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Old 09-21-2009, 05:31 PM   #1
toddtheodd
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Push rod length

Ok... so am I stupid or what??? (don't answer that)

I gots me a set of 23* Trick Flow Cylinder Heads, for my 350 (now355), and they say that with a hydraulic flat tappet cam, and roller rockers, I should be needing a 7.85" push rod.
But when I pull out my trusty push rod measuring thingy, I get 7.6"...
What the crap yo?
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Old 09-21-2009, 05:55 PM   #2
cdowns
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Re: Push rod length

sounds like you need to buy a set of pushrods that are 7.85 in lenngth to use the headss . common enough in custom building that you need to buy new stuff
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Old 09-21-2009, 05:56 PM   #3
toddtheodd
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Re: Push rod length

I guess I should also ask... have y'all built a fresh motor, and when you measured the push rods (10 times) needed, they were WAY OFF of what was recommended?
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Old 09-21-2009, 05:57 PM   #4
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Re: Push rod length

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Originally Posted by cdowns View Post
sounds like you need to buy a set of pushrods that are 7.85 in lenngth to use the headss . common enough in custom building that you need to buy new stuff
No no... I'm saying that the push rod measuring thingy says I need 7.6"
At 7.85, I was almost coming off the outside edge of the valve tip when it opened the valve.
7.6" kept me centered (as best as can be for something moving back and forth) from close to open.
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Last edited by toddtheodd; 09-21-2009 at 05:59 PM.
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Old 09-21-2009, 06:22 PM   #5
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Re: Push rod length

I would go with 7.6.
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Old 09-21-2009, 06:30 PM   #6
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Re: Push rod length

Is your block decked?
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Old 09-21-2009, 08:24 PM   #7
toddtheodd
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Re: Push rod length

Quote:
Originally Posted by Sinister View Post
Is your block decked?
I don't think so...

I'm using the 23 Trick Flow heads, Comp Cams Extreme Energy 274 hydraulic flat tappet cam, and Crane 1.5 Energizer roller rockers.

The heads are the only thing that says anything about push rod length... the cam and roller rockers say nothing...



edit:
Oh... and I measured it with the heads already on the motor, and torqued down... so this is the actual length, and not the length plus compressed head gasket thickness and whatall... it is already compressed.
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Last edited by toddtheodd; 09-21-2009 at 08:32 PM.
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Old 09-21-2009, 08:43 PM   #8
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Re: Push rod length

Quote:
Originally Posted by toddtheodd View Post
I don't think so...

I'm using the 23 Trick Flow heads, Comp Cams Extreme Energy 274 hydraulic flat tappet cam, and Crane 1.5 Energizer roller rockers.

The heads are the only thing that says anything about push rod length... the cam and roller rockers say nothing...



edit:
Oh... and I measured it with the heads already on the motor, and torqued down... so this is the actual length, and not the length plus compressed head gasket thickness and whatall... it is already compressed.
But sinister is right. If your block was decked it would affect push rod length. One way to check is look at the stamp on the passenger side of the block (in front). If the numbers are missing you had some deck work done.
s/t
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Old 09-21-2009, 08:50 PM   #9
toddtheodd
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Re: Push rod length

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Originally Posted by Sport/Truck View Post
But sinister is right. If your block was decked it would affect push rod length. One way to check is look at the stamp on the passenger side of the block (in front). If the numbers are missing you had some deck work done.
s/t
Nope... numbers still there. I noticed them when the motor came back from the machine shop, because I never saw them before under the 14 inches of oil and sludge that was on the motor.
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