Cam Bearing Alignment

[Flyboy1400]

Did you compare the journal diam of new & old cams? It could be the cam journal that is oversize. I had this happen with an Isky cam. I would take a thousandth of the journal rather than 'scrape' the brg.

I have not compared the journals, I'll measure them tomorrow after work. I'm not sure how I would go about evenly taking material off of the journal if it is oversize, as I don't have access to a lathe.

 

[Cranky]

Well I finally got some time this weekend to test fit the new cam and sure enough it's a bit tight. It goes in ok, but wont quite rotate by hand. I put the timing gear on and can easily rotate it with that on, but it does feel tight. After pulling the cam back out I did notice some shiny spots on bearing #2, 4 and 5. So learning to scrape bearings is now the next step for me.

I also did check the runout, new cam has ~0.002, for reference I also measured the old stock cam that came out and it has ~ 0.007 !! I have been unable to find a specified tolerance for cam runout, does anybody here know what an allowable tolerance would be for camshaft runout?

.002 is ok but .000 is better. What did the old cam bearings look like with that .007 cam? Do you know if the engine had been over heated or did the old cam lose a couple of lobes? Can't remember ever pulling out a cam with that much run out but I didn't check every single one that I pulled out....

 

[68 HEMI GTS]

The holes absolutely fine. Pretty normal to have to scrape bearings on a big mopar. The housing bore machining from the factory wasn’t stellar. The shop should have fit a cam when they installed the bearings.

 

[Cranky]

The holes absolutely fine. Pretty normal to have to scrape bearings on a big mopar. The housing bore machining from the factory wasn’t stellar. The shop should have fit a cam when they installed the bearings.

I never stuck an alignment bar into any cam bearing fits in a block before because I didn't see a need since I never had any issues with tight cams until a buddy installed a set of bearings for me. I later learned he was using one of those universal cam bearing tools but don't remember the name brand. He was always having problems with tight cams and after looking at his cam tool, it looked like it might let the bearing compress a little....especially if the bore fit was a bit tight. Years later I made a cam bearing tool and did several with no issues. There were times where the 'plug' was snug in the bearing bore and was a little bit hard to get out but the bearing looked good and the cam still slid in easily.

 

[Flyboy1400]

Did you compare the journal diam of new & old cams?

Measured the journals after work today, and they are dang close no more than 1 thou difference:

New Cam | Old Cam
#1 1.998 1.997
#2 1.981 1.981
#3 1.966 1.966
#4 1.950 1.951
#5 1.747 1.748

What did the old cam bearings look like with that .007 cam? Do you know if the engine had been over heated or did the old cam lose a couple of lobes?

The old bearings didn't look too bad, at least as far as wear goes. The #1 bearing had some chunks of Babbitt missing at the very front edge and #4 had some light scratches from some debris but none were wiped out.

The engine is out of a 68 New Yorker, but I got it as a "package deal" when I bought my Satellite. I believe it came from a junk yard prior to that. So I don't know how it ran. No signs of a blown head gasket or any cracks, it did have one very slightly bent push rod, and was was seized due to rust in the #2 cyl though. It took .006 to true up the deck surface, and the line hone barely touched the mains, so I'm thinking its all pretty straight as far as warpage. Cam lobes are all there and intact, there is some weirdness to the lobes though, almost looks like small cracks, or some kind of erosion of the metal.

I later learned he was using one of those universal cam bearing tools but don't remember the name brand. He was always having problems with tight cams and after looking at his cam tool, it looked like it might let the bearing compress a little....especially if the bore fit was a bit tight. Years later I made a cam bearing tool and did several with no issues.

I think next time around I'll want to tackle installing bearings myself, what cam bearing tool would you recommend? I seem to only find the "universal" types for sale.

 

[Cranky]

Measured the journals after work today, and they are dang close no more than 1 thou difference:

New Cam | Old Cam
#1 1.998 1.997
#2 1.981 1.981
#3 1.966 1.966
#4 1.950 1.951
#5 1.747 1.748


The old bearings didn't look too bad, at least as far as wear goes. The #1 bearing had some chunks of Babbitt missing at the very front edge and #4 had some light scratches from some debris but none were wiped out.

