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Roller rockers for the 4.0

lonecountryboy

NAXJA Forum User
Location
Oregon
Hey anybody run roller rockers on there rig? Quadratec has a set on sale and I was wondering if they add anything to the 4.0 as far as power. I know they make a pretty big difference on a SBC just don't know if they would be worth the cost on a 4.0.
 
I've been thinking of them as a future mod just to add some durability, but have no experience or insight to add. I wouldn't think they'd add much in the way of power, just be easier to rev, less wear on pushrods, stronger rockers to avoid possible breakage, etc.
 
I think power gain is minimal unless you are planning on extending the rev limiter to lets say........... 6k & you also need a roller cam to do that which isnt available for this engine

what you gain is a smoother valvetrain
 
The stock rocker arms are pretty solid, and sufficiant in pretty much any scenario.

I have roller rockers to go in my rig, but we put stock rocker arms on Goatmans KOH buggy's stroker because we wanted the reliability of OEM parts. 4.0's regularly go 300k+ without rocker arm failure, so I don't think you need to worry about it.
 
I think power gain is minimal unless you are planning on extending the rev limiter to lets say........... 6k & you also need a roller cam to do that which isnt available for this engine

what you gain is a smoother valvetrain

roller cams need roller lifters, not roller rockers

i have seen some of the guys on jeepstrokers use the roller rockers, and they seem to like them. thinking of using them in my build, but that is a lot of coin
 
roller cams need roller lifters, not roller rockers

i have seen some of the guys on jeepstrokers use the roller rockers, and they seem to like them. thinking of using them in my build, but that is a lot of coin


I think he was talking about needing a roller cam to get to 6,000 + rpm's.

The harmonics of the camshaft is the limiting factor in AMC 6 RPM's.
 
I think he was talking about needing a roller cam to get to 6,000 + rpm's.

The harmonics of the camshaft is the limiting factor in AMC 6 RPM's.
oops
 
I'm pretty sure Mopar has some in the performance catalogue, but I believe you need to get a taller valve cover, or a spacer to clear them. not absolutely positive but pretty sure. The friction loss should be worth a couple ponies tho.
 
I'm pretty sure Mopar has some in the performance catalogue, but I believe you need to get a taller valve cover, or a spacer to clear them. not absolutely positive but pretty sure. The friction loss should be worth a couple ponies tho.


There are several manufacturers. The better ones (Yella Terra) run about $450 a set, you can get the Scorpian ones for ~$250 or so on Ebay.. some naysayers say they won't hold up, but searching around the interweb they get good reviews.
 
It depends on what the roller rockers are mad of. For daily driving an aluminum rocker will brake sooner or later.

If there a steel or moly ones they'll be fine but exspensive. Most require a taller valve cover or spacer.

I think the stock ones with be more reliable. They just have less moving parts to go wrong.
 
I read on here couple of years ago that you can use chevy big block roller rockers on the 4.0 head. They are readily available and much cheaper. I think I saved a pic of it, let me see if I can dig it up.
 
I read on here couple of years ago that you can use chevy big block roller rockers on the 4.0 head. They are readily available and much cheaper. I think I saved a pic of it, let me see if I can dig it up.

Yup! Here it is.

cbbrollerrockersoni6.jpg
 
woah thats pretty awesome!!! that might be something to look into.
 
Just wondering if anyone is running the 1.7 rocker arm ratio like from Yella Terra, just thinking this might help the stroker breath.
 
Hmm... BBC roller rockers... I have a four cylinder, I could buy some and split the cost with another 2.5 owner... that'd be cool... I'm interested!
 
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