SexyTransAm

iTrader: (6)

ok i have no clue what length pushrods to get. idk if stock length will work, and hell what is stock length?
my cam is .525 on both sides, and i have 1.6 rocker rollers, hydraulic flat tappet lifters. anything else ya need will be on my f-quick page or just ask it goin in a 80 motor, for my 80 TA rebuild. so any help would be great.

Monte Pilot

My advice would be to get these two tools:

Adjustable Pushrod
http://store.summitracing.com/partde...0&autoview=sku

Mocker Rocker Arm
http://store.summitracing.com/partde...9&autoview=sku

Remove one of your current rocker arms and replace it with the mock rocker arm (just slides on. Make sure you get the right one for the correct rocker stud diameter). Then put the adjustable pushrod in the same place as the old pushrod and adjust the length until the top tip just touches the mock rocker. Lock down the adjustable pushrod, remove it, and then measure its length. You can then search on summit or jegs for the correct pushrods. (Note that the blue mock rocker will not rotate. It's meant to simulate the position of the rocker when the tip of the rocker is situated in the center tip of the valve stem).

The pushrods (5/16"dia for SBC, 3/8"dia for BBC) come in a LARGE number of lengths varying from 6.100" to 10.656", so youmight want to measure the adjustable pushrod to within +/-0.001". See link for SBC lengths:
http://store.summitracing.com/egnsea...=KeywordSearch

The other option is to get the adjustable pushrod above and light valve springs:
http://store.summitracing.com/partde...5&autoview=sku

Then what you do is remove one intake rocker and pushrod and one exhaust rocker and pushrod. Remove the valve springs from both intake and exhaust valves and install the light sprngs in their place. Caat the tip of te valve stem (where the rocker would touch) with either machinist's dye, white-out, or even a black permanent marker. Re-assemble the real rockers and the adjustable pushrods. Now adjust the pushrod so the rocker touches the center of the valve tip. Then rotate the engine by hand a couple of times. This will work the rocker face over the tip of the valve stem and scrap off some of the coating - which will allow you to see how the rocker is moving over the stem. You want to readjust the length the pushrod so that the marking is centered in the middle of the valve stem tip as much as possible. Once you found the right length lock down the pushrod, remove it, and measure it's length - again with an accuracy of +/-0.001". (Since you are using the light springs there is almost no pressure on the adjustable pushrod which will keep it from breaking. You will also be able to tell if the valve is going to interfere with the piston when the valve is fully open - though you might still want to check the valve-to-piston clearance with clay if you can remove the cylinder head readily, or perhaps a borescope if you can't remove the head...but ths is more prone to error as you can't really measure the clearance between the valve and the pistion which does indeed need to be no closer than a certain amount to the piston [forgot the amount though]).

And for god's sake do not use the starter to rotate the engine if you still have the light valve springs installed! You will bury the valve in the top of the piston and possible bend the valve stem. (Think of valve float at 400rpm!).

Hope this helps some.

1997bird

iTrader: (2)

Stock lengt is approx. 7.8" on a stock 350 flat tappet cam. If your stock heads have not been machined with what they call a "Louis tool" for the 1.6 rocker arms & the clearance that they need for the pushrod slot, you may not want to try to use them.