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

[Lordofthepings777]

so I’m working on a 400 engine out of my car, and I’m doing a full rebuild. Taking apart the engine wasn’t bad, but I struggled to get the old camshaft out a bit. I actually had to slightly beat it out of the motor with a dead blow hammer.

Anyways, about a month or a month and half ago I took out my old cam bearings in plans to replace them. The old ones look rough, so I opted for new ones installed myself for the first time. Made sure oiling holes lined up and everything. Then- I go to put my new cam in recently and it doesn’t want to go all the way in. I end up buggering these new ones up (clevite brand) because the cam just won’t go in. I figure “it’s my first time maybe I didn’t do it right”. Last time I borrowed by buddies tool, so I bought a used lisle tool of higher quality, and began to take out my newly installed ones one by one to see if I could get it to go in. I removed the cam bearings one by one to see if the reminder would fit with the camshaft in the block, but none would fit.

Lastly, I decided I’d try and install one bearing in the rear of the engine making sure I take proper precautions, and it STILL would not fit after lining up the oiling hole and making sure it was all the way back on the tool so it seats flat in the block.

Now I’m just confused. Has anybody EVER had any cam bearing issues like this before where the new AND old crank will not fit in the block even after changing the bearings? I wish I had checked if it would fit back in before I removed the original ones, but I didn’t.

Keep in mind this motor locked up, and it struggled to turn when it would turn over. Could there be something that dramatically wrong? What should I do?

 

[Davea Lux]

Clevite is a good brand of bearing. That might mean that either the camshaft was not properly machined or there is a serious warping problem with the block. Before getting all excited about that, I would start by having the bearing surfaces of the cam checked with a micrometer. Some of the cams made in China have had a serious problem with being out of spec due to poor quality control. If the cam checks out, the cam bearings should also be checked to be sure that they are in spec with an inside micrometer. Did you oil the cam and bearings well before trying to install the camshaft? If all that is good, take the engine to a machine shop and have the cam bores in the block line checked. Also note that some of the vintage cam bearings were semi finished and needed to be line bored for proper fitment.

Dave

 

[Samplingman]

so I’m working on a 400 engine out of my car, and I’m doing a full rebuild. Taking apart the engine wasn’t bad, but I struggled to get the old camshaft out a bit. I actually had to slightly beat it out of the motor with a dead blow hammer.

Anyways, about a month or a month and half ago I took out my old cam bearings in plans to replace them. The old ones look rough, so I opted for new ones installed myself for the first time. Made sure oiling holes lined up and everything. Then- I go to put my new cam in recently and it doesn’t want to go all the way in. I end up buggering these new ones up (clevite brand) because the cam just won’t go in. I figure “it’s my first time maybe I didn’t do it right”. Last time I borrowed by buddies tool, so I bought a used lisle tool of higher quality, and began to take out my newly installed ones one by one to see if I could get it to go in. I removed the cam bearings one by one to see if the reminder would fit with the camshaft in the block, but none would fit.

Lastly, I decided I’d try and install one bearing in the rear of the engine making sure I take proper precautions, and it STILL would not fit after lining up the oiling hole and making sure it was all the way back on the tool so it seats flat in the block.

Now I’m just confused. Has anybody EVER had any cam bearing issues like this before where the new AND old crank will not fit in the block even after changing the bearings? I wish I had checked if it would fit back in before I removed the original ones, but I didn’t.

Keep in mind this motor locked up, and it struggled to turn when it would turn over. Could there be something that dramatically wrong? What should I do?

When I had my 440 rebuilt I had the short block assembled, leaving the cam and heads for me to finish. I had the same issue with the new cam, drove me crazy. Apparently there is a technique in “shaving” the new cam bearings with the old cam. I had never heard about this before but it is a common practice. You basically cut diagonal cutting groves in the old cam and then slowly turn it while installing creating a “cutting lathe” effect, shaving the new bearings to size, eventually making your way all the way to the end cap. Use lots of assembly lube, and don’t worry about the shavings, they are a soft material that will not hurt the other workings of the engine. Do a search and you should find plenty of discussion on this process. FWIW, next time I’m paying the extra money to have my engine completely assembled by the machine shop!

