what rockers?

aar0s · 11-16-2004, 10:56 PM

what size rockers should i use with my combo (basicly just a cobra intake and 65mm tb) i was going to go 1.7s but am afraid that it will move the hp curve to high in the rpm range and i would loose low end torque. on the other hand would 1.6s be worth the time and money?

Dark_5.0 · 11-17-2004, 09:40 AM

If you have the stock cam then 1.7 roller rockers would be a good upgrade. Your power band will not be affected.

Coupe50h · 11-17-2004, 12:38 PM

I run 1.7 cranes they were cheap, and i saw a good gain, they also work good with my e-cam i have now.

cucho · 11-19-2004, 10:37 AM

1.7 go for it, more lift for you.

procharge94 · 11-20-2004, 03:35 AM

I was under the impression that you would base your rocker size off of your cam? So, if you are running a stock cam, larger rocker arms will just put more stress on your valve springs, or even force your duration to go too far causing many other issues that would need to be dealt with. Someone please correct me if I am wrong.

Coupe50h · 11-20-2004, 01:42 PM

Naw, as long as the springs fit your application, 1.7's wont lift a stock cam a whole lot more, but when i went to the e-cam, it was time for springs, also it depends on how old yours are.

duration shouldnt be affected, just lift.

Unit 5302 · 11-21-2004, 01:16 PM

Stock cams have .444/.444 lift. With 1.7s, it will be .472/.472, still well within the .500 max lift for the stock springs, but with the higher lift, high rpms may see increased valve float.

Duration is changed by changing the ratio of the rockers, just not very much.

Since duration is measured at either .003 (Ford advertised) or .050 lift, the amount of time the valve lift is at that .003 or .050 will be changed. I doubt it would be enough to report an extra degree on the .003 simply because you're dealing with such a minor multiplier (1.0625) when going to 1.7s.

E-303

.498/.498 220*/220* @ .050 Adding 1.7s opens the valve just a little more than what it used to be open so when it was at .048 of lift before (and not counted for duration), it'll now be at .050 (and counted for duration). You may see another degree or two of duration or so.

aar0s · 11-21-2004, 02:56 PM

how much of a power gain would i see? 10-15 hp or less?

Coupe50h · 11-22-2004, 10:50 AM

good info unit.

Well to give you a good idea, i went 13.5 At 99 on a stock motor, with 1-5/8 headers, cai, stock cam and stamped rockers. put the 1.7's on and went 13.2 at 101, so you can expect 15-20 hp.

Rev · 11-22-2004, 04:18 PM

I went with 1.7 RR's using a .456 lift CC hydraulic cam. That made it .486 lift with no problems. Not sure on power increases, but sure didn't hurt anything.

Rev

11-16-2004, 10:56 PM	#1
aar0s Registered Member Join Date: Nov 1998 Location: southern Illinois Posts: 312	what rockers? what size rockers should i use with my combo (basicly just a cobra intake and 65mm tb) i was going to go 1.7s but am afraid that it will move the hp curve to high in the rpm range and i would loose low end torque. on the other hand would 1.6s be worth the time and money? __________________ 88 gt convertable =-= cobra intake, accufab 65 mm tb headers alum underdrives steeda alum.lca's, springs, c/c plates kyb struts 230 hp to da wheels http://www.cybersteed.freeservers.com

11-17-2004, 09:40 AM	#2
Dark_5.0 Registered Member Join Date: Apr 2001 Location: Staging lane Posts: 4,337	Re: what rockers? If you have the stock cam then 1.7 roller rockers would be a good upgrade. Your power band will not be affected. __________________ 92' LX-Big brakes, Lots and lots of suspension, GT40X heads, Ported cobra intake, stock cam, Vortech SC trim. 00' Lightning-Stock 88'CRX-13 second ego killer

11-17-2004, 12:38 PM	#3
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	Re: what rockers? I run 1.7 cranes they were cheap, and i saw a good gain, they also work good with my e-cam i have now. __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

11-19-2004, 10:37 AM	#4
cucho Registered Member Join Date: Oct 2003 Location: Mexico Posts: 50	Re: what rockers? 1.7 go for it, more lift for you.

11-20-2004, 03:35 AM	#5
procharge94 Registered Member Join Date: Oct 2004 Location: Gainesville, FL Posts: 103	Re: what rockers? I was under the impression that you would base your rocker size off of your cam? So, if you are running a stock cam, larger rocker arms will just put more stress on your valve springs, or even force your duration to go too far causing many other issues that would need to be dealt with. Someone please correct me if I am wrong.

11-20-2004, 01:42 PM	#6
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	Re: what rockers? Naw, as long as the springs fit your application, 1.7's wont lift a stock cam a whole lot more, but when i went to the e-cam, it was time for springs, also it depends on how old yours are. duration shouldnt be affected, just lift. __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

11-21-2004, 01:16 PM	#7
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	Re: what rockers? Stock cams have .444/.444 lift. With 1.7s, it will be .472/.472, still well within the .500 max lift for the stock springs, but with the higher lift, high rpms may see increased valve float. Duration is changed by changing the ratio of the rockers, just not very much. Since duration is measured at either .003 (Ford advertised) or .050 lift, the amount of time the valve lift is at that .003 or .050 will be changed. I doubt it would be enough to report an extra degree on the .003 simply because you're dealing with such a minor multiplier (1.0625) when going to 1.7s. E-303 .498/.498 220/220 @ .050 Adding 1.7s opens the valve just a little more than what it used to be open so when it was at .048 of lift before (and not counted for duration), it'll now be at .050 (and counted for duration). You may see another degree or two of duration or so.

11-21-2004, 02:56 PM	#8
aar0s Registered Member Join Date: Nov 1998 Location: southern Illinois Posts: 312	Re: what rockers? how much of a power gain would i see? 10-15 hp or less? __________________ 88 gt convertable =-= cobra intake, accufab 65 mm tb headers alum underdrives steeda alum.lca's, springs, c/c plates kyb struts 230 hp to da wheels http://www.cybersteed.freeservers.com

11-22-2004, 10:50 AM	#9
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	Re: what rockers? good info unit. Well to give you a good idea, i went 13.5 At 99 on a stock motor, with 1-5/8 headers, cai, stock cam and stamped rockers. put the 1.7's on and went 13.2 at 101, so you can expect 15-20 hp. __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

11-22-2004, 04:18 PM	#10
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	Re: what rockers? I went with 1.7 RR's using a .456 lift CC hydraulic cam. That made it .486 lift with no problems. Not sure on power increases, but sure didn't hurt anything. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

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