Issues with cam bearings and clearances. Cam will not fit.

[Lordofthepings777]

Put new bearings and cam in a friends mopar 400 a couple years ago now; the engine is wrapping up its 2nd cruising/show season - probably 10k miles.

As a dedicated YouTube Mechanic, I followed advice of some video (UTG? Nick's Garage??) to install one bearing and a time, working back to front, and then used 400-600-1000 grit paper to get it to fit (EDITED to Add; "...installing the cam (temporarily) after each bearing to make sure spinning smoothly). Primitive, i know, but this was a garage cam swap with the cheap-o cam bearing tool ($65?) and a FB Marketplace cam ($100).

Wouldn’t using sandpaper create uneven surface unless you go in circles with the same force applied? Difficult to do by hand I assume. That would be my only concern with doing it that way.

 

[413]

The cam bearings may need material removed from half of the bearing. Install cam and rotate then remove cam and look at the rub marks on the bearings.

16 valve springs pushing the camshaft down the entire time it is in the engine.

 

[Fury1969WI]

Wouldn’t using sandpaper create uneven surface unless you go in circles with the same force applied? Difficult to do by hand I assume. That would be my only concern with doing it that way.

A couple thoughts; you only need to take out the high spots - you don't necessarily want / need to bore the hole thing and we're talking thousands or tens of thousands of an inch and often only the edges of the bearing need to be cleaned up; mine deformed slightly on the tool edge. You don't need much (at least i didn't) and in some cases the cam would go into the bearing but it was tight when doing the spin check - or became tight when i got it in the next bearing. A little careful work with the 600 was all mine took. My thought at the time was I'd rather take more time using the paper than risk FUBAR with a knife or file - but you do you and maybe you have more material to remove. Go slow and do a LOT of test fitting. An annoying amount and one bearing at a time. For a street build this will be fine IMO. Good luck - would love to hear how it turns out.

 

[wyrmrider]

well knon that the specs in the book are .001off for the #3 i had atoolfor that but you can make a reamer out of a straight old cam just kut some groves in #3 square put in while rotating and it will clearance #3 you can then use dykem and a bearing scraper me x factory zone rep

 

[Toolmanmike]

Is it one bearing or many? Scraping works, so does sanding or a bead hone (hard to get into the bore though) Just make sure you clean up all the material after or use a vacuum near the bearing to suck up the shavings and abrasive. My machine shop asked to keep my old 273 cam and he cut grooves in the journals which acts as a scraper when you rotate the cam. Driving the bearings in a block is not an exact science and the Lisle tool is the most accurate and widely used that I know if.

 

[Retired auto tech]

Ok, I just pulled out my 1967 FSM and looked at the cam bearing journal specs and guess what? They are all a different size!
Camshaft Bearing Journals:
#1- 1.998 to 1.999
#2- 1.982 to 1.983
#3- 1.967 to 1.968
#4- 1.951 to 1.952
#5- 1.748 to 1.749

Camshaft Bearings
Diameter ( after reaming )
#1- 2.000 to 2.001
#2- 1.984 to 1.985
#3- 1.969 to 1.970
#4- 1.953 to 1.954
#5- 1.750 to 1.751

Desired clearance .001 to.003 Max .005

I now understand the reason for using the old camshaft to clearance the bearings but it also shows that the factory used a different sized bearing shell
in each position, especially in the #5 rear bearing. They also reamed them to the correct size. Never paid attention to this before as I have always had the machine shop install the bearings for me. I did know that Ford cam bearings are numbered for correct position and just assumed that all makes we're which is why I never bothered to buy an install tool and left it all up to my machinest. Be interesting to measure an aftermarket bearing set and see how the O.D and I.D. compare
to the spec. Another question, are all big blocks the same or was this changed at sometime in the latter years?

 

[plymouthguy1960]

I had that problem years ago after having my block tanked and new cam bearings installed. I broke a new camshaft trying to get it in and it got stuck. Before trying another one, I used a brake cylinder hone to get the clearances needed to install another cam.

 

[1970FuryConv]

Ok, I just pulled out my 1967 FSM and looked at the cam bearing journal specs and guess what? They are all a different size!
Camshaft Bearing Journals:
#1- 1.998 to 1.999
#2- 1.982 to 1.983
#3- 1.967 to 1.968
#4- 1.951 to 1.952
#5- 1.748 to 1.749

Camshaft Bearings
Diameter ( after reaming )
#1- 2.000 to 2.001
#2- 1.984 to 1.985
#3- 1.969 to 1.970
#4- 1.953 to 1.954
#5- 1.750 to 1.751

Desired clearance .001 to.003 Max .005

I now understand the reason for using the old camshaft to clearance the bearings but it also shows that the factory used a different sized bearing shell
in each position, especially in the #5 rear bearing. They also reamed them to the correct size. Never paid attention to this before as I have always had the machine shop install the bearings for me. I did know that Ford cam bearings are numbered for correct position and just assumed that all makes we're which is why I never bothered to buy an install tool and left it all up to my machinest. Be interesting to measure an aftermarket bearing set and see how the O.D and I.D. compare
to the spec. Another question, are all big blocks the same or was this changed at sometime in the latter years?

