person installing them to verify a camshaft would fit and turn easily.

In some yrs the #1 cam bearing is a different size. So depending yrs & kit, It will have to honed out.I had to blocks that needed this done Rather then buying another kit.I had a machine shop many yrs back Make me a cam That would cut the bearing as I turned it into the bearing.
But it is just easier to have the right kit.Saves time & sometimes money.

Tom

What if we are using one of your turbo cams is that stock journals to fit stock cam bearings (if they have not spun)

My cams are stock journal size. If you measure the cam, all the journals should be the same size.

What year is your engine? As CNCDude was explaining, earlier engines used a different bearing set than.
1962-1970 was one set
1971-87 another set.

This is a 1970 block. The few engines I've done, the machine shop checks the I.D of the cam bearings after installation with a cam but these were on SBC's.

The shop I used is well known around here for drag racing engines but when I picked the block up, we got to bench racing and I didn't ask about the cam bearings. They mainly due sbc/bbc stuff and more than likely didn't have a 6 cylinder cam to try after they installed the cam bearings.

THEN I forget to check them prior to assembly and put the crank and pistons in first so getting to the cam bearings was even more difficult.

Lesson learned...insure cam goes in and spins freely prior to any assembly.

My block is a 62-70 year span do i have to verify that when i order parts from you tom?

just double checked my block is a 352194 on the net it reads 73-84 and the date code on the sides says D 19 5

that's April 19th 1975?

They usually ask you to provide a camshaft if they don't have one, at least a used one.

Also, put the cam in before the rods and pistons, you can bang up the lobes trying to snake the cam in around them. Then after you install the #1 rod and piston, degree the cam before you install the rest of the R&P.

Iearned this lesson the hard way also...Put in the proper cam bearings and the cam will go in perfect every time


1962-1970 was one set
1971-87 another set.

I ran into this when I built the 292 for my car. The holes in the block were not the right size. The machine shop had to hone them out. Joe

I had one once where the back bearing was tight. Could still turn the cam by hand but it was clearly dragging. I chose to polish the last journal on the cam to gain clearance. YMMV.