roller bearing cams

[lyonsd]

Cam bearing seized. Now I have a choice - new block, or machine it for a roller cam.

Are there other options?

Current block is stock, bored 0.040 over. Machined for RCJ girdle.

A new block will have to have all that machine work done to it.

Can it be machined for roller bearing cam? I know it would need to be line bored.

Are there roller bearing cams available for the stock block?

I'm looking at options.

What new blocks are available? I see TA has an aluminum block for $4k. Plus hard telling what else I would have to buy. Aluminum heads too? It would be nice, but no thanks.

Maybe a stage block?

Educate me, please. Thanks.

 

[turbo nasty]

Roller bearing...ugh maybe roller tappett you mean.

 

[chopped39]

I dont think they make a roller cam bearing for our blocks. High end engines have them but not our little 3.8 guys. For the money to machine the block and finding roller bearing cam bearings to work with a 3.8 you could have a new block all done up with a roller cam set up. Anything is possible if you have the cash

 

[turbo nasty]

A lot stuff isn't there for this like priority main oiling etc at least on a 109

 

[lyonsd]

So it looks like I'm going to need a new block, unless there are other alternatives.

I see where Bison mentioned an "old style" cam bearing. Anybody got any info on that?

 

[we4Mateo]

I think you mean something different. As mentioned, you want a roller cam but not roller bearings for your cam. And you don't need special machining to run one. There are full roller kits available.

 

[chopped39]

What he is talking about is a pressed in roller bearing that is used instead of cam bearing. Someone on here had a picture of one in a stage2 block about a month ago. Like stated above there would have to be a oil system mod to make it work. I dont know if they make over sized cam bearings that would fit in worn block. Call a machine shop. The ta block will accept stock heads I believe.

 

[lyonsd]

The cam bearing seized. The hole that the cam bearing was in will not accept a new one. I need a new block. Or, a roller bearing. Or some other bearing that would require enlarging the hole.

 

[we4Mateo]

I see. Thanks for the info.

 

[turbobitt]

The cam bearing seized. The hole that the cam bearing was in will not accept a new one. I need a new block. Or, a roller bearing. Or some other bearing that would require enlarging the hole.

A few options exist in a situation like this,
1 - The damaged bearing hole can be enlarged for a steel or iron insert and pressed in, then bored to the correct size to accept a stock bearing. A really good machine shop can do this. I seen this done and is actually a really good acceptable fix.
2 - To use roller bearings, a stock size cam can be ground down from the 1.78 dia to 1.75. You would need to have a steel cam and have the bearing jurnals re-nitrited for hardness. The block would need to be opened up tp accept the roller bearing. Don't know how feasable this is on a 109 block.
Allan G.

 

[earlbrown]

It seems like the 14bolt blocks have a couple of cam bearings with larger O.D.s than the 20 bolts. It might be worth researching. With any luck you could clean up the bore and use the thicker shell to maintain the right amount of press.

 

[Mike E]

Which bearing? The middle bearings are smaller and can be overboared for a front/rear.

Roller cam bearings require the cam bearing journals to be ground down or buy a custom roller bearing core. Roller cam bearings require some expensive machine work and not every machine shop has the correct tools to do it. It might be close to the price of redoing another block.

I've never seen it done in a car that's regularly street driven, so I'm not sure about durability. They are not pressure fed and rely on splash oiling.

 

[Mike E]

?..
1 - The damaged bearing hole can be enlarged for a steel or iron insert and pressed in, then bored to the correct size to accept a stock bearing. A really good machine shop can do this. I seen this done and is actually a really good acceptable fix.
...

This is probably you best bet. You could also probably get a good shop bore the hole oversize until it cleans up and make you one custom size bronze bearing.

 

[lyonsd]

I'll probably just go with a new block.

What are my options? Any vendors sell new/used blocks?

I know TA Performance has an $4K aluminum block.

 

[robzombie]

I know when I spun a cam bearing on my BB/455 all I had to do was buy another set of cam bearings and like said above they are different sizes.

They cleaned up the offending journal and used the appropiate size bearing for that journal.

Cost was less than 200.00 bucks and the motor had less than a thousand miles on it when it happened. Plus the cost of new cam which the shop paid for all of the parts and labor involved.

I believe they installed it wrong the first time, but was good to go after the repair and didn't spin another one.

Always look for qualified builders when it comes to a buick is what I learned the hard way!!!

 

[turbodave231]

Here is a Stage 2 On center block with Roller cam bearings. I've never seen a 109 block with roller bearings. I'm not sure there is enough material........I wouldn't spend that much time try trying to save a 109 block. Buy a replacement and machine it for your girdle. You'll be farther ahead in the long run.

 

[GNTIM]

Here is a Stage 2 On center block with Roller cam bearings. I've never seen a 109 block with roller bearings. I'm not sure there is enough material........I wouldn't spend that much time try trying to save a 109 block. Buy a replacement and machine it for your girdle. You'll be farther ahead in the long run. View attachment 185466

I have block envy

 

[BlownV6]

There should be oversized OD bearings available for just this situation. I dont know the part number but I have used them in the past. Think about it , throw away a block because of a spun cam bearing?? NO!! Look for cam bearings + .010 or .020 Im sure they are available. Mike