Topic: Higher ratio rocker arms?!

[midnightcwby]

Ok, I've done some searchin’ on this board for a while now and I haven't seen a post talking about replacing the stock rocker arms with new ones that are about .10:1 higher ratio. Maybe I didn't look hard enough, but do any of you know any thing about this for these 2.5l's?  I've replaced my 1.5:1 rockers with 1.6:1 in my small blocks for a long time to get a little bit more lift out of a stock cam. I want to do this to my 2.5l now because I'm too damn busy (and lazy) to pull the cam out and change it properly for the time being. This is a nice little trick to use to get the same total valve lift from an aftermarket camshaft with lower lobe lift. It can actually take a little of the strain off of the cam and place it somewhere else.  It would be real nice to get a higher ratio rocker arm that's roller tipped as well.

From what I can gather by google searching it to death is that the 2.5l and the 4.0l share the same 1.6:1 ratio rockers... at least that's what I've read thus far, please correct me if that's wrong.  So where do I find a 1.7:1 ratio rocker? I've already google searched it and checked at every friggin' Jeep retail/hopup site I can find. No luck yet. Maybe I'm just not wordin' it right or I'm barking up the wrong trees. At any rate, if any of you guys have any information on this topic you wouldn't mind sharing with me, I'm looking to find these new rockers and replace my old ones about the same time I do the 4.0l Throttle Body swap and install the throttle body spacer.

-said the valve to the rocker arm: "Come on, just a little... bit... more..."

[/dev/null]

That's an interesting idea. I forgot about that one, as my other car is OHC... Do you expect any issues with the computer?


Peter

[jwrape]

I'd be interested in hearing what Jeffy has to say about it. Make sense. I don't think it would affect the computer any cause a Cam change doesn't affect it but I think a injector upgrade to the 4.0 Injectors would help get a little more fuel in there.

[Jeffy]

Yes, swapping higher ratio rocker arms will do the same as changing the cam.  Overlap will stay constant though.  I don't think the computer will mind once it resets.

Oh and yes, the 4.0L and 2.5L share the same rockers.  The only performance rockers I know of is Hesco/Mopar Performance and the Auzzie ones from Qtech.  I haven't looked to see what ratio they are though.

[snowbrew]

I have found another company that sells roller rockers for the 4.0L.
www.harlandsharp.com
They are shipping me two of the rockers to see if they will bolt up to my 2.5L.
hopefully they will be here Monday!

[Jeffy]

Take lots of pictues and send them my way if you will.  :wink:

[midnightcwby]

Hey, snowbrew, are those stock ratio, or are they longer? I still think the stock ratio is 1.6:1. If anyone can varify this, or show me I'm wrong, I'd appreciate it  I'm dying to find out where I can get this upgrade, and believe me, once I do, I'll post the entire process with very nice Pic's and the web address of the place I got 'em from.

[TJJim]

Out of the 2000 TJ service manual

Rocker Arm Ratio  1.6:1

Jim

[midnightcwby]

Ok, I just looked at every combination of words and phrases that Google could understand to try and figure out what to do here. I looks like the 2.5l, the 4.0l AND the 4.2l all share common 1.6:1 ratio rockers. The obvious solution here would be to find a 1.7:1 ratio rocker designed to fit at least one of these applications... no such luck yet.  I am seeing people having luck using V-8 rockers on their 6 and 4 cyl. engines though. If this can be done, then I have already found several 1.7:1 rockers for Chrysler and AMC V-8's. I am going to have to go to the bone yard and do some investigation work now... dangit Google, why can't you just tell me what I WANT to know instead of tons of crap I don't. Oh well, I'll post back in a bit when I get some where with this. I'll probably get a stock 1.6 ratio rocker from an AMC or Chrysler that looks the same and swap one of my 2.5's with it and see if I have any problems.

[snowbrew]

I just wanted to say that I found a 1:7 roller rocker from clifford performance.   http://www.cliffordperformance.net/index.html

Yes stock rockers are 1:6 ratio.

hummm hopefully in a few days I will have pics of my new roller rockers and pushrods.

[chrisfranklin]

So what are you saying, somebody buys it for the 8 cyl application and then splits the cost in exchange for 4 of them?  

I guess that works out to $250+ shipping per person.

[jwrape]

So what are you saying, somebody buys it for the 8 cyl application and then splits the cost in exchange for 4 of them?  

I guess that works out to $250+ shipping per person.

Too much for me. I got my Stage 3 cam for $100 shipped.

[BK2LIFE]

where did you get your cam?  i have found hesco ( http://www.hescosc.com/shop.asp?action=details&inventoryID=42889&catId=7758 )
will send you a cam lifter combo for about $230.  

also any luck on those new lifters?

seems like im just gunna get a new cam....

[midnightcwby]

I posted an idea on beachbum's thread about this topic... I think I'm going to get my hands on a 70's AMC v8's rocker arm and compair it to mine.  If they are interchangeable, I'll order a set of 8 stock stamped steel v8 rockers.  I'm just looking for the extra lift they will provide, so the price of the roller rockers isn't justifiable to me.