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1.7 roller rockers
- Thread starter brent
- Start date
2001XJeep
NAXJA Forum User
- Location
- Helena, AL
First, let me say that I've never messed with 4.0 rockers, but I have built many an engine over the years and in my experience rollers have always been less noisy than stamped stockers.
FUNKYTEE5
NAXJA Forum User
- Location
- Vancouver, Wa.
Check your lifter preload first. It may have been altered due to differences in the roller setup from stock rockers. Are you running them on a stock cam?
Dr. Dyno
NAXJA Forum User
- Location
- Al Ain, UAE
brent said:
Do you have the Yella Terra part number?
Did these roller rockers bolt on easily under the stock valve cover, or did you have to have some machining done to the head, valve cover baffles cut, or valve cover spacer installed?
I sent an e-mail to Clifford Performance over a week ago enquiring about the installation and never got a reply.
# on the box is 6628Dr. Dyno said:
they went on fine, but I'm running the aluminum head and its supposed to have enough room to run the ones hesco sells that requires a spacer, but they are not much bigger/taller than the stock stamped ones, so maybe their claim that they will fit under the stock cover is true.
maybe the sound I'm hearing is just different than what it used to be, so it had me a little alarmed.
as far as lifter preload, I did what the distructions said, put the engine at top dead center compression stroke, install the #1 rocker, tighten down till there is some drag on the rods, torque to 25 ft lbs and this should be 1/2 to 3/4 turn more. all was good, should you still be able to turn the rods at this point?
it also said if you only got 1/4 turn to the 25 ft lbs, then to take some off the post they mount to, if you get more than 3/4 turn to add the spacer washer they sent with the rockers,
anyway, midrange is much better than it was before, still trying to decide on the top end
and I'm running Hesco's stroker kit .30 over with their cam, which they claim was a .470 lift
5-90
NAXJA Forum User
- Location
- Hammerspace
On a somewhat unrelated note - would it be possible for me to somehow get a copy of the instructions that came with them? Either scanned or Xeroxed - PM me and let me know, so we can iron something out.
I'd like to be able to add it all to my "tech repository" that I'm building. Like I've said before, what I'm working on is a "one-stop shop" for all things Jeep Tech...
5-90
I'd like to be able to add it all to my "tech repository" that I'm building. Like I've said before, what I'm working on is a "one-stop shop" for all things Jeep Tech...
5-90
Cjmartz2k
NAXJA Forum User
- Location
- Northern VA
5-90
NAXJA Forum User
- Location
- Hammerspace
Thank you. Manipulating a .pdf and reformatting it into .html is a little more difficult than I would like, but I should be able to work with that...
5-90
5-90
MudDawg
NAXJA Member #728
- Location
- Central Florida
What happened to the pushrods??? Bent? Broke? ends worn off?? Are the valve heights set properly for that lift??? I have seen many engines die from coil bind including a few of my own:explosion
I have had a few rocker pivots wear out in the mighty 2.5. I had a set cryo'd last year...so far so good. But if they croak i'm gettin' some rollers too. I ain't gonna go lighter on the valvesprings...I need some pressure there.
I have had a few rocker pivots wear out in the mighty 2.5. I had a set cryo'd last year...so far so good. But if they croak i'm gettin' some rollers too. I ain't gonna go lighter on the valvesprings...I need some pressure there.
karter74
NAXJA Forum User
- Location
- Longview, TX
If you bent 8 pushrods, i would start wondering if you chewed up your cam lobes at the same time....
well after driving the thing arround for a week or so, I've decited I'm not sure I like them. it changed the whole power curve of the jeep, made the bottom end torque suffer, while making the midrange and top end feel, well like a race car, the whole scale is smoother so that was a plus but with the cam I'm running I did loose bottom end torque. so I'm thinking about a programable computer and soft ware, if I don't like it just plug in the laptop and tune away 
Cjmartz2k
NAXJA Forum User
- Location
- Northern VA
Well, I'm glad I went with the 1.6 RR's now. The cam that's in my stroker is freakin huge ( Duration 218 @ 50 for intake, 226 @ 50 for exhuast, lift is .493 for intake and .512 for exhuast with 111 duration)and I'm already worried about a lack of low RPM grunt with it, so I'm sure the 1.7's would have made it even worse. O well, guess I'll know in a few weeks when this thing is installed in the jeep.
update on bent rods, apparently it wan't the pistons hitting the valves, but the springs bottoming, not allowing the valve to open up any more, this is due to the incorrect instalation of the rockers, found this out in changing the cam to a diffrent one and having to do the springs too. some of the inner ribbon springs were broke or cracked and a couple of the valve seals messed up. :shocked:
Cjmartz2k
NAXJA Forum User
- Location
- Northern VA
Hmm. What kind of new cam did you get? Also, yoru keeping the 1.7RR's, right?
Cjmartz2k
NAXJA Forum User
- Location
- Northern VA
So did you get it up and running or are you still doing the install? I was just wondering if you still had the same impressions of the lack of low end and better high end now that they aren't bottoming out springs and what not. I have the yella terra 1.6's, and I was just wondering how the two compare. Maybe if you don't like them, I might want to pick yours up and try them on mine. My cam is .512 lift, i wonder what that would be at 1.7 ratio? Pretty big I'm sure.
Dr. Dyno
NAXJA Forum User
- Location
- Al Ain, UAE
Cjmartz2k said:
You definitely WON'T want to run 1.7 ratio rockers. These will raise valve lift from 0.512" to 0.544" and you'll be asking for trouble. Firstly, at anything over 0.525" of lift, the spring retainers will hit the valve stem oil seals. Secondly, unless you install Mopar valve springs that are rated up to 0.600" lift, the springs will reach coil bind at about 0.525" of lift. Thirdly, you may not have enough piston to valve clearance with 0.544" of lift so that could put the engine at risk of some expensive damage. Fourthly, your head won't flow enough air to justify using any set-up with more than 0.500" of valve lift.
