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1.7 ratio roller rockers

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jeepknowledge View Drop Down
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    Posted: Sep/10/2008 at 3:22pm

Does anyone know if you can use the 1.7 ratio roller rockers with stock internals on a 97 4.0? I think the head flow is about 220cfm I can't seem to find the stock cam specs and I don't know if the bind of the coil will have the .050" clearance recomended. Eventually I want to stroke the motor, port and polish the head maybe even get the aluminum head, put a worm gear driven super charger on it etc. I need to replace the rings right now and don't have the cash for the whole build, but would like to start it. I don't know if the valvetrain can handle the longer stroke of the roller rockers or if it will flowtoo much cfm and cause turbulance. Also Will I need to upgrade my push rods if this does happen to work?

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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Sep/18/2008 at 9:51pm
I think the pushrods will be fine, but I' don't know if you can use stock springs or not. I'd call the roller rocker supplier -- they should know.

Stock lift is 0.405" at valve, lobe lift is 0.253". Valve spring free height is 1.82", 1.20" with valve closed, 1.625" with valve open.  Inside diameter is 0.948-0.946". This is from the 93 factory manual, I believe all 91-06 should be the same. I 'm pretty sure the stock cam is the same for all, but it was advanced a degree or two in later years. 
Frank Swygert
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jeepknowledge View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jeepknowledge Quote  Post ReplyReply Direct Link To This Post Posted: Sep/24/2008 at 3:42pm
Thanks for the info. If the springs wont work do you know who sells them.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote amcramblermarlin Quote  Post ReplyReply Direct Link To This Post Posted: Sep/28/2008 at 3:09pm
I'm pretty sure the stock rocker arms used on the '64-up OHV AMC inline six are already 1.7 to 1 ratio factory stock, so there should be no problem. (I've tried to adapt them for use in place of the 1.6 to 1 stock rockers on AMC V8s but no success) I'd say the expense does not justify the modification because the AMC seven main bearing sixes are not high rpm engines -only if you have most of the "Cliffords Research 6-8" type mods already, and you still have plenty of cash or credit, then upgrade to roller rockers. They won't add much power -because same ratio & because stock AMC rockers are not all that bad when using the steel rocker pivots and steel bridge straps. -Might find the same power increase just by changing to premium synthetic oil and using a friction modifier treatment like Slick 50 or similar additive... for much lower price. Get the steel pivots and bridges at "Performance American Style" -I know sells 'em, if you're looking to replace the aluminum bridges/pivots that normally wear out easier...
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tyrodtom Quote  Post ReplyReply Direct Link To This Post Posted: Sep/28/2008 at 5:39pm
The AMC 6s with rocker shaft are 1.5 rocker arms.
When they went to pedestal mount they were 1.6.
66 American SW, 66 American 2dr, 82 J10, 70 Hornet, Pound, Va.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Thikstik Quote  Post ReplyReply Direct Link To This Post Posted: Jan/22/2010 at 5:24pm
Royal Purple for more hp, low windage.  and its soo cheap..not.  
75 gremlin x, jeep 4L headed 258,Clifford cam, intake,header. 390 holley. I want a 282 VAM motor!

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nali View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote nali Quote  Post ReplyReply Direct Link To This Post Posted: Jan/23/2010 at 12:42am
To modify a 97 , maybe you could found more accurate on one of the website bellow , instead of here . Not that ppl here don t have the competence :)
But it s quite Jeep specific , and this forum is more dedicated to older engine / cars .

http://www.bc4x4.com/tech/bryce/stroker/stroker.cfm
http://www.jeep4.0performance.4mg.com/stroker.html


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jeepknowledge View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jeepknowledge Quote  Post ReplyReply Direct Link To This Post Posted: Jan/24/2010 at 8:06pm
Thanks for the info guys. I'm going to try the build at the end of 2010. I'll let you know how it turns out.
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