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CVO Technical => EVO => Topic started by: ltank on December 13, 2018, 07:34:02 PM

Title: Easy way to check spring spacing for bigger cam
Post by: ltank on December 13, 2018, 07:34:02 PM

S&S built  me Custom V124 with 10.2:1 compression and a 585 cam. Bike runs fine but now I want  more power. I want to install a 600 cam. S&S looked up VIN but can't tell me what the spring packing  was set for.
Normally motor has a 640 cam but I don't know it they set it for the 585 cam that won't  work for the 600 cam. Is there an easy way to check without removing the heads? If I remove the heads then I gotta remove  the cylinders replace  the base gaskets too and new piston  rings. A big hassle but that's the safest thing  I guess.  Can I remove  the forward rocker box, install the new cam and measure the spring  oil seal to collar clearance? Or am I missing  something.  Any help is appreciated. Thanks

Title: Re: Easy way to check spring spacing for bigger cam
Post by: MCE on December 19, 2018, 09:29:54 AM

Leave the piston in the cylinder. Just pull the pin out and leave the piston in the bore, if it comes to that.
(Saves you from disturbing the rings at least)

You'll probably have to pull a head and use the Trock fixture to test the spring compressed height and
clearance. It helps to know what springs (part #) were installed too. Then check those with a spring
tester at the installed/compressed heights.

Otherwise you'd be guessing. Feeling lucky? lol

Title: Re: Easy way to check spring spacing for bigger cam
Post by: johnsachs on December 19, 2018, 06:04:48 PM

Quote from: ltank on December 13, 2018, 07:34:02 PM

S&S built  me Custom V124 with 10.2:1 compression and a 585 cam. Bike runs fine but now I want  more power. I want to install a 600 cam. S&S looked up VIN but can't tell me what the spring packing  was set for.
Normally motor has a 640 cam but I don't know it they set it for the 585 cam that won't  work for the 600 cam. Is there an easy way to check without removing the heads? If I remove the heads then I gotta remove  the cylinders replace  the base gaskets too and new piston  rings. A big hassle but that's the safest thing  I guess.  Can I remove  the forward rocker box, install the new cam and measure the spring  oil seal to collar clearance? Or am I missing  something.  Any help is appreciated. Thanks

Why would you need to replace the piston rings because you pulled the cylinders off if they aren't worn out of specs ?  ???
There is a jig made that may allow you to remove the valve springs with the engine in the frame. Check 1 intake and 1 exhaust. S&S is fairly consistent on their installed heights(valve protrusion) from cylinder to cylinder. Usually 2.040" - 2.060", on both intake and exhaust, both cylinders.
John

Title: Re: Easy way to check spring spacing for bigger cam
Post by: MCE on January 10, 2019, 06:43:21 PM

Protrusion on S&S' stuff is usually very consistent. (Usually within a few thousandths)

Title: Re: Easy way to check spring spacing for bigger cam
Post by: prodrag1320 on January 11, 2019, 06:33:29 AM

why would you have to even remove the cylinder? just try not to disturb it when removing the head.as far as springs go,the head should be removed as valve to valve & valve to piston should also be checked,not just coil bind

Title: Re: Easy way to check spring spacing for bigger cam
Post by: MCE on February 25, 2019, 04:35:29 PM

V-V should be checked. (Good point)