push rod question. help me

[84stangboy]

how do you figure out what length you will need? mine are too long and the valves hit the piston. anything will help. thanks.

[Ford Fan]

The length of the pushrod won't affect how far the valves will open. The only thing that will affect this is camshaft lift, and rocker arm ratio. I would expect you are running to big of a rocker arm. By changing your pushrod length, it will change where the rocker arm contacts the valve. Did you just change rocker arms or what's the situation? Nick

[RyanM]

well if its the 84 pistons they need to be notched depending on what cam and heads you are doing

[84stangboy]

its a block out of an 88'. it has weisco flat tops. just got 1.6 roller rockers. the heads are e7's but they have manley .190 intake valves and stock exhaust. the valve stems are longer on these than stock.the cam i can't remember off hand but it is 520 somthin lift.

[mg72]

how do you know the valve is hitting the piston? If the running engine has tapped the valve, more than likely the valve or valves are bent, preventing the head from sealing. Is this the same motor that won't idle below 1200?

[RyanM]

how do you know the valve is hitting the piston? If the running engine has tapped the valve, more than likely the valve or valves are bent, preventing the head from sealing. Is this the same motor that won't idle below 1200?

hmm good point,bad idle means bent valves

[84stangboy]

motor is out of car. turning it by hand with plato on top and it squished into nothing. it only gets about a third of a turn on the cam and then she hits

[sc0tty8]

Out of couriousity, how does one measure pushrods proper? I'd like to run 1.73's, e-cam, some sort of alum head, and 347 bottom end, want 12:1 compression....

If its smashing the plato, you need to get the pistons notched or go with a lower ratio roller rocker...

[Ford Fan]

Or maybe the cam shaft is not in the correct place. On the timing gears where do you have the dots lined up? Sounds to me like the cam timing is off. Or, you have too big of a cam but I can't believe with only .520 lift and a 1.90 intake valve they would hit.

[Ford Fan]

Out of couriousity, how does one measure pushrods proper? I'd like to run 1.73's, e-cam, some sort of alum head, and 347 bottom end, want 12:1 compression....

If its smashing the plato, you need to get the pistons notched or go with a lower ratio roller rocker...

There is an adjustable Pushrod out their. You put in one hole, and adjust it until you have the correct contact on the tip of the valve, then measure.

[badcobra]

I agree with Nick, sounds like your cam timing is off. Get a degree wheel on there and degree that cam in per the cam specs. With stock E7 heads, should be stock 6.250" length pushrod most likely considering the smallish cam.

[84stangboy]

ok thanks guy. appreciate it. ill give it a go and let ya know.

[sc0tty8]

There is an adjustable Pushrod out their. You put in one hole, and adjust it until you have the correct contact on the tip of the valve, then measure.

where do i get it?

[mg72]

Summit or maybe even checker would have an adjustable pushrod. I went by 84stangboy's place to drop off a performer rpm. The pistons are notched pretty large. We were betting that the timing set wasnt installed properly. Good thing the motor was mostly torn down to begin with. Good luck with the project! Keep us posted.

[Ford Fan]

Yes, I believe Summit carries them otherwise any parts store SHOULD be able to round one up for you. (for a small fee that is)