According to 440 Source, they are all basically the same, even industrial blocks. Click Link below.
440 Source.com Everything you've ever wanted to know about blocks and more....
Also, all cam journals are same for B & RB. I suspect the telescoping increase in cam journal size front to back was to keep some Goomba from installing a camshaft backward.
Clevite bearing example below
Clevite Camshaft Bearings

 

[68PK21 440.6bbl]

Then there is the UTG way... funny, tosses instructions, **** falling off bench, too small of a hammer, where's hammer.



.

 

[68PK21 440.6bbl]

DUH... OH NO! Are Cheby guys smarter than Mopar Maniacs?
(notice how freely the cam spins)



.

 

[Big_John]

My thoughts.... as someone that's spent a lot of his life around precision machining and measuring, and has built a few engines for myself and other. Basically my experiences.....

Full disclaimer: I have always had the machine shop install the cam bearings. Cost was minimal, one less tool to buy, and one less thing to worry about.

With one exception, all has been good. The exception was from the most expensive shop, the one that took far longer than it should and the one that specialized in Mopars... In other words, the one I expected the least problem with. This was in the 70's. I scrapped the bearings to size and that was that... Never went back to that shop.

I did have one shop ask for the cam so they could try it. I can't remember which shop though (LOL). The one I'll use for my next engine (273 for my Barracuda) will be one I've used quite a few times and I've known the owner since he was a kid starting out.

Reading this thread, I've noticed that there's much speculation about what the issue is.

I've seen references to the cam bore being misaligned and the cam being having excessive runout. I can believe there are cams having excessive runout, but I doubt if that is something that happens a lot. If it does happen, increasing the internal size of the cam bearings isn't the way to fix it.

I don't think that alignment of the bore is a real problem. If there was, you'd see problems with the crank bore and more engines needing to be align bored.

What I have not seen here is the simple measurement of the ID of the cam bearings. What would be ideal would be a measurement of the bearing bore ID before installing the bearing, a measurement of the ID and OD of the bearing before installation and finally a measurement of the ID of the installed bearing.

Not many are going to do that much measuring beforehand, but it seems to me that it's pretty freaking simple to measure the installed bearing ID and the size of the cam journal, especially if you are having a problem. I don't see that.... A lot of the bore gauges will be able to measure it but a telescoping gauge and micrometer will do the job (possibly easier too). Basic tools and skills for someone doing an engine rebuild.

As I said, it was the 70's the last time I had a cam bearing problem, so I don't remember the details.... I knew which bearing(s) to scrape, and I had the tools, so chances are I measured and went from there. At approximately 50 years ago, I'm lucky I remember it period.

My thoughts are there are a few problems. First is the bearing needs to be installed straight. The bearing itself is narrow in width compared to diameter, so that doesn't help. Ideally, the tool would align better with the other bores with something better than a cone, but that would mean an expensive tool that just does Mopars.
The second problem is since the bearing is pressed into place, the bearing will "crush" slightly and the ID will shrink. Again, it has to be kept straight so it crushes evenly, but the finished size is what matters.

The third problem could be the stack up of tolerances. Consider everything to be within the manufacturing tolerances here.... The ID of the cam bore is slightly under nominal. The OD of the new bearing is over nominal and the ID under nominal. The cam journal OD is over nominal. All within tolerance, but it stacks up... and that is why there is Geometrical Dimensioning and Tolerance (GD&T) in a lot of automotive manufacturing now, but that's another subject that will put you to sleep.

The final problem is the bearings are just undersize after being pressed in. Quality isn't what it used to be, but I don't think this is a new problem. The thought could be to make the bearing always fit the bore and let the machinist fit it from there. I don't know.

So, again.... Has anyone actually measured the cam journals and bearing ID? If so, let's hear it!

 

[CBODY67]

Certainly, as the cam bearings are an "interference fit", there might be a bit of "crushing" to ensure such and everything stays in place.

Additionally, deformation might happen on the leading/front edge of the cam bearing as it is "forced" into place. Gentle taps rather than fewer "knocks"?

Perhaps putting the cam bearings tin the freezer for 24hours before installation might make them "slide" in easier? Letting expansion as they defrost replace "knocks"?

Cranks bearings used on the assy lines usually have no "protective coating" on th

The use of a brake hone is very ingenius!em, whereas those sold in the aftermarket do. Our old service manager/jet boat racer would use red Scotchbrite to polish all of his new cranks bearings for this reason. When looking at the bearing surface, after I asked about what he was doing, confirmed the presence of a not quite even coating on the base bearing material. But I did not remember seeing the same thing on cam bearings in the machine shop realm of things. My operative usually bought the "white box" bearings when he could. Designed for use by "installers" rather than not. People who knew to check things and lube everything when assembled, for example.

In the case of "polishing" upon oiling and installation, the main issue is to "polish", not remove per se, bearing surfaces. Back then, the "finest" abrasive ScotchBrite there was the "red" item, which I think was close to 600 grit body shop sand paper.

