Roller Cam Bearings

JeffM · 06-16-2008, 01:55 PM

I took my 327 small block to be machined for 50mm roller cam bearings, and when they cut my oil groove .070, they busted into the water jacket.

How deep should this have been? .070 seems a bit too deep. They want to fix with JB weld. Has anyone ran into this to give me some help/advice?

I am sick.......

Rusty Davenport · 06-16-2008, 02:16 PM

call Performance Specialties---Doc Bilbrey-----919-894-3671

Mike Pearson · 06-16-2008, 04:11 PM

The block probably had alot of core shift. OEM blocks vary alot in casting thickness. Any fix with epoxy will not last. you probably should start over with a different block. If you are running super stock I would recomend a bowtie block.

Jesse Knapp · 06-16-2008, 07:21 PM

I used old "010" chevy blocks for my ss engines and when I asked my machinist about cutting the block for the 50 mm cam he warned me not to try that. "Not enough meat in those old blocks". You need to use a bowtie block.

JeffM · 06-17-2008, 11:17 AM

Thanks fellas.

I am a newbie, but can I run any SBC 4.000 block with a 3.25 stroke, or will that put me into the GT classes? Will a Bowtie block put me into the GT class? Not that it matters a whole lot, but I just to know.......

Jesse Knapp · 06-18-2008, 01:11 AM

I don't think I'd trust the JB Weld either. Nothing against the product, I've used it many times successfully, but I wouldn't use it in a cam bore area. You can use the old chevy "60's" blocks, the newer ones, or a bowtie piece. Bowtie is the way to go, but pricey. Has to be the 4" bore for 302, 327, and 350 with the .070 allowance for superstock. You can run the natural classes or the newer gt classes depending on what body style you want to run. You can run the pre 80 cars in gt now. Example: If your car is a 68 camaro and you run the 327 engine, one of a few choices offered in 68 from Chevrolet, it has a natural class in superstock and is allowed to run a gt class if you choose to go that way. I've seen very few old camaros, or old cars period, in gt. I doubt there's much, if any, advantage there. Hope this helps.....

JeffM · 06-18-2008, 08:09 AM

Thank you for all of the input. I really appreciate it.

06-16-2008, 01:55 PM	#1
JeffM Member Join Date: Feb 2007 Posts: 142 Likes: 119 Liked 5 Times in 5 Posts	Roller Cam Bearings I took my 327 small block to be machined for 50mm roller cam bearings, and when they cut my oil groove .070, they busted into the water jacket. How deep should this have been? .070 seems a bit too deep. They want to fix with JB weld. Has anyone ran into this to give me some help/advice? I am sick.......

06-16-2008, 02:16 PM	#2
Rusty Davenport Senior Member Join Date: Jun 2005 Location: Nashville N.C. Posts: 506 Likes: 4 Liked 101 Times in 27 Posts	Re: Roller Cam Bearings call Performance Specialties---Doc Bilbrey-----919-894-3671

06-16-2008, 04:11 PM	#3
Mike Pearson VIP Member Join Date: Mar 2007 Posts: 2,454 Likes: 617 Liked 1,943 Times in 584 Posts	Re: Roller Cam Bearings The block probably had alot of core shift. OEM blocks vary alot in casting thickness. Any fix with epoxy will not last. you probably should start over with a different block. If you are running super stock I would recomend a bowtie block. __________________ Mike Pearson 2485 SS

06-16-2008, 07:21 PM	#4
Jesse Knapp Member Join Date: Jan 2002 Posts: 109 Likes: 0 Liked 0 Times in 0 Posts	Re: Roller Cam Bearings I used old "010" chevy blocks for my ss engines and when I asked my machinist about cutting the block for the 50 mm cam he warned me not to try that. "Not enough meat in those old blocks". You need to use a bowtie block. __________________ Jesse Knapp 4899 STK, SS

06-17-2008, 11:17 AM	#5
JeffM Member Join Date: Feb 2007 Posts: 142 Likes: 119 Liked 5 Times in 5 Posts	Re: Roller Cam Bearings Thanks fellas. I am a newbie, but can I run any SBC 4.000 block with a 3.25 stroke, or will that put me into the GT classes? Will a Bowtie block put me into the GT class? Not that it matters a whole lot, but I just to know....... Last edited by JeffM; 06-17-2008 at 11:20 AM.

06-18-2008, 01:11 AM	#6
Jesse Knapp Member Join Date: Jan 2002 Posts: 109 Likes: 0 Liked 0 Times in 0 Posts	Re: Roller Cam Bearings I don't think I'd trust the JB Weld either. Nothing against the product, I've used it many times successfully, but I wouldn't use it in a cam bore area. You can use the old chevy "60's" blocks, the newer ones, or a bowtie piece. Bowtie is the way to go, but pricey. Has to be the 4" bore for 302, 327, and 350 with the .070 allowance for superstock. You can run the natural classes or the newer gt classes depending on what body style you want to run. You can run the pre 80 cars in gt now. Example: If your car is a 68 camaro and you run the 327 engine, one of a few choices offered in 68 from Chevrolet, it has a natural class in superstock and is allowed to run a gt class if you choose to go that way. I've seen very few old camaros, or old cars period, in gt. I doubt there's much, if any, advantage there. Hope this helps..... __________________ Jesse Knapp 4899 STK, SS

06-18-2008, 08:09 AM	#7
JeffM Member Join Date: Feb 2007 Posts: 142 Likes: 119 Liked 5 Times in 5 Posts	Re: Roller Cam Bearings Thank you for all of the input. I really appreciate it.