Thrust bearing needed for RB Timing Gear if using a Roller Cam?

[Brewzer67]

I am switching to a Bullet roller cam as soon as it gets here and need some advice. Since I have never run a roller cam before I am hoping to get information on doing it right. I ordered a new ProGear 4000 series timing chain set along with a cam button and a roller thrust bearing for it (just in case it's needed). I am clear on the cam button but is a roller thrust bearing needed with a roller cam on a factory 440 block? If so, do I need to get the gear machined? Can I run without one? Is there much to be gained if not needed but it is "a nice to have" instead? I am trying to weigh my needs and option here. Any advice would be appreciated.

 

[lewtot184]

back when i messed with roller stuff i never used the thrust bearing. the cam end play button is a must.

 

[moper]

^^ X2. Need the button, and you should fab a spacer for between the timing cover and waterpump housing if it's stamped steel to keep the cover from flexing.

 

[HEMI-ITIS]

The white nylon button is fine.The roller bearing can come apart creating more trouble than it's worth.As mentioned a stock cover needs reinforcement or it WILL flex.

 

[Brewzer67]

Ok. If the thrust bearing isn't required I'll skip it. I have a good aftermarket cover from CVR that shouldn't flex. Any suggestions on setting end clearance?

 

[HEMI-ITIS]

Degree cam in,install the button and install t-cover.Then you can move the cam fore & aft to check the clearance.

 

[383man]

As said the cam button is definetly needed but that should be all it needs to keep the cam from walking with a roller cam. On my buddies 460 Ford I had to have the cam gear modified at the machine shop for a torrington roller thrust bearing that I had to install with his roller cam but thats because that eng uses a camshaft thrust plate like the smallblock Mopars use. But you dont have to use that since the bigblock dont use a thrust plate. The cam button will work fine when done right. Good luck with your eng. Ron

 

[lewtot184]

i would set the cam end play at whatever the crank end play is. this will control the cam fore and aft but let it move a little as the crank moves to reduce side load on the chain and sprockets. i've done them looser without issue but i think .005"- .007" is plenty of oil clearance between the cam sprocket and block. i like the nylon or delron buttons. i don't like those metal ones with the bearings. the nylon type are a little trail and error to fit but once they're set they last a long time and can be re-used on freshen ups.

 

[hangn0ut]

Be sure to run the oil slinger if your not gonna run a bearing behind the cam gear. I run the bearing behind the gear. A quality bearing will last forever.

 

[Brewzer67]

But to run the bearing I would need to machine the gear, correct?

 

[HEMI-ITIS]

I know several people that had a problem with a cam button roller bearing.When they come apart they cause catastrophic damage.For the unprovable gain,it's not worth the risk IMOP.

 

[hangn0ut]

Running a torrington bearing is a personal preference. Yes,machined to fit between the gear and block. I had a cam gear gall against the block. Kicked out the idler gear and bent a bunch of valves. Installed a bearing and dont worry bout it any more. The bearing and races show no signs of wear. As they should as it is very lightly loaded if at all. I run mostly gear drives. I might speculate that the original failure was caused by a bit of debris that got the ball rolling,started the galling. Weather a bearing could prevent this from happening,who knows? I prefer the bearing. Peace of mind for me.

 

[hangn0ut]

I know several people that had a problem with a cam button roller bearing.When they come apart they cause catastrophic damage.For the unprovable gain,it's not worth the risk IMOP.

We talking bout the same thing? I know some buttons have bearings. I'am talking bout the other side of the gear.LOL. On a side note, some timing chain sets may not have enough 'meat' to install a bearing.

 

[hangn0ut]

i would set the cam end play at whatever the crank end play is. this will control the cam fore and aft but let it move a little as the crank moves to reduce side load on the chain and sprockets. i've done them looser without issue but i think .005"- .007" is plenty of oil clearance between the cam sprocket and block. i like the nylon or delron buttons. i don't like those metal ones with the bearings. the nylon type are a little trail and error to fit but once they're set they last a long time and can be re-used on freshen ups.

Never thought of that. When I lost the gear set I was running a rather heavy clutch. Hmmmmm.

 

[Hemirunner]

But to run the bearing I would need to machine the gear, correct?

If you want to run a torrington behind the gear, it's easier to just buy the timing set with it already on. I normally set the cam thrust up at .003 to .005 for a torrington thrust or .005-.007 for a nylon unit. Maybe a tho or two more for an aluminum button since they'll expand.

 

[HEMI-ITIS]

We talking bout the same thing? I know some buttons have bearings. I'am talking bout the other side of the gear.LOL. On a side note, some timing chain sets may not have enough 'meat' to install a bearing.

LOL<<<<<<<Just reread the thread.I didn't realize both locations were being discussed.I was referring to just the button location.I have heard of the bearing behind the timing gear,just never ran one.

 

[Brewzer67]

Ok, so it doesn't sound like too many people run one so I am definitely going to skip it. Next question I would ask has to do with running a shim between the bronze distributor gear and the bronze intermediate shaft bushing. Anyone know where I can get such an animal? My machinist doesn't have anything like that available. Any suggestions?

 

[HEMI-ITIS]

Did you mock it up?? Do you need it??????

 

[Brewzer67]

Talking to lots of guys at the track years ago and all of them recommended setting it up that way to ensure the longest life from the gear while street driving it lots of miles. Their suggestion was to have a stainless shim between them so that the similar metals didn't chew each other up (kind of like using unbushed iron rockers on a steel shaft and getting the galling that results). Doing this and using a collar to help keep the distributor shaft and oil pump drive from riding up and down guarantees the longest life for the gear and the most stable timing.

 

[hangn0ut]

I know where your going and well,you dont really need it. What you will be doing is checking on that gear. Cause sometimes they last and sometimes they dont.