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Wtf. Pushrods.

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Wtf. Pushrods.

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Old 01-15-2018, 08:34 PM
  #11
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This looks like a set up for a spec class where you’re limited to some cheap parts, and using longer push rods that push the rocker inter the tighter radius of the arc is an easy way find extra lift on a short term engine. Complete **** for an endurance set up, imo.
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Old 01-15-2018, 09:16 PM
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Originally Posted by GPM View Post
He did say he's using a stock stamped steel rocker, the larger pad verses a roller my be how he gets away with it.
Heard some jibber about stamped steel at the beginning yet recall eyeing him just rocking the roller rocker back and forth near the end. Ive seen worse YouTuber know all the tricks but this in my opinion should not be viewed especially by beginners.

He did mention the roller will ride near the back 1/3 or so of the valve tip. I didn't go back and watch it.

Last edited by getrdunn; 01-15-2018 at 09:19 PM.
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Old 01-16-2018, 02:18 PM
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Originally Posted by getrdunn View Post
Heard some jibber about stamped steel at the beginning yet recall eyeing him just rocking the roller rocker back and forth near the end. Ive seen worse YouTuber know all the tricks but this in my opinion should not be viewed especially by beginners.

He did mention the roller will ride near the back 1/3 or so of the valve tip. I didn't go back and watch it.
I wouldn't do it, but I don't run stamped steel rockers either.
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Old 01-16-2018, 08:26 PM
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Originally Posted by getrdunn View Post
Goes against everything. We could go on about all the cons but I'd rather punch the guy and spray paint looser on his white suit. Lol...
Not sure loser would be fitting for a guy who worked, raced, and Pal'd around with guys like Smokey Yunick, Al Unser, and been in the racing industry for about 6 decades in engineering departments.

I'm not seeing the problem with his video. I have done measurements taking lift readings with varying pushrod lengths , and it does change. Even the design of a rocker arm can have varying ratios throughout the lift curve from brand to brand.
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Old 01-16-2018, 08:30 PM
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http://www.nieworld.com/special/racing/thatwasthen16.htm

http://www.hotrod.com/articles/ctrp-0601-crane-cams-rocker-arms/

Last edited by MILD THUNDER; 01-16-2018 at 09:12 PM.
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Old 01-17-2018, 10:11 AM
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Originally Posted by MILD THUNDER View Post
Not sure loser would be fitting for a guy who worked, raced, and Pal'd around with guys like Smokey Yunick, Al Unser, and been in the racing industry for about 6 decades in engineering departments.

I'm not seeing the problem with his video. I have done measurements taking lift readings with varying pushrod lengths , and it does change. Even the design of a rocker arm can have varying ratios throughout the lift curve from brand to brand.
Said looser not loser if you want to be accurate lol... But your right I should not have and was not polite. He made his work history pretty clear Regardless never mind everybody forget what I said and pay close attention to video especially the advice how to achieve more valve lift and HP. I've measured up several and played with different lengths and of course it will change lift however at the end of the day I measure the proper way to get the correct length. Personally if I want more lift I will change out cam or rocker arms. In addition automatically assuming more lift is more power without knowing the heads cfm flow capacity is completely incorrect in fact can actually lose power. Anyway if you want more lift and you want more power install longer pushrods and see what happens.

If your just after how to measure for proper length you can go to comp cams site among numerous others that have great illustrations.
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Old 01-17-2018, 10:53 AM
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I agree, more lift can lose power at some point. Big block Chevys rarely lose power with lift increases. Even if a head stalls at .700 lift, and you put a 750 lift setup, the power will usually increase. Why? Because by increasing the lift to 750, the valve now spends more time at .700, rather than just coming up on .700 lift for a nanosecond and heading back down .

this guys video illustrates what effect the pushrod cup height relative to the rocker centerline effects are on the valves action. Crane discussed this years ago with their "quick lift " rocker design.

http://www.fordmuscle.com/archives/2005/08/QuickLift/
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Old 01-17-2018, 03:26 PM
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You have me agreeing to a point however I'd go no more than .050 and that's assuming it's .050 at or very quickly after peak flow. And obviously that's intakes we're talking. Just many variables in my opinion and experience. I've cammed to the end of flatline but not beyond but I see where your coming from. Back to the push rod length say one was to install .050-.100 longer would it put premature wear on the pushrod cup. I regards to the crane quick lift rockers was actually pretty brilliant especially back then and even now. With all the different lobe families these days I wouldn't see it as effective given you carefully chose your cam for your particular use and build but still cool.

Speaking of which Ive recently been looking at comps lobes and questioned one whether or not it would be semi endurance worthy. Semi meaning not on the pins for hours at a time. Shorter duration higher lift lobes. The hi tech series and rt series. Actually MT you may have posted a while back can't remember.

Anyway good link you posted.
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