Pushrod Problems

Adam95GT · Mar 21, 2008

any more info on this we are going to tackle this tomorrow... I need to know about the rail type having problems with the keepers etc. And what to buy if i need to buy anything...

i found this

http://www.compcams.com/Technical/Instructions/Files/250.pdf

Seems to make alot of sense...

Maryland Stang · Mar 22, 2008

We live, we learn. I've learned from this thread how to tell a rail rocker from the rest. Here's a little info on rail rockers.

289 engines built after mid-1966 and 302 engines use a rail-type rocker arm. These rocker arms have ears that extend downward, forming a rail or channel over the valve stem. This rail maintains proper alignment. The pushrod passes through a loose tolerance hole in the cylinder head, resulting in a cheaper assembly. At high RPM, however, these rockers can jump the track, loosing alignment with the valve stem and resulting in potentially serious engine damage. These engines do not require hardened pushrods.

If you intend to use those rockers be aware of the above. The procedure for checking for correct pushrod length is the same as for any other rocker. Install 2 solid lifters, adjustable pushrods and by lengthening and shortening the pushrod coupled with adjusting the rocker arm up and down on the head get the witness mark into the middle of the valve stem and as small as possible. Once you have the witness mark where you want it remove the adjustable pushrods and measure the length.

reddy351 · Mar 22, 2008

You should be fine with your current combination of VT parts. It WOULD be ideal to have guidplates and poly locks. (Neither are necessary here, though.)

The only "very critical" issue you should face is the PR length. (There are lots of great write-ups on that, so I won't "muddy the waters" with another.)

My rocker adjustment procedure is a little different, dirty and more "hands-on".

I set the PR's up a little loose. Start the engine. (I know, yours isn't in the car yet.) Let it warm up completely. Pull the VC off, start the engine. (Caution! Low flying oil!!! I have a special valve cover that I put on.) Tighten all the rockers till the valves are just barely staying open. (The engine will stumble, a little.) Back off each a 1/2 turn from there. Then, back off every rocker (only one at a time) until it makes the clacking noise. Tighten till the noise JUST goes away and another 1/2 turn and that's it. (Repeat last two steps 15 more times.)

It is a very "entertaining" process. Lots of oil smoke and odd noises but, completely effective. (And COOL, too!)

As far as people telling you that you should get new rockers, they may be right. Rockers, though, can be swapped-out in an afternoon. So, I wouldn't be terribly worried about whether they offer enough "performance" for you. They'll certainly get it on the road. SPRING is coming!

Adam95GT · Mar 22, 2008

I went and used white out on the valve stems to check the trick flow push rods... the marking it left in the white out was basically almost off the valve and toward the exhaust port. I then tried a set of stock lengths to find out that the marking was dead center on the valve! so the size the person had in had to be wrong the stock lengths worked perfect. I did have some problems tightening them down however i took them to zero lash following the instructions. But i had a problem with the nut being far down on the stud. causing the socket to press aginst the rocker and make it seem like i was at 0 lash.... Anyone know a way around this... thin wall socket maybe??? im only having this problem on the exhaust valves. me and chris did get a hell of alot of work done today. We completely got all the lines off the engine. AC power steering etc. DIsconnected all the wireing harness's drained the oil and trans fluid. pulled off the headers, h pipe, and drive shaft, Dropped the trans crossmember. loosened the motor mounts. Took off my k brace and all the grounds. All there is left is to just lift and swing the engine and tras out of the car. Just have to solve this Rocker problem.

Still have to paint the bay.
Hide wires.
Figure out if im keeping the AC/ Smog.
Put on a new top.
Put in the new heater core.
And put the new engine and trans in...

But today took a nice chunk out of everything...

Adam95GT · Mar 23, 2008

Someone said what i did was wrong because i used the lifters that were for the engine not solid ones.

Maryland Stang · Mar 23, 2008

Adam95GT said:
Someone said what i did was wrong because i used the lifters that were for the engine not solid ones.

That is correct. You must either use a solid lifter or checking springs. Checking springs are real weak and you remove the regular valve springs and install the checking springs in their place.

Regular lifters will collapse when the cam pushes the lifters up to open the valve.

Adam95GT · Mar 23, 2008

anyone know where i can get a solid lifter

95mustang_gt · Mar 23, 2008

Adam95GT said:
anyone know where i can get a solid lifter

You can turn the two lifters you have ,into solid lifter.

You take the snap ring off.
then remove the spring
flip the plunger
put back together

when done install the spring back in,and flip the plunger back

here is the article ,go down until you see do it yourself lifter.Dont worry about the grinding part,just flip the plunger.
http://www.trickflow.com/articles/stroker_1/#

Adam95GT · Mar 23, 2008

who sells adjustable push rods cheap??

Adam95GT · Mar 23, 2008

will this work??

http://store.summitracing.com/partdetail.asp?part=TFS-9000&view=32&N=700+115

divit250r · Mar 24, 2008

Adam95GT said:
will this work??

http://store.summitracing.com/partdetail.asp?part=TFS-9000&view=32&N=700+115

That's the type of thing you need, as long as the stockers are within that length range, it should get you an accurate measurement if you can make the lifter 'solid'. For what it's worth, I've always just primed the oil pump to get the lifters pressurized, and never had a problem with them collapsing during adjustment. Good luck!

Scott

Adam95GT · Mar 24, 2008

divit250r said:
That's the type of thing you need, as long as the stockers are within that length range, it should get you an accurate measurement if you can make the lifter 'solid'. For what it's worth, I've always just primed the oil pump to get the lifters pressurized, and never had a problem with them collapsing during adjustment. Good luck!

Scott

now that i think of it... The oil pump was turned by drill... im not sure if that makes a difference???

95mustang_gt · Mar 24, 2008

I got this off sbf tech.com
how to make your own pushrod checker

Take an old pushrod and cut it about 1 to 1.5 inches from either end. Now use a 1/4"-20 tap and tap both open ends, then simply screw in a short piece of 1/4 inch threaded rod with a few jam nuts

ill try to find the link

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