More questoins...Roller rockers (1.6s or 1.7s) and pushrods [Archive] - FSB Forums

: More questoins...Roller rockers (1.6s or 1.7s) and pushrods


magnumpi
02-11-2006, 03:09 PM
I'm starting to look at everything i need for the vavletrain of my new motor and have some more questions....

Whats the advantages of a high ratio roller rocker. For example 1.7s over 1.6s
From what i understand it has something to do with lift. I haven't found too much info on pickin roller rockers thou.

Also, I've read many different methods on measureing pushrod length. Has anyone here done it or know which method is the easiest or best to use? I understand that i have to wait till i get everything together to measure them

I'm running a roller cam and lifters in a F4TE block...the cam im probably gonna use is this one: http://www.powerandperformancenews.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=35-514-8&Category_Code=

Thanks
Josh

RLKBOB
02-11-2006, 07:32 PM
I ordered a set of push rod length checkers from Summit(I think Trick Flow brand). Basically a micrometer in the form of a push rod. You put it in place and adjust your valve lash then roll the engine and look at the rocker tip travel path on the valve tip. Adjust it till you get a perfect travel pattern on the valve tip and now you know exactly what length push rods to order. If you know what range push rod length you'll be in you can get with ordering just one(about $12-$15 each) I ordered a full set(I think it was about $40).
1.7 rockers are just a higher raitio so you will get more lift out of your cam. For example a .480" lift cam is only .480" lift with stock 1.6:1 ratio rockers, if you go with 1.7:1 rockers then you will have .510" lift.

magnumpi
02-12-2006, 01:00 AM
thanks for the answers...

is there such a thing as too much lift? I don't guess going with 1.7's is gonna cause any problems? Will the stock 85 truck vavle covers work?

jopes
02-12-2006, 01:21 AM
yes if you do nto tell the person who is setting up your heads they may just set them up for stock settings. with a stock ratio for the rockers you may be able to go up to .490" lift at the valve but if you strap on a 1.7 ratio rocker you would be exceeding the lift of the springs, which means they would bind and could potentially bend / break pushrods or something else.

plus with the higher lift you generally need higher spring rates

Fireguy50
02-12-2006, 01:23 AM
cam grind specs should match the cylinder heads used.
pick cyliner heads for your vehicles application.
check the flow data for the heads, and get a cam that matches

kemicalburns
10-24-2007, 12:40 PM
sorry to bring up an old thread. i heard that cobra 1.7 pedistal rockers dont require longer pushrods. does anyone have any experience with this?

Larston
10-24-2007, 11:37 PM
I would verify valvetrain geometry on ANY nonstock setup.

dirtmerchant
10-26-2007, 12:12 AM
to run 1.7s, mustang guys just bolt em on to stock roller 5.0's, occasionally needing a shim underneath the pedestal to get the right preload which is .20 to .60. the general rule among stang guys is if you can torque the rocker to 25 ft lbs 1 to 1 1/2 turns after the rocker is finger tight, youre good, if not shim it with shims provided with the roller rockers. i run them with the stock explorer cam, they bolted on with the correct preload using no shims

with that said, i dont even know if youre using pedestal mount rockers vs stud mount rockers which have a stud and locknut, and adjust w/o shims

ive got 4000 miles w the roller rockers (used crane 1.7's with the ford p/n on them, stock on 93 cobras) and i havent had problems , no extra noises, and i cant say if they added to performance cause i changed the whole drivetrain at the time but i do have plenty of power, it pulls past 4500 but i dont really hang around there often...enough;) btw STAY AWAY FROM THE CHEAP ROCKERS theres a few guys on corral.net that have had crappy new sets shatter, destroying the motor...

I ordered a set of push rod length checkers from Summit(I think Trick Flow brand). Basically a micrometer in the form of a push rod. You put it in place and adjust your valve lash then roll the engine and look at the rocker tip travel path on the valve tip. Adjust it till you get a perfect travel pattern on the valve tip and now you know exactly what length push rods to order. If you know what range push rod length you'll be in you can get with ordering just one(about $12-$15 each) I ordered a full set(I think it was about $40).
1.7 rockers are just a higher raitio so you will get more lift out of your cam. For example a .480" lift cam is only .480" lift with stock 1.6:1 ratio rockers, if you go with 1.7:1 rockers then you will have .510" lift.

if youre running an aftermarket cam with high lift (above .480) i d check the pushrod length like hes saying just cause that sounds like a real good idea in the long run with big lift cams building your motor. plus you have a 351, 9.5 in deck height so your pushrods are 1.3 in longer:shocked

in my case the 1.7s just make the explorer cam the size of a stock mustang 5.0 cam with less duration so im fine with stock springs etc.

greenmustanggt on this board and many others on stang boards suggest the crane 2031 cam with 1.7s, something to look at while researching:chili:

dirtmerchant
10-26-2007, 12:27 AM
oh just realized this was for you kemical, a 94 5.8 has flat tappet cam most likely (someone verify this) i havent heard of anyone running 1.7s on a flat tappet cam and 5.8. are you doing a cam too? might as well do heads too if your doing a cam, and its falling dominoes after that.... id say do more research on stang forums and see if you can just bolt on 1.7s, or if you need springs and pushrods id say f#%@ it not worth it for a 20 hp gain if that.

doing heads would be easier...but dont quote me on that....

for vc's stock steel ones dont work, mustang gt aluminums work with trimming , and most aftermarket tall vcs work. DONT get edelbrock elite's, i hate mine, thyre all for looks, get ford racing ones or the bronco sript ones from jbg<-not sure if those work with rr tho