What's the Diff between 1.6 & 1.7 roller rockers?

[hamonkeiser]

Need some help here. I'm rebuilding my motor & I just got a good offer on a new set of Crane 1.6 roller rockers ($120.00). The guy who is selling them went with FMS 1.7's instead. Should I get the 1.6's or just spend the money on some Crane 1.7's (I think Summit has a special on them for around $185)? What's the hp difference & will I feel it? I'm puting them on to a set of Thumper ported E7's (going for combo 3 with the "E" cam & upgraded springs). I don't know if the rest of my mods will make a differnce on which rocker I should use but here it is:

.030 overbore
Thumper ported E7's
FMS "E" Cam
Typhoon Intake (ported/gasket matched)
70mm T/B & EGR
Nitrous (dry 80hp shot)

Thanks

 

[Jkstang78]

I have heard of 10 h.p increase over the stock ones.

 

[87gtconv]

The difference is the bigger lift with the 1.7's Determine if you want your cam to have a bigger lift. I tell you this it is better IMHO just to get the lift that you want with the cam but if you can't then these will work pretty slick!!

 

[Gearbanger 101]

Have you bought the cam yet? If not, I'd buy a better cam and use the 1.6's. There are far better grinds on the market than the E303 and will work better with either spring. The 1.7's are for people like me who plan on sticking with the stock grind, but would like a little more lift. This is find and dandy, but they increase valvetrain friction and wear over time and you're better off adding that extra lift based on your cam selection and running with the 1.6's.

 

[hamonkeiser]

I just wanted to clarify because I know the 1.6 or 1.7 topic has been beat to death... I really just want to know if it would be worth the price differnce for me to spend the extra $65 bucks on the 1.7's. Will I get my money's worth if I go with the 1.7's? Is $120 for the Crane 1.6's a goood deal?


As far as the "E"cam, it's part of the Thumper combo I'm getting (building on a budget). I hava choice of the "E" or the "F" cam & I went with the "E" because I was told it was better for the AOD cars

 

[87gtconv]

Then if you dont want the extra lift stay with the 1.6 if you want a little extra and dont have a clearance problem go with the 1.7's! Your choice really!!

 

[PURESTREET5006]

With that E303 you lift will be .498 with 1.6 rockers and with the 1.72 it'll be .528 or .530 if my calculations are right.

 

[thumper460]

5006 is right!! But the cost of the 1.7s vs the 1.6's ... as far as power there will be by the increase from the cam lift. but if you keep the 1.6s there is less valve train wear over a LONG period of time!! If it is a stock 1.6 to a roller 1.6.... there is a 5 HP increase with the rollers... for 325.00!! ?? I would keep the stock 1.6's get the car on the road.. and if you still feel you need more cam lift... look around for a good price and up grade later!! the E and the AOD ( with a 4* advance on the center line) rocks for the price!! Rollers??? Harland Sharps ! of course...

Just me...........................

Thumper

 

[PURESTREET5006]

See thumper..lol lol!!! i know alittle something but not everthing.