 

[Imperial Pete]

Yep standard affair with big blocks, 99% of the time the cams wont fit. I was a machinist from the mid 80's so it isn't a new issue or a case of " The bearings these days are no good".
Check that your cam is straight is a good idea.
We would use a bearing scraper to slowly take out the high spots and then hand polish those areas with super fine steel wool.
Small block Mopars were never a problem, always the big block Mopars.

 

[1970FuryConv]

so I’m working on a 400 engine out of my car, and I’m doing a full rebuild. Taking apart the engine wasn’t bad, but I struggled to get the old camshaft out a bit. I actually had to slightly beat it out of the motor with a dead blow hammer.

Anyways, about a month or a month and half ago I took out my old cam bearings in plans to replace them. The old ones look rough, so I opted for new ones installed myself for the first time. Made sure oiling holes lined up and everything. Then- I go to put my new cam in recently and it doesn’t want to go all the way in. I end up buggering these new ones up (clevite brand) because the cam just won’t go in. I figure “it’s my first time maybe I didn’t do it right”. Last time I borrowed by buddies tool, so I bought a used lisle tool of higher quality, and began to take out my newly installed ones one by one to see if I could get it to go in. I removed the cam bearings one by one to see if the reminder would fit with the camshaft in the block, but none would fit.

Lastly, I decided I’d try and install one bearing in the rear of the engine making sure I take proper precautions, and it STILL would not fit after lining up the oiling hole and making sure it was all the way back on the tool so it seats flat in the block.

Now I’m just confused. Has anybody EVER had any cam bearing issues like this before where the new AND old crank will not fit in the block even after changing the bearings? I wish I had checked if it would fit back in before I removed the original ones, but I didn’t.

Keep in mind this motor locked up, and it struggled to turn when it would turn over. Could there be something that dramatically wrong? What should I do?

View attachment 738102

This is normal, unfortunately.
The bearings are manufactured under size internal diameter.
At the factory, they line honed the bearings out to full size.
At my machine shop, my machinist used my old camshaft to drill out the new cam bearings. He nicked the rear edge of each cam journal. He oiled the same journals. Then he slowly turned the old cam clockwise as he installed it into the new cam bearings. This created a large number of metal shavings until the cam was fully installed in the journals.
We then pulled out the old cam. Cleaned out the metal shavings and I was able to install the new cam. I would not leave those shavings in the engine, because you don't want anything clogging your oil pickup.
Sounds primitive, but the 440 has had no oil pressure or cam issues in 5 years.

 

[Justin Plant]

I've rebuilt several engines over the years. Many different makes. I've never built a Big Block Chrysler though. None of this makes sense. Why on earth is this "the way" Chrysler intended. I've had to deal with Fords that needed the cam bearings installed in certain holes. But, this just seems silly. Does anyone have any idea why Mopar designed it this way?

 

[bigmoparjeff]

 

[Big_John]

We would use a bearing scraper to slowly take out the high spots and then hand polish those areas with super fine steel wool.

That's the way I've done it.

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

 

[Fury1969WI]

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).

 

[Big_John]

When I had my 440 rebuilt I had the short block assembled, leaving the cam and heads for me to finish. I had the same issue with the new cam, drove me crazy. Apparently there is a technique in “shaving” the new cam bearings with the old cam. I had never heard about this before but it is a common practice. You basically cut diagonal cutting groves in the old cam and then slowly turn it while installing creating a “cutting lathe” effect, shaving the new bearings to size, eventually making your way all the way to the end cap. Use lots of assembly lube, and don’t worry about the shavings, they are a soft material that will not hurt the other workings of the engine. Do a search and you should find plenty of discussion on this process. FWIW, next time I’m paying the extra money to have my engine completely assembled by the machine shop!

I've never seen that, but it makes sense to me.

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.

 

[Fury1969WI]

PS - Part of what I "think" is happening is the bearings are soft and during installation they can get a slight deformation on the tool edge that you need to take off. Old timers may recall a "bearing knife" (https://goodson.com/products/bearing-scraperwhere) you'd basically just whittle them down to fit. Is it as good as a new align hone at the machine shop - probably not. Does it matter on a low buck street engine? IDK but so far so good on this engine. How you approach this may depend on your expectation for your engine (and wallet/budget for the build). Good luck!

