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#1
10-03-2019, 04:57 PM
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Comp 290B spring help
I'm doing a build for a gentleman and he wants to use the Comp 290B cam. It's been so long since I've done a build with a SFT cam I can't remember what kind if closed/open spring rates are ideal for this cam.
Comp recommends the 995 spring for that cam (at 1.700 IH) which they show at 115 on the seat. Seems low but again, I don't know. My BBC bowtie pals said they use like 130# on the seat for solids.
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Jack Ferris RestoRacing LLC www.restoracing.com Sandy, UT --------------------------------------------------- |
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#2
10-03-2019, 07:10 PM
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I've used 130-140# seat and about 380-400# open for SFT cams with good luck.
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1967 Firechicken, 499", Edl heads, 262/266@0.050" duration and 0.627"/0.643 lift SR cam, 3.90 gear, 28" tire, 3550#. 10.01@134.3 mph with a 1.45 60'. Still WAY under the rollbar rule. |
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#3
10-03-2019, 07:45 PM
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Quote:
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#4
10-03-2019, 10:21 PM
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Quote:
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#5
10-04-2019, 04:08 AM
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comp 928 springs may work
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2008KRE Q16 Winner 2014 atco raceway doorslammer winner 86 grand am tube car 8.95 @152 455 eheads solid flat tappet cam Hoffman Racing building and racing Pontiacs for 35 years |
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#6
10-04-2019, 07:53 AM
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Comp 914's on my hyd roller. Would probably work well on the SFT.
165lb @1.8 IH, 385 open. Coil Bind good for .630 lift at 1.8 IH
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 1980 Trans Am - Street/Strip 462 Best: 7.08@95 with 1.49 60' in the 1/8th. 11.17@119.8 in the 1/4. N/A, 3700 lbs, 3.42's, Pump Gas. Admin of Pure Pontiac Powered Outlaws on Facebook. |
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#7
10-04-2019, 11:57 AM
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Dave @ SD is doing the heads. He was just asking what spring I wanted. It's for a customer that I wish would go roller but won't.
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Jack Ferris RestoRacing LLC www.restoracing.com Sandy, UT --------------------------------------------------- |
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#8
10-04-2019, 12:29 PM
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Nothing at all wrong with a SFT cam. They can make good power and are considerably cheaper than a roller. Also make less of a mess when a lifter breaks.
 I'd spend the extra money and go with the Nitrate option. |
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#9
10-04-2019, 12:59 PM
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I use Comp 26918 beehive springs with tool steel retainers on my SFT cam similar to 290B. Works well to 6500 rpm. 125 lbs seat, 367 lbs open.
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www.hobracing.com |
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#10
10-09-2019, 04:02 PM
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Quote:
Figure about a 5% loss after heat cycling should be at 152# |
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