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[Ecotec] Pushrod thickness and radius

King_berald

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Hi guys, just working on an l67 rebuild at the moment and I'm trying to chase down some shorter pushrods. I've sized them up at 6.95" but it seems that the only ones I can find at that size have a larger radius and wall thickness. Has anybody run thicker pushrods in the l67? Do they fit??
If not, where the hell does everyone track down shorter pushrods from?
 
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Pollushon

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The most important factor is the ends, they should be 5/16" ball-type to fit the lifter and rocket snug. That said how much bigger than .080" are you talking? L36 and 67 use the same rods there should be oodles of sizes around. How did you measure the length?
 

King_berald

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I measured the length with an adjustable pushrod and digital caliper.
I've seen a set with .080" and .110" but they both have a radius of 210deg instead of the 180deg from factory.
I'm just wondering if the larger thickness will fit without fouling on anything, and if the extra degrees of radius on the ball is still compatible.
 

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More radius will increase the length over the duration, you're best of sticking to stock. Crow and Crane make .080" 5/16 180 (default radius) in 6.950". You might just have to go a set of 16

Did you do some major work to drop 3mm?
 
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Immortality

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Stock is 7.05" IIRC. Wall thickness does not effect outside diameter, just how strong or rather stiff the push rod is.
 

King_berald

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More radius will increase the length over the duration, you're best of sticking to stock. Crow and Crane make .080" 5/16 180 (default radius) in 6.950". You might just have to go a set of 16

Did you do some major work to drop 3mm?

Yeah I've just rebuilt the thing. New cam, pistons, bearings,etc,
Block and heads have been decked.

I ended up with a set of Trend pushrods. (Pavtek to the rescue) Stock spec except they still have the 210 deg at one end. The guy explained that it would be fine, as it is to allow for higher lift and whatnot.
 
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Deuce

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Correct, more radius at the rocker end means you can use a higher lift cam and tilt the rockers to a greater angle without the pushrod fouling on the rocker as it pushes it to the extreme of it's angle.
 

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It should be fine but I'd personally upgrade the springs from stock to something like a PAC OEM style beehive to ensure no float at high rpm. Stock value springs are a bit soft for the extra push
 

King_berald

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It should be fine but I'd personally upgrade the springs from stock to something like a PAC OEM style beehive to ensure no float at high rpm. Stock value springs are a bit soft for the extra push
I would but my goal ATM is to get it all running stock. It's going to be bolted up to a T5 and I plan to drive this thing daily. One day I'll get my hands on a t56 which will allow me to really have some fun with the motor. Until then I just have to be sensible I guess. Won't see much high rpm for the first 5k lol
 
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