 

[Big_John]

Old timers may recall a "bearing knife" (https://goodson.com/products/bearing-scraperwhere) you'd basically just whittle them down to fit.

Those were often made with an old file. The one I had was.

Bearing Scraper | BS-30

My brother was stabbed in the chest with one by a crazed Toolmaker.

 

[68PK21 440.6bbl]

Here's Nicks garage simpler method and he inspects with a pencil flashlight (as per FSM) and not a stupid cellphone flashlight. I'm not really a fan of hammering in cam bearings and have used a screw press in tool, the lever jack tool in the other video is cool but I'll bet pricey $$$.
If you notice in Nicks video on the last cam bearing install is that his driving tool is off at a slight angle and could be a problem, plus I would of used a slightly bigger ballpeen hammer which would require less forceful 'whacks'.
Hammering skills are learned over many years of time, at least he isn't using a broken claw hammer as seen previously.

The whole cleaning of the block at the end I don't think is necessary, you could area clean with carb/brake cleaner and he should of done that after each bearing polish before the spin test IMHO.

.

 

[Big_John]

at least he isn't using a broken claw hammer

My late buddy Dave was one of the better mechanics I've ever met when it came to old Mopars. He wasn't a guy that was in debt to the Snap-On truck though. He used a broken claw hammer a lot.... Mostly to annoy everyone who wasn't in on the joke.

 

[CBODY67]

Something in the back of my mind seems to remember that each of the journals on the cam are different sizes. Largest on the front and smallest on the back. The cam bearings should be similar, I would think. Or has the cam bearing industry devolved to making the "all the same"? Something tells me "No", IF the company wants their bearings to sell to production machine shops/rebuilders.

I saw my late machine shop operative hand-clearance the rear cam bearing on a 454 Chevy one afternoon. With a somewhat dull pocketknife. Expertly done, too, as I watched. When the cam spun freely, then he stopped at that point . . . and tapped back in the core plug on the back of teh block.

Back in the 1980s, I was getting ready to put together a 440 6bbl motor for my '70 Monaco Brougham. The Chrysler Parts factory closeout sale happened. I bought a '72 440-3 short block from an area dealer where I had a friend in the parts dept. I also ordered some new 452 heads, crank damper. Plus some 400 cranks. I later put the 440 block on an engine stand.

For the cam, I also planned on that. Getting one of the first-series of Comp 268HE cams. I also got a Chrysler Street HEMI grind 284/284 Purple Shaft cam (the original Purple Shaft series!) cam and lifters from the old Gratiot Auto Supply in MI, for good measure. I also got a genuine Mr. Gasket Degree Wheel and magnetic base dial indicator.

One night, I got industrius and set up the dial indicator, one of the Purple Shaft hydraulic lifters, a pushrod, put the degree wheel on the crank, and set the timing indicator "bent wire" to "0".

I lightly lubed the cam lobes and cam bearings and wiped off the #1 cyl cam lobes. Then I put it all together to check the actual (at the top of the pushrod) cam lobe lift and its curve. With EITHER cam, NO issues just easily sliding-in the cam to the block. As I expected it to do! I was also using a lubed double-roller timing chain set.

While I'm "here", I need to also report that the CC 268HE cam verified their advertising of their (then unique) "Assymetrical Lobe Configuration" (open quick, close slow) which ALSO kept the valves at Max Lift for a surprising 10 full degrees of crank rotation! The figures on the cam card also matched.

For the legendary OEM Chrysler Parts Direct Connection Street HEMI Purple Shaft cam, the specs also matched, but in a traditional way. Unfortunately, Max Lift was only operative for 1 degree of crank rotation. Up and down quickly and that was it.