Thanks for the confirmation of the different cam bearing sizes (progressively getting smaller toward the rear of the block) and locations.

Just some thoughts and observations,
CBODY67

 

[Retired auto tech]

I read the 440 source article and although it has a lot of good information there was no mention of cam bore or bearings. I have a 1969 383,
1978, 1974 and 1967 440 engines but am unable to check them out at this time but will definitely be measuring them when I do tear them down.
The 67 will be built as close to the 440 TNT spec as possible and will be the one going into the 67 Newport Convert.

 

[Gerald Morris]

That's the way I've done it.

A magic marker on the bearings will tell you the high spots.

Mimeograph ink used to be The **** for such work. Wonder what else will do so nicely? I'm looking at a couple such jobs in the nearest future I can arrange, and thank EVERYBODY on this thread who has contributed Moparian Lore I can use.

 

[Gerald Morris]

...

One thing that I'm going to start doing is installing the camshaft in the block before anything else. It's a lot easier with the crankshaft out so you can reach down through to hold the cam up as you feed it into the block. Then if there's a problem like this, you can work on it without worry of getting bearing material in the engine.

I think I'll follow your suit on the SECOND cam job I have lined up. Alas, the first will be likely an in situ job on the 383 we have bolted into Gertrude now. This really should have been done 3 yrs ago, when we hired that boy with the "Certified Garage" to do the 915 head installation, but while he just managed to seal those up right enough, it CLEARLY showed by his work on that engine that 1.) He was a "pipe mechanic" meaning his shop did little but exhaust work, 2.) He KNEW his incompetence, especially with an Old Mopar, which he very evidently had never touched before. leading to 3.) He ****** off the job so long that I simply had to take the damned car from him, sans the cam replacement, which he clearly feared taking any part in. I at least thanked him for his honesty that far, but it left us with a worn cam in that engine which should have been replaced when the rest of the rotating assembly was done some decades previous.

So, I plan to get some other family sized car in motion first, then replace the cam in the engine. I'll carefully check the valve action, the clearances on the rocker-arms and pushrods et al, to see just exactly HOW compellingly necessary such work is this December, then make my final judgement w.r.t. WHEN that job needs doing. If I can get another engine running first, THEN I can pull this one, and do the cam and such on a stand instead. Of course, this engine has that cracked deck, so....

 

[Gerald Morris]

Then there is the UTG way... funny, tosses instructions, **** falling off bench, too small of a hammer, where's hammer.



.

Just checked the latest offerings from BeZosZon, and sure as ****, the "Orion" tool is still under $70, in addition to others which look just like it, ranging in price from $60 to $200 for the same identical ****. I think I'll follow Uncle Tony in this matter, unless I can score some Old Gold somewhere.....

 

[Frank Odenthal]

The FSM says camshaft bearing diameter „After reaming „
Was that the standard procedure in the engine plant back then, or is this the workshop procedure only, to correct bearing imperfections in roundness or surface or shrink Caused by the manual press in ?
Reaming would require 5 different tool sizes or a Single tool combining all 5 diameter.
This would be a time consuming process for mass Production.

 

[plymouthguy1960]

The FSM says camshaft bearing diameter „After reaming „
Was that the standard procedure in the engine plant back then, or is this the workshop procedure only, to correct bearing imperfections in roundness or surface or shrink Caused by the manual press in ?
Reaming would require 5 different tool sizes or a Single tool combining all 5 diameter.
This would be a time consuming process for mass Productio

The FSM says camshaft bearing diameter „After reaming „
Was that the standard procedure in the engine plant back then, or is this the workshop procedure only, to correct bearing imperfections in roundness or surface or shrink Caused by the manual press in ?
Reaming would require 5 different tool sizes or a Single tool combining all 5 diameter.
This would be a time consuming process for mass Production.

See #27 and #32 above about using a wheel cylinder hone.

 

[CBODY67]

At the engine plant, it's a production line just like where the cars are assembled. TIME matters. No reaming of cam bearings as they are "supplied to size". Never have known of anybody or any engine shop reaming bearings, period.

They are carefully "knocked in" with an appropriate tool. Takes just a few minutes to do all of them. Once the bearings are started squarely in their respective "hole", it does not take much effort to finish putting them in place. The "reaming" might be the final machining operation for the cam bearing saddles?

NOW, the saddles the bam bearings reside in CAN be "reamed to size" at the engine plant as a part of the machining on the block. A quality control issue which can result in easier and quicker installation on the engine assy line.

Just some thoughts,
CBODY67

 

[Gerald Morris]

I can think of a number of methods for cutting cast iron to accommodate precise diameters, but on a slightly different note, I'm more interested in having the best tool reasonably available for inserting a Mopar B/RB engine's cam bearings. Much as I love UTG, I'm willing to pay a few extra $ to get things right the first time, and, having found this

Mopar Big Block 383 426 440 V8 Cam Bearing Installation Tool Removing Bearings

I wonder if any of you have used this tool, and if so, deem it worth the extra C-note to get it.