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-   General Q & A (https://www.offshoreonly.com/forums/general-q-20/)
-   -   Valve Springs with 741 cam (https://www.offshoreonly.com/forums/general-q/354072-valve-springs-741-cam.html)

fastlane40 05-21-2018 05:27 AM
Valve Springs with 741 cam
 
Will these springs, crane 99876-16 work with the crane 741 cam? O.D.1.565 I.D. 11.146 I.D. 20.740 DamperYes Seat Press.190 lbs @ 1.950 Open Press552 @ 1.250 Coil Bind1.200 Max Net Lift w/ .060 clearance0.690 Rate(lbs/in.)504 lbs/in. Installed Height1.950

sutphen 30 05-21-2018 06:34 AM
no,to much seat pressure,want something around 160 at 1.88"

14 apache 05-21-2018 11:35 AM
You also want to run the spring closer to coil bind they will last longer it takes the oscillation out of the spring.

Baja Rooster 05-21-2018 12:27 PM
I believe the Isky 8005 springs are a common recommendation for that cam.

fastlane40 05-21-2018 01:55 PM
Thanks.
Is this spec too small?

Max Lift: .580
Coil Bind: .740
Intake Install: 145lbs @ 1.9
Exhaust Install: 145lbs @ 1.9
Closed Sear Pressure: 145lbs
Open Seat Pressure: 360lbs

Panther 05-21-2018 03:33 PM
Crane calls for the 99896 with that cam. I've also run the Comp 929 and if memory serves me correctly the Isky 9905 .

fastlane40 05-21-2018 03:42 PM
So the Comp cams 929 springs would work fine?

Baja Rooster 05-21-2018 04:24 PM
Originally Posted by fastlane40 (Post 4627648)
So the Comp cams 929 springs would work fine?
What’s your installed spring height? I just researched springs for the 525EFI cam, near identical to the 741, and the Comp cams catalog called for the 929 springs but the general consensus was they’re junk. I called Comp cams and they recommended the 953 springs. But you really need to find your installed spring height and call a tech line for recommendations.

MILD THUNDER 05-21-2018 07:25 PM
For what its worth. The GM crate ZZ572 ran 200lbs seat, 500lbs open. 630 lift hydraulic roller street engine. 6000rpm max.

it also used 11/32 valves, not the heavier 3/8 valves merc/gm used in alot of engines.

Panther 05-22-2018 12:21 PM
https://cimg7.ibsrv.net/gimg/www.off...675b63a56e.jpg
https://cimg8.ibsrv.net/gimg/www.off...eead5c6ef4.jpg
Originally Posted by Baja Rooster (Post 4627653)


What’s your installed spring height? I just researched springs for the 525EFI cam, near identical to the 741, and the Comp cams catalog called for the 929 springs but the general consensus was they’re junk. I called Comp cams and they recommended the 953 springs. But you really need to find your installed spring height and call a tech line for recommendations.
That's correct about installed heights.. You'll also need to make sure you have the correct retainers, locks and shims to get everything set up where it needs to be and the ID's match the springs you use.

The 525 EFI is a different breed all together in how mercury set them up and require different hardware than conventional style heads and even aftermarket heads.


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