Mocked up the 273 rockers and shafts on the x-heads for the first time the other day. I'm using FedMog 2011R anti pump up lifters that I had set aside for the BB, their tech line said they were the same for SB. Pushrod length checker, on the cam base circle, showed 7.225 with about three threads of the adjuster showing below the rocker. That length is shorter than anything listed as stock for adjustable valve train and hydraulic lifters. Not sure if I am doing the measurement wrong or what! Anyone run into this before? :sad1:
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Adjustable rocker pushrods
- Thread starter busboy
- Start date
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moper
Well-Known Member
It can be a pain, but, you need to trust your results providing you are sure you are doing things right. It is common for shorter pushrods to be needed for different block heights, different cylinder head casting deck surface results, different head gaskets, different cams and/or lifters, and differennt rocker assemblies. For socket (cup) type designs, you need to also take into account the design of the cups. Using the 505 deal I'm doing now as an example... I like Comp Cam's pushrods, and the catalog says a set of 9.030 is perfect for an RB. Comp uses the length of the pushrod from the tip of the ball to the bottom of the cup for a length. So, I use my set-up pushrods with the cup, and with 2-3 threads showing on the adjuster, cold lash set at .020", I come up with 9.142. This engine has a 10.700 deck height, and the Edelbrocks have been milled .040, plus a .043 thick gasket, and Crane 1.5 Golds. Now, my set-up pushrods have a cup end that started life as a /6 mopar pushrod made by Sealed Power. So, my dimension is total length, andd I need to subtract the depth of the cup to match what Comp says. The cup is .142" deep. So really, I need 9.00 in Comp's way of measuring to be perfect. The 9.030 will be fine, because there is plenty of thread room to fit .030 more and still have full thread engagement when everythign is hot and expanded.
In your case, you want to make sure you have enough for a little preload. Check with Federal to be sure what they want. Most anti pump up ones want little preload. But they can tell you to be sure. Just trust what you come up with so long as you are doing it right.
In your case, you want to make sure you have enough for a little preload. Check with Federal to be sure what they want. Most anti pump up ones want little preload. But they can tell you to be sure. Just trust what you come up with so long as you are doing it right.
Thanks for the words of encouragement moper, sometimes that's all you need to hear. I've done the carpenter thing, measure three times, cut once, and am quite sure my measurements are accurate. I did talk with an engine shop yesterday and he said he almost always comes up shorter on the push rod measurement than the books call for. My engine was bought used, same with the rockers, so who knows. The shop did help me track down a set of Isky push rods listed for small block mopar with adjustable valve train at a 7.265 length. That is the shortest length I have found and should work just fine since my measurement was taken with a good three threads showing on the adjuster. Thanks again from a newbie! :salute:
moper
Well-Known Member
No sweat. At least you're concerned with the length. I know a lot of guys that break stuff because they dont notice the details...lol.
340mopar
Sorgermotorsports
340 T/A's had a pushrod length of 7.25" and they are the ball and cup like you need.
Chuck
Chuck
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