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General Forums => The Mess Hall => Topic started by: Hunter02 on August 24, 2014, 10:34:09 PM
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Gentlemen, I just got done reading the 'camshaft' thread started by BoringDave. Got me to thinking. (Jeez that hurts) Back in the day, as the young asshats say, we used to swap rockerarms from one engine to another, as some have a different 'ratio' than others. I was wondering if any other makes rockerarms, with a greater lift ratio, would fit '98 TJ 2.5L? That would cut down on expense and wrenching time as opposed to a camshaft install.
Don't know if this is a stoopid question in this day and age, but the gentleman whose mind I used to mine for this info passed away on me a little over 3 years ago. My buddy knew everything. What a wealth of knowledge our little group lost.
Hunter
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Do a search, there are few guy's on there with different lifters. Yello Terra, Mopar Performance and Harland Sharp come to mind.
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I have a thread in member's projects using 1.7 big block chevy roller rockers, some info in there regarding the actual lift ratio of the stock ones (advertised at 1.6 but in reality more like a bit over 1.5 - can't remember exactly)
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If my mind does not fail me (which it has sometimes), stockers are 1.6 ratio. Sharp did some testing, and found that, because they bend, they are more like 1.5XX (don't remember the exact ratio, but it was mid fifties I think). I use Yella Terra 1.6, which are true 1.6 (much stronger than the stockers, plus rollers on them). Sharp installed 1.7's (also rollers, and also stronger), but he had to modify the pushrods for it to work.
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The only direct-fit 1.7 rockers I could find are Yella Terra.
Any others on the market that are forged/roller type in the 1.6 variety will be a small improvement for the reasons stated above.
I found that even with stock springs on a stock cam, valve float was an issue even with my rev limiter set at 5200. Any cam or lift upgrades will only make it worse unless you keep below 4500 or upgrade the springs. If you are revving over 4k a lot, go with better springs and hardened keepers, or you risk dropping a valve. The only other way to fight the valve float is to find lighter valves.
I have a lot of info posted here: http://4bangerjp.com/forums/index.php/topic,11234.0.html