Which would mean the CC 268HE would have more area under the lift curve as a result. If not more, then close to it. In not so quite as radical a demeanor, which probably is the reason that cam grind became as popular as it became. The downside was that it took about 10K miles for the valve train sounds (a hydraulic lifter that sounded like a solid lifter cam) to quieten down to hydraulic lifter levels. If a Chevy 350 was idled down to 500rpm, it DID sound radical, but by 650rpm, it was purring like a kitten.

The cam bearings on my new 440-3 short block from Chrysler Parts showed nothing but a smooth, satiny bearing surface. No evidence of "grinding to fit" internal diameters. As expected.

From a cam bearing "seller's perspective" and also suspecting that there are only a few factories that make them (then and especially now), but sold under lots of brand names, that they can sell what appears to be a universal set of bearings which need to be "select fitted" to the cams that run in them. I can hear machine shop owners NOT figuring this is normal and ordering another set of bearings from a different source. Nor have I read of any cautions in B/RB Chrysler engine builders mentioning this in any "build" projects in magazines or on cable tv. A "hidden truth"? My late machine shop operative installed the cams in the blocks he built, unless the customer requested not to do that. And there were lots of them over the 40 years I was around his shop after work and on weekends . . . watching and learning. But these forums and other have expanded my knowledge base, too.

Now, FWIW, in building my knowledge base, When I see something, I look at it and figure if it is normal or not. One data point. After three data points, that leads to "a trend". If something different pops up, another data point not on the trend line, which is then investigated to see why it is there. Soon, credibility happens, which can further validate the data points. From valid trends, credible knowledge can result. In a steady situation, rather than using ONE data point to predict the trend. BTAIM After One knows what One is looking at, things can happen quicker and reliably.

Sorry for the length. Looking at things from both the customer's and parts sellers' perspectives.

Just MY experiences. YMMV
CBODY67

 

[68PK21 440.6bbl]

If they have a lathe in their shop why not just chuck the cam in the lathe and polish down the tight journals?
Way less time spent ($$$$) than making the swaging tool Ya'think?
And of course mic everything to eliminate the try and see if it fits scenario. But then that may not make the 20 minute Tube standard for content video. Oh wait they are already past that by 30+ minutes (minus the promo segment), never mind.


.

 

[413]

You don't polish the cam journal because the bearings may just need shaved on one side. Install cam dry and see where the bearings are rubbed.

This tight cam doesn't happen on every BB Chrysler, just to some.

Yes the bearings could be getting buggered up by the tool.
I agree don't leave the bearing material in the engine, doesn't matter how soft it is, it wil embed itself in the other bearings.

On final engine assembly after all the check outs and mock ups, the first moving part to install is the camshaft. Waiting on the cam and installing the rotating assembly first is backwards.

 

[68PK21 440.6bbl]

He wasn't a guy that was in debt to the Snap-On truck though.

The John Deere dealer I worked for paid 50% of the cost of my tools I bought from the Snap On guy, office paid him up fully and took a weekly percentage out of my check. Did the same with Sears/Craftsman tools as we had a account with Sears only thing I had to do was bring a purchase order with me. You won't find many companies that will do that now-a-days. Hell I've met people that had to wash they're company provide uniforms and when they left the company if one item was missing they were charged for it. scheech.
I had Craftsman ballpeen hammers, a hammer is a hammer nothing special about the Snap On hammers back decades ago. (I'm sure there is now thou).

.

 

[Cranky1]

Are these cam bearing installation tools the 'universal' ones? After a buddy of mine had problems with just about every single Mopar engine build, I made my own cam install tool. Built several engines over the years and never had a problem so long as the cam was on size and straight. Yes, I have a lathe in my shop to check that sort of thing and it surprised me at how many new cams had .005" run out or more! Usually the bearing journals were fine.

 

[Lordofthepings777]

Are these cam bearing installation tools the 'universal' ones? After a buddy of mine had problems with just about every single Mopar engine build, I made my own cam install tool. Built several engines over the years and never had a problem so long as the cam was on size and straight. Yes, I have a lathe in my shop to check that sort of thing and it surprised me at how many new cams had .005" run out or more! Usually the bearing journals were fine.

It’s a lisle brand tool. Bought used though so I have no clue what condition it’s in aside form just looking. Hard to tell how flat it is after years of being used.