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rods hitting cam

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Old Feb 15, 2009 | 08:35 AM
  #1  
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Car: 1983 camaro
Engine: 383sbc
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rods hitting cam

I am building a 383 for my 1983 camaro i have cleranced the block for the crank and the rods but when i installed my cam number 1 and 5 connecting rods hit my cam i was wondering if anyone has experanced this and any advice you cound give me thanks
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Old Feb 15, 2009 | 08:58 AM
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From: Fairview Heights Illinois
Car: 1986 Irocz
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Re: rods hitting cam

http://www.carcraft.com/techarticles...y_stroker.html
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Old Feb 15, 2009 | 09:54 AM
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Re: rods hitting cam

Yeah you have to use the small base circle ground cam. requires different timing set as well
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Old Feb 16, 2009 | 03:15 PM
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Re: rods hitting cam

i was told i could grind my rods by my local machine shop to clear the cam as long as it is balanced after
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Old Feb 16, 2009 | 07:17 PM
  #5  
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From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: rods hitting cam

Originally Posted by cmack
i was told i could grind my rods by my local machine shop to clear the cam as long as it is balanced after
It depends how much you're taking off, and where. Usually it's the shoulders of the rod bolts that need to be clearanced, and they're iffy enough strength-wise even before you start grinding on them.

Did you install the cam before or after the crank and pistons?
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Old Feb 16, 2009 | 07:18 PM
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From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: rods hitting cam

Originally Posted by jjlabinski
requires different timing set as well
It does?
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Old Feb 16, 2009 | 07:23 PM
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Car: 1983 camaro
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Re: rods hitting cam

i installed the cam before the rods i also have arp rod bolts not studs and nuts
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Old Feb 16, 2009 | 07:38 PM
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From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: rods hitting cam

Which rods are you using then?
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Old Feb 16, 2009 | 07:53 PM
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From: kissimmee fl
Car: 88 iroc-z z-28
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Re: rods hitting cam

never had to clearance for my cam. weird. and no you do not need another timing set. double roller i suggest f you dont already have one
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Old Feb 16, 2009 | 07:56 PM
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Re: rods hitting cam

I forget the exact difference but much to my surprise a few years back there is a difference. I could go look cause I have both cams but I think the bolt pattern is different for the small base circle cam or it had to do with the back face. I could look next time I go outside.
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Old Feb 16, 2009 | 08:31 PM
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From: Saskatoon, SK, Canada
Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
Re: rods hitting cam

Originally Posted by jjlabinski
I forget the exact difference but much to my surprise a few years back there is a difference. I could go look cause I have both cams but I think the bolt pattern is different for the small base circle cam or it had to do with the back face. I could look next time I go outside.
There shouldn't be any difference in the timing set, as the only thing different between a generic cam and a small base circle cam is that the lobes are smaller. Timing end of it is the same.
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Old Feb 17, 2009 | 03:25 AM
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From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: rods hitting cam

Originally Posted by jjlabinski
there is a difference. I could go look cause I have both cams but I think the bolt pattern is different for the small base circle cam
There isn't, and it's not.
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Old Feb 17, 2009 | 08:46 AM
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Re: rods hitting cam

I used a small base circle cam, well after the rods took out the cc306
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Old Feb 17, 2009 | 02:36 PM
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Re: rods hitting cam

yeah, i would look into the small base circle cam, i have a 383 small block, with a .600 lift cam, and even with the huge eagle h-beam rods, i still had plenty of clearance, call comp, that what cam i have, they should set you straight
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Old Feb 17, 2009 | 05:39 PM
  #15  
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From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: rods hitting cam

It's the duration that causes more problems than the lift.
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Old Feb 17, 2009 | 10:07 PM
  #16  
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From: Wesley Chapel, Florida
Car: 1991 Camaro Z28
Engine: Dart SHP 406ci T88 turbo
Transmission: T56
Axle/Gears: QP 35 spline Ford 9" 3.50 gears
Re: rods hitting cam

Originally Posted by cmack
I am building a 383 for my 1983 camaro i have cleranced the block for the crank and the rods but when i installed my cam number 1 and 5 connecting rods hit my cam i was wondering if anyone has experanced this and any advice you cound give me thanks
Yes I had the same problem and my heart sank and I broke out in a cold sweat when it happened. I ground down the rods a little to clear. Here are the before and after pics.
Attached Thumbnails rods hitting cam-rod2.jpg   rods hitting cam-rod.jpg  

Last edited by pwdbychevy; Feb 17, 2009 at 10:20 PM.
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Old Feb 18, 2009 | 04:25 PM
  #17  
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From: Saskatoon, SK, Canada
Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
Re: rods hitting cam

Originally Posted by jjlabinski
I forget the exact difference but much to my surprise a few years back there is a difference.
The only way I can think of there being a difference is if one was drilled with the pre-roller-block bolt pattern, and one was drilled with the GM-roller-block bolt pattern, as I think the GM-roller-block timing gear bolt pattern was slightly smaller on the camshaft, because of the retainer plate IIRC.

I could be wrong about that, I`m not 100% sure here. I remember hearing about that somewhere a few years back. Has nothing to do with whether or not its a small base circle cam though.
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Old Feb 18, 2009 | 04:37 PM
  #18  
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From: Grand Junction, Co
Car: '83 WS6 T/A 65,000 miles
Engine: 5.0L vin H stock, 406SBC right now
Transmission: T-5
Axle/Gears: Corp. 3.73
Re: rods hitting cam

Originally Posted by pwdbychevy
Yes I had the same problem and my heart sank and I broke out in a cold sweat when it happened. I ground down the rods a little to clear. Here are the before and after pics.
This is the same action I took in my 406. 270 Comp cam, Eagle 5.7 inch I beam rods...a little grindage and no more rubbage. 36,000 miles no problems.
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