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  #1  
Old 09-15-2005, 07:56 PM
mygn87 mygn87 is offline
 
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Smile adjustable push rods

hello, i;m puting a new cam 208/208,i would like to use adj. push rods, what do you guys thank, this is my second cam, so may be using adj, rods will save this one..joe
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Old 09-16-2005, 02:24 AM
cherrypie cherrypie is offline
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Default Re: adjustable push rods

Adjustable push rods are really nice. You set the valve lash to exactly what you want. I used them in several motors i have rescently built including my own. The stamped steel rocker arms very alot. Roller rockers are very costly and you have to have the pedistals machined. Figure about 125.00 for the hardened adjustables from Smith Brothers or 450.00 for the best roller rockers from T&D. There are cheaper harland sharpe gold roller rockers but they make excessive valve train noise. The cam i run is a com 218/218 and they work perfect.
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Old 09-16-2005, 09:46 AM
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Default Re: adjustable push rods

I personally don't advise adjustable pushrods, if you can go with the rollers and adjust there, it's easier on the valve train.

Adjustables are heavy and not as rigid as a proper push rod of the proper length.

I use an adjustable to check valve train geometry and then order a set of hardened push rods the correct length (and a little bigger around than stock). You won't have to worry about an adjuster backing out.
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Old 09-16-2005, 10:34 AM
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Default Re: adjustable push rods

I was in the same situation as you and decided to go with the conventional wisdom against adjustables. So, I made myself a fixed height lifter with the exact preload and measured the length needed for each push rod. I then had Smith Bros make up the fixed length push rods. The results were good, no valve train noise at all and I had the proper geometry.

I will do things a bit different next time around. #1 is I'll use GM lifters rather than the Comp Cam lifters. I get some noise at startup with the Comp Cams lifters. #2 is I'll use the same push rod for all measurements and I'll send it to Smith Bros as the reference. #3 is I'll use the same lifter cup from a GM lifter to make all measurements.

You should be able to really dial in the preload with a roller rocker set up. I'm going to bite the bullet and pay for the T&D setup for my second bullet.
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Old 09-16-2005, 01:59 PM
cherrypie cherrypie is offline
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Default Re: adjustable push rods

The adjustables are rigid because they are hardened. The nice thing about the adjustables is, If you ever decide to change cams you can set your lash. If you get head work done as valve job work your valve stem height verys,stock heights are uneven, head gasket thinkness change verys, lifter brand verys. Smith Brothers builds in enough thread material to get the proper lash needed. Lock nuts will not come loose unless you forget to tighten them. They do weigh a little more then a fixed pushrod does. But certainly not as heavy as a set of roller rockers do.
I would not recommend using adjustables for a roller cam application and that is mainly because of the heavy roller lifters and heavy valve spring pressures.

I would invest in a 12 inch caliper to get the exact push rod length when assembling the valve train.
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Old 09-16-2005, 05:14 PM
mygn87 mygn87 is offline
 
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Default Re: adjustable push rods

Thanks for the advice, i think i will go with the adjustable push rods and see how it go's, this is the second time i wiped a cam,206/206.so now i will try a208/208.. thanks again.. joe

Last edited by mygn87; 09-16-2005 at 05:16 PM.
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Old 09-21-2005, 11:06 AM
Ormand Ormand is offline
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Default Re: adjustable push rods

Quote:
The adjustables are rigid because they are hardened
They may be STRONGER, and they may be more rigid if they are thicker. But they are NOT rigid because they are hardened. If you take a bar of steel, measure the stiffness (modulus of elasticity) then harden, the modulus will NOT change. You can heat it, beat it, polish it, paint it, freeze it, x-ray it, etc, and since the stiffness is a fundamental property of the metal, it won't get one bit stiffer. So, don't kid yourself by thinking that hardened pushrods are stiffer. SOME things are stiffer after hardening, but not pushrods.
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Old 09-21-2005, 04:09 PM
cherrypie cherrypie is offline
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Default Re: adjustable push rods

I guess i will have to leave the hardening,stiffening, and rigidity (IF thickness wall) to the pushrod builders like the Smith Brothers who know what they are doing. I have had great luck with their product and am only passing of an alterative to valvetrain adjustabilty. Really wish buick would have had a adjustable valvetrain like chevy. Life would be so much easier. So lets stop kidding ourselves.
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Old 09-21-2005, 04:41 PM
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Default Re: adjustable push rods

Who would've thunk that Gramma's Buick would be putting out 500+ HP back when they built these things!
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1987 GN original owner 650+ HP Black
2015 BMW 328xi XDrive wagon
2012 Volkswagen Tiguan (the Tig!) Night Blue Met (sold)
2006 Trailblazer SS Red Jewel Tint 395 HP AWD (sold)
2014 Silverado LTZ Crew 4WD
2012 Honda VFR 1200F Tahitian Blue (sold)
2015 BMW S1000R Racing Red
2013 Honda CBR500R Red (wife's bike)
2014 Triumph Bonneville T100
2003 Harley Davidson V Rod Anniversary Edition
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Old 09-21-2005, 04:55 PM
Ormand Ormand is offline
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Wink Re: adjustable push rods

I guess I thought the Smith Brother's made cough drops. To go with Gramma's Buick?
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