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oldman · 08-08-2020, 11:32 AM

The conical look good but they do have a LOT of pressure. It was interesting to know that when superchevy did a VVT cam install on the Vette, they went with conical springs on the VVT lifter?!? what???? I honestly think conical would be complete overkill on a mild lobe. GM use OEM springs on the hot cam with a max rec rev of 6600 RPM. I do think a beehive would work for mild lobe cams. I did not do any further research as I already had TSP twin springs and these do seem to work well enough on my low lift gentle ramp cam motion cam.

https://www.texas-speed.com/p-6431-p...-pac-1219.aspx

The srpring rate of the conical is 519 lbs / inch with a 145 # seat. That is heck of stiff... just off the cuff it looks to be TWICE as stiff.
https://www.compcams.com/675-lift-co...m-lt1-ls7.html

Here is the TSP twin spring and and it looks to be 246 lbs over .650" that would mean a .575 cam would see 218 lbs + 145 seat = 363 open. So with a low lift cam the TSP twin spring becomes pretty reasonable to my mind in terms of open pressure. Which makes sense as it is designed for .650 lift aggressive ramp cams.
https://www.texas-speed.com/p-5440-t...-seatseal.aspx

So to address boost, we know GM went to a titanium valve to make the intake that much lighter for a boosted application, slightly small cam too. All it all it must mean the LT1 under boost must be marginal at best with the stock cam lobe, diffidently would NOT meet OEM longevity / reliability spec.

08-08-2020, 11:32 AM	#18
oldman Drives: SS 6 speed of course Join Date: Jan 2016 Location: Hilo, HI Posts: 4,346	The conical look good but they do have a LOT of pressure. It was interesting to know that when superchevy did a VVT cam install on the Vette, they went with conical springs on the VVT lifter?!? what???? I honestly think conical would be complete overkill on a mild lobe. GM use OEM springs on the hot cam with a max rec rev of 6600 RPM. I do think a beehive would work for mild lobe cams. I did not do any further research as I already had TSP twin springs and these do seem to work well enough on my low lift gentle ramp cam motion cam. https://www.texas-speed.com/p-6431-p...-pac-1219.aspx The srpring rate of the conical is 519 lbs / inch with a 145 # seat. That is heck of stiff... just off the cuff it looks to be TWICE as stiff. https://www.compcams.com/675-lift-co...m-lt1-ls7.html Here is the TSP twin spring and and it looks to be 246 lbs over .650" that would mean a .575 cam would see 218 lbs + 145 seat = 363 open. So with a low lift cam the TSP twin spring becomes pretty reasonable to my mind in terms of open pressure. Which makes sense as it is designed for .650 lift aggressive ramp cams. https://www.texas-speed.com/p-5440-t...-seatseal.aspx So to address boost, we know GM went to a titanium valve to make the intake that much lighter for a boosted application, slightly small cam too. All it all it must mean the LT1 under boost must be marginal at best with the stock cam lobe, diffidently would NOT meet OEM longevity / reliability spec. __________________ Forged short block, large duration sub .600 lift Cam Motion cam, 7200 RPM fuel cut, Pray Ported Heads, 3.85 pulley D1X, stage II intercooler, DSX secondary low side, DSX E85 sensor, Lingenfelter big bore 2.0 pump, ported front cats, 60608 Borla, LT4 injectors, ZL1 1LE driveshaft and Katech ported TB, ported MSD intake, BTR valvetrain, ARP studs, ProFlow valves, PS4 tires. Last edited by oldman; 08-08-2020 at 12:12 PM.