The engine is out of a 68 New Yorker, but I got it as a "package deal" when I bought my Satellite. I believe it came from a junk yard prior to that. So I don't know how it ran. No signs of a blown head gasket or any cracks, it did have one very slightly bent push rod, and was was seized due to rust in the #2 cyl though. It took .006 to true up the deck surface, and the line hone barely touched the mains, so I'm thinking its all pretty straight as far as warpage. Cam lobes are all there and intact, there is some weirdness to the lobes though, almost looks like small cracks, or some kind of erosion of the metal.
View attachment 1369990View attachment 1369991View attachment 1369992


I think next time around I'll want to tackle installing bearings myself, what cam bearing tool would you recommend? I seem to only find the "universal" types for sale.

I've seen cams look like that before too. Not sure if it was made that way or wear or both. As for a cam bearing tool.... that's why I made my own. And your .001 bigger journal might be why that cam is snug. Do you have a way to measure the bearing IDs?

 

[Flyboy1400]

I have a dial bore gauge, not sure off the top of my head if it will go that small though. If not I also have some of those telescoping T gauges that will fit. I'll see about getting a measurement tomorrow. Interestingly, I just looked up the specs for cam journal size in the FSM and both cams appear to be on the smaller side of the range. I suppose comparing it to the actual bearing ID would be the next logical step.

 

[Cranky]

I have a dial bore gauge, not sure off the top of my head if it will go that small though. If not I also have some of those telescoping T gauges that will fit. I'll see about getting a measurement tomorrow. Interestingly, I just looked up the specs for cam journal size in the FSM and both cams appear to be on the smaller side of the range. I suppose comparing it to the actual bearing ID would be the next logical step.

View attachment 1370069

The snap gauges are iffy unless you have a lot of experience with them especially measuring something with soft metals like bearings. Need a real light touch with the lock and then measure several times to see if they repeat. An inside mic would be better for doing that but the DBG might work in there too if you can calibrate it and if it will fit.

 

[Flyboy1400]

I was able to get bearing 1,2 and 4 with the dial bore gauge and used the telescoping gauges for 3 and 5, here's what I came up with.

Bearing ID
#1 2.0015
#2 1.985
#3 1.968
#4 1.954
#5 1.750

Which gives journal to bearing clearance of
#1 .0035
#2 .004
#3 .002
#4 .004
#5 .003

Bearing 2 and 5 had a ring of scuffing around the ID after the test fit, I'm thinking gently scraping this with a bearing knife might do the trick?

 

[68 HEMI GTS]

Yep, just needs a little touch up.. I’d say #2 looks like it was probably installed just a touch cocked. I always polish them with a red scotch brite after I hit them with the Bearing knife.

 

[Cartel]

Measured the journals after work today, and they are dang close no more than 1 thou difference:

New Cam | Old Cam
#1 1.998 1.997
#2 1.981 1.981
#3 1.966 1.966
#4 1.950 1.951
#5 1.747 1.748


The old bearings didn't look too bad, at least as far as wear goes. The #1 bearing had some chunks of Babbitt missing at the very front edge and #4 had some light scratches from some debris but none were wiped out.

The engine is out of a 68 New Yorker, but I got it as a "package deal" when I bought my Satellite. I believe it came from a junk yard prior to that. So I don't know how it ran. No signs of a blown head gasket or any cracks, it did have one very slightly bent push rod, and was was seized due to rust in the #2 cyl though. It took .006 to true up the deck surface, and the line hone barely touched the mains, so I'm thinking its all pretty straight as far as warpage. Cam lobes are all there and intact, there is some weirdness to the lobes though, almost looks like small cracks, or some kind of erosion of the metal.
View attachment 1369990View attachment 1369991View attachment 1369992


I think next time around I'll want to tackle installing bearings myself, what cam bearing tool would you recommend? I seem to only find the "universal" types for sale.

My 383 cam that was the original looked just like yours. I think from rust pitting after sitting for years