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Custom comp cam question

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Old Nov 1, 2013 | 06:05 PM
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St. Jude Donor '10
Default Comp Cam just ground....question

Just had a cam ground by comp and was wondering if an "R" suffix is supposed to be listed after the lobe in the grind #? The cam they ground for me just lists the lobe number on the cam card, no "R". In the comp catalog it list "R" as the suffix required for the LS lobe size. Not sure if it matters since it's ground on an LS1 core, but want to make sure it's correct as all other cards I've seen have the "R" after the lobe in the grind number like this:
13018R/13161R HR 113
My card is below and picture of same cam card below that but with the R suffix in the grind #. Should I be concerned that lobes are exactly not what I wanted?
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Last edited by turboffr; Nov 2, 2013 at 10:00 AM. Reason: added pic
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Old Nov 1, 2013 | 07:22 PM
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I should add the lobes are 231 LSL and 238 LXL
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Old Nov 2, 2013 | 09:42 AM
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added pic of cam card.
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Old Nov 2, 2013 | 10:49 AM
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Several of Comps lobe sku's end with "R".

You can always tell a Comp lobe by the total valve lift. All the XE-R, LSL, LSK, etc all have their own designated total valve lift per duration. LSL lobes also tend to be odd numbers, rather than even ones.

In this case, that cam looks to be what you ordered.

Make sure you measure pushrod length. If installing on stock heads, that cam will not call for a 7.4" pushrod.
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Old Nov 2, 2013 | 11:27 AM
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Originally Posted by Josh@SpartanLSX
Several of Comps lobe sku's end with "R".

You can always tell a Comp lobe by the total valve lift. All the XE-R, LSL, LSK, etc all have their own designated total valve lift per duration. LSL lobes also tend to be odd numbers, rather than even ones.

In this case, that cam looks to be what you ordered.

Make sure you measure pushrod length. If installing on stock heads, that cam will not call for a 7.4" pushrod.
Thanks for the reply. Understood that lobes have designated lift per duration. I guess since the LSL lobes were designed for the LS core I should be fine without the R suffix but I'll call comp on Monday just to be sure

Per comp's catalog:

Roller Cam Lobe Suffix Codes
When it comes to ordering a roller cam, there are two things that need to be considered:journal diameter and roller lifter wheel diameter. Journal size and wheel diameter are very important in making sure the lobe is performing to the specifications you require .
For example, if you were selecting lobes for a custom grind Big Block Chevrolet cam then you would need to make sure the lobes were designed for a Big Block Chevrolet journal diameter (1 .948") . If Small Block Chevrolet lobes were used instead, the specifications of the cam would be inaccurate . The journal diameter of a Small Block Chevrolet is 1 .868" . The lobes on the big block cam would “grow” approximately 2 degrees if ground using small block lobe designs . The same principle applies to various roller lifter wheel diameters .
COMP Cams® has done the math for you, so all you need to do is make sure you order the lobes with the right suffixes to signify the correct journal diameter and roller lifter wheel diameter .
Master Suffix Codes for Various Roller Cam Journal Diameters:
T –1.750" (Very Small-V6 Buick, etc.)
N –0.900" Base Circle Diameter (AnyJournal Size)
S –1.868" (Small Block Chevrolet)
B –1.948" or 1.968" (BigBlock Chevrolet or 50mm)
F –2.036", 2.051" or2.081" (Small Block Ford and Cleveland)
R –2.1653" or 2.1234"(55mm, LS1 or BigBlockFord)
M –2.3622" (60mm)

Examples: If you wanted to order a cam using lobe #4314 on the intake and lobe #4074 on the exhaust for a Big Block Chevy cam with standard journals, standard .750” lifter wheel diameter and a 110° lobe separation, your grind number would be: CB 4314B/4074B r110 However, if you wanted to order a cam with the same specs for a Big Block Chevy but with 55mm journals and a .812” lifter wheel diameter, your grind number would be: CB 4314rE/4074rE r110
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Old Nov 4, 2013 | 09:19 AM
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Comp looked up serial # and confirmed it was ground with R suffix code for LS. They said if suffix code is not provided they look it up and assign the correct code for the cam being ground. In this case LS core would = R suffix code for the lobes. It was just not added to cam card.
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