1.7s with Tfs stage 1 cam?

[fastfox90]

thanks to everyone for all the help. I called trick flow today and talked to tech svc. They said not to use 1.7's that I need to use the 1.6's and that even though my gt40's have double springs (they are off a marine moter ) that i still need to use their spring kit? I thought they were good for about 550 lift, and the double springs were strong enough to handle a stage1... guess not?

 

[Mustang5L5]

I found this info on the TFS stage 1 cam. They even list the springs to use with the 1.6 and 1.7 rr's

http://trickflow.com/product/prfeature_index.htm
Valve Setting Intake: .000 in.
Valve Setting Exhaust: .000 in.
Advertised Duration (Degrees): 275 intake/279 exhaust
Duration at .050 in. Lift (Degrees): 221 intake/225 exhaust
Camshaft Lift: .312 in. intake/.319 in. exhaust
Valve Lift with 1.6 Rocker Arms: .499 in. intake/.510 in. exhaust
Lobe Separation (Degrees): 112
Intake Cam Timing at .050 in. Valve Lift:
Opens 3 degrees BTDC
Closes 38 degrees ABDC
Max lift: 108 degrees ATDC
Exhaust Cam Timing at .050 in. Valve Lift:
Opens 49 degrees BBDC
Closes 4 degrees BTDC
Max lift: 116 degrees BTDC
Firing Order: 1-3-7-2-6-5-4-8
Characteristics: Good idle, strong mid-range power. Aftermarket intake, heads, and headers recommended. Requires modified Mass Airflow sensor. Best with 9:1-10.5:1 compression ratio.
Valve Springs with 1.6 Rocker Arms: TFS-51400413
Valve Springs with 1.7 Rocker Arms: TFS-31400414

w 1.6 RR's (specs make me think these are the springs sold in the TFS spring kit)

Trick Flow Specialties TFS-51400413 - Trick Flow® Valve Springs - Overview - SummitRacing.com

w/ 1.7 RR's
Trick Flow Specialties TFS-31400414 - Trick Flow® Valve Springs - Overview - SummitRacing.com

 

[joel5.0]

Either buy a drop in kit from Thumper or the TFS upgrade kit with the retainers and locks. The TFS-51400413 springs are the ones in the kit. They have a 1.800" installed height and a 1.100" coil bind height specification, so..... 1.8 - 1.1 = .700" lift to coil bind..... add a minimum .060" gap before coil bind, and the available working lift is .640" however, this is "on paper"..... you need to check them or have them checked for the actual coil bind height.

I've used the FRPP A50 springs...... X-303 + 1.72 rockers = .583" theoretical lift. The spring specs are: 110# @1.820" (mine are at 1.800") and coil bind height = 1.130" so, 1.800 - 1.130 = .670" lift to coil bind - .060" minimum gap = .610" allowed lift. .610 - .583 = .027" add the minimum .060" already mentioned, and the A50 springs I've been using are with a .087" clearance gap from coil bind.